The IEEE 802.15 Task Group 6 has recently issued a new standard, the IEEE 802.15.6 specification, specifically targeted at WBANs [3].Apart from the local sensor interconnection handled by the WBAN, it is important to provide an end-to-end communication bridge between the patient and the healthcare provider. Depending on the application scenario, this task can be accomplished through different technologies, from long-range cellular 3G/4G systems to local deployments of wireless sensor networks (WSNs). The latter solution is very appealing when radio limitations are present, as, for example, in indoor environments with poor cellular coverage (e.g., a hospital ward). Recently, the deployment of ambient WSNs for healthcare applications is being considered in the literature.

Ambient sensors are usually employed to enhance context-awareness, by providing relevant environmental information for the patient’s surroundings [4,5]. However, it is also possible to use the deployed sensors as relays that forward the data collected by the WBAN to the medical server [6,7].The design of efficient medium access control (MAC) protocols and routing techniques is crucial to handle the flow of information through the distribution WSN. The application of random linear network coding (RLNC) [8] over the MAC and network layers has been studied as an innovative way for data dissemination and forwarding, especially in relay networks. The main idea behind RLNC is to transmit linear combinations over a block of original data packets, created by multiplying each packet with a random coefficient drawn by a finite Galois field.

For instance, a relay can forward a linear combination of its received packets. Thus, the destination does not need to acknowledge each packet individually, but instead, it has to receive a sufficient number of linearly-independent encoded packets to be able to extract the original information.In the context of relay-assisted WBANs, RLNC techniques are often employed as a means to enhance reliability. The work presented in [9] shows the potential throughput improvement under error-prone channels through the application of RLNC, as a function of the number of redundancy packets, the employed relays and the number of sink nodes. More advanced schemes, such as cooperative diversity coding, where both coded and uncoded data packets Carfilzomib are transmitted, can yield even better results [10].

A tree topology has been assumed in [11], where multiple nodes communicate with the coordinator through a small number of relays. The nodes send their uncoded data to the relays, which, in turn, forward a set of both coded and uncoded packets to the destination. The obtained results show that RLNC can offer higher reliability with respect to traditional redundancy schemes, where multiple retransmissions of uncoded packets take place.