Mobile communication system

• US 6,526,036 B1
• Filed: 03/12/1999
• Issued: 02/25/2003
• Est. Priority Date: 08/20/1997
• Status: Expired due to Term

• Current Assignee: TCL Communication Technology Holdings Ltd. (TCL Technology Group Corp.)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Matsumoto, Shinji, Uchida, Yoshinori
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): SCHULTZ, WILLIAM C
• Application Number:
  US09/254,714
• Time in Patent Office: 1,446 Days
• Field of Search: 370/321, 370/310, 370/329, 370/320, 370/319, 370/335, 370/336, 370/337, 370/342, 370/343, 370/345, 370/348, 370/441, 370/442, 370/443, 370/326
• US Class Current: 370/342
• CPC Class Codes: H04B 7/2618 using hybrid code-time division multiple access [CDMA-TDMA]
• CPC Class Codes: H04J 13/00 Code division multiplex systems for frequency hopping H04B1/713

Abstract

In a mobile communication system in which a TDMA system and a time-divided CDMA system are commonly used, a high-speed TDMA data transmission system is introduced, and down-links, from base stations (1 to 3) to mobile stations (31 to 34, 41, 42, 51 and 52) and up-links, from mobile stations to base stations, comprise different communication capacities from each other and a couple of a down-link and an up-link having different communication capacities are handled as one communication channel (asymmetric channel). A mobile communication system which is to transmit a large quantity of high-speed data and is able to correspond to multimedia circumstances may be realized by assigning the above-mentioned asymmetric channel to the mobile communication system.

Claims

1. A mobile communication system, comprising:

a plurality of mobile stations and at least one base station, said mobile stations and said base station being radio-connected to each other using a multiple access system of a time-slot-shared and frequency-channel-shared type having a TDMA signal, and either a time-slot-shared and frequency-channel-shared time-divided CDMA signal, or a time-slot-shared time-divided CDMA signal,

wherein at least some of said plurality of said mobile stations include a high-speed data transmitter that has a high-speed data transmission function and are radio-connected to said at least one base station with a high-speed data channel, and

wherein said communication system includes a single communication channel between said base station and at least one high-speed data transmission function mobile station in said mobile communication system is constituted as an asymmetric channel using said high-speed data channel for high-speed data transmission, and using one of said TDMA signal, time-slot shared and frequency-channel-shared time-divided CDMA signal or time-slot-shared time-divided CDMA signal for communication signal transmission other than high-speed data transmission, such that an information quantity in a down-link from said base station to one of said high-speed data transmission function mobile stations, and an information quantity in an up-link from said one mobile station to said base station are different from each other.

2. A mobile communication system according to claim 1, wherein said communication system with a TDD system changes a ratio between a total information quantity in the down-link transmitted from said base station, and a total information quantity in the up-link received in said base station by shifting a TDD line in the direction of time axis in a frame, said TDD line forming a border between the down-link and the up-link in coordinate axes of a frame-time axis and a frequency axis.

3. A mobile communication system according to claim 1, wherein said system comprises an asymmetric channel in which a down-link from a base station to a mobile station is a high-speed TDMA data channel and an up-link from said mobile station to said base station is a low-speed TDMA data channel.

4. A mobile communication system according to claim 1, wherein said system comprises an asymmetric channel such that a down-link from a base station to a mobile station is a high-speed TDMA data channel, and that an up-link from said mobile station to said base station is a low-speed time-divided CDMA data channel.

5. A mobile communication system according to claim 1, wherein said system comprises an asymmetric channel such that a down-link from a base station to a mobile station is a low-speed TDMA data channel, and that an up-link from said mobile station to said base station is a high-speed TDMA data channel.

6. A mobile communication system according to claim 1, wherein said system comprises an asymmetric channel such that a down-link from a base station to a mobile station is a low-speed time-divided CDMA data channel, and that an up-link from said mobile station to said base station is a high-speed TDMA data channel.

7. A mobile communication system according to claim 1, wherein said system comprises either of at least one TDMA burst signal or at least one time-divided CDMA burst signal or both of them.

8. A mobile communication system according to claim 1, wherein said system comprises a mobile switching center having a function to instruct said at least one base station to change an information quantity in an up-link from a mobile station to said base station, and to change an information quantity in a down-link from said base station to said one mobile station.

