Telefonaktiebolaget Lm Ericsson (publ)

Erik Bengt Lennart Dahlman

Gregory Edward Bottomley

Ali S Khayrallah

Patrik Nils Lundqvist

Mats Cedervall

Karim Jamal

Johan Nystr&ouml;m

A system and method for adapting a broadcast service in a cellular communication network. A base station receives indications of channel quality from registered users of the broadcast service, and adapts broadcast transmission parameters to improve channel quality for the broadcast users if at least one of the broadcast users indicates that channel quality needs to be improved. If none of the broadcast users indicates that channel quality needs to be improved, the base station adapts the transmission parameters to decrease channel quality for the broadcast users. The transmission parameters may be adapted by techniques such as changing the broadcast transmit power, changing the level of FEC encoding and modulation, changing the number of channel resources allocated, or changing the transmission data rate for the broadcast service. When multiple base stations transmit the broadcast information, a base station controller may minimize network resource utilization by coordinating adaptation control among the base stations.

System and method for adaptive broadcast service

A method and system are disclosed for facilitating the timing (e.g., the known relative timing differences) of base stations (BSs) in asynchronous CDMA mobile communications systems. A plurality of mobile stations (MSs) measure the relative time differences between various pairs of BSs, and these measurements are stored by the BSs. A source BS sends to an MS, in a neighbor list message, estimates of the relative time difference between the source BS and each of the BSs on the neighboring cell list. Each BS on the list can maintain a relative time difference estimate table, which can be updated continuously from the reports received from MSs. Subsequently, the BSs can send entries from this table to the MS in the neighbor list message. Using this novel technique, the BSs have known relative timing differences. Consequently, when the MS initiates a cell-search for a candidate BS, the MS already has an estimate of the timing of that BS as compared to its source BS. As such, the resulting cell-search procedure has a lower level of complexity and thus can be accomplished much quicker than with prior procedures. In addition, the relative time difference estimates can be compared with corresponding time differences that are measured by a second mobile station. Based on this comparison, the propagation delays of signals between the second MS and various BSs can be calculated to determine the position of the second MS.

Method and system for facilitating timing of base stations in an asynchronous CDMA mobile communications system

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Bromma, Sweden

Erik Bengt Lennart Dahlman