Abstract-In contrast to the traditional wireless sensor network (WSN) applications that perform only data collection and aggregation, new generation of information processing applications, such as pursuit-evasion games, tracking, evacuation, and disaster relief applications, require in-network information storage and querying. Due to the resource limitations of WSNs, it is challenging to implement in-network information storage and querying in a resilient, energy-efficient, and distributed manner. To address these challenges, we exploit location information and geometry of the network and present an in-network querying infrastructure, namely distributed quad-tree (DQT) structure. DQT satisfies efficient in-network information storage as well as distance-sensitive querying: the cost of answering a query for an event is at most a constant factor (in our case

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Abstract-In a mobile ad hoc network, tracking protocols need to deal with-in addition to the mobility of the target-the mobility of the intermediate nodes that maintain a track toward the target. To address this problem, we propose the MDQT (Mobility-enhanced Distributed QuadTree) tracking framework. MDQT employs a static cell abstraction to mask the mobility of the nodes and provide the illusion of a logical static network overlaid on the mobile network. MDQT implements this virtual static network layer in a lightweight/communication-free manner by exploiting the soft-state principle and the snooping feature of wireless communication.Using simulations, we study the effects of the mobility speed and the percentage of mobile nodes on the performance of our MDQT framework. We find that even at very high mobility speeds (50 meters per second), low update rates (1 update per second), and 100% node mobility, the success rate of MDQT tracking is above 85% and the latency is comparable with that of static networks.

In mobile ad hoc networks(MANET), the limited wireless spectrum, distributed multiple access control, low complexity, and high mobility together impose significant challenges for MAC protocol design to provide reliable wireless communications with high data rates. In contention based MAC protocols, such as 802.11 MAC, each multi-hop data flow encounters contentions not only from the transmissions of itself, but also from other flows that bypassing the neighborhood. This paper presents a Dynamic Token Ring based MAC protocol(DRP) for mobile ad hoc networks, which aims to solve the intra-flow and inter-flow contention problems in MAC layer. It is called dynamic, since the token ring in a cluster can be a low-priority ring or a high priority ring. The node can join high priority ring dynamically according to transmission status. The simulation results show that DRP has superior performance in improving data delivery efficiency and avoiding collisions. It is a good solution for inter-flow/intra-flow contention as well as hidden/exposed terminal problems.