A unifying link abstraction for wireless sensor networks

Recent technological advances and the continuing quest for greater efficiency have led to an explosion of link and network protocols for wireless sensor networks. These protocols embody very different assumptions about network stack composition and, as such, have limited interoperability. It has been suggested [3] that, in principle, wireless sensor networks would benefit from a unifying abstraction (or “narrow waist ” in architectural terms), and that this abstraction should be closer to the link level than the network level. This paper takes that vague principle and turns it into practice, by proposing a specific unifying sensornet protocol (SP) that provides best-effort single-hop broadcast semantics. The two goals of a unifying abstraction are generality and ef-ficiency: it should be capable of running over a broad range of link-layer technologies and supporting a wide variety of network protocols, and doing so should not lead to a significant loss of ef-ficiency. To investigate the extent to which SP meets these goals, we implemented SP (in TinyOS) on top of two very different ra-dio technologies: B-MAC on mica2 and IEEE 802.15.4 on Telos. We also built a variety of network protocols on SP, including ex-amples of collection routing [54], dissemination [26], and aggrega-tion [33]. Measurements show that these protocols do not sacrifice performance through the use of our SP abstraction