## 3 Review of WBASN MAC Protocols for IEEE 802.15.4 and IEEE 802.15.6
### Superframe Modification Approaches
\begin{table}
\begin{tabular}{p{56.9 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Protocol** & **Year** & **Standard** & **Access scheme** & **Shortcomings** & **QoS** \\ \hline DQBAN [100] & 2009 & IEEE 802.15.4 & Hybrid & Requires the management of different queues as well as fuzzy-logic system implementation in every sensor node & R, C \\ \hline EELDC [101] & 2009 & IEEE 802.15.4 & TDMA & Fixed scheduling is used for data transmission, which does not fulfil the application diversity in WBASNs & E, R \\ \hline BDD [102] & 2009 & IEEE 802.15.4 & TDMA & The performance is only validated for one biomedical sensor, i.e., ECG; hence, QoS performance in a scalable environment is a concern & E \\ \hline HUA-MAC [104] & 2010 & IEEE 802.15.4 & Slotted ALOHA & Shows QoS limitations in the scalable and diverse application scenarios & D, R \\ \hline PNP-MAC [105] & 2010 & IEEE 802.15.4 & Hybrid & The traffic loads of low-priority biomedical sensors are ignored, which may cause delay and consume more energy in the case of retransmission & D, E \\ \hline U-MAC [103] & 2010 & IEEE 802.15.4 & Slotted ALOHA & Complex and involve overheads in terms of data categorisation and identification of retransmission packets & D \\ \hline CA-MAC [106] & 2011 & IEEE 802.15.4 & Hybrid & Dynamic change in the frame structure, which is not easy to implement with the IEEE 802.15.4/IEEE802.15.6 standard & R \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Comparison of WBASN MAC protocols. \begin{table}
\begin{tabular}{p{56.9 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**MAC Optimisation Approaches** & **Advantages** & **Disadvantages** \\ \hline \multirow{4}{*}{Parameter tuning} & \(\bullet\) & No explicit modification is required for IEEE 802.15.4 & \(\bullet\) & Application-specific solutions Restricted to a theoretical range of parameters \\  & \(\bullet\) & One-time parameters tuning is required applicable to other standards, i.e., IEEE 802.15.6 & \(\bullet\) & Overhead of the control messages High latency concerning medical applications \\ \hline \multirow{4}{*}{Cross-layer} & \(\bullet\) & Optimal performance by using the information from other layers & \(\bullet\) & Add overhead to the coordinator for analysis and processing \\  & \(\bullet\) & Adaptive to the situation & & \\ \hline \multirow{4}{*}{Duty-cycle-based} & \(\bullet\) & Adaptable with minimum modification to IEEE 802.15.4/ IEEE 802.15.6 & \(\bullet\) & Add overhead to the coordinator for analysis and processing \\  & \(\bullet\) & Various opportunities to save power with the original standard & & and processing \\ \hline Priority-based & \(\bullet\) & Provide the required QoS to the transmitting nodes & \(\bullet\) & Introduce operating and processing overheads \\ \hline Superframe modification & \(\bullet\) & Provide scalability, multiple topologies support, make IEEE 802.15.4/ IEEE 802.15.6 & \(\bullet\) & Major changes in operations of the standard Adaptability demands resource usage for sensor and coordinator nodes \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Comparative analysis of optimisation approaches.