Radio communications system and method for radio communications

• US 20050075121A1
• Filed: 09/28/2004
• Published: 04/07/2005
• Est. Priority Date: 10/03/2003
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Hasegawa, Naoki
• Granted Patent: US 7,567,816 B2
• Time in Patent Office: Days
• US Class Current: 455/518
• CPC Class Codes: H04W 4/10 Push-to-Talk [PTT] or Push-On-Call services
• CPC Class Codes: H04W 76/45 for Push-to-Talk [PTT] or Push-to-Talk over cellular [PoC] services

Abstract

A radio communications system that eliminates limitation on usage forms of radio communication and enables users to implement radio communication easily. CUG (Closed User Group) servers of communication carriers are provided to an outside company such as ASP (Application Service Provider), and group information of PTT communication terminal devices for performing radio communication processing among particular PTT communication terminal devices is registered in the CUG servers provided outside so that the PTT communication terminal devices are controlled.

Claims

1. A radio communications system comprising a plurality of communication terminal devices for performing radio communications with a press-talk switch, a server for establishing radio communication processing among said communication terminal devices, and a plurality of CUG servers for controlling said communication terminal devices for establishing said radio communication processing, said server and said CUG server respectively being owned by different companies, wherein

said CUG server has:

group information storage means for making a group among particular communication terminal devices to implement radio communication with said press-talk switches, and storing group information where CUG identification information for identifying CUG servers is given to the made group,

said communication terminal device has;

radio communications group acquisition means for acquiring, from said CUG servers, the group information among particular communication terminal devices for implementing radio communication with said press-talk switches; and

audio information notification requesting means for transmitting to said server, together with said group information, an audio information notification request for notifying audio information to a second communication terminal device in the group information acquired by said radio communications group acquisition means, and

said server has;

radio communications establishment means for acquiring, on receipt of the audio information notification request from said communication terminal device, based on the CUG identification information in the group information received together with said audio notification request, the group information of said communication terminal device from said CUG server, establishing radio communication among the communication terminal devices in the acquired group information, and transmitting audio information to the second communication terminal device in said group information.

5. The radio communications system according to claim 1, wherein:

said communication terminal device further has group information storage means for storing said group information acquired from said CUG server by said radio communication group acquisition means; and

said audio information notification requesting means transmits to said server, together with said group information, an audio information notification request for notifying audio information to the second communication terminal device in said group information stored by said group information storage means.

9. The radio communications system according to claim 1, wherein:

said radio communications group acquisition means makes connection with said CUG server, and acquires said group information from said CUG server; and

said audio information notification requesting means transmits to said server, together with said group information, an audio information notification request for notifying audio information to a second PTT communication terminal device in said group information acquired by connection to said CUG server.

13. The radio communications system according to claim 5, wherein:

said radio communications group acquisition means makes connection with said CUG server, and acquires said group information from said CUG server; and

said audio information notification requesting means transmits to said server, together with said group information, an audio information notification request for notifying audio information to a second PTT communication terminal device in said group information acquired by connection to said CUG server.

21. The radio communications system according to claim 5, wherein:

said communication terminal device further has audio information simultaneous notification requesting means for transmitting to said server, audio information to the second communication terminal device, together with an audio information notification request for notifying audio information to the second communication terminal device in said group information acquired from said CUG server; and

said server further has audio information simultaneous transmission means for transmitting to said second communication terminal device, the audio information received together with said audio information notification request from said communication terminal device.

25. The radio communications system according to claim 9, wherein:

said communication terminal device further has audio information simultaneous notification requesting means for transmitting to said server, audio information to the second communication terminal device, together with an audio information notification request for notifying audio information to the second communication terminal device in said group information acquired from said CUG server; and

said server further has audio information simultaneous transmission means for transmitting to said second communication terminal device, the audio information received together with said audio information notification request from said communication terminal device.

29. The radio communications system according to claim 13, wherein:

said communication terminal device further has audio information simultaneous notification requesting means for transmitting to said server, audio information to the second communication terminal device, together with an audio information notification request for notifying audio information to the second communication terminal device in said group information acquired from said CUG server; and

said server further has audio information simultaneous transmission means for transmitting to said second communication terminal device, the audio information received together with said audio information notification request from said communication terminal device.

35. The radio communications system according to claim 1, wherein:

the second communication terminal device in said group information comprises at least one of communication terminal devices in said group information; and

said communication terminal device further has second communication terminal device setting means for selecting at least one of communication terminal devices in said group information and setting the second communication terminal device in said group information.

39. The radio communications system according to claim 5, wherein:

the second communication terminal device in said group information comprises at least one of communication terminal devices in said group information; and

said communication terminal device further has second communication terminal device setting means for selecting at least one of communication terminal devices in said group information and setting the second communication terminal device in said group information.

43. The radio communications system according to claim 9, wherein:

the second communication terminal device in said group information comprises at least one of communication terminal devices in said group information; and

said communication terminal device further has second communication terminal device setting means for selecting at least one of communication terminal devices in said group information and setting the second communication terminal device in said group information.

53. The radio communications system according to claim 21, wherein, if the authentication result received from said CUG server is an authentication result that information of said communication terminal device is stored in the group information stored by said group information storage means, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

57. The radio communications system according to claim 25, wherein, if the authentication result received from said CUG server is an authentication result that information of said communication terminal device is stored in the group information stored by said group information storage means, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

61. The radio communications system according to claim 29, wherein, if the authentication result received from said CUG server is an authentication result that information of said communication terminal device is stored in the group information stored by said group information storage means, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

69. The radio communications system according to claim 21, wherein, if it is determined that the information of said communication terminal device is registered in said CUG control database, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

73. The radio communications system according to claim 25, wherein, if it is determined that the information of said communication terminal device is registered in said CUG control database, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

77. The radio communications system according to claim 29, wherein, if it is determined that the information of said communication terminal device is registered in said CUG control database, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

2. A radio communications system comprising a plurality of communication terminal devices for performing radio communications with a press-talk switch, a server for establishing radio communication processing among said communication terminal devices, a plurality of CUG servers for controlling said communication terminal devices for establishing said radio communication processing, and a CUG control database for controlling said CUG servers, said server and said CUG server respectively being owned by different companies, wherein

said CUG server has:

group information storage means for making a group among particular communication terminal devices to implement radio communication with said press-talk switches, and storing group information where CUG identification information for identifying CUG servers is given to the made group; and

group information registration means for registering said group information stored by said group information storage means in said CUG control database,

said communication terminal device has;

radio communications group acquisition means for acquiring, from said CUG servers, the group information among particular communication terminal devices for implementing wireless communication with said press-talk switches; and

audio information notification requesting means for transmitting to said server, together with said group information, an audio information notification request for notifying audio information to a second communication terminal device in the group information acquired by said radio communications group acquisition means, and

said server has;

radio communications establishment means for acquiring, on receipt of the audio information notification request from said communication terminal device, based on the CUG identification information in the group information received together with said audio notification request, the group information of said communication terminal device from said CUG control database, establishing radio communication among the communication terminal devices in the acquired group information, and transmitting audio information to the second communication terminal device in said group information.

