Method and apparatus for radio communication with control according to priority of data to be transmitted

• US 5,966,375 A
• Filed: 06/15/1995
• Issued: 10/12/1999
• Est. Priority Date: 06/20/1994
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kagaya, Naoto
• Primary Examiner(s): NGUYEN, CHAU T
• Application Number:
  US08/490,738
• Time in Patent Office: 1,580 Days
• Field of Search: 370/321, 370/337, 370/445, 370/447, 370/448, 370/455, 370/461, 370/462, 370/463, 370/338, 370/347, 375/200, 375/202, 375/205, 375/206, 340/825.5, 340/825.05
• US Class Current: 370/338
• CPC Class Codes: H04L 12/40013 Details regarding a bus controller
• CPC Class Codes: H04L 12/40143 involving priority mechanisms hybrid switching fabrics H04L12/6402; intermediate storage or scheduling H04L49/90; time-division multiplex systems H04J3/00
• CPC Class Codes: H04L 12/413 with random access, e.g. carrier-sense multiple-access with collision detection [CSMA-CD]
• CPC Class Codes: H04W 74/0875 with assigned priorities based access

Abstract

Radio communication method and apparatus that performs communication as follows. When a radio communication apparatus receives data transmitted by data terminal equipment, the radio communication apparatus identifies the type of the data, and checks whether another data terminal equipment is transmitting data by detecting a carrier. If no carrier is detected, the radio communication apparatus monitors occurrence of a carrier for a time period determined depending on the priority of data to be transmitted. After elapse of the above time period, it is determined whether another data terminal equipment is transmitting a carrier indicating intention to start data transmission. If it is concluded that no such a carrier is detected, the radio communication apparatus transmits a carrier a predetermined number of times, and then starts data transmission. This technique allows data having a high priority to be transmitted earlier than low-priority data.

Claims

1. A radio communication apparatus for avoiding a collision between data to be transmitted and data transmitted by another radio communication apparatus, by notifying another radio communication apparatus of transmitting data by transmitting a first carrier prior to the data transmission, and by transmitting the first carrier after a predetermined time has passed in a case where a second carrier transmitted by another radio communication apparatus is detected before transmitting the first carrier, said apparatus comprising;

distinction means for distinguishing priority of data to be transmitted;

determining means for determining a time for transmitting said first carrier to notify of transmitting the data, according to the priority distinguished by said distinction means;

detection means for detecting said second carrier transmitted by another radio communication apparatus while the time determined by said determining means passes;

first transmission means for transmitting said first carrier, according to the detection by said detection means; and

second transmission means for transmitting data after said first carrier has been transmitted by said first transmission means.

2. A radio communication apparatus according to claim 1, wherein said detection means performs said detection when the data transmission by another radio communication apparatus ends.

3. A radio communication apparatus according to claim 1, wherein said determining means also determines a transmission interval of the first carrier transmitted in succession by said first transmission means.

4. A radio communication apparatus according to claim 1, wherein said determining means determines a time for transmitting said first carrier in a random manner within predetermined limits.

5. A radio communication apparatus according to claim 1, wherein said determining means determines the time to be a shorter value when said data to be transmitted has a higher priority.

6. A radio communication apparatus for avoiding a collision between data to be transmitted and data transmitted by another radio communication apparatus, by notifying another radio communication apparatus of transmitting data by transmitting a first carrier into a predetermined time slot in a communication frame prior to the data transmission using the communication frame, and by transmitting the first carrier after a predetermined time has passed in a case where a second carrier transmitted by another radio communication apparatus is detected before transmitting the first carrier, said apparatus comprising:

distinction means for distinguishing a priority of data to be transmitted;

detection means for detecting said second carrier transmitted by another radio communication apparatus;

first transmission means for transmitting said first carrier using a time slot in accordance with the priority distinguished by said distinction means, according to the detection by said detection means; and

second transmission means for transmitting data after said first carrier has been transmitted by said first transmission means.

7. A radio communication apparatus according to claim 6, wherein said detection means performs said detection when the data transmission by another radio communication apparatus ends.

8. A radio communication apparatus according to claim 6, wherein said detection means also detects said second carrier in accordance with the data to be transmitted.

9. A radio communication apparatus according to claim 6, wherein said first carrier is transmitted by using the time slot which differs in accordance with whether the radio communication apparatus to transmit said first carrier is a calling side or a called side.

10. A radio communication apparatus according to claim 9, wherein said first carrier is transmitted by using a high priority time slot in a case where said first carrier is transmitted by the calling radio communication apparatus and a low priority to the time slot in a case where said first carrier is transmitted by the called radio communication apparatus.

11. A radio communication apparatus according to claim 9, wherein said first carrier is transmitted by using a high priority time slot in a case where said first carrier is transmitted by the called radio communication apparatus and a low priority time slot in a case where said first carrier is transmitted by the calling radio communication apparatus.

