# Adaptive Thermal-Aware Routing Protocol for Wireless Body Area Network
## 2 Related Work
#### Taxonomy of Routing Protocols in WBAN
At the end of this phase, each node is assigned a ring level value and these nodes are separated according to their ring level value. In data transmission phase, each node is arranged according to their assigned ring level value. The sensor node sends the packet, broadcasts the packet to its neighboring node and the process continues until the packet is reached to the sink node. Ordinarily, the little size of the battery in WBAN suggests that the capacity of the battery is low with little energy. Different schemes have been utilized to utilize power eruditely for the broadened life of remote systems (wireless network). Some power sparing schemes maintain a strategic distance from repetitive retransmissions, diminish the frequency of sending system control messages, lessening the size of message headers and utilizing the standby or sleep mode when conceivable [48]. Among the various difficulties of WBAN, energy utilization is an essentially vital long-term arrangement of WBANs, which is elaborated in various studies (ESR [14; 15; 16; 17; 23]). Here we shed a light on some of the energy-aware routing protocols including SIMPLE [49], Co-CESat [50], RSSI [51], MEPF [52], DARE [53] and ESR [54]. The routing algorithm of QoS- aware are modular based and use various modules for different types of QoS metrics. The complexity and synchronization of the modules make it a challengeable task to design a QoS protocols. To provide QoS in WBAN, routing demands significant consideration as the patient's data (normal or critical) should be transmitted to medical server efficiently and reliably. Broadly, the QoS routing protocols can be classified into reliability-based routing and delay-tolerant based protocols. The reliability-based routing does not consider delay and ensures throughput. The delay-tolerant based routing protocols guarantee in-time delivery of packets. Some of the important QoS-aware routing protocols are RL-QRP [55], LOCALMOR [56], DMQoS [57], EPR [53], QPRD [58] and QPRR [59] etc. The third routing class of WBAN is cluster-based routing that is known as an appropriate protocol for increasing the lifespan of a network by reducing energy consumption. In this approach, WBAN network is divided into clusters and each cluster chooses Cluster Head (CH) that is responsible for communication to the base station to minimize the energy consumption of the other sensing nodes. The responsibilities of a CH include collecting, aggregating and forwarding of data. The two main cluster based WBAN routing protocols are Hybrid Indirect Transmissions (HIT) [60] and Anybody [61]. In WBAN topology the communication among the nodes frequently come across with the issues of disconnection and partitioning due to postural movements of the human body. Various studies have been conducted to resolve this issue and a cost function is defined in WBAN, that is updated at intervals. These protocols send packet with least cost on the basis of path selection from bio-medical sensor to base station. The routing protocols based on postural movements are postural-based routing protocol Probabilistic Routing (PRPLC) [62], On-Body Store and Flood Routing (OBSFR) [63], Dynamic Postural Partitioning (DVRPLC) [64], opportunistic routing protocol [65] and Energy Efficient Thermal and Power Aware Routing (ETPA) [66]. A Cross-layered routing protocol is the fifth class of WBAN routing. The Cross-layered scheme improves the synchronization between the layers without disturbing the main functions of the layers. The research community remained interested in the areas related to WSN because of its effective implementation in WSN. These protocols contribute in improving the performance of the network by addressing the challenges and issues faced in network and MAC layers simultaneously.