Channel Reservation in Cellular Wireless Networks with Spectrum Leasing

It is undesired to drop an ongoing call in wireless systems; however, call dropping may occur in two situations, one of which is hand-off between cells in cellular wireless networks, the other of which is channel withdrawal in wireless systems with spectrum leasing. Channel reservation is a common solution to reduce the two types of call dropping. Optimal numbers of reservation channels were separately found before to reduce the two types of call dropping respectively. This paper studies a cellular wireless network which leases spectrum bands from another system. Due to the gain of resource sharing, the two reservations can be combined into a reservation pool, which, however, increases the complexity of selecting the optimal number of the channels in the pool; this selection is further complicated for heterogenous traffic because different traffic types have different tolerances to the exhaustion of channels. Therefore, it is critical to reserve the optimal number of channels in a pool such that the quality-of-services of different types of traffic are satisfied while throughput is maximized. We develop a three-dimensional Markov chain to analyze the performances of the channel reservation in a cellular wireless network with spectrum leasing. Based on the analysis, we use an example to demonstrate that the selected parameters of reservation guarantee the quality-ofservice requirements of different types of traffic while maximize throughput.