Radio data transmission system

• US 5,883,887 A
• Filed: 04/16/1996
• Issued: 03/16/1999
• Est. Priority Date: 04/18/1995
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Otsuka, Akira, Take, Keijiro
• Primary Examiner(s): Ton, Dang
• Assistant Examiner(s): HOM, SHICK C
• Application Number:
  US08/632,876
• Time in Patent Office: 1,064 Days
• Field of Search: 370/312, 370/313, 370/314, 370/316, 370/322, 370/326, 370/328, 370/329, 370/331, 370/336, 370/337, 370/338, 370/310, 370/335, 370/342, 370/320, 370/280, 370/294
• US Class Current: 370/329
• CPC Class Codes: H04W 74/006 in the downlink, i.e. towards the terminal

Abstract

A base station and a base station controller are used for providing data communication channels using random access (RACHs) for mobile stations. The base station or the base station controller provides for notifying channel information on an RACH. Each mobile station provide for determining whether or not a packet can be sent and for shifting from one RACH to another based on the channel information. The base station and the base station controller further provide for transferring a packet to a mobile station over the RACH. The base station controller provides for terminal identifier management and packet division and reconstruction for transferring a packet between mobile stations or between a mobile station and the LAN.

Claims

1. A radio data transmission system, comprising:

a plurality of base stations;

a plurality of mobile stations; and

a base station controller;

wherein radio channels between each base station and a plurality of mobile stations consist of a control channel (CCH) and a plurality of communication channels (TCHs); and

wherein each base station comprises means for notifying channels that can be used as data communication channels using a random access method (RACHS) among the TCHs over the CCH, means for transmitting channel information concerning each RACH over each RACH, and means for notifying another RACH to which a shift can be made.

2. A radio data transmission system, comprising:

a plurality of base stations;

a plurality of mobile stations; and

a base station controller;

wherein radio channels between each base station and a plurality of mobile stations includes a control channel (CCH) and a plurality of communication channels (TCHs);

wherein each base station comprises means for transmitting channel information concerning each RACH over each RACH;

wherein a base station using a plurality of TCHs as data communication channels using a random access method (RACHS) transmits a packet transmission disable notification and a shift destination RACH notification on one of the RACHs by said channel information notifying means; and

wherein said mobile station receiving the notification on the RACH shifts from the RACH to another RACH specified in the shift destination RACH notification with the notification reception as a trigger.

3. A radio data communication system as claimed in claim 2, wherein each mobile station comprises means for calculating RACH shifting probability Pa, means for comparing the probability Pa with a threshold value stored in said mobile station, means for executing RACH shifting if the probability is greater than the threshold value, and means for postponing RACH shifting for time T1 if the probability is less than the threshold value.

4. A radio data transmission system, comprising:

a plurality of base stations;

a plurality of mobile stations;

a base station controller, in which radio channels between each base station and a plurality of mobile stations consist of a control channel (CCH) and a plurality of communication channels (TCHS) wherein each of said base stations uses a plurality of TCHs as data communication channels using a random access method (RACHs);

means for deleting the RACH assigned to a telephone call from a managed RACH group when one of said base stations using a plurality of TCHs as RACHs and said base station controller for controlling said base station require a TCH as a new telephone call occurs;

means for transmitting channel information concerning each RACH over each RACH;

means for sending a departure instruction notification of the RACH from said base station to mobile stations acquiring the RACH through said notification mean and sending a message to the effect that the RACH becomes unavailable as an RACH on all other RACHs managed by said base station through said notification means; and

means for changing registration of the mobile stations registered in the RACH to a shift destination RACH specified on the RACH by said base station controller.

5. A radio data transmission system, comprising:

determination means for cyclically determining data communication channels using a random access method (RACHS) managed by one base station to which mobile stations can shift among the RACHs managed by said base station;

means for transmitting channel information concerning each RACH over each RACH;

notification means for notifying mobile stations of a cyclic RACH sequence determined by said determination means through said notification means by said base station; and

means for shifting channels in sequence in response to the notification.

6. A radio data communication system, comprising:

means for calculating probability Pb of continuing RACH shift for each mobile station when a mobile station having a send packet makes an RACH shift in sequence according to shift destination RACHs notified from a base station if an RACH acquired by the mobile station is used for packet transmission of another mobile station, and all RACHs are used for other mobile stations at a stage where all RACHs managed by the base station have been cycled in RACH shift based on cyclic RACH specification;

comparison means for comparing the calculated probability Pb with a threshold value stored in the mobile station; and

means being responsive to the comparison result of said comparison means for again starting RACH shifting based on the cyclic RACH specification if the probability Pb is greater than the threshold value and for postponing RACH shifting for time T if the probability Pb is less than the threshold value.

