Performance evaluation of type-of-service based directed retry strategy in cellular mobile networks

Type-of-service based directed retry strategy is investigated to achieve efficient channel utilization for different types of users in mobile cellular environments. Directed retry takes advantage of inevitable overlap among cells to increase the channel utilization and reduce the blocking probability in each cell. A M/M/m/k queue is used to model the channel occupancy statement. Several parameters, such as traffic load, queue length, blocking probability and overlapped area fraction, are studied for comparisons among different types of users, e.g., delay-sensitive and delay non-sensitive. Additional handoff processing load, which is due to directed retry and related to overlapped area fraction and mean path length, is estimated. The results show that the additional handoff probability caused by directed retry is quite small, even in the case of delay-sensitive services.