Analysis of Bi-class call admission control scheme in CDMA cellular network for variation in soft handoff threshold parameters

In CDMA cellular system, the coverage area and cell capacity is greatly influenced by soft handoff process. The variation in soft handoff coverage area can be taken as the parameter influencing the performance parameters of the CDMA cellular system. In this paper, an analytical model is developed and analyzed for the concerned target cell in CDMA cellular network. The model proposed in this paper is for Bi-class services mainly integrated data and voice. It is based on priority reservation for handoff voice and data calls along with call queuing scheme for handoff data calls. Upper channel limits are set for new voice as well as data calls to give priority to handoff calls. Two dimensional Markov birth-death process is used for modeling the problem. The data handoff queue capacity is considered as function of soft handoff coverage area which depends on the two soft handoff threshold parameters T_ADD and T_DROP. Variation in these threshold parameters is stated in term of variation in handoff data call queue capacity. The performance parameters of the model mainly new voice and data call blocking probabilities and handoff voice and data dropping probabilities are analyzed for variation in upper channel limit for new voice call and handoff data call queue capacity.