# Adaptive Thermal-Aware Routing Protocol for Wireless Body Area Network
## 3 Proposed Method of ATAR  
### Temperature Rise of Sensor Node  
In this modern era, patients are remotely being monitored using a variety of techniques such as telemedicine, telemonitoring, online patient monitoring, etc. The sensor nodes are implanted in the human body, thus, forming wireless body area network (WBAN) based IoT [7]. These nodes transmit vital signs information of the patient like heartbeat monitoring, glucose level, blood pressure and pulse rate to the Sink nodes as well as the central controller. The devices transmitting these vital reading must establish new route each time when data is required to be sent to remote locations [8].  
These sensor nodes have a special requirement that distinguishes them from other ad hoc networks [71]. In the WBAN based IoT, the implanted nodes continuously transmit the data over the network to find an efficient path from source node to the destination nodes. The temperature of implanted nodes increases during data transmission over a specific time interval and this temperature rise may harm to human tissue. This issue has become a serious concern for the adaptability of these nodes. The detailed problem of heat-rise of WBAN sensors at different phases is explained below with help of an example. We have 10 numbers of nodes that are implanted in a human body as shown in Figure 2 that is a glimpse of a normal communication taking place on in the WBAN based IoT.  
Figure 2 indicates that the path A, B and C have been established and the network is converged on to a common routing table. The actual communication is following the paths as indicated in the above routing path. The paths have been established through a common link state routing protocols that have done their working before the communication started.  
Figure 3 shows the source has selected the shortest path B for its data transmission.  
Figure 3: Communication Path in WBAN: A glimpse of a normal communication taking place in the network. The path B from source to destination is selected for communication.  
Figure 2: Topology of Communication in IoT: A glimpse of a normal communication taking place in the network different path from source to destination is selected for communication.  
However, the temperature of a sensor node like node 8 as indicated red in Figure 4 increased due to a continuous flow of data on the same path. Since the sensor node has become the hotspot, therefore, further transmission of data through this path will damage the human tissue.  
In Figure 5 protocol rework its convergence and uses two remaining paths that are available for communication from source to destination. Therefore, instead of always using path B, the alternative path-ways automatically get selected for communication.  
Now the alternative path is also processing continuous streams of data from source to destination and over time because of continuous processing its temperature has also increased. Therefore, in Figure 6 for the next set of the data stream, the node 2 (highlighted in red color) will automatically backtrack thus the entire convergence will have to be reworked for the entire network. Hence, it will adopt a new path for the rest of the communication.  
Figure 4: Hot Spot creation in IoT Network: A glimpse of a normal communication taking place in the network. The path from source to destination is selected for communication. The red node represents hotspot node that has a high temperature. Whenever the packet will be transferred to hotspot node, it will backtrack the packet to the previous node.  
Figure 5: Alternative path for traffic: The red node represents hotspot node that has a high temperature. Whenever the packet will be transferred to hotspot node it will backtrack the packet to previous node and communication will continue from the alternative path.  
As a result, the entire communication has become halted and communication will not be forwarded due to the temperature rise, as shown in Figure 7.