7. A radio data communication system having a plurality of mobile stations, each of said mobile stations comprising:

means for storing the number of times a shift channel cyclic sequence has been cycled in RACH shift based on cyclic RACH specification;

means being responsive to the number of times it has been cycled for calculating cyclic probability Pc at a stage where the mobile station shifts on the shift channel cyclic sequence based on shift channel information notified from a base station and has shifted all RACHs managed by the base station;

means for comparing the calculated probability Pc with a threshold value previously stored in the mobile station and judging continuation or postponement of the shifting; and

means for changing postponement time T in response to the number of times if postponement is judged.

8. A radio data transmission system, comprising:

a plurality of base stations;

a plurality of mobile stations; and

a base station controller, in which radio channels between each base station and a plurality of mobile stations consist of a control channel (CCH) and a plurality of communication channels (TCHS) wherein each of said base stations uses a plurality of TCHs as data communication channels using a random access method (RACHs);

wherein each base station comprises means for managing a plurality of RACHs and that said base station controller comprises means, when one of said mobile stations requests use of a new RACH over a CCH, for specifying a RACH to be used for said mobile station and means for assigning different RACHs in sequence to mobile stations making use requests in sequence.

9. A radio data transmission system, comprising:

a plurality of base stations;

a plurality of mobile stations; and

a base station controller in which radio channels between each base station and a plurality of mobile stations consist of a control channel (CCH) and a plurality of communication channels (TCHS) and down channels of the TCHs include an attendant CCH using a time division multiple access (TDMA) as a radio access between said base stations and said mobile stations;

wherein each of said mobile stations comprises means for generating a packet in a format that can be sent to a local area network (LAN), means for dividing the packet into segments, and means for adding a synchronization bit and a number identifying the mobile station to a first segment for generating segments, that each of said base stations comprises means, when one of said mobile stations sends the first segment to a transmittable RACH and said base station normally receives the segment, for notifying the mobile station number of said mobile station and information indicating that the mobile stations other than said mobile station are disabled from transmitting on the RACH on the down attendant CCH of the RACH, thereby notifying said mobile station of use right of the RACH and inhibiting other mobile stations acquiring the RACH from transmitting a packet and means for establishing up synchronization by using the first segment, that each of said mobile stations comprises means for adding numbers for identifying the segments, and that said base station controller or each of said base stations comprises means for releasing the use right of the RACH upon reception of the last segment according to the segment identification numbers.

10. A radio data transmission system, comprising:

a plurality of base stations;

a plurality of mobile stations; and

a base station controller connected to a local area network (LAN) and having a channel configuration in which radio channels between each base station and a plurality of mobile stations consist of a control channel (CCH) and a plurality of communication channels (TCHS) wherein each of said base stations uses a plurality of TCHs as data communication channels using a random access method (RACHs);

wherein said base station controller comprises means for assembling segments sent from one of said mobile stations into a packet in a format that can be sent to the LAN, means for sending the packet to the LAN, a conversion table for representing correspondence among mobile station numbers TNs identifying said mobile stations, addresses TAs identifying said mobile stations in the LAN, and channel numbers CNs identifying RACHS, means for searching said conversion table upon reception of an RACH use request from one of said mobile stations, means, if the TN of said mobile station does not exist in said conversion table, for registering the TN and the CN of an RACH specified by the channel assignment system as claimed in claim 9 in said conversion table, means, if the TN of said mobile station is registered, for changing the CN corresponding to the registered TN to the CN of RACH specified by the channel assignment system, and means for changing said conversion table if upon reception of a packet over RACH from the mobile station identified by TN, the CN of the RACH differs from the CN stored in said conversion table.

