Energy efficiency and resource allocation of IEEE 802.15.6 IR-UWB WBANs: Current state-of-the-art and future directions

Network life time of Wireless Body Area Network (WBANs) is essential for its operation. An integral part of the network life time is the energy efficiency of the devices and enabling their transmissions with the optimal choice of Physical layer (PHY) and Medium Access Control (MAC) parameters. Particularly, in the next generation wireless networks, where devices and sensors are heterogeneous and coexist in the same geographical area creating possible collisions and interference to each other, the battery power needs to be efficiently used. This paper consists of four complementing parts. In the first two parts, we study the two optimization algorithms proposed in our prior work. The first algorithm, Cross-Layer Optimization for Energy Efficiency (CLOEE), enables us to carry out a cross-layer resource allocation that addresses the rate and reliability trade-off in the PHY as well as the frame size optimization and transmission efficiency for the MAC layer. The second algorithm, Energy Efficiency Optimization of Channel Access Probabilities (EECAP), studies the case where the nodes access the medium in a probabilistic manner and jointly determines the optimal access probability and payload frame size for each node. These two algorithms address the problem from an optimization perspective. In the third part of the paper, we study the same problem from a game theoretical point of view. The last part of the paper is devoted to summarizing the challenges ahead and future research directions to increase the energy efficiency and network life time of WBANs.