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This paper presents the design, implementation and performance evaluation of a hybrid MAC protocol, called Z-MAC, for wireless sensor networks that combines the strengths of TDMA and CSMA while offsetting their weaknesses. Like CSMA, Z-MAC achieves high channel utilization and low-latency under low contention and like TDMA, achieves high channel utilization(More)
—Congestion control in wireless multi-hop networks is challenging and complicated because of two reasons. First, interference is ubiquitous and causes loss in the shared medium. Second, wireless multihop networks are characterized by the use of diverse and dynamically changing routing paths. Traditional end point based congestion control protocols are(More)
This paper presents a distributed implementation of RAND, a randomized time slot scheduling algorithm, called DRAND. DRAND runs in <i>O</i>(&#948;) time and message complexity where &#948; is the maximum size of a two-hop neighborhood in a wire-less network while message complexity remains <i>O</i>(&#948;), assuming that message delays can be bounded by an(More)
Congestion control in wireless multi-hop networks is challenging because of two reasons. First, broadcast is an inherent feature of wireless networks and motivates many creative protocols including opportunistic routing and network coding. These protocols enable the use of many diverse, yet dynamically changing routing paths. Congestion control for these(More)
— A randomized dining philosophers algorithm is presented for a realistic semi-synchronous model where message delays vary within an unknown bound, and clocks may run at a different speed without any synchronization. In order to predict the unknown bounds, the algorithm employs a simple network delay measurement technique. The algorithm has an expected(More)
Topology control is an important feature for energy saving, and many topology control protocols have been proposed. Yet, little work has been done on quantitatively measuring practical performance gains that topology control achieves in a real sensor network. This is because many existing protocols either are too complex or make too impractical assumptions(More)
—Space Division Multiple Access (SDMA) based Medium Access Control (MAC) protocols have been proposed to enable concurrent communications and improve link throughput in Multi-Input Multi-Output (MIMO) Ad Hoc networks. For the most part, the works appearing in the literature make idealized and simplifying assumptions about the underlying physical layer as(More)
—Existing wireless MACs are known to have fairness and QoS problems 1. In response, the wireless community have come up with numerous " point solutions " , with one-to-one comparison of their solution with existing MACs for the specific fairness model they target. However, with some tradeoff of flexibility and efficiency, many of these MACs can be made(More)