Quality of Activation (QoA) for Dynamic Service Flows in IEEE 802.16 Networks

The connection-oriented nature of IEEE 802.16 (WiMAX) protocol facilitates the handling of quality of service (QoS). In IEEE 802.16 (WiMAX) networks, QoS-guaranteed connections, also referred to as service flows, can be dynamically activated between the base station and the subscriber stations, by using a three-way handshake protocol, called dynamic service addition (DSA). However, the unreliability of the radio medium may require multiple retransmission of DSA messages, leading to a delayed or even unsuccessful activation of a service flow. This paper proposes the novel concept of Quality of Activation (QoA) to guarantee the performance of the DSA protocol. Unlike QoS concept, QoA concept aims at guaranteeing the quality of the DSA message transmissions, rather than that of data transmission. In this paper, QoA is defined in terms of signaling blocking and maximum latency and is achieved by determining a set of constraints that limit the range of DSA protocol parameters. The impact of QoA requirements on protocol parameters is evaluated for various channel quality scenarios and for different types of service flows, i.e., from delay-sensitive service flows to critical and delay-insensitive service flows.