Medium access control scheme for data transmission on code division multiple access (CDMA) wireless systems
AssigneeNorthern Telecom Limited
InventorsAhmad Jalali, Witold Krzymien, Paul Mermelstein
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Abstract
A synchronous discontinuous transmission medium access control (SDTX-MAC) method and apparatus for more efficiently using existing uplink channels by sharing these uplink channels between multiple terminals engaged in bursty data transmission. This is accomplished by assigning each mobile terminal an individual time slot and by not requiring each mobile terminal to broadcast its identity. This results in a reduction in the number of receivers on each base station and a reduction in the length of the synchronization message.
Claims16
A code division multiple access (CDMA) communication system comprising a base station and a plurality of assigned mobile terminals coupled at least one said base station, wherein said base station communicates with said plurality of assigned mobile terminals using at least one transmitter and at least one receiver to transfer at least one of many data bursts, and said transmitter and receiver communicate using a plurality of communication channels comprising:
- forward link channels which include a pilot channel, a synchronization channel, at least one paging channel, at least one forward traffic channel, and at least one reservation response channel;
- reverse link channels which include at least one access channel, at least one reverse traffic channel, and at least one synchronous synchronization-reservation channel;
- and
- means for establishing a communication link between said base station and said plurality of assigned mobile terminals.
A method of operating a code division multiple access (CDMA) communication system comprised of a plurality of mobile terminals operating in sector of a cell which is assigned to a base station, wherein said base station communicates with said plurality of assigned mobile terminals using at least one transmitter and at least one receiver to transfer at least one of many data bursts, the method comprising the steps of:
- maintaining a constant link between said base station and said plurality of mobile terminals with a pilot signal;
- accessing said base station by a first of said mobile terminals with an origination message;
- assigning a synchronous synchronization-reservation channel time slot to the first mobile terminal by said base station in response to said origination message;
- synchronizing the first mobile terminal with said base station using said assigned time slot;
- sending a channel assignment message to the first mobile terminal after the base station synchronizes with the first mobile terminal;
- broadcasting data frames from said plurality of mobile terminals to said base station on a traffic channel designated by said channel assignment message sent by said base station;
- and
- turning off said transmitter of said first mobile terminal once said broadcasting is completed by said first mobile terminal.
Dependencies are inferred from the claim text.