11. A radio data transmission system, comprising:

a plurality of base stations;

a plurality of mobile stations; and

a base station controller connected to a local area network (LAN) and having a channel configuration wherein radio channels between each base station and a plurality of mobile stations consist of a control channel (CCH) and a plurality of communication channels (TCHS) wherein each of said base stations uses a plurality of TCHs as data communication channels using a random access method (RACHs);

wherein said base station controller comprises means, upon reception of a packet destined for one of said mobile stations from the LAN, for searching the conversion table for channel number TN of an RACH acquired by said mobile station and sending a call incoming notification with the TN of the packet destined for said mobile station to said base station managing the RACH, that said base station comprises means for passing on the packet incoming notification over down CCHs corresponding to all RACHs managed by said base station when receiving the packet incoming notification from said base station controller, that said mobile station comprises means, if said mobile station is shifting from one RACH to another for sending a packet, for stopping the channel shifting and returning to the channel shifting start RACH upon reception of the call incoming notification, that said base station controller comprises means for transmitting the packet to the RACH corresponding to the mobile station number of said mobile station stored in the conversion table in time Tp after sending the packet incoming notification, and that said base station comprises means for passing on the packet received from said base station controller on a radio channel.

12. A radio data transmission system, comprising:

a plurality of base stations;

a plurality of mobile stations;

a base station controller, wherein radio channels between each base station and a plurality of mobile stations consist of a control channel (CCH) and a plurality of communication channels (TCHs);

means for handling two or more of TCHs managed by one base station fixedly as one integrated RACH, means, when a telephone call occurs, for assigning one TCH in the integrated RACH to the telephone call; and

means for integrating the remaining TCHs determined to be the integrated RACH other than the TCH assigned to the telephone call and handling them as one RACH, wherein said base station and said base station controller comprise means for combining the TCH released from the telephone call upon the end of the call and the RACH into one RACH for operation.

13. A radio data transmission system, comprising:

a plurality of base stations;

a plurality of mobile stations; and

a base station controller wherein a channel configuration wherein radio channels between each base station and a plurality of mobile stations consist of a control channel (CCH) and a plurality of communication channels (TCHS) wherein each of said base stations uses a plurality of TCHs as data communication channels using a random access method (RACHs);

wherein, when said base station uses two or more TCHs for RACH, said base station and said base station controller comprise means for assembling some of the TCHs into one RACH, means for dividing the RACH into a plurality of RACHs for operation, and means for operating a plurality of RACHs different in speed.

14. A radio data transmission system, comprising:

identification means for identifying the order of segments transmitted consecutively on a plurality of communication channels making up integrated communication channels using random access from one mobile station and means for assembling the segments ordered by said identification means into a packet that can be transmitted to a local area network (LAN).

15. A radio data transmission system, comprising:

a plurality of base stations;

a plurality of mobile stations;

a base station controller, wherein radio channels between each base station and a plurality of mobile stations consist of a control channel (CCH) and a plurality of communication channels (TCHS) wherein all or some of said base stations use one or more TCHs as data communication channel using a random access method (RACHS);

means, if said base station or said base station controller does not receive a segment from a mobile station having use right of RACH during time TT, for assuming that packet transmission on the RACH has abnormally ended and releasing the RACH;

means for holding segments received so far from the mobile station, means for storing segments that cannot be transmitted on the RACH by the mobile station;

means, when the mobile station newly gets use right of RACH, for again transmitting on the RACH the segments that cannot be transmitted; and

means for assembling the segments held by one of said base station and said base station controller and newly received segments into a packet.

16. A radio data transmission system, comprising

a plurality of base stations;

a plurality of mobile stations;

a base station controller, wherein radio channels between each base station and a plurality of mobile stations consist of a control channel (CCH) and a plurality of communication channels (TCHS) wherein each of said base stations uses a plurality of TCHs as data communication channels using a random access method (RACHs);

means for inhibiting the TCHs used as the RACHs from being used as VCHs used for telephone calls; and

means for determining the number of channels of the TCHs inhibited from being assigned to the VCHs in response to the number of mobile stations using the RACHS.

17. A radio data transmission system, comprising:

a plurality of base stations;

a plurality of mobile stations;

a base station controller, in which radio channels between each base station and a plurality of mobile stations include a control channel (CCH) and a plurality of communication channels (TCHS) wherein each of said base stations uses a plurality of TCHs as data communication channels using a random access method (RACHs);

means for measuring line use efficiency of each RACH managed by one base station;

means for comparing the measured line use efficiency of one RACH with that of another RACH;

means for selecting an RACH having lower line use efficiency than other RACHs based on the comparison result; and

means for deleting the selected RACH from the RACH group, inhibiting use of the RACH, and deleting the RACH from shift destination RACHS.