Hybrid routing and bridging strategies for large scale mobile ad hoc networks

Multi-hop packet radio networks (or mobile ad-hoc networks) are an ideal technology to establish instant communication infrastructure for military and civilian applications in which both hosts and routers are mobile. In this dissertation, a position-based/link-state hybrid, proactive routing protocol (Position-guided Sliding-window Routing - PSR) that provides for a flat, mobile ad-hoc routing architecture is described, analyzed and evaluated. PSR is based on the superposition of link-state and position-based routing, and it employs a simplified way of localizing routing overhead, without having to resort to complex, multiple-tier routing organization schemes. A set of geographic routing zones is defined for each node, where the purpose of the ith routing zone is to restrict propagation of position updates, advertising position differentials equal to the radius of the (i-i )th routing zone. Thus, the proposed protocol controls position-update overhead generation and propagation by making the overhead generation rate and propagation distance directly proportional to the amount of change in a node\u27s geographic position. An analytical model and framework is provided, in order to study the various design issues and trade-offs of PSR routing mechanism, discuss their impact on the protocol\u27s operation and effectiveness, and identify optimal values for critical design parameters, under different mobility scenarios. In addition an in-depth performance evaluation, via modeling and simulation, was performed in order to demonstrate PSR\u27s operational effectiveness in terms of scalability, mobility support, and efficiency. Furthermore, power and energy metrics, such as path fading and battery capacity considerations, are integrated into the routing decision (cost function) in order to improve PSR\u27s power efficiency and network lifetime. It is demonstrated that the proposed routing protocol is ideal for deployment and implementation especially in large scale mobile ad hoc networks. Wireless local area networks (WLAN) are being deployed widely to support networking needs of both consumer and enterprise applications, and IEEE 802.11 specification is becoming the de facto standard for deploying WLAN. However IEEE 802.11 specifications allow only one hop communication between nodes. A layer-2 bridging solution is proposed in this dissertation, to increase the range of 802.11 base stations using ad hoc networking, and therefore solve the hotspot communication problem, where a large number of mobile users require Internet access through an access point. In the proposed framework nodes are divided into levels based on their distance (hops) from the access point. A layer-2 bridging tree is built based on the level concept, and a node in certain level only forwards packets to nodes in its neighboring level. The specific mechanisms for the forwarding tree establishment as well as for the data propagation are also introduced and discussed. An analytical model is also presented in order to analyze the saturation throughput of the proposed mechanism, while its applicability and effectiveness is evaluated via modeling and simulation. The corresponding numerical results demonstrate and confirm the significant area coverage extension that can be achieved by the solution, when compared with the conventional 802.1 lb scheme. Finally, for implementation purposes, a hierarchical network structure paradigm based on the combination of these two protocols and models is introduced

Models and Protocols for Resource Optimization in Wireless Mesh Networks

Wireless mesh networks are built on a mix of fixed and mobile nodes interconnected via wireless links to form a multihop ad hoc network. An emerging application area for wireless mesh networks is their evolution into a converged infrastructure used to share and extend, to mobile users, the wireless Internet connectivity of sparsely deployed fixed lines with heterogeneous capacity, ranging from ISP-owned broadband links to subscriber owned low-speed connections. In this thesis we address different key research issues for this networking scenario. First, we propose an analytical predictive tool, developing a queuing network model capable of predicting the network capacity and we use it in a load aware routing protocol in order to provide, to the end users, a quality of service based on the throughput. We then extend the queuing network model and introduce a multi-class queuing network model to predict analytically the average end-to-end packet delay of the traffic flows among the mobile end users and the Internet. The analytical models are validated against simulation. Second, we propose an address auto-configuration solution to extend the coverage of a wireless mesh network by interconnecting it to a mobile ad hoc network in a transparent way for the infrastructure network (i.e., the legacy Internet interconnected to the wireless mesh network). Third, we implement two real testbed prototypes of the proposed solutions as a proof-of-concept, both for the load aware routing protocol and the auto-configuration protocol. Finally we discuss the issues related to the adoption of ad hoc networking technologies to address the fragility of our communication infrastructure and to build the next generation of dependable, secure and rapidly deployable communications infrastructures

