Current geocasting algorithms for VANETs are being designed to enable either private or reliable communications, but not both. Existing algorithms preserve privacy by minimizing the information used for routing, and sacrifice message delivery success. On the other hand, reliable protocols often store node information that can be used to compromise a vehicle's privacy. We have designed two private and reliable geocasting protocols for VANETs that ensure confidentiality. One is a probabilistic algorithm that uses direction-based dissemination, while the other is a deterministic algorithm that uses transmission-coverage dissemination. To preserve privacy, we create unlinkable and pseudonymous channels of communication with geocasting. For encryption and authentication, we use a public key technique. Our probabilistic forwarding model depends on message rate and cumulative payload, as well as the value of the angle of spreading of the direction-based scheme. To reduce message duplication, we apply dynamic traffic restriction and probabilistic forwarding techniques. The deterministic forwarding algorithm delays forwarding messages based on its uncovered transmission area after neighbouring nodes have broadcast the message. We prove that both algorithms ensure node privacy with appropriate message encryption security, and we ran simulations to demonstrate that both meet the message delivery requirements. From the gathered data, we observe that both algorithms behave differently depending on the scenario, with node density affecting the deterministic algorithm, while the angle of spreading does have a significant impact on the probabilistic protocol.

Current geocasting algorithms for VANETs are being designed to enable either private or reliable communications, but not both. Existing algorithms preserve privacy by minimizing the information used for routing, and sacrifice message delivery success. On the other hand, reliable protocols often store node information that can be used to compromise a vehicle's privacy. We have designed two private and reliable geocasting protocols for VANETs that ensure confidentiality. One is a probabilistic algorithm that uses direction-based dissemination, while the other is a deterministic algorithm that uses transmission-coverage dissemination. To preserve privacy, we create unlinkable and pseudonymous channels of communication with geocasting. For encryption and authentication, we use a public key technique. Our probabilistic forwarding model depends on message rate and cumulative payload, as well as the value of the angle of spreading of the direction-based scheme. To reduce message duplication, we apply dynamic traffic restriction and probabilistic forwarding techniques. The deterministic forwarding algorithm delays forwarding messages based on its uncovered transmission area after neighbouring nodes have broadcast the message. We prove that both algorithms ensure node privacy with appropriate message encryption security, and we ran simulations to demonstrate that both meet the message delivery requirements. From the gathered data, we observe that both algorithms behave differently depending on the scenario, with node density affecting the deterministic algorithm, while the angle of spreading does have a significant impact on the probabilistic protocol.

The subject-matter of the degree work is an analysis of forwarding and courier services in Czech Republic (the ``Analysis{\crqq}). The Analysis is prepared based on seven biggest forwarding companies in Czech Republic, i.e. Česká pošta, s.p. (Czech Postal Service, a State-owned Firm), DPD, s.r.o., DHL, s.r.o., PPL, s.r.o., TNT, s.r.o., FedEx, s.r.o. and UPS, s.r.o. The logistics are described as a whole in the first part of the degree work, all this upon findings obtained from special literature. The second part of the degree work includes a detailed description of the forwarding services as provided by selected forwarding companies doing business on the Czech Republic territory, an analysis of comparison, incl. The last part of the degree work is devoted to an assessment of data obtained from questionnaires submitted for answers to legal persons (entities) using the services of the forwarding companies subject to the Analysis.

Current geocasting algorithms for VANETs are being designed to enable either private or reliable communications, but not both. Existing algorithms preserve privacy by minimizing the information used for routing, and sacrifice message delivery success. On the other hand, reliable protocols often store node information that can be used to compromise a vehicle's privacy. We have designed two private and reliable geocasting protocols for VANETs that ensure confidentiality. One is a probabilistic algorithm that uses direction-based dissemination, while the other is a deterministic algorithm that uses transmission-coverage dissemination. To preserve privacy, we create unlinkable and pseudonymous channels of communication with geocasting. For encryption and authentication, we use a public key technique. Our probabilistic forwarding model depends on message rate and cumulative payload, as well as the value of the angle of spreading of the direction-based scheme. To reduce message duplication, we apply dynamic traffic restriction and probabilistic forwarding techniques. The deterministic forwarding algorithm delays forwarding messages based on its uncovered transmission area after neighbouring nodes have broadcast the message. We prove that both algorithms ensure node privacy with appropriate message encryption security, and we ran simulations to demonstrate that both meet the message delivery requirements. From the gathered data, we observe that both algorithms behave differently depending on the scenario, with node density affecting the deterministic algorithm, while the angle of spreading does have a significant impact on the probabilistic protocol.

Vehicular Ad hoc Networks (VANET) consist of radio-equipped vehicles and roadside units (RSU) and support many safety and commercial applications. Multi-hop forwarding can extend the communication range of both RSUs and vehicular broadcasts. Recently, the use of Positive Orthogonal Codes (POC) as transmission patterns of repetition-based broadcast medium access control (MAC) for safety messages has been proposed. This thesis proposes a cooperative forwarding protocol in which multiple relays at each forwarding hop form a virtual relay and coordinate their transmission times to correspond to a POC codeword. The protocol thereby exploits spatial diversity while conforming to the POC-based MAC, resulting in fewer collisions and mitigating the effect of hidden terminals. The design is validated through NS2 simulations, which show comparable performance with other forwarding schemes while producing significantly less performance degradation for safety message broadcasts on the same channel.