6. The radio communications system according to claim 2, wherein:

said communication terminal device further has group information storage means for storing said group information acquired from said CUG server by said radio communication group acquisition means; and

said audio information notification requesting means transmits to said server, together with said group information, an audio information notification request for notifying audio information to the second communication terminal device in said group information stored by said group information storage means.

10. The radio communications system according to claim 2, wherein:

said radio communications group acquisition means makes connection with said CUG server, and acquires said group information from said CUG server; and

said audio information notification requesting means transmits to said server, together with said group information, an audio information notification request for notifying audio information to a second PTT communication terminal device in said group information acquired by connection to said CUG server.

14. The radio communications system according to claim 6, wherein:

said radio communications group acquisition means makes connection with said CUG server, and acquires said group information from said CUG server; and

said audio information notification requesting means transmits to said server, together with said group information, an audio information notification request for notifying audio information to a second PTT communication terminal device in said group information acquired by connection to said CUG server.

22. The radio communications system according to claim 6, wherein:

said communication terminal device further has audio information simultaneous notification requesting means for transmitting to said server, audio information to the second communication terminal device, together with an audio information notification request for notifying audio information to the second communication terminal device in said group information acquired from said CUG server; and

said server further has audio information simultaneous transmission means for transmitting to said second communication terminal device, the audio information received together with said audio information notification request from said communication terminal device.

26. The radio communications system according to claim 10, wherein:

said communication terminal device further has audio information simultaneous notification requesting means for transmitting to said server, audio information to the second communication terminal device, together with an audio information notification request for notifying audio information to the second communication terminal device in said group information acquired from said CUG server; and

said server further has audio information simultaneous transmission means for transmitting to said second communication terminal device, the audio information received together with said audio information notification request from said communication terminal device.

30. The radio communications system according to claim 14, wherein:

said communication terminal device further has audio information simultaneous notification requesting means for transmitting to said server, audio information to the second communication terminal device, together with an audio information notification request for notifying audio information to the second communication terminal device in said group information acquired from said CUG server; and

said server further has audio information simultaneous transmission means for transmitting to said second communication terminal device, the audio information received together with said audio information notification request from said communication terminal device.

36. The radio communications system according to claim 2, wherein:

the second communication terminal device in said group information comprises at least one of communication terminal devices in said group information; and

said communication terminal device further has second communication terminal device setting means for selecting at least one of communication terminal devices in said group information and setting the second communication terminal device in said group information.

40. The radio communications system according to claim 6, wherein:

the second communication terminal device in said group information comprises at least one of communication terminal devices in said group information; and

said communication terminal device further has second communication terminal device setting means for selecting at least one of communication terminal devices in said group information and setting the second communication terminal device in said group information.

44. The radio communications system according to claim 10, wherein:

the second communication terminal device in said group information comprises at least one of communication terminal devices in said group information; and

said communication terminal device further has second communication terminal device setting means for selecting at least one of communication terminal devices in said group information and setting the second communication terminal device in said group information.

54. The radio communications system according to claim 22, wherein, if the authentication result received from said CUG server is an authentication result that information of said communication terminal device is stored in the group information stored by said group information storage means, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

58. The radio communications system according to claim 26, wherein, if the authentication result received from said CUG server is an authentication result that information of said communication terminal device is stored in the group information stored by said group information storage means, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

62. The radio communications system according to claim 30, wherein, if the authentication result received from said CUG server is an authentication result that information of said communication terminal device is stored in the group information stored by said group information storage means, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

70. The radio communications system according to claim 22, wherein, if it is determined that the information of said communication terminal device is registered in said CUG control database, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

74. The radio communications system according to claim 26, wherein, if it is determined that the information of said communication terminal device is registered in said CUG control database, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

78. The radio communications system according to claim 30, wherein, if it is determined that the information of said communication terminal device is registered in said CUG control database, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

3. A radio communications system comprising a plurality of communication terminal devices for performing radio communications with a press-talk switch, a server for establishing radio communication among said communication terminal devices, and a plurality of CUG servers for controlling said communication terminal devices for establishing said radio communications, said server and said CUG server respectively being owned by different companies, wherein

said CUG server has:

group information storage means for making a group among particular communication terminal devices to implement radio communication with said press-talk switches, and storing group information where CUG identification information for identifying CUG servers is given to the made group; and

authentication response transmission means for, on receipt of an authentication request of a communication terminal device from said server, determining whether or not information of said communication terminal device is stored in the group information stored by said group information storage means, and transmitting the authentication result to said server,

said communication terminal device has;

radio communications group acquisition means for acquiring, from said CUG servers, the group information among particular communication terminal devices for implementing radio communication with said press-talk switches;

audio information notification requesting means for transmitting to said server, together with said group information, an audio information notification request for notifying audio information to a second communication terminal device in the group information acquired by said radio communications group acquisition means; and

audio information transmission means for, on receipt of a response result that said audio information notification request is to be responded, from said server to which said audio information notification request has been transmitted with said audio information notification requesting means, transmitting to said server, audio information to said second communication terminal device; and

said server has;

authentication request transmission means for, on receipt of the audio information notification request from said communication terminal device, selecting said CUG server based on the CUG identification information in the group information received together with said audio information notification request, and transmitting an authentication request of said communication terminal device to said CUG server;

audio information notification response means for, on receipt of an authentication result from said CUG server to which an authentication request has been transmitted by said authentication request transmission means, establishing radio communication among the communication terminal devices in the group information of said communication terminal devices in accordance with the authentication result, and transmitting to said communication terminal device a response result whether or not to respond to the audio information notification request received from said communication terminal device; and

audio information relaying means for, on receipt of the audio information to said second communication terminal device from said communication terminal device, transmitting said received audio information to said second communication terminal device.

7. The radio communications system according to claim 3, wherein:

said communication terminal device further has group information storage means for storing said group information acquired from said CUG server by said radio communication group acquisition means; and

said audio information notification requesting means transmits to said server, together with said group information, an audio information notification request for notifying audio information to the second communication terminal device in said group information stored by said group information storage means.

