This diploma thesis aims to study VANET (vehicular ad hoc network), to describe the theory of this networks and describe attributes of these networks and to set the starting point for practical part. Thesis includes VANETs possibilities, its signal transportation and description of routing protocols. Another goal was to familiarize program NS-3 and set up simulation models in its interface. The main output of the practical part is program which simulates vehicle movement in Brno city and set the communication module which is adapted to fulfill the most realistic transmission capabilities. Practical part is divided to two parts. The goal of the first one was to simulate basic communication in theorized unrealistic scenario and the second part was the more realistic scenario. Overall, throughout the practical part was tested a variety of attributes, such as mobility models, standards, routing protocols and other parameters that provided diversity in final results. All the results, which consisted of summary of basic transmission capabilities and reclassification of the applicability of those technologies in real world, are discussed in the summary of the simulations output.

Information dissemination is an important issue for mobile ad-hoc communities. This issue is very challenging due to the dynamic and fragile nature of the mobile ad-hoc networks, in which participants have limited computing resources and battery, intermittent network connections, and mobile tasks. To address the aforementioned issue, this thesis proposes an efficient semantics-based publish/subscribe strategy. In our proposed publish/subscribe system, distributed mobile participants are organized into clusters based on their location proximity. A compact semantics-based indexing scheme is provided to guide information flow. Intra- and inter- cluster routings are proposed to assist efficient propagation of event notifications. A comprehensive set of simulation experiments prove the effectiveness of the proposed scheme.

Tato diplomová práce se zabývá metodami pro výběr nejbližší RTP proxy k VoIP klientům s použitím IP anycastu. RTP proxy servery jsou umístěny v síti Internetu a přeposílají RTP data pro VoIP klienty za síťovými překladači adres(NAT). Bez zeměpisně rozmístěných RTP proxy serverů a metod pro nalezení nejbližšího RTP proxy serveru by došlo ke zbytečnému poklesu kvality přenosu médialních dat a velkému zpoždení. Tento dokument navrhuje 4 metody a jejich porovnání s podrobnějšími rozbory metod s využitím DNS resolvování a přímo SIP protokolu. Tento dokument také obsahuje měření chování IP anycastu v porovnání mezi metrikami směrování a metrikami časovými. Nakonec dokumentu je také uvedena implemetace na SIP Express Router platformě.

The first part focuses on general routing of computer networks. It describes the importance of routing, basic elements, algorithms and protocols. It also describes the so-called MANET networks, where there are discussed routing protocols in these networks. The next chapter deals with the analysis of routing protocols OSPF version 3 and OLSR protocol. For both protocols basic algorithms, their use and structure are described. In OSPF protocol there is also described historical development and differences between versions 2 and 3. The OLSR protocol properly describes the principle of MPR nodes, which is one of the most important parts of the protocol which differs it from the others. Next there is a brief introduction of a powerful simulation tool OPNET Modeler which allows simulating the operation and behavior of almost any computer network with a very extensive possibility of options for the functioning of the entire network, as well as nodes it selves. The practical part is divided into five parts. The first section describes the structure of process models, the basic elements, variables, and block editors OSLR routing protocol in OPNET Modeler program. The second part is devoted to the ICI data structure, which is used for inter-process communication and verify the creation and reception of messages using this function. The third part deals with the process model of OLSR routing model. There is a description of various blocks and functions involved in its function of protocol and significance. The fourth chapter shows an extension of data unit protocol OLSR HELLO messages to other fields, which is able to transmit a numeric value between neighboring stations, and these values print it in the console. The last block of the practical part is dedicated to creating its own message which is broadcast between stations like part of the OLSR packet messages. This message includes the parameter of actual data traffic rate of each communicating stations. These values are for each station exported to an external file for later processing.

The master thesis „IP traffic performance“ is focused on traffic testing in IP networks. Theoretical section explains routing issue in an autonomous system. This work contains a detailed description of OSPF protocol. This work also deals with behavior of a link failure. There are described mechanisms that are used to link failure detection and subsequent traffic rerouting. The next section describes mechanisms to ensure quality of service. In master thesis are explained InterServ and DiffServ mechanisms. A large part is devoted to DiffServ mechanism that ensures distinction of data flows and classification packets into different classes. The routers than can process the individual data streams with different priorities. The practical section includes the design of experimental network and creation of simulation in Opnet Modeler. By using several scenarios are compared the characteristics of routing protocols and impact of QoS on the transmission characteristics of the network. Part of practical section is the improvement of OSPF protocol by adding a new metric and implementing a new metric in software suite Quagga.

Support of multicast routing and its implementation is one of the main goals in nowadays computer networks. Adapting new technology could be often challenging and connected with difficulties. For this reason its better to try it in some simulating enviroment and implement it only after successful results of tests and simulations. The aim of this diploma thesis is to familiarize the reader with the multicast routing, describe the possibilities of network testing in OMNeT++ and come up with new multicast routing framework for this discrete simulation tool.

