# Energy Harvested and Cooperative Enabled Efficient Routing Protocol (EHCRP) for IoT-WBAN
## 1 Introduction  
The Internet of Things (IoT) and WBAN have an integrated future [1, 2]. The IoT is one of the most modern promising research areas and is becoming a common platform where smart objects stayconnected to the Internet for transmitting and receiving smart data [3; 4; 5]. The world is embracing the adoption of 5G while the 6G protocol [6; 7; 8], which is the next generation of advancement in wireless technology, is around the corner that will be a much great enhancer of IoT-based technologies. The IoT continues to grow as more and more devices are connected to it. General estimates reveal that the number of smart IoT devices will approach over 50 billion by 2022. The IoT landscape is evolving ever rapidly than before and is impacting the global economy. The Gartner Report sees its advantages in terms of economic impacts in 2022 to be around 2 trillion USD [9]. Wireless body area networks (WBANs) are one of the most focused type of wireless sensor network (WSN) [10], in which communication takes place between individuals and machines through wireless technologies. A WBAN is defined as \"using tiny sensors, in, on or around the human body for medical or any other purposes.\" [11; 12; 13]. A WBAN may be used easily with IoT-based technology for monitoring of human body 24/7 [14]. In the healthcare domain, a properly established WBAN coupled with modern IoT-based devices has the potential to inform doctors in advance about the condition and criticality of the patient leading to improved quality of life. Heterogeneous IoT WBANs will bring revolutionary changes in healthcare in the future and a wide range of research areas as shown in Figure 1. It is believed that this technology will bring green changes in the field of medical. The required medical data is sensed by tiny low power sensors and forwarded to sink nodes where doctors take the necessary actions based on sensed data. A WBAN is an outstanding improvement in technology and its usage for the treatment of human beings is no less than a boon. It is embedded with IoT technology so the patient does not need to be in bed or in a hospital as happens currently in most circumstances [15]. However, the network challenges such as throughput, network delay, etc. cannot be ignored when using IoT technology for WBANs [16; 17]. Because of physical size constraints, the sensors are equipped with very low power batteries [18]. These days, along with other limitations in WBANs such as buffer size, bandwidth, sensing power, etc. the most burning issue in this type of network is the availability of power for a long time [19]. In WBANs there are two types of data: normal data and emergency data [20]. To resolve all these issues the main focus currently is on the routing protocols used in WBANs. The routing techniques used in WBANs are proactive, reactive and clustering [21]. The traditional routing protocol is not a suitable solution for this type of network due to resource limitations [12]. A single-hop communication for data transmission is not considered a decent solution in WBANs. Instead, multi-hop data transmission works the best [20; 21; 22; 23; 24; 25; 26]. The existing solutions in WBANs for routing packets from source to destination have some limitations which we attempt to address in this research work in order to improve the efficiency further. Figure 1: IoT-WBAN Communication structure. To solve the issues of energy limitation and WBANs' lifetime enhancement a new scheme is proposed, named \"Energy Harvested and Cooperative enable Routing Protocol\" or EHCRP. In this protocol, energy harvesting is integrated inside the SNs to provide additional energy that enhances the network lifetime. Furthermore, link statistics are taken into consideration while forwarding the data to the next hop, which achieves better throughput and less end-to-end delay. This scheme works on the basis of multi-hop communication. The node with greater path cost estimation (PCE) will be nominated as data forwarder.