Fuzzy adaptive guard channel assignment strategy for handoff in PCS system
Choong-Ho Cho, YouChang Ko, Hyung Lee-Kwang · 2002
The known channel allocation schemes in a personal communications service (PCS) operating with fixed guard channels for handoff calls can lead to failure in utilizing the limited channels since the handoff traffic which depends on mobility of users is not always stationary. We use a fuzzy logic controller (FLC) to generate proper guard channels according to the fluctuating handoff traffic pattern so as not to waste or not to lack the valuable resources. Also we introduce the fuzzy adaptive guard channel with handoff queueing scheme (FA GCHQS) which combines FLC with a previous guard channel plus queueing priority scheme (GCHQS). For performance evaluation we regard originating call blocking probability, handoff forced termination probability, and grade of service of the network as the system performance criteria. Finally we show that the proposed method yields better performance than that of a previous one through the analytical results of an M/M/C/K queueing model on an assumed handoff traffic pattern of a city environment.