## 4 Energy Efficient Protocols, and Scheduling in WBSNs
### Energy Efficient Protocols in MAC Layer
\begin{table}
\begin{tabular}{l l l l l l l l l} \hline
**PROTOCOL** & **BLE** & **ZIGREE** & **WIFI** & **4G LTE** & **ANT+** & **NFC** & **NIKE+** \\ \hline STANDARD & & & & & & & & & \\ RANAGE & 1 to 100 m & 10 to 100 m & \(\sim\)100 m & 1–10 miles & \(\sim\)30 m & \(<\)0.2 m & \(\sim\)10 m \\
[33, 35, 42] & & & & & & & \\ \hline TOPOLOGY & & & & & & & \\
[33, 34, 42] & Star-bus & Mesh, Star, Point & Star, Point to Point. & Ring, Star, chain, mixed. & Peer to Peer, Mesh & Point to Point & Point to Point \\ \hline EFFICENCY & & & & & & & \\
[33] & 0.153 μWbit & 185.9 μWbit & 0.00525 μWbit & 0.011 μWbit & 0.71 μWbit & Not specified & 2.48 μWbit \\ \hline LATENCY & & & & & & & \\
[33, 39, 42] & \(\sim\)3 ms & & \(<\)5 ms (bencouless mode, at 250 kbps) & 1.5 ms & 10 ms & Zero & Polled typically every second & \(\sim\)1 s \\ \hline \multirow{4}{*}{USES FOR WBSNs} & Intra-BAN Communication: & Communication: & & & & & \\ glucose, Blood pressure, SPO2, Temperature, Heart & glucose, Blood pressure, SPO2, Temperature, Heart & Inter-BAN and Beyond & Inter-BAN and Beyond & Communication: Heart & Intra-BAN communication: Heart & Communication: \\  & Rate, ECO, watches and smartphones & Temperature, Heart Rate and ECG. & BAN Communication: & BAN Communication: Smartphones, wireless & Root applications for & Heart Rate, \\ \hline \end{tabular}
\end{table} 
Table 2: _Cont._When the communication is from BAN coordinator to body sensors, the BAN coordinator uses a feedback frame to synchronize the attached body sensors to the BAN coordinator. In addition enabled power management solutions and energy-aware radio activation policies among different time intervals is proposed with the intent to increase network lifetime. The protocol has been extended to have a fuzzy logic system in order to reduce scheduling collisions [20]. Each sensor should have a fuzzy logic system to deal with multiple cross-layer input variables of diverse nature in an independent manner. If the sensor node has the imperative need to send information since it has very low residual power or because the package to send has a significant delay, the sensor will be able to demand a \"collision free\" time slot. Also, the sensor can refrain from transmitting in the event that the sensor does not find the necessary conditions to do so (e.g., bad link channel). The implementation of a system like this offers the opportunity to optimize the MAC layer in terms of energy consumption and quality of service. Another way to increase the lifetime of the network is through the use of the Lower Energy Adaptive Clustering Hierarchy (LEACH) protocol. It consists of introducing collection points in the network, _i.e._, nodes receiving data from neighboring nodes, and nodes that perform data processing for subsequent transmission to the destination. In LEACH, the nodes organize themselves into local clusters, with one node as Cluster Head (CH), and each node determines its CH by choosing the CH that requires the minimum communication energy. Once all the nodes are organized into clusters, each CH creates a schedule for the nodes in its cluster. However, LEACH presents some problems at this collection points or CHs; a possible bottleneck is responsible for different tasks and data aggregation could be lost and never sent to the base station. A new improved LEACH protocol is developed to solve the potential problems in [43] which adds a Mediation Device (MD) node for all clusters responsible for synchronization between CH and its nodes. MD allows the CH to go to sleep mode periodically and to wake up only when it receives a wakeup signal from MD to receive data. Transmission of data during their time slots is based on a TDMA schedule. Once the CH has all the data from the nodes in its cluster, the CH node aggregates the data and then transmits the compressed data to the base station. BODY MAC is proposed in [44], as an energy efficient MAC protocol with a frame structure, band allocation schemes and sleep mode as main tools.