3,464 research outputs found
Coverage Protocols for Wireless Sensor Networks: Review and Future Directions
The coverage problem in wireless sensor networks (WSNs) can be generally
defined as a measure of how effectively a network field is monitored by its
sensor nodes. This problem has attracted a lot of interest over the years and
as a result, many coverage protocols were proposed. In this survey, we first
propose a taxonomy for classifying coverage protocols in WSNs. Then, we
classify the coverage protocols into three categories (i.e. coverage aware
deployment protocols, sleep scheduling protocols for flat networks, and
cluster-based sleep scheduling protocols) based on the network stage where the
coverage is optimized. For each category, relevant protocols are thoroughly
reviewed and classified based on the adopted coverage techniques. Finally, we
discuss open issues (and recommend future directions to resolve them)
associated with the design of realistic coverage protocols. Issues such as
realistic sensing models, realistic energy consumption models, realistic
connectivity models and sensor localization are covered
Optimizing the beacon exchange rate for proactive autonomic configuration in ubiquitous MANETs
Proactive self-configuration is indispensable for MANETs like ubiquitous sensor networks (USNs), as component devices of the network are usually exposed to natural or man-made disasters due to the hostile deployment and ad hoc nature of the USNs. Network state beacons (NSBs) are exchanged among the key nodes of the network for crucial and effective monitoring of the network for steady state operation. The rate of beacon exchange (F/sub E/) and its contents, define the time and nature of the proactive action. Therefore it is very important to optimize these parameters to tune the functional response of the USN. This paper presents a comprehensive model for monitoring and proactively reconfiguring the network by optimizing the F/sub E/. The results confirm the improved throughput while maintaining QoS over longer periods of network operation
Multimedia Content Distribution in Hybrid Wireless Networks using Weighted Clustering
Fixed infrastructured networks naturally support centralized approaches for
group management and information provisioning. Contrary to infrastructured
networks, in multi-hop ad-hoc networks each node acts as a router as well as
sender and receiver. Some applications, however, requires hierarchical
arrangements that-for practical reasons-has to be done locally and
self-organized. An additional challenge is to deal with mobility that causes
permanent network partitioning and re-organizations. Technically, these
problems can be tackled by providing additional uplinks to a backbone network,
which can be used to access resources in the Internet as well as to inter-link
multiple ad-hoc network partitions, creating a hybrid wireless network. In this
paper, we present a prototypically implemented hybrid wireless network system
optimized for multimedia content distribution. To efficiently manage the ad-hoc
communicating devices a weighted clustering algorithm is introduced. The
proposed localized algorithm deals with mobility, but does not require
geographical information or distances.Comment: 2nd ACM Workshop on Wireless Multimedia Networking and Performance
Modeling 2006 (ISBN 1-59593-485
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