11. The radio communications system according to claim 3, wherein:

said radio communications group acquisition means makes connection with said CUG server, and acquires said group information from said CUG server; and

said audio information notification requesting means transmits to said server, together with said group information, an audio information notification request for notifying audio information to a second PTT communication terminal device in said group information acquired by connection to said CUG server.

15. The radio communications system according to claim 7, wherein:

said radio communications group acquisition means makes connection with said CUG server, and acquires said group information from said CUG server; and

said audio information notification requesting means transmits to said server, together with said group information, an audio information notification request for notifying audio information to a second PTT communication terminal device in said group information acquired by connection to said CUG server.

17. The radio communications system according to claim 3, wherein:

if the authentication result received from said CUG server to which the authentication request has been transmitted by said authentication request transmission means is an authentication result that information of said communication terminal device is stored in the group information stored by said group information storage means, said audio information notification response means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices and transmits to said communication terminal device a response result that said audio information notification request is to be responded; and

if the authentication result is an authentication result that information of said communication terminal device is not stored in the group information stored by said group information storage means, said audio information notification response means does not establish radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said communication terminal device, a response result that said audio information notification request is not be to be responded.

19. The radio communications system according to claim 3, wherein:

said communication terminal device further has audio information simultaneous notification requesting means for transmitting to said server, audio information to the second communication terminal device, together with an audio information notification request for notifying audio information to the second communication terminal device in said group information acquired from said CUG server; and

said server further has audio information simultaneous transmission means for transmitting to said second communication terminal device, the audio information received together with said audio information notification request from said communication terminal device.

23. The radio communications system according to claim 7, wherein:

said communication terminal device further has audio information simultaneous notification requesting means for transmitting to said server, audio information to the second communication terminal device, together with an audio information notification request for notifying audio information to the second communication terminal device in said group information acquired from said CUG server; and

said server further has audio information simultaneous transmission means for transmitting to said second communication terminal device, the audio information received together with said audio information notification request from said communication terminal device.

27. The radio communications system according to claim 11, wherein:

said communication terminal device further has audio information simultaneous notification requesting means for transmitting to said server, audio information to the second communication terminal device, together with an audio information notification request for notifying audio information to the second communication terminal device in said group information acquired from said CUG server; and

said server further has audio information simultaneous transmission means for transmitting to said second communication terminal device, the audio information received together with said audio information notification request from said communication terminal device.

31. The radio communications system according to claim 15, wherein:

said communication terminal device further has audio information simultaneous notification requesting means for transmitting to said server, audio information to the second communication terminal device, together with an audio information notification request for notifying audio information to the second communication terminal device in said group information acquired from said CUG server; and

said server further has audio information simultaneous transmission means for transmitting to said second communication terminal device, the audio information received together with said audio information notification request from said communication terminal device.

33. The radio communications system according to claim 17, wherein:

said communication terminal device further has audio information simultaneous notification requesting means for transmitting to said server, audio information to the second communication terminal device, together with an audio information notification request for notifying audio information to the second communication terminal device in said group information acquired from said CUG server; and

said server further has audio information simultaneous transmission means for transmitting to said second communication terminal device, the audio information received together with said audio information notification request from said communication terminal device.

37. The radio communications system according to claim 3, wherein:

the second communication terminal device in said group information comprises at least one of communication terminal devices in said group information; and

said communication terminal device further has second communication terminal device setting means for selecting at least one of communication terminal devices in said group information and setting the second communication terminal device in said group information.

41. The radio communications system according to claim 7, wherein:

the second communication terminal device in said group information comprises at least one of communication terminal devices in said group information; and

said communication terminal device further has second communication terminal device setting means for selecting at least one of communication terminal devices in said group information and setting the second communication terminal device in said group information.

45. The radio communications system according to claim 11, wherein:

the second communication terminal device in said group information comprises at least one of communication terminal devices in said group information; and

said communication terminal device further has second communication terminal device setting means for selecting at least one of communication terminal devices in said group information and setting the second communication terminal device in said group information.

47. The radio communications system according to claim 17, wherein:

the second communication terminal device in said group information comprises at least one of communication terminal devices in said group information; and

said communication terminal device further has second communication terminal device setting means for selecting at least one of communication terminal devices in said group information and setting the second communication terminal device in said group information.

49. The radio communications system according to claim 19, wherein:

the second communication terminal device in said group information comprises at least one of communication terminal devices in said group information; and

said communication terminal device further has second communication terminal device setting means for selecting at least one of communication terminal devices in said group information and setting the second communication terminal device in said group information.

51. The radio communications system according to claim 19, wherein, if the authentication result received from said CUG server is an authentication result that information of said communication terminal device is stored in the group information stored by said group information storage means, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

55. The radio communications system according to claim 23, wherein, if the authentication result received from said CUG server is an authentication result that information of said communication terminal device is stored in the group information stored by said group information storage means, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

59. The radio communications system according to claim 27, wherein, if the authentication result received from said CUG server is an authentication result that information of said communication terminal device is stored in the group information stored by said group information storage means, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

63. The radio communications system according to claim 31, wherein, if the authentication result received from said CUG server is an authentication result that information of said communication terminal device is stored in the group information stored by said group information storage means, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

65. The radio communications system according to claim 33, wherein, if the authentication result received from said CUG server is an authentication result that information of said communication terminal device is stored in the group information stored by said group information storage means, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

67. The radio communications system according to claim 19, wherein, if it is determined that the information of said communication terminal device is registered in said CUG control database, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

71. The radio communications system according to claim 23, wherein, if it is determined that the information of said communication terminal device is registered in said CUG control database, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

75. The radio communications system according to claim 27, wherein, if it is determined that the information of said communication terminal device is registered in said CUG control database, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

79. The radio communications system according to claim 31, wherein, if it is determined that the information of said communication terminal device is registered in said CUG control database, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

81. The radio communications system according to claim 33, wherein, if it is determined that the information of said communication terminal device is registered in said CUG control database, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