12. A radio communication apparatus according to claim 6, wherein, in a case where data to be transmitted is a top priority, said first carrier is transmitted by using a highest priority time slot.

13. A radio communication apparatus according to claim 6, wherein said second transmission means performs its transmission operation according to a frequency hopping technique.

14. An exchange system including a main apparatus having exchanging capability and also including radio communication apparatus for avoiding a collision between data to be transmitted and data transmitted by another radio communication apparatus, by notifying another radio communication apparatus of transmitting data by transmitting a first carrier into a predetermined time slot in a communication frame prior to the data transmission using the communication frame, and by transmitting the first carrier after a predetermined time has passed in a case where a second carrier transmitted by another radio communication apparatus is detected before transmitting the first carrier, said exchange system comprising:

distinction means for distinguishing priority of data to be transmitted;

detection means for detecting said second carrier transmitted by another radio communication apparatus;

first transmission means for transmitting said first carrier using a time slot in accordance with the priority distinguished by said distinction means, according to the detection by said detection means; and

second transmission means for transmitting data after said first carrier has been transmitted by said first transmission means.

15. An exchange system according to claim 14, wherein said detection means performs said detection when the data transmission by another radio communication apparatus ends.

16. An exchange system according to claim 14, wherein said detection means detects said second carrier in a time slot in accordance with data to be transmitted.

17. An exchange system according to claim 14, wherein said first carrier is transmitted by using the time slot which differs in accordance with whether the radio communication apparatus to transmit said first carrier is a calling side or a called side.

18. An exchange system according to claim 17, wherein said first carrier is transmitted by using a high priority time slot in a case where said first carrier is transmitted by the calling radio communication apparatus and a low priority time slot in a case where said first carrier is transmitted by the called radio communication apparatus.

19. An exchange system according to claim 17, wherein said first carrier is transmitted by using a high priority time slot in a case where said first carrier is transmitted by the called radio communication apparatus and a low priority time slot in a case where said first carrier is transmitted by the calling radio communication apparatus.

20. An exchange system according to claim 14, wherein, in a case where data to be transmitted is a top priority, said first carrier is transmitted by using a highest priority time slot.

21. An exchange system according to claim 14, wherein said second transmission means performs its transmission operation according to a frequency hopping technique.

22. A control method of a radio communication apparatus for avoiding a collision between data to be transmitted and data transmitted by another radio communication apparatus, by notifying another radio communication apparatus of transmitting data by transmitting a first carrier prior to the data transmission, and by transmitting the first carrier after a predetermined time has passed in a case where a second carrier transmitted by another radio communication apparatus is detected before transmitting the first carrier, said method comprising the steps of:

distinguishing priority of data to be transmitted;

determining a time for transmitting said first carrier to notify of transmitting the data, according to the priority distinguished in said distinguishing step;

detecting said second carrier transmitted by another radio communication apparatus while the time determined in said determining step passes;

first transmitting said first carrier, according to the detection in said detecting step; and

secondly transmitting data after said first carrier has been transmitted in said first transmitting step.

23. A radio communication method according to claim 22, wherein said detecting step performs said detection when the data transmission by another radio communication apparatus ends.

24. A radio communication method according to claim 22, wherein said determining step further includes the step of determining a transmission interval of the first carrier transmitted in succession in the first transmitting step.

25. A radio communication method according to claim 22, wherein said determining step determines a time for transmitting said first carrier in a random manner within predetermined limits.

26. A radio communication method according to claim 22, wherein said determining step determines the time to be a shorter value when said data to be transmitted has a higher priority.

27. A control method of a radio communication apparatus for avoiding a collision between data to be transmitted and data transmitted by another radio communication apparatus, by notifying another radio communication apparatus of transmitting data by transmitting a first carrier into a predetermined time slot in a communication frame prior to the data transmission using the communication frame, and by transmitting the first carrier after a predetermined time has passed in a case where a second carrier transmitted by another radio communication apparatus is detected before transmitting the first carrier, said method comprising the steps of:

distinguishing priority of data to be transmitted;

detecting said second carrier transmitted by another radio communication apparatus;

first transmitting said first carrier using a time slot in accordance with the priority distinguished in said distinguishing step, according to the detection in said detecting step; and

second transmitting data after said first carrier has been transmitted in said first carrier transmitting step.

28. A radio communication method according to claim 27, wherein said detecting step performs said detection when the data transmission by another radio communication apparatus ends.

29. A radio communication method according to claim 27, wherein said detection step includes detecting said second carrier in accordance with data to be transmitted.

30. A radio communication method according to claim 29, wherein, in a case where data to be transmitted is a top priority, said first carrier is transmitted by using a highest priority time slot.

31. A radio communication method according to claim 27, wherein said first carrier is transmitted by using the time slot which differs in accordance with whether the radio communication apparatus to transmit said first carrier is a calling side or a called side.