9. A mobile communication system, comprising:

a plurality of mobile stations and at least one base station, said mobile stations and said base station being radio-connected to each other using a multiple access system of a time-slot-shared and frequency-channel-shared type having a TDMA signal, and either a time-slot-shared and frequency-channel-shared time-divided CDMA signal, or a time-slot-shared time-divided CDMA signal,

wherein at least some of said plurality of said mobile stations include a high-speed data transmitter that has a function of high-speed data transmission and are radio-connected to said at least one base station with a high-speed data channel,

wherein said system further comprises an asymmetric communication channel using said high-speed data channel for high-speed data transmission, and using one of said TDMA signal, time-slot shared and frequency-channel-shared time-divided CDMA signal or time-slot-shared time-divided CDMA signal for communication signal transmission other than high-speed data transmission, such that the information quantity in a down-link from said base station to at least one high-speed transmission function mobile station, and the information quantity in an up-link from said at least one high-speed transmission function mobile station to said base station are different from each other, and

wherein when data transmission of a large information quantity is finished in either or both of said up-link and said down-link, the asymmetric communication channel is immediately switched over to a small quantity data transmission channel.

10. A mobile communication system according to claim 9, wherein when a base station and a mobile station are radio-connected with a small quantity data transmission channel, and if for a predetermined period of time, data transmission is not executed, said small quantity data transmission channel is switched over to a control channel for connection which transmits only control data.

11. A mobile communication system according to claim 10, wherein in a state that a base station and a mobile station are radio-connected with a control channel for connection, if there occurs a necessity of data transmission of a large information quantity in either of an up-link from said mobile station to said base station, or a down-link from said base station to said mobile station, or both of them, said control channel for connection may be immediately switched over to a large quantity data transmission channel.

12. A mobile communication system according to claim 10, wherein when a base station and a mobile station are radio-connected with a control channel for connection, if a necessity occurs of transmission of data of small information quantity in either of an up-link from said mobile station to said base station, or a down-link from said base station to said mobile station, or both of them, said control channel for connection is immediately switched over to a small quantity data transmission channel.

13. A mobile communication system according to claim 9, wherein when a base station and a mobile station are radio-connected with a small quantity data transmission channel, if a necessity occurs of data transmission of a large information quantity in either of an up-link from said mobile station to said base station, or a down-link from said base station to said mobile station, or both of them, said small quantity data transmission channel is immediately switched over to a large capacity data transmission channel.

14. A mobile communication system according to claim 9, wherein said system comprises a mobile switching center provided with a function to instruct at least one base station to perform the management of an asymmetric communication channel and the changeover of said asymmetric communication channel.

15. A mobile communication system, comprising:

a plurality of mobile stations and at least one base station, said mobile stations and said base station being radio-connected to each other using a multiple access system of a time-slot-shared and frequency-channel-shared type having a TDMA signal, and either a time-slot-shared and frequency-channel-shared time-divided CDMA signal, or a time-slot-shared time-divided CDMA signal,

wherein at least some of said plurality of said mobile stations include a high-speed data transmitter that has a high-speed data transmission function and are radio-connected to said at least one base station with a high-speed data channel,

wherein said mobile communication system further comprises an asymmetric communication channel using said high-speed data channel for high-speed data transmission, and using one of said TDMA signal, time-slot shared and frequency-channel-shared time-divided CDMA signal or time-slot-shared time-divided CDMA signal for communication signal transmission other than high-speed data transmission, in which the information quantity in a down-link from said base station to at least one high-speed transmission function mobile station, and the information quantity in an up-link from said at least one high-speed transmission function mobile station to said base station are different from each other, and

wherein said mobile communication system further comprises small capacity data transmission channels utilizing a multi-frame system which are independent of each other in said up-link and down-link respectively.

16. A mobile communication system according to claim 15, wherein during the period of time while data are not transmitted between a base station and a mobile station, said small capacity data transmission channel is a control information channel for intermittent connection for transmitting control data.

17. A mobile communication system according to claim 16, wherein the control information channel for intermittent connection transmits, besides ordinary control data, control data showing that no data are being transmitted during a period of time from a transmission of a large information quantity of data from a base station to a mobile station until a response to receipt of said large information quantity of data has been transmitted by said mobile station.