4. A radio communications system comprising a plurality of communication terminal devices for performing radio communications with a press-talk switch, a server for establishing radio communication among said communication terminal devices, a plurality of CUG servers for controlling said communication terminal devices for establishing said radio communications, and a CUG control database for controlling said CUG servers, said server and said CUG server respectively being owned by different companies, wherein

said CUG server has:

group information storage means for making a group among particular communication terminal devices to implement radio communication with said press-talk switches, and storing group information where CUG identification information for identifying CUG servers is given to the made group; and

group information registration means for registering said group information stored by said group information storage means in said CUG control database,

said communication terminal device has;

radio communications group acquisition means for acquiring, from said CUG servers, the group information among particular communication terminal devices for implementing radio communication with said press-talk switches;

audio information notification request means for transmitting to said server together with said group information, an audio information notification request for notifying audio information to a second communication terminal device in the group information acquired by said radio communications group acquisition means; and

audio information transmission means for, on receipt of a response result that said audio information notification request is to be responded, from said server that has transmitted said audio information notification request with said audio information notification requesting means, transmitting to said server, audio information to said second communication terminal device, and

said server has;

audio information notification response means for, on receipt of an audio information notification request from said communication terminal device, determining whether or not information of said communication terminal devices is registered in said CUG control database based on CUG identification information in the group information received together with said audio information notification request, establishing radio communication among the communication terminal devices in the group information of said communication terminal devices in accordance with the determination result, and transmitting to said communication terminal device, a response result whether or not to respond to the audio information notification request received from said communication terminal device; and

audio information relaying means for, on receipt of the audio information to said second communication terminal device from said communication terminal device, transmitting said received audio information to said second communication terminal device.

8. The radio communications system according to claim 4, wherein:

said communication terminal device further has group information storage means for storing said group information acquired from said CUG server by said radio communication group acquisition means; and

said audio information notification requesting means transmits to said server, together with said group information, an audio information notification request for notifying audio information to the second communication terminal device in said group information stored by said group information storage means.

12. The radio communications system according to claim 4, wherein:

said radio communications group acquisition means makes connection with said CUG server, and acquires said group information from said CUG server; and

said audio information notification requesting means transmits to said server, together with said group information, an audio information notification request for notifying audio information to a second PTT communication terminal device in said group information acquired by connection to said CUG server.

16. The radio communications system according to claim 8, wherein:

said radio communications group acquisition means makes connection with said CUG server, and acquires said group information from said CUG server; and

said audio information notification requesting means transmits to said server, together with said group information, an audio information notification request for notifying audio information to a second PTT communication terminal device in said group information acquired by connection to said CUG server.

18. The radio communications system according to claim 4, wherein:

if it is determined that the information of said communication terminal device is registered in said CUG control database, said audio information notification response means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said communication terminal device, a response result that the audio information notification request received from said communication terminal device is to be responded; and

if it is determined that the information of said communication terminal device is not registered in said CUG control database, said audio information notification response means does not establish radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said communication terminal device a response result that the audio information notification request received from said communication terminal device is not to be responded.

20. The radio communications system according to claim 4, wherein:

said communication terminal device further has audio information simultaneous notification requesting means for transmitting to said server, audio information to the second communication terminal device, together with an audio information notification request for notifying audio information to the second communication terminal device in said group information acquired from said CUG server; and

said server further has audio information simultaneous transmission means for transmitting to said second communication terminal device, the audio information received together with said audio information notification request from said communication terminal device.

24. The radio communications system according to claim 8, wherein:

said communication terminal device further has audio information simultaneous notification requesting means for transmitting to said server, audio information to the second communication terminal device, together with an audio information notification request for notifying audio information to the second communication terminal device in said group information acquired from said CUG server; and

said server further has audio information simultaneous transmission means for transmitting to said second communication terminal device, the audio information received together with said audio information notification request from said communication terminal device.

28. The radio communications system according to claim 12, wherein:

said communication terminal device further has audio information simultaneous notification requesting means for transmitting to said server, audio information to the second communication terminal device, together with an audio information notification request for notifying audio information to the second communication terminal device in said group information acquired from said CUG server; and

said server further has audio information simultaneous transmission means for transmitting to said second communication terminal device, the audio information received together with said audio information notification request from said communication terminal device.

32. The radio communications system according to claim 16, wherein:

said communication terminal device further has audio information simultaneous notification requesting means for transmitting to said server, audio information to the second communication terminal device, together with an audio information notification request for notifying audio information to the second communication terminal device in said group information acquired from said CUG server; and

said server further has audio information simultaneous transmission means for transmitting to said second communication terminal device, the audio information received together with said audio information notification request from said communication terminal device.

34. The radio communications system according to claim 18, wherein:

said communication terminal device further has audio information simultaneous notification requesting means for transmitting to said server, audio information to the second communication terminal device, together with an audio information notification request for notifying audio information to the second communication terminal device in said group information acquired from said CUG server; and

said server further has audio information simultaneous transmission means for transmitting to said second communication terminal device, the audio information received together with said audio information notification request from said communication terminal device.

38. The radio communications system according to claim 4, wherein:

the second communication terminal device in said group information comprises at least one of communication terminal devices in said group information; and

said communication terminal device further has second communication terminal device setting means for selecting at least one of communication terminal devices in said group information and setting the second communication terminal device in said group information.

42. The radio communications system according to claim 8, wherein:

the second communication terminal device in said group information comprises at least one of communication terminal devices in said group information; and

said communication terminal device further has second communication terminal device setting means for selecting at least one of communication terminal devices in said group information and setting the second communication terminal device in said group information.

46. The radio communications system according to claim 12, wherein:

the second communication terminal device in said group information comprises at least one of communication terminal devices in said group information; and

said communication terminal device further has second communication terminal device setting means for selecting at least one of communication terminal devices in said group information and setting the second communication terminal device in said group information.

48. The radio communications system according to claim 18, wherein:

the second communication terminal device in said group information comprises at least one of communication terminal devices in said group information; and

said communication terminal device further has second communication terminal device setting means for selecting at least one of communication terminal devices in said group information and setting the second communication terminal device in said group information.

50. The radio communications system according to claim 20, wherein:

the second communication terminal device in said group information comprises at least one of communication terminal devices in said group information; and

said communication terminal device further has second communication terminal device setting means for selecting at least one of communication terminal devices in said group information and setting the second communication terminal device in said group information.

52. The radio communications system according to claim 20, wherein, if the authentication result received from said CUG server is an authentication result that information of said communication terminal device is stored in the group information stored by said group information storage means, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

56. The radio communications system according to claim 24, wherein, if the authentication result received from said CUG server is an authentication result that information of said communication terminal device is stored in the group information stored by said group information storage means, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

60. The radio communications system according to claim 28, wherein, if the authentication result received from said CUG server is an authentication result that information of said communication terminal device is stored in the group information stored by said group information storage means, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

64. The radio communications system according to claim 32, wherein, if the authentication result received from said CUG server is an authentication result that information of said communication terminal device is stored in the group information stored by said group information storage means, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

66. The radio communications system according to claim 34, wherein, if the authentication result received from said CUG server is an authentication result that information of said communication terminal device is stored in the group information stored by said group information storage means, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

68. The radio communications system according to claim 20, wherein, if it is determined that the information of said communication terminal device is registered in said CUG control database, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

72. The radio communications system according to claim 24, wherein, if it is determined that the information of said communication terminal device is registered in said CUG control database, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

76. The radio communications system according to claim 28, wherein, if it is determined that the information of said communication terminal device is registered in said CUG control database, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

80. The radio communications system according to claim 32, wherein, if it is determined that the information of said communication terminal device is registered in said CUG control database, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

82. The radio communications system according to claim 34, wherein, if it is determined that the information of said communication terminal device is registered in said CUG control database, said audio information simultaneous transmission means establishes radio communication among the communication terminal devices in the group information of said communication terminal devices, and transmits to said second communication terminal device the audio information received together with said audio information notification request from said communication terminal device.