Enabling cost aware routing with auctions in wireless ad-hoc networks

Battery power is a precious resource in wireless ad-hoc networks, and most routing protocols that have been proposed so far do not generate cost efficient routes. In this thesis, a novel auction-based cost-aware routing scheme, called CARA, is presented. CARA is designed as an extension of the MAC layer, and is shown to improve the cost efficiency of existing ad-hoc routing protocols through dynamic power control, while introducing only minimal additional overhead. The MAC layer at each node is given the capability to run local sealed-bid second-price auctions for the user data packets that need to be transmitted, and to determine any neighbor nodes that reduce the transmission cost to the next hop identified by the network layer. Existing network layer routing protocols are utilized with no changes or impact on their operation. Selforganized networks, where nodes are greedy and selfish, are being supported through the proposed auction-based framework

Mobile Ad hoc Networking: Imperatives and Challenges

Mobile ad hoc networks (MANETs) represent complex distributed systems that comprise wireless mobile nodes that can freely and dynamically self-organize into arbitrary and temporary, "ad-hoc" network topologies, allowing people and devices to seamlessly internetwork in areas with no pre-existing communication infrastructure, e.g., disaster recovery environments. Ad hoc networking concept is not a new one, having been around in various forms for over 20 years. Traditionally, tactical networks have been the only communication networking application that followed the ad hoc paradigm. Recently, the introduction of new technologies such as the Bluetooth, IEEE 802.11 and Hyperlan are helping enable eventual commercial MANET deployments outside the military domain. These recent evolutions have been generating a renewed and growing interest in the research and development of MANET. This paper attempts to provide a comprehensive overview of this dynamic field. It first explains the important role that mobile ad hoc networks play in the evolution of future wireless technologies. Then, it reviews the latest research activities in these areas, including a summary of MANET\u27s characteristics, capabilities, applications, and design constraints. The paper concludes by presenting a set of challenges and problems requiring further research in the future

Improving Performance of IEEE 802.11p MAC Layer for Emergency Message Dissemination

Vehicular ad-hoc networking is the most promising subfield of mobile ad-hoc networks, which may become the ad-hoc networking technology in near future for vehicles communicating amongst themselves on road. It uses IEEE 802.11p MAC protocol as wireless networking technology. The IEEE 802.11p MAC protocol has inherent problems in wireless ad-hoc networking environment due its heterogeneous, infrastructureless and highly dynamic nature. The performance of IEEE 802.11p MAC layer for vehicular ad-hoc networking is based on performance of one-hop broadcasting. The performance of IEEE 802.11p one-hop broadcasting is of major concern regarding emergency message dissemination. The CSMA/CA protocol used in IEEE 802.11p is far from optimal solution for emergency message dissemination due to inherent properties of random access, higher delivery delays and retransmissions. Techniques to improve emergency message dissemination delivery rate and minimize time latency of message dissemination, such as, disabling backoff and synchronous transmission, have been mentioned in this thesis out of which one technique such as disabling backoff is being evaluated through simulation results. The goal of this thesis work is to evaluate a technique, modifying the IEEE 802.11p MAC layer protocol using Network Simulator 3 (NS3). The technique is based on introducing a separate EDCA queue and a separate EDCAF function for emergency messages in QoS EDCA priority queues, disabling backoff for emergency messages and giving highest priority to emergency messages in a station having different AC queues seeking for transmission opportunity. Disabling backoff for emergency messages may reduce time latency arising from exponential backoff algorithm. As the backoff is disabled, more than one station may start transmitting emergency message at the same time. So, it can be deduced that such technique could be beneficial for simple emergency applications. The simulation results show that this technique could be useful for emergency applications utilizing a buzz signal for hazardous warnings on road

Development of a Drone-Mounted Wireless Attack Platform

The commercial drone market has grown rapidly due to the increasing utility and capabilities of drones. This new found popularity has made it possible for inexpensive drones capable of impressive carry capacities and flight times to reach the consumer market. These new features also offer an invaluable resource to wireless hackers. Capitalizing on their mobility, a wireless hacker can equip a drone with hacking tools to surpass physical security (e.g. fences) with relative ease and reach wireless networks. This research seeks to experimentally evaluate the ability of a drone-mounted wireless attack platform equipped with a directional antenna to conduct wireless attacks effectively at distances greater than 800 meters. To test this hypothesis, the “skypie v2” prototype conducts computer network attacks against a target network and captured data is used to evaluate the effectiveness of the platform. Results showed that capture of a WPA2 handshake was possible at a RSSI of -72 dBm or 2400 meters from a network located in a open field. Additionally, nmap scans were conducted with a RSSI value of -74 dBm or nearly 3000 meters from the target network