32. A radio communication method according to claim 31, wherein said first carrier is transmitted by using a high priority time slot in a case where said first carrier is transmitted by the calling radio communication apparatus and a low priority time slot in a case where said first carrier is transmitted by the called radio communication apparatus.

33. A radio communication method according to claim 31, wherein said first carrier is transmitted by using a high priority time slot in a case where said first carrier is transmitted by the called radio communication apparatus and a low priority time slot in a case where said first carrier is transmitted by the calling radio communication apparatus.

34. A radio communication method according to claim 27, wherein said second transmitting step performs its transmission operation according to a frequency hopping technique.

35. A control method for an exchange system including a main apparatus having exchanging capability and also including radio communication apparatus for avoiding a collision between data to be transmitted and data transmitted by another radio communication apparatus, by notifying another radio communication apparatus of transmitting data by transmitting a first carrier into a predetermined time slot in a communication frame prior to the data transmission using the communication frame, and by transmitting the first carrier after a predetermined time has passed in a case where a second carrier transmitted by another radio communication apparatus is detected before transmitting the first carrier, said method comprising the steps of:

distinguishing priority of data to be transmitted;

detecting said second carrier transmitted by another radio communication apparatus;

first transmitting said first carrier using a time slot in accordance with the priority distinguished in said distinguishing step, according to the detection in the detection step; and

second transmitting data after said first carrier has been transmitted in said first transmitting step.

36. A radio communication method according to claim 35, wherein said detecting step performs said detection when the data transmission by another radio communication apparatus ends.

37. A radio communication method according to claim 36, wherein, in a case where data to be transmitted is a top priority, said first carrier is transmitted by using a highest priority time slot.

38. A radio communication method according to claim 35, wherein said detection step includes detecting said second carrier in accordance with data to be transmitted.

39. A radio communication method according to claim 35, wherein said first carrier is transmitted by using the time slot which differs in accordance with whether the radio communication apparatus to transmit said first carrier is a calling side or a called side.

40. A radio communication method according to claim 39, wherein said first carrier is transmitted by using a high priority time slot in a case where said first carrier is transmitted by the calling radio communication apparatus and a low priority time slot in a case where said first carrier is transmitted by the called radio communication apparatus.

41. A radio communication method according to claim 39, wherein said first carrier is transmitted by using a high priority time slot in a case where said first carrier is transmitted by the called radio communication apparatus and a low priority time slot in a case where said first carrier is transmitted by the calling radio communication apparatus.

42. A radio communication method according to claim 35, wherein said second transmitting step performs its transmission operation according to a frequency hopping technique.

43. A communication apparatus for performing communication using a time-division multiplexing technique, said apparatus comprising:

identifying means for identifying the priority of communication data;

selecting means for selecting a usable one time slot from among three time slots, in which a first time slot is used for performing a predetermined notification at a calling side communication apparatus, a second time slot is used for performing the predetermined notification at a called side communication apparatus, and a third time slot, usable at both the calling side communication apparatus and the called side communication apparatus, is used for performing the predetermined notification at a high priority according to the identified result by said identifying means; and

notifying means for performing the predetermined notification by using the time slot based on the selection by said selection means.

44. A communication apparatus according to claim 43, wherein said notification is performed by sending a request-to-send for notifying another communication apparatus of transmitting data in the first time slot, the second time slot, or the third time slot, according to the result of identification by said identifying means.

45. A communication apparatus according to claim 43, wherein said notification is performed by transmitting a carrier serving as a request-to-send.

46. A communication apparatus according to claim 43, further comprising detecting means for detecting said request-to-send transmitted in the first time slot, the second time slot, or the third time slot, wherein said notification is performed by using a fourth time slot, if said request to send is not detected by said detecting means.

47. A communication apparatus according to claim 43, wherein said notification is performed via a radio wave.

48. A communication method for performing communication using a time-division multiplexing technique, said method comprising the steps of:

identifying the priority of communication data;

selecting a usable one time slot from among three time slots, in which a first time slot is used for performing a predetermined notification at a calling side communication apparatus, a second time slot is used for performing the predetermined notification at a called side communication apparatus, and a third time slot, usable at both the calling side communication apparatus and the called side communication apparatus, is used for performing the predetermined notification at a high priority according to the identified result in said identifying step; and

performing the predetermined notification by using the time slot based on the selection in said selecting step.

49. A communication method according to claim 48, wherein said notification is performed by sending a request-to-send for notifying another communication apparatus of transmitting data in the first time slot, the second time slot, or the third time slot according to the result obtained in said identifying step.

50. A communication method according to claim 49, further comprising the step of detecting said request-to-send transmitted in the first time slot, the second time slot, or the third time slot, wherein said notification is performed by using a fourth time slot, if said request-to-send is not detected.

51. A communication method according to claim 48, wherein said notification is performed by transmitting a carrier serving as a request-to-send.

52. A communication method according to claim 48, wherein said notification is performed via a radio wave.