An efficient cooperative MAC protocol for enhancing QoS of IEEE 802.11e EDCA in saturated conditions

A Modified IEEE 802.15.6 Mac Scheme to Enhance Performance of Wireless Body Area Networks in E-Health Applications

“…There are several MAC protocols based on IEEE 802.15.6 standard have been proposed for WBAN by modifying the mechanisms and/orparameters ofthe IEEE 802.15.6 standard [18][19][20]. Yuan et al [19] proposed an adaptive MAC (A-MAC) protocol that defines three user priorities node according to the type of service andimproves the superframe structure based on IEEE 802.15.6which consists of four adjustable access phases according to the traffic flow: beacon phase, contention access phase, non-contention access phase and inactive phase.The contention access phase is further divided into three adjustable sub-phases according to the data priority that are accessed bythe three user prioritiesindividually.The simulation results show that the proposed A-MAC protocol is achieved better performance compared to CA-MAC protocol and IEEE 802.15.6 MAC protocol in terms of normalized throughput, average energy consumption and average delay.However, in the contention access phase, lower user priority nodes suffer from a bounded delay due to presence of sub-phases.Moreover, the three user priorities are not sufficient to cover all traffic instead of eight user priorities defined in IEEE 802.15.6 standard.Sultana et al [20] proposed a collaborative medium access control (CMAC) protocol for critical and noncritical traffic whichare generated in wireless body area network.The protocol classify the critical traffic into three priorities based on delay deadlines whereas noncritical traffic is divided into three priorities based on energy level.…”

“…We develop a 2-D Markov chain model to describe the backoff procedure of modified IEEE 802.15.6 MAC scheme according to 𝑀/𝐺/1 queuing model, which is shown in Figure 6. There are some studies where Markov chain-based analytical model were presented to evaluate the performance of CSMA/CA mechanism [8]- [18].In this Markov chain, the state of each𝑈𝑃 𝑖 nodeis denoted by (𝑖, 𝑗, 𝑘)where 𝑖,𝑗and 𝑘 indicates user priority of the node, backoff stage numberand backoff counter value, respectively. The initial value of 𝑗for a new frame is 0 and is incremented by one after every failure transmission until it reaches the retry limit (𝑚 𝑖 + 𝑥 𝑖 ).…”

QoS mechanisms for MAC protocols in wireless sensor networks: a survey

“…Roy et al [66] proposed a novel medium access mechanism for IEEE 802.11e in an attempt to mitigate the adverse fading effects while maintaining prioritised channel access for high‐priority traffic. This is achieved by introducing a cooperative communication mechanism in 802.11e MAC to enhance the QoS support under the fading wireless networks.…”