Accurate Traffic Shaping algorithms for IEEE 802.16-2012 based WiMAX networks

Quality of Service (QoS) support is crucial for IP based communication systems in order to guarantee the functionality of especially real-time applications. Beside QoS aware scheduling, traffic monitoring and policing are required when QoS guarantees shall be provided. Well known traffic policing algorithms are the leaky bucket and the token bucket. These algorithms can be applied to enforce an agreed traffic pattern in popular systems, such as LTE and DOCSIS. In contrast, WiMAX based on the IEEE 802.16-2012 standard does not support these algorithms due to a strict time limitation of the integration interval of the traffic monitoring. A survey of the existing literature revealed that none of the existing algorithms completely fulfill the standard requirements. Therefore, we propose two Traffic Shaping (TS) algorithms for WiMAX. The first denoted as Accurate Traffic Shaping Algorithm for WiMAX (ACC) exactly realizes the standard requirements. If these requirements are slightly relaxed, our second TS algorithm Approximate Traffic Shaping Algorithm for WiMAX (APP) provides a less memory demanding alternative. Both algorithms are compared with an existing approach in terms of goodput, delay, packet loss, as well as the ratio of non-conforming packets by simulative studies. They prove that only ACC is compatible with the IEEE 802.16-2012 standard. Drawbacks can be compensated by increasing the duration of the integration interval. Therefore, our algorithms may be applied in other systems where a strict limitation of the integration interval is desired.