Poster: Motivating an inter-networking architecture for WSN/IoT

Growing commercial development of WSN/WBAN/IoT solutions will eventually lead to their ubiquitous deployment. Inevitably, there will be environments that contain many independent, co-located networks with overlapping areas of wireless coverage. Examples of high density scenarios include transit stations and urban housing. Because these various networks and applications will be owned by different people and because they mostly operate in ISM bands, there is no trusted authority that can coordinate their activity. Cross-technology interference has been widely studied, e.g. between IEEE 802.11 and IEEE 802.15.4, but very little work has addressed inter-network interference between co-located WSNs using the same communication technology. However, the potentially large number of co-located networks and fairly small number of channels suggests that this will not be an unusual situation. The risk of external frames being received and misinterpreted as local frames is studied in [2], which emphasized the need for authentication on all frames. Interference between co-located IEEE 802.15.4 PANs is demonstrated in [3]. This work reflects a similar interest in timing and interference interactions between networks that can receive and identify, but not decrypt, each other’s frames. The diversity of IEEE 802.15.4-based WSN protocols is the motivating use case. These protocols use the same PHY/ MAC in very different ways, from pure unslotted CSMA to the scheduled mesh in WirelessHART. Such significant differences in channel access mechanisms can lead to adverse interactions between independent networks, which will not be able to explicitly negotiate (or even infer) how to share the channel efficiently. Thus the long-term goal of this work-in-progress is to motivate the development of architecture and design principles that can mitigate problems of inter-network interference. As a specific example, consider two kinds of asynchronous MAC layers. Figure 1 shows interactions between networks using an X-MAC [1] type protocol (i.e. sender strobes, receivers periodically listen) and an RI-MAC [4] type protocol