Performance Analysis of Channel Rate Selection Schemes in Systems with Tight Reuse

In GSM cellular networks, half-rate channels are specified as a bandwidth alternative to full-rate channels for the support of voice services under good conditions. In this paper, we propose and analyze channel rate selection algorithms upon initial call setup. Three different algorithms are considered: (a) Rate selection based on the serving sector signal strength measurements; (b) Rate selection based on signal strength and two-tiers of co-channel interfence measurements; (c) Practical hybrid approach that uses the metris reported by the terminal, i.e., either signal strength only or signal and interference measurements depending on the information that can be erived from the measurement report.