A mobile ad hoc network is a collection of wireless nodes, all of which may be mobile, that dynamically create a wireless network amongst them without using any infrastructure. Ad hoc wireless networks come into being solely by peer-to-peer interactions among their constituent mobile nodes, and it is only such interactions that are used to provide the necessary control and administrative functions supporting such networks. Mobile hosts are no longer just end systems; each node must be able to function as a router as well to relay packets generated by other nodes. As the nodes move in and out of range with respect to other nodes, including those that are operating as routers, the resulting topology changes must somehow be communicated to all other nodes as appropriate. In accommodating the communication needs of the user applications, the limited bandwidth of wireless channels and their generally hostile transmission characteristics impose additional constraints on how much administrative and control information may be exchanged, and how often. Ensuring effective routing is one of the greatest challenges for ad hoc networking. As a practice, ad hoc routing protocols make routing decisions based on individual node mobility even for applications such as disaster recovery, battlefield combat, conference room interactions, and collaborative computing etc. that are shown to follow a pattern. In this thesis we propose an algorithm that performs routing based on underlying mobility patterns. A mobility pattern aware routing algorithm is shown to have several distinct advantages such as: a more precise view of the entire network topology as the nodes move; a more precise view of the location of the individual nodes; ability to predict with reasonably accuracy the future locations of nodes; ability to switch over to an alternate route before a link is disrupted due to node movements. / Master of Science

This thesis presents a comparison between a basic shortest path routing policy of the Destination-Sequence Distance Vector (DSDV) protocol and two power-aware policy variations of it. In the two modified versions, the routes are selected based on the energy available on the nodes and not only the shortest path distance to the destination. Simulations are conducted for a given situation of nodes and the energy efficiency of the three aforementioned policies are evaluated for example scenarios. First, a brief overview of the theory behind the study is presented. It consists of an description of ad hoc networking, DSDV, and our energy-aware modifications to DSDV. After the fundamental theory, the method is presented. It consists of a description of how the simulated scenarios relates to a real-world scenario and the simplifications made in the model. We present an overview of the model used for simulation and the operation of the program. This section ends with an explanation of the three simulated policies: shortest path, simple weighted and doubled weighted. When the theory behind the thesis are completed, the simulations are conducted. The results are examined and a summary of their meaning is discussed. It is explained how the assumptions effect the reliability of the study and an estimation of the accuracy of the results are presented. We find that the power-aware policy variations (simple weighted and double weighted) both achieve better network lifetime than the basic shortest path policy, at the cost of slightly longer per-packet paths. These results are encouraging and show that very simple modifications to DSDV can achieve significant gains in the network lifetime, helping users get the most out of their networks. Future investigation could try to optimize these gains.

AODV (Ad hoc On-demand Distance Vector routing), DSDV (Destination-Sequenced Distance-Vector routing), DSR (Dynamic Source Routing), and OLSR (Optimized Link State Routing protocol) are protocols used for routing management in ad-hoc networks. In a specific sensor data network application, nodes need information about the network topology, i.e. the network nodes and the connections between them. OLSR provides nodes with this information, while the three other protocols do not. This thesis investigates how OLSR compares to AODV, DSDV,and DSR in a low bandwidth network scenario. Two cases were analyzed: One where AODV, DSDV, and DSR distribute topology information in the application layer and one where they do not. The sensor data application was not finished when this thesis project started. Instead, a simplified traffic model of the application was used. In addition to a protocol comparison, this thesis investigates if traffic generated from the model results in high rates of packet loss, assuming low bandwidth conditions. The ns-3 network simulator was used for these investigations. This thesis shows that AODV outperforms the three other protocols regardless of whether AODV, DSDV, and DSR distribute topology information in the application layer or not. Furthermore, it is shown that running the traffic model in the low bandwidth environment is not possible without high rates of packet loss.

The diploma thesis "QoS model for Mobile ad hoc network" focuses on the quality of services in MANET (Mobile Ad-hoc) networks. It describes MANET networks and covers the theoretical analysis of routing protocols with QoS (Quality of Service) support. Furthermore, there is processed the creation process of model MANET networks with the routing protocol DSDV (Destination-Sequenced Distance Vector) in the simulation environment NS-3 (Network Simulator 3) and its extension of QoS support. The used QoS model is subsequently modified to improve core operating parameters. The implementation of QoS parameters as well as the improvement of delay and jitter (the delay between selected packets) is verified by the functional simulation.

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Wireless mobile ad-hoc networks consist of a collection of peer mobile nodes that form a network and are capable of communicating with each other without help from stationary infrastructure such as access points. The availability of low-cost, com-modity network interface cards (NICs) has made the IEEE 802.11 medium access control (MAC) protocol the de facto MAC protocol for wireless mobile ad-hoc net-works, even though it is not optimal. The IEEE 802.11 MAC protocol is designed to have stations share a single channel in a given network. However, many of the IEEE 802.11 physical (PHY) layer specifications define multiple channels and allow the simultaneous, non-interfering use of some of these channels. Therefore, multiple communications can occur at the same time, offering the opportunity to increase the effective network capacity. We present an innovative routing protocol that utilizes multiple channels to im-prove the performance of wireless ad-hoc networks. The basic idea of the protocol is to use multiple channels so that multiple useful transmissions can occur simultane-ously, thus increasing network capacity. The proposed scheme requires minor changes to existing proactive ad-hoc routing protocols and no modifications to the current IEEE 802.11 MAC protocol. To reduce inefficiencies due to periodic updates in the proactive routing protocols, the proposed scheme divides the network layer into control and data planes. Nodes send routing updates using the control channel and user packets using the data channel. To demonstrate the multi-channel routing scheme, we extend the Destination-Sequenced Distance-Vector (DSDV), Open Shortest Path First-Minimal Connected Dominating Set (OSPF-MCDS), and Optimized Link State Routing (OLSR) protocol to multiple channel (MC) versions, denoted as DSDV-MC, OSPF-MCDS-MC, and OLSR-MC, respectively. Simulation results for DSDV-MC, OSPF-MCDS-MC, and OLSR-MC are presented and experimental results for OLSR-MC are presented. Simulation results indicate that DSDV-MC and OSPF-MCDS-MC effectively exploit multiple channels to improve network capacity. Goodput, the throughput consider-ing only useful error-free packets, increases with an increased number of available channels as the number of nodes and network load increase in both single-hop and multiple-hop networks. Experimental results with OLSR-MC also support that the proposed scheme increases network capacity without modification to the MAC proto-col in a real implementation. Although simulation and experimental results show that proposed scheme im-proves network capacity by exploiting multiple channels, problems exist with channel distribution. We introduce a new metric, the Channel Distribution Index (CDI) to in-vestigate these issues. The CDI indicates the fairness of the channel distribution. We identify the channel convergence problem, where a particular channel is over-utilized, and propose a channel reallocation scheme to mitigate the impact of the channel convergence problem using the CDI. / Ph. D.

This work deals with routing protocols for ad hoc wireless networks. First ad hoc networks are introduced. Routing protocols are then classified according to several criteria. Four routing protocols algorithms are described. They are proactive protocols DSDV and CGSR, reactive DSR and hybrid ZRP. Next AODV routing protocol is described in details. Advantages and disadvantages of AODV and two variants of AODV are also introduced. A new protocol is designed based on the disadvantages of the AODV protocol. This work also describes the implementation and integration of the new protocol in the ns-2 simulator. Results of the simulations are presented.