CaWuQoS-MAC: Collision Avoidance and QoS Based MAC Protocol for Wake-Up Radio Enabled IoT Networks.

IoT applications have different requirements in terms of quality of service (QoS). For real-time applications, data must be processed as fast as possible. In contrast, some applications are delay-tolerant and support long data delivery delay. Recently, Wake-up radio (WuR) technology has gained great attention by eliminating idle listening and overhearing. However, so far QoS has not been a concern in WuR-based MAC protocols. In this paper, a Collision Avoidance QoS- and WuR-based MAC protocol (CaWuQoS-MAC) is proposed in order to support delay requirements for real-time IoT applications. CaWuQoS-MAC offers the possibility to specify the delay limit within which the packet needs to be delivered and after which is considered as expired. We develop a discrete-time Markov chain model to evaluate the performance of the proposed protocol. CaWuQoS-MAC is compared with another WuR protocol that does not perform Collision Avoidance prior to Wake-up Call (WuC) transmission in terms of reliability, delay, and power consumption under both error-free and error-prone channel conditions. Numerical results show that CaWuQoS-MAC supports the desired QoS requirements when the channel is error-free under both light and heavy traffic loads and with a high network density.