Optimal assignment of mobile station serving sector for the forward link of a time-shared wireless packet data channel

Abstract

Recent developments in wireless networks have focused on improved data performance (e.g., 1xEV-DV, 1xEV-DO and HSDPA). In these networks the forward packet data channel is time shared among the data users. In order to be able to take advantage of fast fading effects (i.e., schedule users when they are in good radio conditions), the scheduling of users is performed at the base station (BS). This implies that it is not possible to support soft handoff on this forward packet data channel since this would require that the BSs synchronize their schedules. However, macro-diversity gains can be achieved by fast cell switching. The mobile is served from the base station with the best forward link quality which is reported through the reverse channel quality indicator channel. However, the BS with the best forward link quality is not necessarily the best BS to serve the mobile since it may be congested. In this paper, we describe a procedure whereby a mobile switches to the cell that can provide it with the highest throughput rather than best channel conditions. We demonstrate why this approach is preferable and describe the framework necessary to support this mechanism.