18. A mobile communication system according to claim 16, wherein said mobile communication system comprises a mobile switching center which performs the management of a control information channel for intermittent connection and comprises a function to instruct at least one base station in the starting, switching, and suspension of said control information channel for intermittent connection.

19. A mobile communication system, comprising:

a plurality of mobile stations and at least one base station, said mobile stations and said base station being radio-connected to each other using a multiple access system of a time-slot-shared and frequency-channel-shared type having a TDMA signal, and either a time-slot-shared and frequency-channel-shared time-divided CDMA signal, or a time-slot-shared time-divided CDMA signal,

wherein at least some of said plurality of said mobile stations include a high-speed data transmitter that has a high-speed data transmission function and are radio-connected to said at least one base station with high-speed data channels,

wherein said mobile communication system further comprises an asymmetric communication channel using said high-speed data channel for high-speed data transmission, and using one of said TDMA signal, time-slot shared and frequency-channel-shared time-divided CDMA signal or time-slot-shared time-divided CDMA signal for communication signal transmission other than high-speed data transmission, such that an information quantity in a down-link from said base station to at least one high-speed transmission function mobile station, and the information quantity in an up-link from said at least one high-speed transmission function mobile station to said base station are different from each other, and

wherein a TDMA data channel is used as a high-speed data channel and a time slot in said TDMA data channel is composed of a plurality of micro time slots connected in series.

20. A mobile communication system according to claim 19, wherein the bit constitution of a micro time slot in a high-speed data channel is the same as that of a time slot in a low-speed TDMA data transmission channel.

21. A mobile communication system according to claim 19, wherein an equalizer to be used for a high-speed TDMA data channel is arranged to have the same constitution an equalizer to be used in a low-speed TDMA data channel except the operation speed.

22. A mobile communication system according to claim 19, wherein when a high-speed TDMA data channel is constituted with a plurality of micro time slots, the guard time of the high-speed TDMA data channel is changed in the unit of a micro time slot according to the moving speed of a mobile station.

23. A mobile communication system according to claim 19, wherein said system comprises a mobile switching center which manages the constitution of a micro time slot in a high-speed TDMA data channel and is provided with a function to instruct at least one base station to change the constitution of a micro time slot including the length of a guard time of said high-speed TDMA data channel.

24. A mobile communication system, comprising:

a plurality of mobile stations and at least one base station, said mobile stations and said base station being radio-connected to each other using a multiple access system of a time-slot-shared and frequency-channel-shared type having a TDMA signal, and either a time-slot-shared and frequency-channel-shared time-divided CDMA signal, or a time-slot-shared time-divided CDMA signal,

wherein at least some of said plurality of said mobile stations include a high-speed data transmitter that has a high-speed data transmission function and are radio-connected to said at least one base station with a high-speed data channel,

wherein said mobile communication system further comprises an asymmetric communication channel using said high-speed data channel for high-speed data transmission, and using one of said TDMA signal, time-slot shared and frequency-channel-shared time-divided CDMA signal or time-slot-shared time-divided CDMA signal for communication signal transmission other than high-speed data transmission, such that an information quantity in a down-link from said base station to at least one high-speed transmission function mobile station, and an information quantity in an up-link from said at least one mobile station to said base station are different from each other, and

wherein said base station and said at least one mobile station are provided with switches respectively for selecting a communication system which is able to transmit a necessary information quantity in synchronization with time slots.

25. A mobile communication system according to claim 24, wherein said base station comprises a memory for channel assignment which enables a down-link and an up-link to and from a mobile station in a communication channel to be set to be independent of each other, said communication channel being constituted with a combination of a frequency and a time slot.

26. A mobile communication system according to claim 24, wherein said mobile communication system further comprises a mobile switching center which controls channel assignment and i s provided with a function to instruct said base station in the assignment of communication channels.

