Handoff Performance in Wireless Mobile Networks with Unreliable Fading Channel

摘要

Handoff is an indispensable operation in wireless networks to guarantee continuous, effective, and resilient services during a Mobile Station (MS) mobility. Handoff counting, handoff rate, and handoff probability are important metrics to characterize the handoff performance. Handoff counting defines the number of handoff operations during an active call connection. Handoff rate specifies the expected number of handoff operations during an active call, or equivalently, the average handoff counting. Handoff probability refers to the probability that an MS will perform a handoff before call completion. In the literature, the fading channel is not incorporated in deriving these metrics. In addition, the teletraffic parameters are usually simplified into exponentially distributed variables for the sake of analytical tractability. In this paper, we derive the formulas for these metrics over Rayleigh fading. In particular, the results can demonstrate the explicit relationship between the handoff metrics and the physical layer characteristics, e.g., carrier frequency, maximum Doppler frequency, and fade margin. Furthermore, the formulas are developed with the generalized teletraffic parameters. Numerical examples are presented to demonstrate the impact of physical layer on the handoff metrics. The techniques and the results are significant for both deploying practical wireless networks and evaluating the system resilience over an unreliable radio channel.