# Multipath Routing in Wireless Body Area Sensor Network for Healthcare Monitoring
## 3 Proposed Methodology
### Design of Region-Based Energy Efficient Multipath Routing Algorithm
The multipath solution also reduces the load on a single node or link; hence, link reliability is improved. Multipath scheduling also avoids the collision of packets, reducing retransmission requirements and the generation of excessive control messages. REMR is a reactive protocol, and only region-based propagation is needed. BS selects CRs on the bases of their distance to each node, and it picks multiple nodes to serve as representatives of different intermediate clusters with no direct access to the base station. Clusters near BS will route traffic through multiple paths CRs. The proposed solution decreases the energy consumption in network propagation, and route discovery, and avoids excessive control messages. Another rather important criterion for the selection of CR is based on the signal strength of the RFID. Once the CR is selected based on the shortest distance to BS and energy value, that particular CR selects the RFID device/identifier that is installed nearest to it. In a healthcare scenario, where there is a requirement for more than one RFID device/identifier, the identifications of the tags/sensors/nodes are based on uniform distribution. This is performed to keep this clustering of sensors/tags based on RFIDdevices region at a secondary level. The primary clustering will be based on the received signal strength indication (RSSI) of the CR. The RFID identifier grabs the information of every tag and stores it in its memory. The RFID identifier stores the tag information through the reading order function r = {EPC, Reader ID, time}, where EPC is the electronic product code of the tag/sensor. Each identifier creates its unique key for the tags under its radar. The unique key helps in the identification of the tag by other RFID identifiers in case the tag/sensor is mobile. Each RFID identifier has \(t\) number of tags. Our algorithm assigns a unique ID to each RFID identifier. This unique ID is shared with all the tags of that particular RFID identifier. Suppose a sensor/tag \(S_{t}\) belongs to the RFID identifier \(R_{i}\), then \(K_{R{i}}\) is the ID of \(R_{i}\) stored in \(S_{t}\). \(S_{t}\) needs to have this information to identify the region so that once \(S_{t}\) comes back to the same region, it does not have to restore the same information. The same goes for the \(R_{i}\) when it has to identify \(S_{t}\) again. The RFID identifier is connected to BS. The BS receives all the secret information by the RFID identifier regarding tags during the deployment of the algorithm. The RFID identifier issues a set of secret information to BS for each RFID identifier of the system. The set of secret keys along mapping to respective tags is denoted by \(z=\{(K_{R{i}}\Sigma_{i})\ |\ 1\leq i\leq t\}\), where \(K_{R{i}}\) is the secret key of the RFID identifier and \(\Sigma_{i}\) is the mapping of the identifiers of the group \(\beta_{i}\) with the secret keys of the tags, and \(t\) is the number of tags. Now there are two regions also shown in Figure 1. The rectangular region \(R_{e}(x,y)\), which is the RFID identifier and the circular region \(C_{r}(x,y)\), where \(x\) is the location of the tag/sensor, and \(y\) is the probability of the range \(x\). To ensure the security and energy efficiency of the system, our algorithm makes sure each RFID identifier communicates only with the CR besides sharing some secret ID information. It is the job of the CR to let other tags/sensors/nodes know about the reliability of the information. The CR through secret ID information identifies and trusts the information coming from the RFID identifier, and the RFID identifier has its own algorithm to verify the certainty of the data. Among both regions \(R_{e}(x,y)\) and \(C_{r}(x,y)\), the priority by the algorithm for ensuring energy efficiency and reliability of the information is given to the \(C_{r}(x,y)\) because \(C_{r}(x,y)\) interacts with more tags/sensors and makes a trustable relation and energy-efficient routing. The RFID identifiers are usually backed up with power backups.