We focus on interference mitigation and energy conservation within a single wireless body area network (WBAN). We adopt two-hop communication scheme supported by the the IEEE 802.15.6 standard (2012). In this paper, we propose a dynamic channel allocation scheme, namely DCAIM to mitigate node-level interference amongst the coexisting regions of a WBAN. At the time, the sensors are in the radius communication of a relay, they form a relay region (RG) coordinated by that relay using time division multiple access (TDMA). In the proposed scheme, each RG creates a table consisting of interfering sensors which it broadcasts to its neighboring sensors. This broadcast allows each pair of RGs to create an interference set (IS). Thus, the members of IS are assigned orthogonal sub-channels whereas other sonsors that do not belong to IS can transmit using the same time slots. Experimental results show that our proposal mitigates node-level interference and improves node and WBAN energy savings. These results are then compared to the results of other schemes. As a result, our scheme outperforms in all cases. Node-level signal to interference and noise ratio (SINR) improved by 11dB whilst, the energy consumption decreased significantly. We further present a probabilistic method and analytically show the outage probability can be effectively reduced to the minimal.
Furthermore, authors of @cite_11 explore the problem of interference among multiple coexisting WBANs. The proposed scheme enables two or three WBANs to agree on a common TDMA schedule. This scheme reduces the whole interference amongst them. The work in @cite_3 investigates the problem of coexisting WBANs. It adopts a TDMA scheme within a WBAN and a carrier sensing mechanism to deal with inter-WBAN interference. The coordinator checks the channel whether free before polling the sensor to avoid inter-WBANs interference.
@cite_3 @cite_11
2087357817 2032297769
A Wireless Body Area Network (WBAN) consists of different tiny physiological wearable sensors to monitor the vital signs of a human body and these sensor nodes transmit in real-time the sensed physiological information to the on-body coordinator or server over a wireless medium. Any radio frequency based wireless device suffers from interference due to the existence of other wireless devices operating in the same frequency band. In this paper we address the problem of interference when multiple WBANs come in the proximity of one another. We propose a TDMA-based solution that creates a common schedule between these WBANs, so that there is seamless communication with their sensors without interference among them, while increasing the cost of latency per node. Also, when these TDMA based WBANs come in the close proximity of one another, they sense the existence of other interfering WBANs. Our solution proposed a scheme that defines the time when to exchange their TDMA schedules. We simulated the proposed solution using NS-3 network simulator and it is observed that there is improvement in the percentage of packet delivery by using the proposed scheme. It is also observed that the increase of speed of WBANs leads to decrease in the percentage of packet delivery. In this paper, coexistence of multiple mobile wireless body area networks (WBANs), where there is no coordination between WBANs, is investigated for the case where the WBAN-of-interest employs cooperative communications. A decode-and-forward protocol with two dual-hop links, two relays and selection combining (SC) at the hub (or gateway device) is chosen for the WBAN-of-interest. A suitable time-division-multiple-access (TDMA) scheme is used, enabling intra-network and inter-network operation, to allocate slots for each Tx Rx link packet transmission. Realistic channel models are employed with various amounts of shadowing, small-scale fading and white noise introduced between WBANs. For the WBAN-of-interest, many hours of measured channel gain data is employed to emulate the channel for this WBAN. It is found that the chosen cooperative communications provides significantly better co-channel interference mitigation than single-link star topology WBAN communications in a mobile, dynamic, scenario, hence the signal-to-interference-plus-noise ratio (SINR) for 10 outage probability at the hub is greatly improved by up-to 12 dB. It is also demonstrated that the location of the hub, given three typical locations, has significant impact on the performance of the cooperative WBAN communications.