Call-holding-time-based random early blocking in hierarchical cellular multiservice networks

An appropriate call admission control in the next generation wireless netwo rks is expected to make efficient use of scarce wireless resource and impro ve quality-of-service, while supporting multimedia services. On one hand, b locking handoff calls is normally more annoying than blocking new calls. On the other hand, blocking new calls reduces resource utilization. More impo rtantly, handoff call arrival rate depends strongly on call holding time. A novel Call-Holding-Time-Based Random Early Blocking (CHTREB) scheme is pro posed to achieve the aforesaid goals in a two-tier cellular voice/data netw ork. With CHTREB, new calls are accepted according to some acceptance proba bility taking into account the call hloding time difference between voice a nd data calls. An iterative algorithm is developed to calculate performance measures of interest, i.e., new call blocking probability and forced termi nation probability. First, simulation results are shown to verify analytica l results. Then, numerical results are presented to show the robustness of CHTREB. It is found that CHTREB outperforms TR and CHTREB-FAP under both st ationary and nonstationary traffic scenarios. Last but not least, the studi ed 2-tier system is compared with 1-tier counterpart. It is shown that 2-ti er system performs better in terms of average number of handoffs per data c all.