In wireless ad hoc networks, the resources such as bandwidth, power, computing ability, etc., for end users are limited by the environments and hardware. In addition, the mobility of each user is different. Furthermore, the varied wireless networks with different properties such as transmission rate, coverage, power and protocols make it rarely difficult to establish and maintain the communications through the multiple intermediate nodes which are mobile devices. This dissertation will focus on the following three issues: 1. Most homogeneous wireless networks only considering one or less resources of the mobile device can not select and distribute the routes. In addition, it can cause the load of the intermediate nodes to increase. 2. The various wireless networks have different characteristics of resources. The route selection and distribution algorithms proposed before in homogeneous wireless networks are not adapted for the heterogeneous wireless networks. 3. Most route selection and distribution algorithms are designed for specific type of wireless environments (such as only for proactive type or reactive type). For different environment and different mobility, its cost will be different. To allow an environment-aware based adaptive management for heterogeneous wireless networks with different characteristics of resources becomes an important issue. In homogeneous wireless ad hoc networks, the resources of the mobile devices such as bandwidth, power, computing ability, etc., are limited and different by the environments and hardware. To evaluate the individual resource of each mobile device, the route distribution and selection algorithm considering the multiple resource variations in wireless ad hoc networks is proposed. First, the evaluation and management for individual resource of each mobile device such as bandwidth, power, and computing ability, are proposed. Second, according to the proposed algorithm, a mobile device can be estimated whether it supports the QoS or not. In addition, these resources evaluation results are transformed as the bottleneck resource information. At last, according to the bottleneck resource information of all the found routes, the route distributed through different intermediate nodes with most resources is selected for load distribution and balance. Considering the wireless network infrastructure today including 3G wireless communication, IEEE 802.11 wireless local area network, and wireless ad hoc networks, the characteristics such as transmission rates, bandwidth, power consumption, and transmission range of these wireless structures are not the same. In other words, the routing selection algorithm for homogeneous wireless networks may not be flexible for another wireless network. In this thesis, these different wireless network structures are integrated into one heterogeneous wireless network. Individual characteristics such as transmission rates, bandwidth, power consumption, and transmission range of these wireless structures are evaluated. According to the adaptive resource evaluation and route selection algorithm for the heterogeneous wireless networks, the route with the lowest cost and most resources is selected based on the integrated information of each resource estimation and the bottleneck information of each route found. Besides considering the characteristic of the heterogeneous wireless networks, the module (type) of the route selection and distribution algorithms also induces different costs and performance. The existing algorithms can be defined and divided into two typical types: proactive (table-driven) protocol and reactive (source initiated) protocol. The proactive type protocol pays the memory and periodical update (bandwidth consumption) costs for selecting the routing directly. In opposite, the reactive type protocol saves the costs but may increase the overhead for finding a routing path to the destination. To decrease the total costs of finding and maintaining routing paths, the environment-aware based adaptive management for heterogeneous wireless networks is proposed in this thesis. Corresponding to the movement of the users, the appropriate type of the routing algorithm should be selected for reducing the total costs of finding routing paths. In the adaptive management, we propose the type selection process to individually evaluate the cost of the two type protocols (proactive and reactive) via considering the protocols and the mobility of the users. According to the evaluation results, the appropriate protocol with less cost will be selected for finding and maintaining the routes in the heterogeneous wireless networks. According to the simulation, the routing selection and distribution algorithm proposed in this dissertation can not only effectively distribute the routing paths but also balance the load within homogeneous or heterogeneous wireless networks. Corresponding to the mobility of the users, the suitable type of routing protocol can be selected. Furthermore, the cost for routing paths searching, selection and maintenance is decreased. The block rate of these routing paths is reduced. Overall, according to the simulation, this dissertation makes the major contributions as follows: 1. The individual resource evaluations and managements for the mobile devices in the homogeneous wireless networks are proposed. The routes which satisfy the QoS can be selected and distributed according to the proposed algorithm. 2. The various wireless networks with different are integrated into a heterogeneous wireless network. The route search, selection, and maintenance algorithm for the hybrid properties heterogeneous wireless networks is proposed. 3. The classification to separate and classify the route search and selection algorithms is proposed. Corresponding to the mobility of the users, the environment-aware based adaptive management for heterogeneous wireless networks is proposed to reduce the costs caused by route search, selection, and maintenance.

WiMAX (Worldwide Interoperability for Microwave Access) provides wide transmission range and broadband network services. However, in IEEE 802.16 standard, there is no specific definition for SS (Subscriber Station) to select an optimal route in a mesh-based WiMAX network. In this thesis, we propose an Optimal Route Selection Scheme (ORSS) for SS to select a route to its BS (Base Station). ORSS basically considers three influential factors, the bandwidth SS to be assigned, the number of interference nodes around SS, and the hop counts to BS. We also investigate QoS (Quality of Service) issue in a mesh-based WiMAX network; an SS transferring the rtPS traffic type will share bandwidth with the neighboring SS of the same level that transmit the same traffic type. To ensure the selected route that can meet the bandwidth requirements of rtPS and the delay constraints, we estimate the average transmission delay from SS to BS. For the purpose of evaluation, we establish a mathematical model to analyze the proposed ORSS and discuss the impact of varying network parameters on the successful rate of route selection. Through the Matlab simulation, we validate our mathematical model. The simulation results demonstrate that our ORSS, in comparison to a previous work, is more effective in ensuring the delay constraints when selecting a route to transfer rtPS traffic.

