Sensor nodes transmit the sensed information to the sink through wireless sensor networks (WSNs). They have limited power, computational capacities and memory. Portable wireless devices are increasing in popularity. Mechanisms that allow information to be efficiently obtained through mobile WSNs are of significant interest. However, a mobile sink introduces many challenges to data dissemination in large WSNs. For example, it is important to efficiently identify the locations of mobile sinks and disseminate information from multi-source nodes to the multi-mobile sinks. In particular, a stationary dissemination path may no longer be effective in mobile sink applications, due to sink mobility. In this paper, we propose a Sink-oriented Dynamic Location Service (SDLS) approach to handle sink mobility. In SDLS, we propose an Eight-Direction Anchor (EDA) system that acts as a location service server. EDA prevents intensive energy consumption at the border sensor nodes and thus provides energy balancing to all the sensor nodes. Then we propose a Location-based Shortest Relay (LSR) that efficiently forwards (or relays) data from a source node to a sink with minimal delay path. Our results demonstrate that SDLS not only provides an efficient and scalable location service, but also reduces the average data communication overhead in scenarios with multiple and moving sinks and sources.

/pdf/sink-oriented-dynamic-location-service-protocol-for-mobile-j4b2hinlyk.pdf

Sink-oriented Dynamic Location Service Protocol for Mobile Sinks with an Energy Efficient Grid-Based Approach

High-resolution data collection using low-cost wireless sensor networks has recently become feasible due to advances in electronics and wireless networking technologies. High quality data collection over an extended period of time requires consideration of a number of orthogonal goals including scalability, versatility, reliability and energy efficiency. This paper focuses on the reliability aspects of our proposed routing protocol for wireless sensor networks, the Geographic Grid Routing protocol. Experimental results show GGR to be a robust solution while simultaneously satisfying the remaining goals of a sensor network routing protocol.

Geographic grid routing: designing for reliability in wireless sensor networks

Purpose – The purpose of this paper is to explore grid‐based routing in wireless sensor networks and to compare the energy available in the network over time for different grid sizes.Design/methodology/approach – The test area is divided into square‐shaped grids of certain length. Energized nodes are placed randomly in the terrain area with the sink node in a fixed position. One node per grid is elected as the leader node based on the highest energy level and the proximity to the centre of the grid. The sink node floods the network to identify a path from sink to source. The path from the sink to the source through the leader nodes are computed using three different methods: shortest path; leader nodes which have the highest energy; and leader nodes based on their received signal strength (RSS) indicator values. After the path is computed, transmission of data is continued until the leader nodes run out of energy. New leader nodes are then elected using the same mechanism to replace the depleted ones.Find...

Energy efficient grid‐based routing in wireless sensor networks

In this paper, we extend previous work on geographic random forwarding (GeRaF) by considering a more efficient paradigm whereby on/off cycles are exploited and every node can participate to packet relaying, as long as it wakes up during any handshake procedure. The protocol is fully distributed, as routing decisions are made hop by hop based on geographic metrics and using a joint channel access/routing procedure, like in the first version of GeRaF. In addition, a previously defined analytical model for GeRaF is used to analyze the protocol, after extending it to cover the new channel access and relay selection procedure. The model is employed to find optimal choices for the parameters of the protocol, before comparing analytical results with ns2 simulations. Results confirm that the geographic paradigm remains a very good solution for energy-constrained, density-constrained, and latency-constrained networks, and that small yet very effective protocol optimizations can achieve remarkable performance improvements. Copyright © 2011 John Wiley & Sons, Ltd.

https://www.onlinelibrary.wiley.com/doi/pdf/10.1002/wcm.1152

A detailed analytical and simulation study of geographic random forwarding

Wireless sensor networks (WSNs) offer much promise for target tracking and environmental monitoring. While many WSN routing protocols have been proposed to date, most of these focus on the mobility of observers and assume that targets are fixed. However, in reality, many applications require for sensing data to be propagated from multiple mobile targets to multiple mobile observers. In addition, WSNs often operate under strict energy constraints, and therefore reducing energy dissipation is also an important issue. In this paper, we present a grid-based routing scheme known as TRENS. First, we address the issue of the WSN comprising multiple mobile targets and observers--with TRENS being the first scheme of its kind to use tracking technology to increase the efficiency of routing procedures in the context of dynamic topology. Next, we introduce a shortcutting approach to resolve energy issues by optimizing routing paths and thus decreasing communication costs and latency. Finally, we conduct extensive simulations to show how TRENS conserves energy and performs better than other grid-based schemes.

A Tracking-Assisted Routing Scheme for Wireless Sensor Networks

High resolution data collection using low-cost wireless sensor networks has recently become feasible due to advances in electronics and wireless networking technologies. The geographic grid routing (GGR) protocol described in this paper aims to provide robust task dissemination and data collection from large sensor networks such that the useful lifetime of the network is prolonged. The work builds on a previously developed routing protocol called two-tier data dissemination (TTDD). Our work is differentiated by the use of multiple paths, a more efficient and useful data collection model, and more authentic environmental assumptions, including the presence of asymmetric links. Extensive and realistic experiments were used to evaluate the performance of GGR. The results show GGR to be a highly efficient, scalable, versatile and robust solution.

http://dspace.library.uvic.ca:8080/bitstream/handle/1828/602/hornsberger_2004.pdf?sequence=1

Jeff Hornsberger

Papers

Geographic grid routing for wireless sensor networks

Geographic grid routing: designing for reliability in wireless sensor networks