Hybrid Channel Access Towards Real-Time Applications in Healthcare

With the rapid development of the Internet-of-Things (IoT) enabled healthcare, the coexistence of real-time applications (RTA) and non-RTA is urgently needed to be supported as healthcare often involves various applications. Different techniques toward this goal have been developed in wired and cellular networks, while limited efforts are dedicated to Wi-Fi networks. To address this issue, we propose a hybrid channel access by admission and contention (HCAAC) scheme in this paper to achieve the coexistence of RTA and non-RTA while optimizing the delay performance of RTA in healthcare. With this scheme, the access point can schedule the transmission of RTA packets and temporarily interrupt the transmission procedure of non-RTA packets to guarantee a quick channel access for RTA packets. Moreover, we analyze the performance of RTA packets and illustrate how to tune the backoff parameters to minimize the delay performance of RTA. It is revealed that the optimal backoff parameters only depend on the number of stations and the packet input rate of RTA packets. Simulations show that with the proposed HCAAC scheme, the delay performance of RTA can achieve a dramatic improvement, while the performance of nonRTA does not deteriorate, which sheds significant light on the design of the IoT-Health infrastructure.