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Localization schemes using hop-counts to reference nodes of known positions have been proposed to localize nodes in a sensor network. However, these schemes usually work well only when the networks have uniform and dense node distribution. A novel density-aware hop-count localization (DHL) algorithm is described to improve the accuracy of location(More)
In an ad hoc sensor network clock synchronization is a serious issue as nodes in the sensor network have different clock drifts. One of the common solutions for the time synchronization among these nodes is the active transmission of time stamp messages. However this method consumes some resources and channel bandwidth, and is not suitable for resource(More)
— Localization of wireless micro-sensors which are non-uniformly scattered over a region is a challenging problem. Solutions relying on simple inter-node ranging and then summing up ranges between a node and reference nodes do not necessarily provide reliable position estimation. Besides, in multihop localization, error in distance estimation tends to(More)
— This paper discusses and investigates the effects of mobility on positioning of wireless ad hoc networks. We present a Mobility-enhanced Ad hoc Positioning (MAP) scheme, where we leverage on the mobility of nodes within the network. The scheme uses the hop counts information from fixed reference nodes to perform positioning and improves accuracy by using(More)
We address the problem of minimizing the worst-case broadcast delay in multi-rate wireless mesh networks (WMN) in a distributed and localized fashion. Efficient broadcasting in such networks is especially challenging due to the multi-rate transmission capability and the interference between wireless transmissions of WMN nodes. We propose connecting(More)
We address the problem of minimizing the worst-case broadcast delay in ldquomulti-radio multi-channel multi-rate wireless mesh networksrdquo (MR<sup>2</sup>-MC WMN) in a distributed and localized fashion. Efficient broadcasting in such networks is especially challenging due to the desirability of exploiting the ldquowireless broadcast advantagerdquo (WBA),(More)
A wireless mesh network (WMN) that utilizes multiple interfaces and multiple channels has been shown to improve network performance by reducing the interference and increasing the available bandwidth. However, the contention delay experienced by a frame along every hop of the WMN can still limit the performance. In addition, cross-layer delay occurs when a(More)
As more wireless networks are being deployed in a given geographic area, the problem of interference and coexistence of these independently operated networks is becoming an increasing problem. This paper looks at the coexistence of independent multihop Wireless Mesh Networks (WMNs). We argue that cooperation is difficult in such scenarios. We define a(More)
Amidst the numerous active research efforts in wireless sensor networks which aim to push beyond the limits, we aim to significantly enhance the effectiveness of wireless sensors by integrating controlled mobility to realize a networked system of mobile sensors that functions collectively as an integrated unit. The All-teRrain Advanced Network of Ubiquitous(More)
Wireless sensor networks have specifically unique characteristics with regards to energy, memory, computational and complexity limitations. This paper shares the experiences gained in designing and implementing a wireless sensor network when we take these considerations into account. We also highlight some challenges faced in the implementation of the(More)