83. A radio communications method implemented with a radio communications system comprising a plurality of communication terminal devices for performing radio communication with a press-talk switch, a server for establishing radio communication among said communication terminal devices, and a plurality of CUG servers for controlling said communication terminal devices for establishing said radio communication, said server and said CUG server respectively being owned by different companies, said method comprising:

a group information registration step of, by said CUG server, making a group among particular communication terminal devices to implement radio communication with said press-talk switches, and registering group information where CUG identification information for identifying CUG servers is given to the made group, in a storage section of said CUG server;

an audio information notification requesting step of, by a first communication terminal device, acquiring said group information from said CUG server, and transmitting to said server, together with said group information, an audio information notification request for notifying audio information to a second communication terminal device in the acquired group information; and

a radio communications establishment step of, by said server, acquiring, on receipt of the audio information notification request from said first communication terminal device, based on the CUG identification information in the group information received together with said audio notification request, the group information of said first communication terminal device from said CUG control database, establishing radio communication among the communication terminal devices in the acquired group information, and transmitting audio information to the second communication terminal device in said group information.

87. The radio communications method according to claim 83, wherein, in said audio information notification requesting step, said first communication terminal device stores said group information acquired from said CUG server in a storage section of said first communication terminal device, and transmits to the server together with the group information, an audio information notification request for notifying audio information to the second communication terminal device in the stored group information.

91. The radio communications method according to claim 83, wherein, in said audio information notification requesting step, said first communication terminal device accesses said CUG server, acquires said group information from said CUG server, and transmits to said server together with said group information an audio information notification request for notifying audio information to the second communication terminal device in the acquired group information.

99. The radio communications method according to claim 87, further comprising:

an audio information simultaneous notification requesting step of, by said first communication terminal device, transmitting to said server together with an audio information notification request for notifying audio information to the second communication terminal device in said group information acquired by said CUG server, the audio information to said second communication terminal device; and

an audio information simultaneous transmission step of, by said server, transmitting to said second communication terminal device, the audio information received together with said audio information notification request from said first communication terminal device.

103. The radio communications method according to claim 91, further comprising:

an audio information simultaneous notification requesting step of, by said first communication terminal device, transmitting to said server together with an audio information notification request for notifying audio information to the second communication terminal device in said group information acquired by said CUG server, the audio information to said second communication terminal device; and

an audio information simultaneous transmission step of, by said server, transmitting to said second communication terminal device, the audio information received together with said audio information notification request from said first communication terminal device.

109. The radio communications method according to claim 83, wherein the second communication terminal device in said group information comprises at least one of communication terminal devices in said information group, and the method comprises a step of, by said first communication terminal device, selecting at least one of communication terminal devices in said group information, and said first communication terminal device sets the second communication terminal device in said group information.

113. The radio communications method according to claim 87, wherein the second communication terminal device in said group information comprises at least one of communication terminal devices in said information group, and the method comprises a step of, by said first communication terminal device, selecting at least one of communication terminal devices in said group information, and said first communication terminal device sets the second communication terminal device in said group information.

117. The radio communications method according to claim 91, wherein the second communication terminal device in said group information comprises at least one of communication terminal devices in said information group, and the method comprises a step of, by said first communication terminal device, selecting at least one of communication terminal devices in said group information, and said first communication terminal device sets the second communication terminal device in said group information.

127. The radio communications method according to claim 99, wherein in said audio information simultaneous transmission step, if the authentication result that said server has received from said CUG server is an authentication result that the information of said first communication terminal device is registered in the group information registered in said CUG server, said server transmits to said second communication terminal device, the audio information that said server has received together with said audio information notification request from said first communication terminal device.

131. The radio communications method according to claim 103, wherein in said audio information simultaneous transmission step, if the authentication result that said server has received from said CUG server is an authentication result that the information of said first communication terminal device is registered in the group information registered in said CUG server, said server transmits to said second communication terminal device, the audio information that said server has received together with said audio information notification request from said first communication terminal device.

139. The radio communications method according to claim 99, wherein, in said audio information simultaneous transmission step, if said server determines that the information of said first communication terminal device is registered in said CUG control database, said server transmits to said second communication terminal device, the audio information received together with said audio information notification request from said first communication terminal device.

143. The radio communications method according to claim 103, wherein, in said audio information simultaneous transmission step, if said server determines that the information of said first communication terminal device is registered in said CUG control database, said server transmits to said second communication terminal device, the audio information received together with said audio information notification request from said first communication terminal device.

84. A radio communications method implemented with a radio communications system comprising a plurality of communication terminal devices for performing radio communication with a press-talk switch, a server for establishing radio communication among said communication terminal devices, a plurality of CUG servers for controlling said communication terminal devices for establishing said radio communication, and a CUG control database for controlling said CUG servers, said server and said CUG server respectively being owned by different companies, said method comprising:

a group information registration step of, by said CUG server, making a group among particular communication terminal devices to implement radio communication with said press-talk switches, and registering group information where CUG identification information for identifying CUG servers is given to the made group, in a storage section of said CUG server;

a second group information registration step of, by said CUG server, registering the group information registered in said storage section, in said CUG control database;

an audio information notification requesting step of, by a first communication terminal device, acquiring said group information from said CUG server, and transmitting to said server, together with said group information, an audio information notification request for notifying audio information to a second communication terminal device in the acquired group information; and

a radio communications establishment step of, by said server, acquiring, on receipt of the audio information notification request from said first communication terminal device, based on the CUG identification information in the group information received together with said audio notification request, the group information of said first communication terminal device from said CUG control database, establishing radio communication among the communication terminal devices in the acquired group information, and transmitting audio information to the second communication terminal device in said group information.

88. The radio communications method according to claim 84, wherein, in said audio information notification requesting step, said first communication terminal device stores said group information acquired from said CUG server in a storage section of said first communication terminal device, and transmits to the server together with the group information, an audio information notification request for notifying audio information to the second communication terminal device in the stored group information.

