# Realistic Simulation for Body Area and Body-To-Body Networks
###### Abstract  
In this paper, we present an accurate and realistic simulation for body area networks (BAN) and body-to-body networks (BBN) using deterministic and semi-deterministic approaches. First, in the semi-deterministic approach, a real-time measurement campaign is performed, which is further characterized through statistical analysis. It is able to generate link-correlated and time-varying realistic traces (_i.e._, with consistent mobility patterns) for on-body and body-to-body shadowing and fading, including body orientations and rotations, by means of stochastic channel models. The full deterministic approach is particularly targeted to enhance IEEE 802.15.6 proposed channel models by introducing space and time variations (_i.e._, dynamic distances) through biomechanical modeling. In addition, it helps to accurately model the radio link by identifying the link types and corresponding path loss factors for line of sight (LOS) and non-line of sight (NLOS). This approach is particularly important for links that vary over time due to mobility. It is also important to add that the communication and protocol stack, including the physical (PHY), medium access control (MAC) and networking models, is developed for BAN and BBN, and the IEEE 802.15.6 compliance standard is provided as a benchmark for future research works of the community. Finally, the two approaches are compared in terms of the successful packet delivery ratio, packet delay and energy efficiency. The results show that the semi-deterministic approach is the best option; however, for the diversity of the mobility patterns and scenarios applicable, biomechanical modeling and the deterministic approach are better choices. body area networks (BAN); body-to-body networks (BBN); deterministic channel and mobility modeling; semi-deterministic channel modeling; realistic simulation; accurate mobility and radio link modeling; IEEE 802.15.6 Standard  
optimization [5; 6]. However, due to many assumptions in the analytical derivations, the models often are not realistic. Further, while modeling multiple functionalities, the mathematical models become very complex. To develop analytical expressions for diverse BAN applications (having space and time channel variations, dynamic mobility patterns and varying radio links), the resultant models are highly complex and difficult to develop [9]. Another approach is to execute measurement campaigns by deploying various antennas on the body to communicate between sensors and coordinating device [6; 7; 8]. Such measurement campaigns help to acquire real-time data, which can be transformed to mathematical models and statistical distributions. However, there are a number of limitations, especially to realize measurements for dynamic mobility, which are critical to various applications. Further for the applications, where body-to-body communication is important, large-scale deployment is required, which is often not feasible. Finally, there are also storage and processing constraints with miniaturized wearable devices to handle real-time data and processing. Network-level packet-oriented simulation is another choice with a key advantage that an extensive analysis can be performed by having many variations of the parameters and models from all of the layers of the communication and protocol stack. Consequently, with a large-scale, extensive and realistic performance evaluation of the new approaches, algorithms can be achieved. Concerning the BAN simulators, there is more need for realistic simulators than before. For example, in healthcare and fitness with the possibility to deeply analyze medical signals, new signal processing algorithms and techniques based on real data are rapidly emerging [10; 11; 12]. Such new approaches and algorithms need to be evaluated at the network scale by taking into account the impact of the communication and protocol stack. This requires a realistic and cross-layer BAN-specific packet-oriented network simulation environment.