Transport mechanism for wireless micro sensor network

Wireless sensor network (WSN) is a wireless ad hoc network that consists of very large number of tiny sensor nodes communicating with each other with limited power and memory constrain. WSN demands real-time routing which requires messages to be delivered within their end-to-end deadlines (packet lifetime). This report proposes a novel real-time with load distribution (RTLD) routing protocol that provides real time data transfer and efficient distributed energy usage in WSN. The RTLD routing protocol ensures high packet throughput with minimized packet overhead and prolongs the lifetime of WSN. The routing depends on optimal forwarding (OF) decision that takes into account of the link quality, packet delay time and the remaining power of next hop sensor nodes. RTLD routing protocol possesses built-in security measure. The random selection of next hop node using location aided routing and multi-path forwarding contributes to built-in security measure. RTLD routing protocol in WSN has been successfully studied and verified through simulation and real test bed implementation. The performance of RTLD routing in WSN has been compared with the baseline real-time routing protocol. The simulation results show that RTLD experiences less than 150 ms packet delay to forward a packet through 10 hops. It increases the delivery ratio up to 7 % and decreases power consumption down to 15% in unicast forwarding when compared to the baseline routing protocol. However, multi-path forwarding in RTLD increases the delivery ratio up to 20%. In addition, RTLD routing spreads out and balances the forwarding load among sensor nodes towards the destination and thus prolongs the lifetime of WSN by 16% compared to the baseline protocol. The real test bed experiences only slight differences of about 7.5% lower delivery ratio compared to the simulation. The test bed confirms that RTLD routing protocol can be used in many WSN applications including disasters fighting, forest fire detection and volcanic eruption detection

QoS-Based and Secure Multipath Routing in Wireless Sensor Networks

With the growing demand for quality of service (QoS) aware routing protocols in wireless networks, QoS-based routing has emerged as an interesting research topic. A QoS guarantee in wireless sensor networks (WSNs) is difficult and more challenging due to the fact that the available resources of sensors and the various applications running over these networks have different constraints in their nature and requirements. Furthermore, due to the increased use of sensor nodes in a variety of application fields, WSNs need to handle heterogeneous traffic with diverse priorities to achieve the required QoS. In this thesis, we investigate the problem of providing multi-QoS in routing protocols for WSNs. In particular, we investigate several aspects related to the application requirements and the network states and resources. We present multi-objective QoS aware routing protocol for WSNs that uses the geographic routing mechanism combined with the QoS requirements to meet diverse application requirements by considering the changing conditions of the network. The protocol formulates the application requirements with the links available resources and conditions to design heuristic neighbor discovery algorithms. Also, with the unlimited resource at the sink node, the process of selecting the routing path/paths is assigned to the sink. Paths selection algorithms are designed with various goals in order to extend network lifetime, enhance the reliability of data transmission, decrease end-to-end delay, achieve load balancing and provide fault tolerance. We also develop a cross-layer routing protocol that combines routing at network layer and the time scheduling at the MAC layer with respect to delay and reliability in an energy efficient way. A node-disjoint multipath routing is used and a QoS-aware priority scheduling considering MAC layer is proposed to ensure that real time and non-real time traffic achieve their desired QoS while alleviating congestion in the network. Additionally, we propose new mechanism for secure and reliable data transmission in multipath routing for WSNs. Different levels of security requirements are defined and depending on these requirements, a selective encryption scheme is introduced to encrypt selected number of coded fragments in order to enhance security and thereby reduce the time required for encryption. Node-disjoint multipath routing combined with source coding is used in order to enhance both security and reliability of data transmission. Also, we develop an allocation strategy that allocates fragments on paths to enhance both the security and probability of successful data delivery. Analysis and extensive simulation are conducted to study the performance of all the above proposed protocols

Exploring Wireless Data Center Networks: Can They Reduce Energy Consumption While Providing Secure Connections?

