Traffic eavesdropping based scheme to deliver time-sensitive data in sensor networks

Due to the broadcast nature of wireless channels, neighbouring sensor nodes may overhear packets transmissions from each other even if they are not the intended recipients of these transmissions. This redundant packet reception leads to unnecessary expenditure of battery energy of the recipients. Particularly in highly dense sensor networks, overhearing or eavesdropping overheads can constitute a significant fraction of the total energy consumption. Since overhearing of wireless traffic is unavoidable and sometimes essential, a new distributed energy efficient scheme is proposed in this paper. This new scheme exploits the inevitable overhearing effect as an effective approach in order to collect the required information to perform energy efficient delivery for data aggregation. Based on this approach, the proposed scheme achieves moderate energy consumption and high packet delivery rate notwithstanding the occurrence of high link failure rates. The performance of the proposed scheme is experimentally investigated a testbed of TelosB motes in addition to ns-2 simulations to validate the performed experiments on large-scale network

Robust geometric forest routing with tunable load balancing

Although geometric routing is proposed as a memory-efficient alternative to traditional lookup-based routing and forwarding algorithms, it still lacks: i) adequate mechanisms to trade stretch against load balancing, and ii) robustness to cope with network topology change. The main contribution of this paper involves the proposal of a family of routing schemes, called Forest Routing. These are based on the principles of geometric routing, adding flexibility in its load balancing characteristics. This is achieved by using an aggregation of greedy embeddings along with a configurable distance function. Incorporating link load information in the forwarding layer enables load balancing behavior while still attaining low path stretch. In addition, the proposed schemes are validated regarding their resilience towards network failures

Dynamic Diffusion for Congestion Avoidance in Wireless Sensor Networks

Wireless Sensor Networks (WSNs) are employed for either continuous monitoring or event detection in the target area of interest. In event-driven applications, it is critical to report the detected events in the area, and with sudden bursts of traffic possible due to spatially-correlated events or multiple events, the data loss due to congestion will result in information loss or delayed arrival of the sensed information. Congestion control techniques detect congestion and attempt to recover from packet losses due to congestion, but they cannot eliminate or prevent the occurrence of congestion. Congestion avoidance techniques employ proactive measures to alleviate future congestion using parameters like queue length, hop count, channel conditions, and priority index. However, maintaining and processing such information becomes a significant overhead for the sensor nodes and degrades the performance of the network. We propose a congestion avoidance MAC protocol that uses the queue buffer length of the sensor nodes to estimate the congestion and diffuse traffic to provide a congestion-free routing path towards the base station. This protocol provides event reporting, packet delivery ratio, by dynamically diffusing the traffic in the network using multiple forwarders in addition to backup forwarding. We used the standard Network Simulator (NS2) to evaluate the performance of our protocol. Results show that our protocol significantly improves event reporting in terms of packet delivery ratio, throughput, and delay by avoiding congestion while diffusing the traffic effectively

A Scheme for Detecting the Sinkhole for Secured WSN

Because of the limited computation capability as well as transmissions being broadcasted in a wireless sensor network (WSN) they are supposed to be more susceptible for attacks related to the security. As present wireless sensor networks have low-power constraints as well as increased complexity, thus for nodes’ performance analysis related to the embedded software and network simulation efficient approaches are required. Additionally, as these networks are used to deal with the sensitive information and operated in the adverse unattended environments, thus, security feature must be added in most of these wireless sensor networks. In this paper a novel scheme for detecting various sinkhole nodes for wireless sensor network (WSN). The results of this proposed scheme show the 1.75% fake positive rate and 96% of detection rate. In comparison to the previous schemes, these aspects are considerably better. In addition to these aspects, our scheme also achieves the communication as well as computational efficiencies. As a result of which, this proposed scheme proved to have better results in many applications.

Energy-Efficient Design of Adhoc and Sensor Networks

Adhoc and sensor networks (ASNs) are emerging wireless networks that are expected to have significant impact on the efficiency of many military and civil applications. However, building ASNs efficiently poses a considerable technical challenge because of the many constraints imposed by the environment, or by the ASN nodes capabilities themselves. One of the main challenges is the finite supply energy.Since the network hosts are battery operated, they need to be energy conserving so that the nodes and hence the network itself does not expire. In this thesis different techniques for anenergy-efficient design for ASNs are presented. My work spans two layers of the network protocol stack; these are the Medium Access Layer (MAC) and the Routing Layer. This thesis first identifies and highlights the different sources of energy inefficiency in ASNs, and then it describes how each of these inefficiencies is handled. Toward this goal, I first focus on the Medium Access (MAC) Layer and present my work that handles the wasted energy in transmission and describe how the transmission distance is optimized to extend the network lifetime. I then describe BLAM, an energy-efficient extension for the IEEE 802.11, that handles the wasted energy in collisions. Next, TDMA-ASAP, a new MAC protocol for sensor networks, is introduced. TDMA-ASAP targets the wasted energy in idle listening. I also investigate energy-efficiency at the routing layer level. First, the ``Flooding-Waves' problem is identified. This is a problem in any cost-based energy-efficient routing protocol for adhoc networks, different ways of solving this problem are presented. For sensor networks routing trees are usually used, I introduce a new routing scheme called RideSharing which is energy-efficient and fault-tolerant. RideSharing will deliver a better aggregate result to the end user while masking network linkfailures. Next, I present how to extend the RideSharing scheme to handle different link quality models. Finally, I introduce GroupBeat,a new health detection system for sensor networks, which when combined with RideSharing can deliver the information to the end user even in case of node failures