92. The radio communications method according to claim 84, wherein, in said audio information notification requesting step, said first communication terminal device accesses said CUG server, acquires said group information from said CUG server, and transmits to said server together with said group information an audio information notification request for notifying audio information to the second communication terminal device in the acquired group information.

100. The radio communications method according to claim 88, further comprising:

an audio information simultaneous notification requesting step of, by said first communication terminal device, transmitting to said server together with an audio information notification request for notifying audio information to the second communication terminal device in said group information acquired by said CUG server, the audio information to said second communication terminal device; and

an audio information simultaneous transmission step of, by said server, transmitting to said second communication terminal device, the audio information received together with said audio information notification request from said first communication terminal device.

104. The radio communications method according to claim 92, further comprising:

an audio information simultaneous notification requesting step of, by said first communication terminal device, transmitting to said server together with an audio information notification request for notifying audio information to the second communication terminal device in said group information acquired by said CUG server, the audio information to said second communication terminal device; and

an audio information simultaneous transmission step of, by said server, transmitting to said second communication terminal device, the audio information received together with said audio information notification request from said first communication terminal device.

110. The radio communications method according to claim 84, wherein the second communication terminal device in said group information comprises at least one of communication terminal devices in said information group, and the method comprises a step of, by said first communication terminal device, selecting at least one of communication terminal devices in said group information, and said first communication terminal device sets the second communication terminal device in said group information.

114. The radio communications method according to claim 88, wherein the second communication terminal device in said group information comprises at least one of communication terminal devices in said information group, and the method comprises a step of, by said first communication terminal device, selecting at least one of communication terminal devices in said group information, and said first communication terminal device sets the second communication terminal device in said group information.

118. The radio communications method according to claim 92, wherein the second communication terminal device in said group information comprises at least one of communication terminal devices in said information group, and the method comprises a step of, by said first communication terminal device, selecting at least one of communication terminal devices in said group information, and said first communication terminal device sets the second communication terminal device in said group information.

128. The radio communications method according to claim 100, wherein in said audio information simultaneous transmission step, if the authentication result that said server has received from said CUG server is an authentication result that the information of said first communication terminal device is registered in the group information registered in said CUG server, said server transmits to said second communication terminal device, the audio information that said server has received together with said audio information notification request from said first communication terminal device.

132. The radio communications method according to claim 104, wherein in said audio information simultaneous transmission step, if the authentication result that said server has received from said CUG server is an authentication result that the information of said first communication terminal device is registered in the group information registered in said CUG server, said server transmits to said second communication terminal device, the audio information that said server has received together with said audio information notification request from said first communication terminal device.

140. The radio communications method according to claim 100, wherein, in said audio information simultaneous transmission step, if said server determines that the information of said first communication terminal device is registered in said CUG control database, said server transmits to said second communication terminal device, the audio information received together with said audio information notification request from said first communication terminal device.

144. The radio communications method according to claim 104, wherein, in said audio information simultaneous transmission step, if said server determines that the information of said first communication terminal device is registered in said CUG control database, said server transmits to said second communication terminal device, the audio information received together with said audio information notification request from said first communication terminal device.

85. A radio communications method implemented with a radio communications system comprising a plurality of communication terminal devices for performing radio communication with a press-talk switch, a server for establishing radio communication among said communication terminal devices, a plurality of CUG servers for controlling said communication terminal devices for establishing said radio communication, said server and said CUG server respectively being owned by different companies, said method comprising:

a group information registration step of, by said CUG server, making a group among particular communication terminal devices to implement radio communication with said press-talk switches, and registering group information where CUG identification information for identifying CUG servers is given to the made group, in a storage section of said CUG server;

an audio information notification requesting step of, by a first communication terminal device, acquiring said group information from said CUG server, and transmitting to said server, together with said group information, an audio information notification request for notifying audio information to a second communication terminal device in the acquired group information;

an authentication request transmission step of, by said server, on receipt of the audio information notification request from said first communication terminal device, selecting said CUG server based on the CUG identification information in the group information received together with said audio information notification request, and transmitting an authentication request of said first communication terminal device to said CUG server;

an authentication response transmission step of, by said CUG server, on receipt of an authentication request of the first communication terminal device from said server, determining whether or not information of said first communication terminal device is registered in the group information registered in said storage section by said group information registration step, and transmitting the authentication result to said server;

an audio information notification response step of, by said server, on receipt of an authentication result from said CUG server, establishing radio communication among the communication terminal devices in the group information of said communication terminal devices in accordance with the authentication result, and transmitting to said first communication terminal device a response result whether or not to respond to the audio information notification request received from said first communication terminal device;

an audio information transmission step of, by said first communication terminal device, on receipt of said response result from said server, if said response result is an response result that said audio information notification request is to be responded, transmitting to said server, audio information to said second communication terminal device; and

an audio information relaying step of, by said server, on receipt of the audio information to said second communication terminal device, transmitting said received audio information to said second communication terminal device.

89. The radio communications method according to claim 85, wherein, in said audio information notification requesting step, said first communication terminal device stores said group information acquired from said CUG server in a storage section of said first communication terminal device, and transmits to the server together with the group information, an audio information notification request for notifying audio information to the second communication terminal device in the stored group information.

93. The radio communications method according to claim 85, wherein, in said audio information notification requesting step, said first communication terminal device accesses said CUG server, acquires said group information from said CUG server, and transmits to said server together with said group information an audio information notification request for notifying audio information to the second communication terminal device in the acquired group information.

95. The radio communications method according to claim 85, wherein:

in said audio information notification response step, if the authentication result that said server has received from said CUG server is an authentication result that the information of said first communication terminal device is registered in the group information registered in said CUG server, said server establishes radio communication among communication terminal devices in the group information of said first communication terminal device, and transmits to said first communication terminal device, a response result that said audio information notification request is to be responded; and

in said audio information notification response step, if the authentication result is an authentication result that the information of said first communication terminal device is not registered in the group information registered in said CUG server, said server does not establish radio communication among communication terminal devices in the group information of said first communication terminal device, and transmits to said first communication terminal device, a response result that said audio information notification request is not to be responded.

97. The radio communications method according to claim 85, further comprising:

an audio information simultaneous notification requesting step of, by said first communication terminal device, transmitting to said server together with an audio information notification request for notifying audio information to the second communication terminal device in said group information acquired by said CUG server, the audio information to said second communication terminal device; and

an audio information simultaneous transmission step of, by said server, transmitting to said second communication terminal device, the audio information received together with said audio information notification request from said first communication terminal device.

