# Energy Harvested and Cooperative Enabled Efficient Routing Protocol (EHCRP) for IoT-WBAN
## 2 Related Literature  
The integration of WBANs and the IoT brings a new concept to the arena of sensor networks. WBANs fall under the WSN umbrella but differ as they have some unique characteristics. With the passage of time state-of-the-art techniques have been adopted to remove deficiencies in the internal working structure of WBANs. In different references numerous energy-efficient routing protocols have been anticipated for WBANs for diverse purposes such as thermal-conscious schemes, congestion control techniques and maximizing battery efficiency to extend the network lifetime. WBANs are mostly used in health-related applications that sense human body data, which in most cases is critical. Therefore, its timely transmission for further analysis to medical-related servers is of the utmost importance. Among all other technologies, routing is one of the main technologies, because the SNs' sensed data needs to be forwarded to the medical-related server efficiently and in no time. Furthermore, due to resource constraints, such as limited battery capacity and transmission power due to the small size of the SNs, the network lifetime is compromised. Therefore, researchers nowadays are more focused on developing energy-efficient routing mechanisms along with other means of providing energy for WBANs. The aim of developing an energy-efficient routing mechanism is to enhance the network lifetime, network stability, and throughput and reduce end-to-end delay among others. A few state-of-the-art routing protocols are discussed below. [PERSON] et al. [26], presented an efficient and reliable routing protocol for wireless body area sensor networks. It is claimed to be stable and efficient in terms of power consumption. A total of eight sensor nodes are deployed at different positions of human body which gather normal and critical data. Out of the total number of sensor nodes, two of the sensor nodes do not take part in multi-hop communication, but rather directly send data to the sink node. The remaining six sensor nodes forward the data to the best forwarder node, which is selected best on the calculated cost function. The parameters to select the best forwarder node are distance to the sink node and residual energy of the entire network. Extensive simulations are performed to prove the stable results. [PERSON] et al. [27] presented a routing scheme known by the name \"Energy-efficient Harvested-aware Clustering and cooperative-based routing protocol for WBAN (E-HARP)\". E-HARP is a multi-attribute-based harvested energy routing protocol, which takes different network-related parameters into consideration and selects an optimal forwarder node towards the sink node. In this scheme the sensed data is transmitted in case of need. It is duty of the cost function to select a cluster head (CH) that uses four main parameters such as SNR, residual energy, total energy and transmission power. The duplicated data is not forwarded by the SN to CH. Before transmitting the data forward, it is checked for its possible duplication with the previous rounds. Hence much of the network energy is saved by the removal of any duplicated data from the transmission pool. [PERSON] et al. [20] proposed a technique named Priority-based Congestion-avoidance Routing Protocol (PCRP). This algorithm is grounded on IoT technology, which is used for medical purposes. It uses multi-hop communication for data transmission and chooses a congestion-free path for quality of service (QoS) and emergency data to be forwarded for the purpose of increasing the efficiency. In this algorithm the authors have used a fitness function on the basis of residual energy (RE), node congestion level (NCL) and SNR. For highly important data they have supposed a priority bit. [PERSON] et al. [28], proposed an energy-efficient routing protocol for WBANs. In the proposed protocol the routing decision is based on the sensor node's remaining energy, communication type, path-loss in the communication link and some other relevant parameters. It works based on three steps.