# BNS: A Framework for Wireless Body Area Network Realistic Simulations
## 1 Introduction  
The miniaturization of devices that can be used as wearables or attached to the human body has made possible the emergence of new communication networks. Thus, Wireless Body Area Networks (WBAN) are networks made up of small devices with low energy consumption and wireless communication capabilities. The main function of this type of network is to monitor and act on human bodies and the environment [1]. The composition of a WBAN network is made by sensor and actuator nodes that interact with a coordinator node. The coordinator node is responsible for collecting and sending the required information to the sensor/actuator nodes, in turn, the coordinator node offers communication with other types of networks. The nodes of a WBAN can collect data of vital and physiological signals, monitoring, processing, and communicating those data in real time without causing discomfort to patients. The increase in older adults and patients with congenital, degenerative and other diseases, together with the medical expenses that they cause, resulted in the appearance of new technologies. Thus, WBAN was created to be applied to healthcare (e-health) for monitoring patients at a low cost and thus alleviating medical and economical expenses. However, the use of WBAN is not restricted to the health area and can be applied to other fields such as entertainment, sports, military services and others [2]. IEEE 802.15.6 [3] published in 2012 is the standard that best defines WBAN, which specifies wireless communications on and around the human body. The standard defines an architecture with three levels: Intra-WBAN, Inter-WBAN and Beyond-WBAN. IEEE 802.15.6 defines the functionalities of the Physical (PHY) and Medium Access Control (MAC) layers. In addition, it shows its main characteristics related to low energy consumption, reliability and transmission rate. We also find definitions of network topology, such as star topology, extended star and security levels with different security and protection properties [4]. After the IEEE 802.15.6 standard publication, research work focused on layers not defined in the standard. However, more recent studies propose modifications to the WBAN standard. For example, in [5], modifications to the MAC layer is proposed. The results of that work show that the proposed protocol works better than the WBAN standard in terms of throughput, energy consumption and packet delivery delay. Together with the advances of WBANs, new social and technical challenges arise. Ease of use, data security and privacy, interoperability, cost, physical security, and user well-being are social challenges to be overcome. Technically the wireless channel dynamics, the computational power limitations, the energy efficiency and the operation of the transceiver are the main challenges. Other challenges such as device overheating, heterogeneous environment, Quality of Service (QoS) provision must be evaluated in WBAN to allow practical adoption [6; 7]. Another interesting point of WBANs is the heterogeneity of their components, i.e., for monitoring vital and physiological signals, different types of sensor nodes are needed that clearly differ in computational resources, storage capacity, energy consumption and sampling rates. In addition, wireless communication between sensor nodes is carried out through the human body, which leads to its degradation, causing in many cases the fading of the communication channel, loss of trajectory, and high latency. Additionally, the movement of the human body, such as the movement of arms and legs can cause the breakdown of the network topology. Thus, we say that the environment where WBAN communication takes place is highly dynamic and unstable, where a specific communication channel must be considered that guarantees the good performance of communication in highly dynamic and unstable environments [4]. The increase in temperature is one of the most relevant challenges for WBAN.