Vehicular Ad hoc Networks (VANET) consist of radio-equipped vehicles and roadside units (RSU) and support many safety and commercial applications. Multi-hop forwarding can extend the communication range of both RSUs and vehicular broadcasts. Recently, the use of Positive Orthogonal Codes (POC) as transmission patterns of repetition-based broadcast medium access control (MAC) for safety messages has been proposed. This thesis proposes a cooperative forwarding protocol in which multiple relays at each forwarding hop form a virtual relay and coordinate their transmission times to correspond to a POC codeword. The protocol thereby exploits spatial diversity while conforming to the POC-based MAC, resulting in fewer collisions and mitigating the effect of hidden terminals. The design is validated through NS2 simulations, which show comparable performance with other forwarding schemes while producing significantly less performance degradation for safety message broadcasts on the same channel.

In wireless packet-forwarding networks, the nodes or users are always selfish to maximize their utilities in nature. Selfish users would not like to help others for forward each others¡¦ packets, which will cause the network performance degrades severely. To solve the packet-forwarding problem, we propose a novel coalitional game approach based orthogonal decode-and-forward (ODF) relaying scheme to encourage the selfish users for cooperation. In the game-theoretic analysis, we study the properties and stability of the coalitions thoroughly. Furthermore, we prove that the cohesive behavior can be obtained by the aspect of outage probability indeed in this game. Simulation results show that the proposed ODF coalitional game can enforce cooperation exactly and it is always beneficial to form the cooperative groups for all users.

Wireless Sensor Network (WSN) is composed of sink and sensors. Sensors transmit data to sink through wireless network after collecting data. Because multi-hop routing and forwarding may be required on WSN, sensors closer to sink will consume more energy than other nodes due to hop-by-hop forwarding. In this Thesis, we propose pipelined forwarding for cluster-based WSN to solve these problems. First, we divide a WSN into several clusters such that the distance between sensors and sink is reduced and packet transmission delay can be decreased. However, since reducing the distance can increase the number of clusters significantly, multiple mobile sinks are embedded in the system to increase overall throughput. Second, we change the direction of pipelined forwarding to avoid from running out of energy of some sensors. We derive mathematical equations to analyze and validate the proposed scheme. From the analytical results, we prove that the proposed scheme can decrease packet transmission delay. The results also show that system throughput can be improved by increasing the length of pipeline and the number of mobile sinks. Finally, we demonstrate that the proposed scheme can increase energy throughput more efficiently than conventional non-pipelined forwarding scheme.

Broadcasting is a fundamental primitive in local area networks (LANs).Operations of many data link protocols, for example, ARP (Address Resolution Protocol) and IGMP (Internet Group Management Protocol), must rely on this LAN primitive. To develop the broadcasting service in mobile ad hoc wireless LANs (WLANs) is a challenge. This is because a mobile ad hoc WLAN is a multi-hop wireless network in which messages may travel along several links from the source to the destination via a certain path. Additionally, there is no fixed network topology because of host moving. Furthermore, the broadcast nature of a radio channel makes a packet be transmitted by a node to be able to reach all neighbors. Therefore, the total number of transmissions (forward nodes) is generally used as the cost criterion for broadcasting. The problem of finding the minimum number of forward nodes in a static radio network is NP-complete. Almost all previous works, therefore, for broadcasting in the WLAN are focusing on finding approximation approaches in a, rather than, environment. In this paper, we propose a novel distributed protocol in WLANs to significantly reduce or eliminate the communication overhead in addition to maintaining positions of neighboring nodes. The important features of our proposed protocol are the adaptability to dynamic network topology change and the localized and parameterless behavior. The reduction in communication overhead for broadcasting operation is measured experimentally. From the simulation results, our protocol not only has the similar performance as the approximation approaches in the static network, but also outperforms existing ones in the adaptability to host moving.

Project deals with the legal regulations of freight forwarding contract mainly focusing on the provisions of Civil Code of the Republic of Lithuania as one of the main mandatory instruments regulating the contract mentioned above. The aim of this project is to indicate the peculiarities of freight forwarding services and contract. The article begins with analysis of functions and concept of freight forwarder. As well different titles used for freight forwarding contract are analyzed. The analysis continues with the discussion of freight forwarding contract elements such as contracting parties, their rights and obligations, form of the contract. As well this article approaches comparative analyses of the contract of freight forwarding, carriage and other civil contracts. Freight forwarding and carriage contracts are clearly connected, however, this connection as well as differing aspects are not self evident and in some cases very problematic. The project suggests some essentials that can be used for contract legal evaluation. The article concludes that the freight forwarding contract dissociation from other contract and especially from carriage contract may determinate the liability of the party. In case of international carriage of goods by road the interaction of the mandatory 1956 Geneva Convention on the contract for the International carriage of goods by Road (CMR) and the Lithuanian Civil Code provisions concerning the carriage and freight forwarding in the... [to full text]