101. The radio communications method according to claim 89, further comprising:

an audio information simultaneous notification requesting step of, by said first communication terminal device, transmitting to said server together with an audio information notification request for notifying audio information to the second communication terminal device in said group information acquired by said CUG server, the audio information to said second communication terminal device; and

an audio information simultaneous transmission step of, by said server, transmitting to said second communication terminal device, the audio information received together with said audio information notification request from said first communication terminal device.

105. The radio communications method according to claim 93, further comprising:

an audio information simultaneous notification requesting step of, by said first communication terminal device, transmitting to said server together with an audio information notification request for notifying audio information to the second communication terminal device in said group information acquired by said CUG server, the audio information to said second communication terminal device; and

an audio information simultaneous transmission step of, by said server, transmitting to said second communication terminal device, the audio information received together with said audio information notification request from said first communication terminal device.

107. The radio communications method according to claim 95, further comprising:

an audio information simultaneous notification requesting step of, by said first communication terminal device, transmitting to said server together with an audio information notification request for notifying audio information to the second communication terminal device in said group information acquired by said CUG server, the audio information to said second communication terminal device; and

an audio information simultaneous transmission step of, by said server, transmitting to said second communication terminal device, the audio information received together with said audio information notification request from said first communication terminal device.

111. The radio communications method according to claim 85, wherein the second communication terminal device in said group information comprises at least one of communication terminal devices in said information group, and the method comprises a step of, by said first communication terminal device, selecting at least one of communication terminal devices in said group information, and said first communication terminal device sets the second communication terminal device in said group information.

115. The radio communications method according to claim 89, wherein the second communication terminal device in said group information comprises at least one of communication terminal devices in said information group, and the method comprises a step of, by said first communication terminal device, selecting at least one of communication terminal devices in said group information, and said first communication terminal device sets the second communication terminal device in said group information.

119. The radio communications method according to claim 93, wherein the second communication terminal device in said group information comprises at least one of communication terminal devices in said information group, and the method comprises a step of, by said first communication terminal device, selecting at least one of communication terminal devices in said group information, and said first communication terminal device sets the second communication terminal device in said group information.

121. The radio communications method according to claim 95, wherein the second communication terminal device in said group information comprises at least one of communication terminal devices in said information group, and the method comprises a step of, by said first communication terminal device, selecting at least one of communication terminal devices in said group information, and said first communication terminal device sets the second communication terminal device in said group information.

123. The radio communications method according to claim 97, wherein the second communication terminal device in said group information comprises at least one of communication terminal devices in said information group, and the method comprises a step of, by said first communication terminal device, selecting at least one of communication terminal devices in said group information, and said first communication terminal device sets the second communication terminal device in said group information.

125. The radio communications method according to claim 97, wherein in said audio information simultaneous transmission step, if the authentication result that said server has received from said CUG server is an authentication result that the information of said first communication terminal device is registered in the group information registered in said CUG server, said server transmits to said second communication terminal device, the audio information that said server has received together with said audio information notification request from said first communication terminal device.

129. The radio communications method according to claim 101, wherein in said audio information simultaneous transmission step, if the authentication result that said server has received from said CUG server is an authentication result that the information of said first communication terminal device is registered in the group information registered in said CUG server, said server transmits to said second communication terminal device, the audio information that said server has received together with said audio information notification request from said first communication terminal device.

133. The radio communications method according to claim 105, wherein in said audio information simultaneous transmission step, if the authentication result that said server has received from said CUG server is an authentication result that the information of said first communication terminal device is registered in the group information registered in said CUG server, said server transmits to said second communication terminal device, the audio information that said server has received together with said audio information notification request from said first communication terminal device.

135. The radio communications method according to claim 107, wherein in said audio information simultaneous transmission step, if the authentication result that said server has received from said CUG server is an authentication result that the information of said first communication terminal device is registered in the group information registered in said CUG server, said server transmits to said second communication terminal device, the audio information that said server has received together with said audio information notification request from said first communication terminal device.

137. The radio communications method according to claim 97, wherein, in said audio information simultaneous transmission step, if said server determines that the information of said first communication terminal device is registered in said CUG control database, said server transmits to said second communication terminal device, the audio information received together with said audio information notification request from said first communication terminal device.

141. The radio communications method according to claim 101, wherein, in said audio information simultaneous transmission step, if said server determines that the information of said first communication terminal device is registered in said CUG control database, said server transmits to said second communication terminal device, the audio information received together with said audio information notification request from said first communication terminal device.

145. The radio communications method according to claim 105, wherein, in said audio information simultaneous transmission step, if said server determines that the information of said first communication terminal device is registered in said CUG control database, said server transmits to said second communication terminal device, the audio information received together with said audio information notification request from said first communication terminal device.

147. The radio communications method according to claim 107, wherein, in said audio information simultaneous transmission step, if said server determines that the information of said first communication terminal device is registered in said CUG control database, said server transmits to said second communication terminal device, the audio information received together with said audio information notification request from said first communication terminal device.

86. A radio communications method implemented with a radio communications system comprising a plurality of communication terminal devices for performing radio communication with a press-talk switch, a server for establishing radio communication among said communication terminal devices, a plurality of CUG servers for controlling said communication terminal devices for establishing said radio communication, and a CUG control database for controlling said CUG servers, said server and said CUG server respectively being owned by different companies, said method comprising:

a first group information registration step of, by said CUG server, making a group among particular communication terminal devices to implement radio communication with said press-talk switches, and registering group information where CUG identification information for identifying CUG servers is given to the made group, in a storage section of said CUG server;

a second group information registration step of, by said CUG server, registering said group information registered in said storage section, in said CUG control database;

an audio information notification requesting step of, by a first communication terminal device, acquiring said group information from said CUG server, and transmitting to said server, together with said group information, an audio information notification request for notifying audio information to a second communication terminal device in the acquired group information;

an audio information notification response step of, by said server, on receipt of said audio information notification request from said first communication terminal device, determining whether or not information of said communication terminal devices is registered in said CUG control database based on CUG identification information in the group information received together with said audio information notification request, establishing radio communication among the communication terminal devices in the group information of said first communication terminal devices in accordance with the determination result, and transmitting to said first communication terminal device, a response result whether or not to respond to the audio information notification request received from said first communication terminal device;

an audio information transmission step of, by said first communication terminal device, on receipt of said response result from said server, if the response result is a response result that said audio information notification request is to be responded, transmitting to said server, audio information to said second communication terminal device; and

an audio information relaying step of, by said server, on receipt of the audio information to said second communication terminal device, transmitting said received audio information to said second communication terminal device.