27. A mobile communication system, comprising:

a plurality of mobile stations and at least one base station, said mobile stations and said base station being radio-connected to each other using a multiple access system of a time-slot-shared and frequency-channel-shared type having a TDMA signal, and either a time-slot-shared and frequency-channel-shared time-divided CDMA signal, or a time-slot-shared time-divided CDMA signal,

wherein at least some of said plurality of said mobile stations include a high-speed data transmitter that has a high-speed data transmission function and are radio-connected to said at least one base station with a high-speed data channel,

wherein said mobile communication system further comprises an asymmetric communication channel using said high-speed data channel for high-speed data transmission, and using one of said TDMA signal, time-slot shared and frequency-channel-shared time-divided CDMA signal or time-slot-shared time-divided CDMA signal for communication signal transmission other than high-speed data transmission, in which an information quantity in a down-link, from said base station to at least one high-speed transmission function mobile station, and an information quantity in an up-link, from said at least one mobile station to said base station, are different from each other, and

a mobile switching center connected to said plurality of mobile stations, said mobile switching center being provided with a mobile station information memory for storing mobile information including the information showing the services to be provided to said mobile stations which are under the control of said mobile switching center.

28. A mobile communication system according to claim 27, wherein a mobile switching center performs the management of mobile station information concerning mobile stations being under the control of said mobile switching center and comprises a function to instruct at least one base station in the starting, switching and suspension of services based on said mobile station information.

29. A mobile communication system according to claim 27, wherein a mobile switching center performs the management of the mobile station information concerning the mobile stations being under the control of said mobile switching center, and in a case that an amendment occurs in said mobile station information, said mobile switching center is provided with a function to transfer the amended mobile station information to the database of said mobile communication system which contains the mobile station information concerning all mobile stations in said mobile communication system.

30. A mobile communication system, comprising:

a plurality of mobile stations and at least one base station, said mobile stations and said base station being radio-connected to each other using a multiple access system of a time-slot-shared and frequency-channel-shared type having a TDMA signal, and either a time-slot-shared and frequency-channel-shared time-divided CDMA signal, or a time-slot-shared time-divided CDMA signal,

wherein at least some of said plurality of said mobile stations include a high-speed data transmitter that has a high-speed data transmission function and are radio-connected to said at least one base station with a high-speed data channel,

wherein said mobile communication system further comprises an asymmetric communication channel using said high-speed data channel for high-speed data transmission, and using one of said TDMA signal, time-slot shared and frequency-channel-shared time-divided CDMA signal or time-slot-shared time-divided CDMA signal for communication signal transmission other than high-speed data transmission, in which an information quantity in a down-link, from said base station to at least one high-speed transmission function mobile station, and an information quantity in an up-link, from said at least one mobile station to said base station, are different from each other, and

a mobile switching center connected to said base station, said mobile switching center being provided with a memory device for high-speed data communication to temporarily store the high-speed data transmitted to said at least one mobile station.

31. A mobile communication system according to claim 30, wherein when the high-speed data transmitted from a mobile switching center through a connected base station are normally received in a mobile station, said mobile station detects a time slot number of the last high-speed data and transfers the slot number as a normal slot number to said mobile switching center through said base station.

32. A mobile communication system according to claim 31, wherein a mobile switching center performs the management of high-speed data to be transmitted to a mobile station and receives said normal time slot number transmitted from said mobile station which has received said high-speed data, and stores high-speed data having slot numbers on and after the slot number next to the normal slot number in the memory device for high-speed communication.

33. A mobile communication system according to claim 32, wherein a mobile switching center performs the management of high-speed data to be transmitted to a mobile station, and when there is a request from said mobile station to said mobile switching center to transmit said high-speed data again, said switching center reads the high-speed data having time slot numbers on and after the time slot number next to the normal time slot number out of the memory device for high-speed data communication and transmits the high-speed data to said mobile station through the base station.

34. A mobile communication system according to claim 30, wherein when a mobile switching center receives the high-speed data to be transmitted to a mobile station from the call originating source of the high-speed data through a public switching telephone network in which said mobile switching center is accommodated and stores the data in said memory device for high-speed communication, the high-speed data are sectioned into blocks of data so that each block of data may be transmitted in a time slot, and each block is numbered with a storage information number for management.

35. A mobile communication system according to claim 34, wherein a base station which transmitted high-speed data to a mobile station contrasts the time slot number of the transmitted high-speed data to the storage information number numbered by the mobile switching center to which the base station is connected, and incorporates said time slot number and said storage information number into a set of information and notifies the information to said mobile switching center.

