Segment-by-Segment QoS Routing Protocols Grid-based In MANETs

Mobile Ad-hoc NETworks (MANETs) are multi-hop temporary autonomous system of mobile nodes equipped with wireless transceivers and receivers. Due to the prevalence of multimedia applications, QoS issue has been regarded as an important research field in MANETs. However, it is a hard problem to provide QoS in MANETs characterized with multi-hop, dynamic network topology and limited bandwidth resource.This thesis first proposes a QoS-aware segment-by-segment routing protocol in large-scale MANETs. Each routing path is built segment by segment with linear approximation. At the routing discovery phase, the node on the line from source node to destination node has highest priority to be chosen as the next forwarding node. At the route maintenance phase, it independently maintains the routing path segment by segment. So it can reduce the cost of route maintenance and scale well in large-scale MANETs.This thesis also proposes a QoS-aware routing protocol based on hexagonal grids. First, it proposes an intuitive and simple two-dimensional logical coordinate system for hexagonal grids. Based on this coordinate system, it maps the hexagonal grids to rectangular grids, and then gives some algorithm to compute the physical and logical coordinate of each node in the networks. Finally, it proposes a QoS-aware routing protocol based on hexagonal grids, and gives analysis and simulation compared with QoS-aware routing protocol based on square grids.This thesis further proposes an adaptive QoS routing protocol of supporting differentiated services in MANETs based on hexagonal grids model. According to the characteristics of all traffic, its priority level is divided into different types. It adaptively selects routing based of the changes of the network, as well as the different priorities. Finally, it proposes a forecast strategy about the mobility of the node, which real-timely updates the location information of the routing table, makes the path optimal and reduces the packet loss rate as far as possible.Analysis and Simulation studies show that the proposed QoS routing protocols can improve the successful ratio of routing. It also can get short routing path, low routing delay and have good performance in large scale networks.