90. The radio communications method according to claim 86, wherein, in said audio information notification requesting step, said first communication terminal device stores said group information acquired from said CUG server in a storage section of said first communication terminal device, and transmits to the server together with the group information, an audio information notification request for notifying audio information to the second communication terminal device in the stored group information.

94. The radio communications method according to claim 86, wherein, in said audio information notification requesting step, said first communication terminal device accesses said CUG server, acquires said group information from said CUG server, and transmits to said server together with said group information an audio information notification request for notifying audio information to the second communication terminal device in the acquired group information.

96. The radio communications method according to claim 86, wherein:

in said audio information notification response step, if it is determined that the information of said first communication terminal device is registered in said CUG control database, said server establishes radio communication among communication terminal devices in the group information of said first communication terminal device, and transmits to said first communication terminal device, a response result that said audio information notification request received from said first communication terminal device is to be responded; and

in said audio information notification response step, if it is determined that the information of said first communication terminal device is not registered in said CUG control database, said server does not establish radio communication among communication terminal devices in the group information of said first communication terminal device, and transmits to said first communication terminal device, a response result that said audio information notification request received from said first communication terminal device is not to be responded.

98. The radio communications method according to claim 86, further comprising:

an audio information simultaneous notification requesting step of, by said first communication terminal device, transmitting to said server together with an audio information notification request for notifying audio information to the second communication terminal device in said group information acquired by said CUG server, the audio information to said second communication terminal device; and

an audio information simultaneous transmission step of, by said server, transmitting to said second communication terminal device, the audio information received together with said audio information notification request from said first communication terminal device.

102. The radio communications method according to claim 90, further comprising:

an audio information simultaneous notification requesting step of, by said first communication terminal device, transmitting to said server together with an audio information notification request for notifying audio information to the second communication terminal device in said group information acquired by said CUG server, the audio information to said second communication terminal device; and

an audio information simultaneous transmission step of, by said server, transmitting to said second communication terminal device, the audio information received together with said audio information notification request from said first communication terminal device.

106. The radio communications method according to claim 94, further comprising:

an audio information simultaneous notification requesting step of, by said first communication terminal device, transmitting to said server together with an audio information notification request for notifying audio information to the second communication terminal device in said group information acquired by said CUG server, the audio information to said second communication terminal device; and

an audio information simultaneous transmission step of, by said server, transmitting to said second communication terminal device, the audio information received together with said audio information notification request from said first communication terminal device.

108. The radio communications method according to claim 96, further comprising:

an audio information simultaneous notification requesting step of, by said first communication terminal device, transmitting to said server together with an audio information notification request for notifying audio information to the second communication terminal device in said group information acquired by said CUG server, the audio information to said second communication terminal device; and

an audio information simultaneous transmission step of, by said server, transmitting to said second communication terminal device, the audio information received together with said audio information notification request from said first communication terminal device.

112. The radio communications method according to claim 86, wherein the second communication terminal device in said group information comprises at least one of communication terminal devices in said information group, and the method comprises a step of, by said first communication terminal device, selecting at least one of communication terminal devices in said group information, and said first communication terminal device sets the second communication terminal device in said group information.

116. The radio communications method according to claim 90, wherein the second communication terminal device in said group information comprises at least one of communication terminal devices in said information group, and the method comprises a step of, by said first communication terminal device, selecting at least one of communication terminal devices in said group information, and said first communication terminal device sets the second communication terminal device in said group information.

120. The radio communications method according to claim 94, wherein the second communication terminal device in said group information comprises at least one of communication terminal devices in said information group, and the method comprises a step of, by said first communication terminal device, selecting at least one of communication terminal devices in said group information, and said first communication terminal device sets the second communication terminal device in said group information.

122. The radio communications method according to claim 96, wherein the second communication terminal device in said group information comprises at least one of communication terminal devices in said information group, and the method comprises a step of, by said first communication terminal device, selecting at least one of communication terminal devices in said group information, and said first communication terminal device sets the second communication terminal device in said group information.

124. The radio communications method according to claim 98, wherein the second communication terminal device in said group information comprises at least one of communication terminal devices in said information group, and the method comprises a step of, by said first communication terminal device, selecting at least one of communication terminal devices in said group information, and said first communication terminal device sets the second communication terminal device in said group information.

126. The radio communications method according to claim 98, wherein in said audio information simultaneous transmission step, if the authentication result that said server has received from said CUG server is an authentication result that the information of said first communication terminal device is registered in the group information registered in said CUG server, said server transmits to said second communication terminal device, the audio information that said server has received together with said audio information notification request from said first communication terminal device.

130. The radio communications method according to claim 102, wherein in said audio information simultaneous transmission step, if the authentication result that said server has received from said CUG server is an authentication result that the information of said first communication terminal device is registered in the group information registered in said CUG server, said server transmits to said second communication terminal device, the audio information that said server has received together with said audio information notification request from said first communication terminal device.

134. The radio communications method according to claim 106, wherein in said audio information simultaneous transmission step, if the authentication result that said server has received from said CUG server is an authentication result that the information of said first communication terminal device is registered in the group information registered in said CUG server, said server transmits to said second communication terminal device, the audio information that said server has received together with said audio information notification request from said first communication terminal device.

136. The radio communications method according to claim 108, wherein in said audio information simultaneous transmission step, if the authentication result that said server has received from said CUG server is an authentication result that the information of said first communication terminal device is registered in the group information registered in said CUG server, said server transmits to said second communication terminal device, the audio information that said server has received together with said audio information notification request from said first communication terminal device.

138. The radio communications method according to claim 98, wherein, in said audio information simultaneous transmission step, if said server determines that the information of said first communication terminal device is registered in said CUG control database, said server transmits to said second communication terminal device, the audio information received together with said audio information notification request from said first communication terminal device.

142. The radio communications method according to claim 102, wherein, in said audio information simultaneous transmission step, if said server determines that the information of said first communication terminal device is registered in said CUG control database, said server transmits to said second communication terminal device, the audio information received together with said audio information notification request from said first communication terminal device.

146. The radio communications method according to claim 106, wherein, in said audio information simultaneous transmission step, if said server determines that the information of said first communication terminal device is registered in said CUG control database, said server transmits to said second communication terminal device, the audio information received together with said audio information notification request from said first communication terminal device.

148. The radio communications method according to claim 108, wherein, in said audio information simultaneous transmission step, if said server determines that the information of said first communication terminal device is registered in said CUG control database, said server transmits to said second communication terminal device, the audio information received together with said audio information notification request from said first communication terminal device.