Real-time communication over 802.11e wireless network using a publish-subscribe model

In this paper, we propose a real-time publish-subscribe communication scheme for wireless local area network (WLAN) infrastructure. This new strategy was called Group Sequential Communication (GSC). The GSC has the main goal to reduce the overhead due to the polling and acknowledgment frames of Hybrid Coordination Function Controlled Channel Access (HCCA) in IEEE 802.11e, because it uses a Virtual Token Passing (VTP) procedure to priority the real-time communication over WLAN. In order to improve the confiability of the new scheme is presented a fault-tolerant mechanism based on block acknowledgment strategy to avoid missing real-time messages. The GSC was implemented in Network Simulator 2 Platform (NS-2) and the simulation result was compared to HCCA scheme, showing advantage to real-time industrial application, where the size of the packets are usually small and there are transmission errors due to noisy channel.