Mobility-Based Routing Overhead Management in Reconfigurable Wireless Ad Hoc Networks Routing Overheads are the non-data message packets whose roles are establishment and maintenance of routes for data packets as well as neighbourhood discovery and maintenance. They have to be broadcasted in the network either through flooding or other techniques that can ensure that a path exists before data packets can be sent to various destinations. They can be sent reactively or periodically to neighbours so as to keep nodes updated on their neighbourhoods. While we cannot do without these overhead packets, they occupy much of the limited wireless bandwidth available in wireless networks. In a reconfigurable wireless ad hoc network scenario, these packets have more negative effects, as links need to be confirmed more frequently than in traditional networks mainly because of the unpredictable behaviour of the ad hoc networks. We therefore need suitable algorithms that will manage these overheads so as to allow data packet to have more access to the wireless medium, save node energy for longer life of the network, increased efficiency, and scalability. Various protocols have been suggested in the research area. They mostly address routing overheads for suitability of particular protocols leading to lack of standardisation and inapplicability to other protocol classes. In this dissertation ways of ensuring that the routing overheads are kept low are investigated. The issue is addressed both at node and network levels with a common goal of improving efficiency and performance of ad hoc networks without dedicating ourselves to a particular class of routing protocol. At node level, a method hereby referred to as "link availability forecast", that minimises routing overheads used for maintenance of neighbourhood, is derived. The targeted packets are packets that are broadcasted periodically (e.g. hello messages). The basic idea in this method is collection of mobility parameters from the neighbours and predictions or forecasts of these parameters in future. Using these parameters in simple calculations helps in identifying link availabilities between nodes participating in maintenance of networks backbone. At the network level, various approaches have been suggested. The first approach is the cone flooding method that broadcasts route request messages through a predetermined cone shaped region. This region is determined through computation using last known mobility parameters of the destination. Another approach is what is hereby referred as "destination search reverse zone method". In this method, a node will keep routes to destinations for a long time and use these routes for tracing the destination. The destination will then initiate route search in a reverse manner, whereby the source selects the best route for next delivery. A modification to this method is for the source node to determine the zone of route search and define the boundaries within which the packet should be broadcasted. The later method has been used for simulation purposes. The protocol used for verification of the improvements offered by the schemes was the AODV. The link availability forecast scheme was implemented on the AODV and labelled AODV_LA while the network level implementation was labelled AODV_RO. A combination of the two schemes was labelled AODV_LARO.

This report presents a solution procedure to accomplish efficient routing of vehicles. Specifically, the routing of delivery trucks to transport bulk poultry feed from a single feed mill to various customer farms located in the surrounding region at nearly 50 miles radius was studied. The goal was to minimize the total distance traveled for all routes. The project was divided into two phases. In the first phase, truck delivery records were developed through a system of forms over a period of one week at Purdue, Inc. of Salisbury, Maryland. These records were used for preparation of the data required in the second phase of the project. In the second phase, the 'Sweep' Algorithm by Gillette and Miller was used to generate truck routes on a digital computer. The results obtained through the recommended solution procedure were compared with the routes designed by the dispatcher at Purdue, Inc. These results showed significant savings in total distance traveled over all routes. / Master of Science

Optimized Routing and Scheduling (RS) for mobile caregivers is essential for the efficient management of Home Health Care services. Unexpected events, such as traffic jams and visits lasting longer or shorter than expected, may affect the initial caregiver’s schedule by delaying or accelerating visits. Therefore, the RS should be continuously updated to deliver services that respect the problem constraints, e.g., patients’ and caregivers’ availability, caregivers’ breaks, etc., while minimizing the total costs of services. The services costs include travel, overtime, time exceeding patient time windows, and working time differences among caregivers. In this research, we formulate and solve a mixed-integer linear programming RS model that considers delays and earliness throughout the day. Once delays or earliness arise, we propose a rescheduling approach capable of updating the current schedule to consider the time difference and instantly provide a new optimal outcome. Results show a decrease in total costs in 48% of the cases, with an average saving of 349$ per day when rescheduling patients. 15% of the cases present an increase in total costs by an average of 143$ per day. No change is observed in 37% of the cases. Finally, when applying the rescheduling approach, results show that larger time windows provide more significant savings when delays are observed throughout the day.

FPGAs provide parallel computing that is fit for speeding up the computation of a large range of problems. Programming an FPGA involves a complex tool flow for which several CAD tools have been developed. These tools compute solutions to many problems such as packing, placement, and routing, which map a circuit design onto an FPGA. These computations require a great deal of memory, of which the Routing Resource Graph contributes the most of any individual data structure. If the RRGraph could be represented in a more compact manner, performance of the tool flow algorithms may be improved due to an increase in memory caching benefits. This work presents four variations on RRGraph folding which vary in memory usage reduction and runtime, with the most aggressive method reducing the RRGraph size by up to 4x while maintaining similar performance to the original representation.