Handoff modeling in cellular CDMA with finite sources and state-dependent bandwidth requirements

Abstract

It is envisioned that small cells are going to play an important role in future cellular networks. Due to limited coverage areas of small cells and increased user mobility, a proper analysis and evaluation of handoff traffic is of major importance. In this paper, we propose a novel teletraffic model for the analysis of handoff traffic in cellular CDMA networks. When the cell load is above a predefined threshold, we allow the handoff calls to reduce their bandwidth requirements in order to avoid blocking. Our model also realistically assumes a finite number of traffic sources in the cell and enables analytical determination of uplink blocking probabilities for new and handoff calls. To this end, the CDMA system has been described as a continuous-time Markov chain in order to derive an efficient recursive formula for the calculation of system state probabilities. The proposed analytical model has been validated through simulation experiments, which show good accuracy of the derived results.