An adaptive wakeup scheme to support fast routing in sensor networks.
ABSTRACT We propose a novel routing asynchronous wakeup scheme - Adaptive Wakeup Schedule Function (AWSF), which adapts to deployment topography to support fast routing in sensor networks. Unlike most other wakeup schemes such as the random and cyclic designs, AWSF guarantees hard delay bounds, have better average delays and smaller delay variances, and eliminates the "Lonely Node" problem where nodes wakeup to find no communicable neighbours. Since AWSF assumes complete radio turn-off in the "sleep" mode, it is largely different from most data-centric wakeup schemes where the radio modules are only put to "idle" mode for "data snooping" where real energy savings cannot be achieved. We provide simulation results to support our claims and have implemented our solution on real Crossbow Mica2 motes.
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ABSTRACT: In this paper, we present an efficient data reporting control scheme in a cluster-based hierarchical wireless sensor network, which has two components: (i) intra-cluster data reporting control (IntraDRC) scheme and (ii) inter-cluster control (InterDRC) scheme. The IntraDRC scheme controls the amount of traffic generated in a cluster by selecting a certain number of data reporting nodes based on the desired throughput specified by the end system. On the other hand, the InterDRC scheme offers differentiated reporting paths from a cluster to a sink based on the traffic characteristics. InterDRC considers two parameters: one is the hop counts to a sink to deal with the end-to-end delay constraint while the other is the amount of traffic, generated in a cluster and forwarded from its adjacent clusters, to deal with energy consumption. The proposed scheme applies the block design concept from Combinatorial theory to design a novel data reporting node selection approach. IntraDRC employs the node sets created by block designs as the initial reporting schedule. This schedule can be updated by the request of a reporting node when its queue size approaches a predefined threshold. We consider two network models in the paper. The first model considers homogeneous networks in which every node has the same capabilities and adjacent cluster heads are connected in a multi-hop manner. The second model considers heterogeneous networks in which the cluster heads have high capabilities in terms of processing power and transmission range to directly reach adjacent cluster heads in a single-hop manner. Simulation results show that our scheme achieves good throughput performance while providing stable data reporting that is independent of the network density. The scheme also allows for energy savings by using load balanced data reporting paths.Computer Communications. 01/2010;
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ABSTRACT: Delay in a duty-cycled network occurs when the sender waits for its receiver to be awake. Exploiting multiple receivers instead of a single receiver at each hop allows the sender to use the node that wakes up the soonest and so reduce delay. However, current MAC-layer anycast protocols either suffer from high signaling or synchronization overhead and are only appropriate for low duty cycle, low traffic scenarios. In this paper, we propose Any-MAC - a generic, low overhead extension that can be applied to any existing asynchronous MAC protocol to enable MAC-layer anycast. The extensive research in duty-cycle protocols provides us many MAC protocols, each appropriate for a particular network and application scenario. Thus, to construct an anycast solution to reduce delay for a specific network scenario, Any-MAC simply needs to extend the appropriate MAC protocol designed for that scenario. By applying anycast to existing protocols, X-MAC and NPM, we show that Any-MAC uses only simple modification to the base protocols and improves the performance significantly. Our evaluations in ns-2 show that with Any-MAC, both protocols can achieve 30% improvements in delay by exploiting the inherent route level redundancy in the network.Proceedings of the 8th Annual IEEE Communications Society Conference on Sensor, Mesh and Ad Hoc Communications and Networks, SECON 2011, June 27-30, 2011, Salt Lake City, UT, USA; 01/2011
Conference Paper: Know your neighborhood: A strategy for energy-efficient communication[Show abstract] [Hide abstract]
ABSTRACT: Wireless sensor networks typically conserve energy by following a periodic wakeup-sleep schedule: nodes minimize idle time and spend most of their time in a low power sleep state. In order to communicate and exchange data in such a network, the current duty-cycling MAC protocols either require tight synchronization between the neighbor wakeup schedules or spend a significant amount of energy in signaling the sleeping nodes. In contrast, this paper presents Neighborhood-based Power Management (NPM), an energy efficient asynchronous MAC protocol that minimizes signaling overhead through opportunistically gained knowledge about neighbor wakeup schedules. Unlike the synchronization-based MAC protocols, NPM does not require a priori knowledge of the wakeup schedules. Using only a minimal exchange of schedule information, NPM reduces the signaling overhead by shortening the wakeup signal. Furthermore, NPM uses its wakeup signal to awaken all receivers in the neighborhood of the sender, enabling all sender-receiver pairs in that neighborhood to communicate. Our extensive evaluations show that NPM outperforms popular B-MAC, X-MAC and SCP protocols under all network conditions. NPM reduces the signaling overhead, with up to 74% savings in energy and 80% reduction in delay.Mobile Adhoc and Sensor Systems (MASS), 2010 IEEE 7th International Conference on; 12/2010