Data centers have become the digital backbone of the modern world. To support the growing demands on bandwidth, Data Centers consume an increasing amount of power. A significant portion of that power is consumed by information technology (IT) equipment, including servers and networking components. Additionally, the complex cabling in traditional data centers poses design and maintenance challenges and increases the energy cost of the cooling infrastructure by obstructing the flow of chilled air. Hence, to reduce the power consumption of the data centers, we proposed a wireless server-to-server data center network architecture using millimeter-wave links to eliminate the need for power-hungry switching fabric of traditional fat-tree-based data center networks. The server-to-server wireless data center network (S2S-WiDCN) architecture requires Line-of-Sight (LoS) between servers to establish direct communication links. However, in the presence of interference from internal or external sources, or an obstruction, such as an IT technician, the LoS may be blocked. To address this issue, we also propose a novel obstruction-aware adaptive routing algorithm for S2S-WiDCN. S2S-WiDCN can reduce the power consumption of the data center network portion while not affecting the power consumption of the servers in the data center, which contributes significantly towards the total power consumption of the data center. Moreover, servers in data centers are almost always underutilized due to over-provisioning, which contributes heavily toward the high-power consumption of the data centers. To address the high power consumption of the servers, we proposed a network-aware bandwidth-constrained server consolidation algorithm called Network-Aware Server Consolidation (NASCon) for wireless data centers that can reduce the power consumption up to 37% while improving the network performance. However, due to the arrival of new tasks and the completion of existing tasks, the consolidated utilization profile of servers change, which may have an adverse effect on overall power consumption over time. To overcome this, NASCon algorithm needs to be executed periodically. We have proposed a mathematical model to estimate the optimal inter-consolidation time, which can be used by the data center resource management unit for scheduling NASCon consolidation operation in real-time and leverage the benefits of server consolidation. However, in any data center environment ensuring security is one of the highest design priorities. Hence, for S2S-WiDCN to become a practical and viable solution for data center network design, the security of the network has to be ensured. S2S-WiDCN data center can be vulnerable to a variety of different attacks as it uses wireless links over an unguided channel for communication. As being a wireless system, the network has to be secured against common threats associated with any wireless networks such as eavesdropping attack, denial of services attack, and jamming attack. In parallel, other security threats such as the attack on the control plane, side-channel attack through traffic analysis are also possible. We have done an extensive study to elaborate the scope of these attacks as well as explore probable solutions against these issues. We also proposed viable solutions for the attack against eavesdropping, denial of services, jamming, and control-plane attack. To address the traffic analysis attack, we proposed a simulated annealing-based random routing mechanism which can be adopted instead of default routing in the wireless data center

A survey of potential security issues in existing wireless sensor network protocols

The increasing pervasiveness of wireless sensor networks (WSNs) in diverse application domains including critical infrastructure systems, sets an extremely high security bar in the design of WSN systems to exploit their full benefits, increasing trust while avoiding loss. Nevertheless, a combination of resource restrictions and the physical exposure of sensor devices inevitably cause such networks to be vulnerable to security threats, both external and internal. While several researchers have provided a set of open problems and challenges in WSN security and privacy, there is a gap in the systematic study of the security implications arising from the nature of existing communication protocols in WSNs. Therefore, we have carried out a deep-dive into the main security mechanisms and their effects on the most popular protocols and standards used in WSN deployments, i.e., IEEE 802.15.4, Berkeley media access control for low-power sensor networks, IPv6 over low-power wireless personal area networks, outing protocol for routing protocol for low-power and lossy networks (RPL), backpressure collection protocol, collection tree protocol, and constrained application protocol, where potential security threats and existing countermeasures are discussed at each layer of WSN stack. This paper culminates in a deeper analysis of network layer attacks deployed against the RPL routing protocol. We quantify the impact of individual attacks on the performance of a network using the Cooja network simulator. Finally, we discuss new research opportunities in network layer security and how to use Cooja as a benchmark for developing new defenses for WSN systems

Energy-aware and secure routing with trust levels for wireless ad hoc and sensor networks

This dissertation focuses on the development of routing algorithms for secure and trusted routing in wireless ad hoc and sensor network. The first paper presents the Trust Level Routing (TLR) protocol, an extension of the optimized energy-delay routing (OEDR) protocol, focusing on the integrity, reliability and survivability of the wireless network...The second paper analyzes both OLSR and TLR in terms of survivability and reliability to emphasize the improved performance of the network in terms of lifetime and proper delivery of data...The third paper proposes a statistical reputation model that uses the watchdog mechanism to observe the cooperation of the neighboring nodes...The last paper presents the results of the hardware implementation of Energy-Efficient Hybrid Key Management --Abstract, page iv