Performance of Dynamic Service Addition in mobile WiMAX networks

In WiMAX mobile networks (IEEE 802.16e-802.16m), connections, also referred to as service flows, can be dynamically activated between the base station and the mobile stations, by using a three-way handshake protocol referred to as Dynamic Service Addition (DSA). However, degraded channel quality and unreliable message retransmissions may lead to a delayed or even unsuccessful activation of a service flow. In this paper, a thorough analysis of DSA protocol performance is carried out under a variety of scenarios. Blocking probability, admission control probability, and latency of DSA protocol are evaluated, by means of simulations, for different conditions of mobility and parameters of PHY and MAC layers. Results show the negative impact of a long channel coherence time caused by low mobility and of the loss of channel reciprocity. Results offer indications on how to compensate such effects.