Multipath routing and QoS provisioning in mobile ad hoc networks

PhDA Mobile Ad Hoc Networks (MANET) is a collection of mobile nodes that can communicate with each other using multihop wireless links without utilizing any fixed based-station infrastructure and centralized management. Each mobile node in the network acts as both a host generating flows or being destination of flows and a router forwarding flows directed to other nodes. Future applications of MANETs are expected to be based on all-IP architecture and be capable of carrying multitude real-time multimedia applications such as voice and video as well as data. It is very necessary for MANETs to have an efficient routing and quality of service (QoS) mechanism to support diverse applications. This thesis proposes an on-demand Node-Disjoint Multipath Routing protocol (NDMR) with low broadcast redundancy. Multipath routing allows the establishment of multiple paths between a single source and single destination node. It is also beneficial to avoid traffic congestion and frequent link breaks in communication because of the mobility of nodes. The important components of the protocol, such as path accumulation, decreasing routing overhead and selecting node-disjoint paths, are explained. Because the new protocol significantly reduces the total number of Route Request packets, this results in an increased delivery ratio, smaller end-to-end delays for data packets, lower control overhead and fewer collisions of packets. Although NDMR provides node-disjoint multipath routing with low route overhead in MANETs, it is only a best-effort routing approach, which is not enough to support QoS. DiffServ is a standard approach for a more scalable way to achieve QoS in any IP network and could potentially be used to provide QoS in MANETs because it minimises the need for signalling. However, one of the biggest drawbacks of DiffServ is that the QoS provisioning is separate from the routing process. This thesis presents a Multipath QoS Routing protocol for iv supporting DiffServ (MQRD), which combines the advantages of NDMR and DiffServ. The protocol can classify network traffic into different priority levels and apply priority scheduling and queuing management mechanisms to obtain QoS guarantees

Cyber-Attack Drone Payload Development and Geolocation via Directional Antennae

The increasing capabilities of commercial drones have led to blossoming drone usage in private sector industries ranging from agriculture to mining to cinema. Commercial drones have made amazing improvements in flight time, flight distance, and payload weight. These same features also offer a unique and unprecedented commodity for wireless hackers -- the ability to gain ‘physical’ proximity to a target without personally having to be anywhere near it. This capability is called Remote Physical Proximity (RPP). By their nature, wireless devices are largely susceptible to sniffing and injection attacks, but only if the attacker can interact with the device via physical proximity. A properly outfitted drone can increase the attack surface with RPP (adding a range of over 7 km using off-the-shelf drones), allowing full interactivity with wireless targets while the attacker can remain distant and hidden. Combined with the novel approach of using a directional antenna, these drones could also provide the means to collect targeted geolocation information of wireless devices from long distances passively, which is of significant value from an offensive cyberwarfare standpoint. This research develops skypie, a software and hardware framework designed for performing remote, directional drone-based collections. The prototype is inexpensive, lightweight, and totally independent of drone architecture, meaning it can be strapped to most medium to large commercial drones. The prototype effectively simulates the type of device that could be built by a motivated threat actor, and the development process evaluates strengths and shortcoming posed by these devices. This research also experimentally evaluates the ability of a drone-based attack system to track its targets by passively sniffing Wi-Fi signals from distances of 300 and 600 meters using a directional antenna. Additionally, it identifies collection techniques and processing algorithms for minimizing geolocation errors. Results show geolocation via 802.11 emissions (Wi-Fi) using a portable directional antenna is possible, but difficult to achieve the accuracy that GPS delivers (errors less than 5 m with 95% confidence). This research shows that geolocation predictions of a target cell phone acting as a Wi-Fi access point in a field from 300 m away is accurate within 70.1 m from 300 m away and within 76 meters from 600 m away. Three of the four main tests exceed the hypothesized geolocation error of 15% of the sensor-to-target distance, with tests 300 m away averaging 25.5% and tests 600 m away averaging at 34%. Improvements in bearing prediction are needed to reduce error to more tolerable quantities, and this thesis discusses several recommendations to do so. This research ultimately assists in developing operational drone-borne cyber-attack and reconnaissance capabilities, identifying limitations, and enlightening the public of countermeasures to mitigate the privacy threats posed by the inevitable rise of the cyber-attack drone