36. A mobile communication system according to claim 31, wherein a mobile switching center performs the management of the high-speed data to be transmitted to mobile stations and is provided with a function to erase the high-speed data having time slot numbers on and before the normal time slot number from the memory device in which the high-speed data are stored.

37. A mobile communication system according to claim 31, wherein a mobile switching center performs the management of the high-speed data to be transmitted to mobile stations and is provided with functions such that when a mobile station finishes communication, the information quantity of high-speed data left in the memory device for high-speed data communication having time slot numbers on and after the time slot number next to the normal time slot number transmitted from said mobile station through the base station is notified to the call originating source of said high-speed data.

38. A mobile communication system according to claim 33, wherein a mobile switching center performs the management of the high-speed data to be transmitted to mobile stations and the mobile switching center is provided with a function such that when said high-speed data requested by said mobile station are being transmitted to a base station, at the point of time when the information quantity of said high-speed data left in the memory device for high-speed data communication reaches a level lower than a predetermined level, the mobile switching center requests the transmission of the succeeding high-speed data for the call originating source of the high-speed data through the public switching telephone network.

39. A mobile communication system according to claim 30, wherein when high-speed data transmitted from a mobile switching center through connected base station are not received normally by a mobile station, the mobile station detects the time slot number of the transmitted high-speed data and transmits the number as an abnormal time slot number to said mobile switching center through the connected base station.

40. A mobile communication system according to claim 39, wherein a mobile switching center performs the management of the high-speed data to be transmitted to mobile stations, and when said high-speed data are not received normally in a mobile station, the mobile switching center, at the reception of the abnormal time slot number, reads the high-speed data having the same time slot number as the abnormal time slot number out of the memory device for high-speed data communication, and transmits the high-speed data again to said mobile station.

41. A mobile communication system, comprising:

a plurality of mobile stations and at least one base station, said mobile stations and said base station being radio-connected to each other using a multiple access system of a time-slot-shared and frequency-channel-shared type having a TDMA signal, and either a time-slot-shared and frequency-channel-shared time-divided CDMA signal, or a time-slot-shared time-divided CDMA signal,

wherein at least some of said plurality of said mobile stations include a high-speed data transmitter that has a high-speed data transmission function and are radio-connected to said at least one base station with high-speed data channels,

wherein said mobile communication system further comprises an asymmetric communication channel using said high-speed data channel for high-speed data transmission, and using one of said TDMA signal, time-slot shared and frequency-channel-shared time-divided CDMA signal or time-slot-shared time-divided CDMA signal for communication signal transmission other than high-speed data transmission, such that an information quantity in a down-link from said base station to at least one high-speed transmission function mobile station, and the information quantity in an up-link from said at least one high-speed transmission function mobile station to said base station are different from each other,

a mobile switching center connected to said at least one base station, said mobile switching center being provided with a mobile station management memory for storing a communication channel management table to be used for the management of communication channels connecting said mobile switching center and respective mobile stations, and

wherein said mobile switching center assigns a time slot corresponding to the transmission type and after the operation of assignment of the time slot corresponding to the present transmission type is finished, the assigning operation of the time slot is stored in said mobile station management memory as a history, and in a case that the same transmission type is requested again, the time slot having an actual use in the past existing in the history stored in said mobile station management memory is used.

42. A mobile communication system according to claim 41, wherein when the name of a time slot which has a history of actual use in the past is stored in a mobile station management memory as a time slot presently being not used, only when a time slot name which does not have a history of actual use in the past of the same kind of transmission type is not found in said mobile station management memory, the history of the time slot name which has the history of actual use in the past is erased from said mobile station management memory and it is assigned to a new mobile station.

43. A mobile communication system according to claim 41, wherein when the name of a time slot which has a history of actual use in the past is stored in a mobile station management memory as a time slot not being used presently, when a time slot name which does not have a history of actual use in the past of the same kind of transmission type is not found in said mobile station management memory and the history of the time slot name which has the history of actual use in the past is erased from said mobile station management memory, a time slot which has the oldest history of actual use in the past is selected and it is assigned to a new mobile station.