No abstract

No abstract

In this paper, a new direction-based handoff' call control scheme (DBHCCS) for CDMA cellular systems is proposed. In the proposed scheme, a neighbor base station ignores unnecessary soft handoff calls requested by mobile stations which are not actually approaching the neighboi base station, while protecting real soft handoff calls by employing a queue. We proposed a new method of determining the priorities of queued handoff calls In this method, a mobile s:ation predicts the time when its handoff call is forcedly terminated, by using the changing rate of the received pilot strength from the serving BS and using the current time broadcast by thc sync channel of the serving BS as a reference time. The service priority of queued handoff calls is determined based on the predicted forced termination time reported by mobile stations.In this paper, the performance of the DBHCCS is compared with that of the first-inlfirst-out (FIFO) scheme [I] and the measurement-based prioritization scheme (MBPS) [2]. The simulation results show that the probability of new call blocking for the DBHCCS is lower than that of the FIFO scheme or the MBPS queuing discipline. It is also showed that the probability of forced termination for the DBHCCS iq; less than or equal to that of the conventional CDMA cellular system with the MBPS queuing discipline.

No abstract

In this paper, in order to increase the probability of soft handoff at the time of handoff, optimum reserved resource allocation scheme for handoff in CDMA cellular system is proposed, which allocates reserved resource to each frequency channel according to the number of neighbor cells using the same frequency channel. Performance analysis shows that the proposed scheme has higher probability of soft handoff compared to allocate resource irrelevantly to neighbor cells.