# Adaptive Thermal-Aware Routing Protocol for Wireless Body Area Network
## 2 Related Work
#### Taxonomy of Routing Protocols in WBAN
The last phase is data transmission phase wherein data is sent to sink node within their allocated time slot. [PERSON] et al. in [34]\(M_{2}E_{2}\) Multi-hop Routing Protocol is a thermal and energy efficient routing protocol. The protocol is divided into four phases including initialization, routing, scheduling and data transmission phase. The initialization phase is responsible for calculating distance of nodes from sink node by broadcasting \"Hello Message\". The routing phase is responsible to send data to the medical server. If Home-Signal is received then one of the implanted nodes in the human will establish a link with routing table of the home node. In this way, a direct link is used to send the data from sink node to medical server. In the direct link, there is no energy restriction because critical data is sent over the selected link. If Home-Signal is not received then routing table formed from implanted nodes and multi-hop link get established for communication of data. This phase is also responsible for hotspot avoidance. In scheduling phase, time slot is assigned to sink and root nodes for communication of data. The root and sink nodes communicate within their assigned time slot. The last phase is data transmission phase wherein data is sent to sink node in their allocated time slot. Thermal-aware localized QoS routing protocol (TLQoS) is a thermal-aware routing protocol which aims to address the required QoS demand of implanted bio-medical sensor in a human body. [PERSON] et al. in [35] presented the temperature of the node at an acceptable level to avoid heating or damaging of tissue. The protocol also prevents loop formation during communication and avoid unnecessary routes with a large number of hop from sink to control delay in the network. The localized approach is used for selecting suitable forwarder nodes among all neighboring nodes in a routing table. [PERSON] et al. [36] introduced an integrated rate control technique which ultimately aims to decrease the thermal effect of the implanted bio-medical sensor node and avoid congestion during communication between nodes. Trust and Thermal-Aware Routing Protocol (TTRP) is another thermal-aware routing protocol which provides trusted and hotspot free network communication between the implanted bio-medical sensor nodes. [PERSON] et al. in [37] stated that the communication is protected from malicious and faulty nodes within or outside the network. The TTRP is divided into three phases: trust estimation phase, route discovery phase and route maintenance phase. The trust estimation phase is further divided into two sub-phases: direct trust and indirect trust. The trust estimation phase is responsible for evaluating the trustiness of intermediate nodes. The route discovery phase is responsible for selecting trustworthy and hotspot free node route for communication in the network. In route maintenance phase, if the node becomes hotspot during communication inactive route then route maintenance phase re-initiates the route discovery phase. The self-healing thermal-aware RPL routing protocol is a self-adaptive routing protocol. In this protocol, if the node is marked as a hotspot node, then the node itself decides the efficient path for communication of data. The selection of efficient path is based on low temperature and low power metrics. In [38] the protocol work on IPv6 routing protocol for low power and lossy networks (RPL). In Multipath ring routing (MRRP) [47], multiple paths are constructed to the destination to avoid congestion in the network. The protocol is divided into two phases: Multipath construction phase and Data transmission phase. In Multipath construction phase, a setup request packet is sent by the sink to all its neighboring nodes with ring level 0. Nodes which received packet will update its ring level by incrementing its value to 1 in it and broadcast the packet. The main aim of this phase is to organize the sensor nodes in the form of ring level.