Recently, according to people's requirements for safe and congestion-free driving in the public transportation system, the intelligent transportation system (ITS) has been widely concerned. To achieve a safe and time-saving driving experience in ITS, various data sharing methods are proposed to provide traffic information for drivers to perceive their surrounding driving environment. However, the high dynamic characteristic of the vehicular network (VNET) results in a challenging environment for establishing stable communication among vehicles. To face this challenge, a Cellular network-assisted Reliable Traffic-Aware Routing protocol (CRTAR) is proposed in this thesis to provide support for vehicle’s data routing process in a heterogeneous vehicular-cellular network environment. In the method, city-wide traffic information, i.e., traffic density and data transmission density of the road segments, is introduced into vehicle's data routing process to assist the vehicle in selecting the optimal data transmission route to deliver data packets. To further improve the stability of inter-vehicle communication, the link lifetime between vehicles is also considered to select the next forwarder that can establish relatively robust communication. CRTAR takes advantage of the reliability and low-latency features of the communication technology in the cellular network and combines the cellular network with VNET to achieve real-time and reliable Vehicle-to-Infrastructure (V2I) communication. Meanwhile, it realizes the Vehicle-to-Vehicle (V2V) communication by the Dedicated Short Range Communication (DSRC) to mitigate the overload of backbone resources caused by using the cellular network. To be specific, in the method, vehicles can request city-wide traffic information via the cellular network from a cloud service that is connected to the remote data center located in the traffic management agency without latency. According to the real-time traffic information, the source vehicle can execute the data routing process with a global view of the system to calculate the data transmission route that has sufficient transmission resources to the target vehicle. The source vehicle then transmits data to the target via the vehicles in the calculated transmission route. During the forwarding process, vehicles prefer to forward the data packet to the next vehicle with a longer link lifetime. Furthermore, effective backup and recovery strategies are designed for route maintenance. The effectiveness of CRTAR is further verified by conducting simulation experiments.

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<p>In today’s fast-paced data-driven world, accumulating and organizing streams of high-resolution information plays a vital role in numerous decision and design tasks. The transportation sector is a prime example of this. Fine-scale information on traffic exposure at specific observation periods is critical to the successful analysis of road safety. Annual Average Daily Traffic (AADT) and hourly traffic volumes represent essential statistics to predict crash risk under time-dependent conditions, such as, weather and seasonal traffic variations. State highway agencies including the Indiana Department of Transportation (INDOT) collect traffic count data using multiple permanent and coverage count stations. However, approximately ten percent of the local-administered road segments in Indiana are included in their database. To impute the missing data, predictive models that can accurately forecast AADT and consequently, hourly traffic volumes, will be of great value.</p> <p><br></p> <p>To address this problem, this thesis proposes a methodology to predict traffic volumes in different classes of urban road segments in Indiana. Two sets of regression models have been developed: (1) AADT Estimation Model, and (2) Hourly Traffic Volume Model. These models include effects of spatial and temporal variations, land use, roadway characteristics and, previously-overlooked in such models, road network connectivity and route selection. These, in turn, address two important research questions: (1) how trips are generated and (2) how people choose routes. The spatial and temporal effects that were considered in the analysis are travel propensity, travel time excess index, road class, hour of day, day of week and seasonal variations. While travel propensity captures particulars of network connectivity and land-use characteristics in traffic analysis zones (TAZ), the travel time excess index accounts for commuters’ route-choice. The estimation results indicate that all these variables are strongly correlated with traffic volumes on considered roadways. Reasonable estimations of hourly traffic volumes on a network scale can be achieved using the proposed model. In addition to aiding safety management at disaggregate level, hourly traffic predictions can help highway agencies in other system-wide analysis where such traffic information is needed.</p>

Mobile Ad Hoc Networks (MANETs) are a class of infrastructure less network architecture which are formed by a collection of mobile nodes that communicate with each other using multi-hop wireless links. They eliminate the need for central management, hence each node must operate cooperatively to successfully maintain the network. Each node performs as a source, a sink and a router. Future applications of MANETs are expected to be based on all-IP architecture, carrying a multitude of real-time multimedia applications such as voice, video and data. It would be necessary for MANETs to have an efficient routing and quality of service (QoS) mechanism to support diverse applications. This thesis proposes a set of cooperative protocols that provide support for QoS routing. The first is the on-demand, Non-Disjoint Multiple Routes Discovery protocol (NDMRD). NDMRD allows the establishment of multiple paths with node non-disjoint between source and destination node. It returns to the source a collection of routes with the QoS parameters. The second part of the protocol is the Node State Monitoring protocol for the purpose of monitoring, acquisition, dissemination and accumulation of QoS route information. The third part of the protocol implements the QoS route selection based on a Genetic Algorithm. The GA is implemented online with predetermined initial population and weighted-sum fitness function which operates simultaneously on the node bandwidth, media access delay, end to end delay and the node connectivity index (NCI). The term node connectivity index is a numerical value designed to predict comparatively the longest time a node-pair might be connected wirelessly.