Broadcast strategies and performance evaluation of IEEE 802.15.4 in wireless body area networks WBAN

Wireless Body Area Networks (WBANs) can be considered as an evolution of wireless sensor networks towards wearable and implanted technologies. Radio propagation and mobility are particular in this context, as they are influenced by the characteristics and movement of the human body and by the necessity to keep the transmission power at its minimum to save energy and limit interactions with the wearer. In this paper, we investigate the broadcasting problem in which a node, typically the gateway, tries to send a packet to all other nodes in the network at minimal cost. This problem is not as trivial as it looks and we show through simulation that forwarding strategies coming from the Delay Tolerant Networks world cannot be transposed without adaptation. We enriched the Omnet++ simulator with a WBAN-specific channel model from the literature, and use this model to evaluate 9 classes of broadcasting algorithms, including our own proposals, with respect to their ability to cover the whole network, their completion delay, their cost in terms of transmissions volume and their capability to preserve multiple packets order (i.e. total order broadcast). Our study shows that there is a subtle compromise to find between verbose strategies that achieve good performance at the cost of numerous transmissions, ultimately provoking collisions and more cautious solutions that miss transmission opportunities because of mobility. (C) 2019 Elsevier B.V. All rights reserved.