IEEE 802.11p is currently being developed international standard, which specifies physical (PHY) and medium access control (MAC) protocols for car-to-car and car-to-infrastructure communication and should become a basis for safety-related and infotainment applications in future vehicular ad-hoc networks (VANETs). In VANETs beaconing is one of the most important communication modes, which is used to advertise the presence of a car to its neighbor cars. For different applications timely and successful delivery of beacons containing speed, direction and position of a car is extremely important. In this paper, we present analytical methods for car-to-car communication analysis and investigate the influence of beacon generation rate on the mean beacon transmission delay and probability of a successful beacon reception in the IEEE 802.11p-based network in both saturated and unsaturated cases.

In this paper dissemination algorithms to transfer warning messages from the originator node to the remaining recipient nodes within a specified geographic area are considered. Analytical methods are developed to obtain time-probabilistic characteristics of these algorithms for linear network topology and fixed success probability of one-hop transmission. The applicability of the obtained results to the vehicular ad-hoc networks is discussed.

In this paper, a centralized Telematics Peer-to-Peer (C-TP2P) execution framework and paradigm is proposed to provide efficient and feasible Telematics-centric service discovery. Unlike the close Telematics service discovery system provided by car manufacturers, the proposed C-TP2P is a novel and open framework using the P2P-like paradigm based on our somecast protocol. When a user needs a service on the road, two issues that need to be considered for Telematics service discovery are (1) how to have the candidate list of service providers and (2) how to select suitable service providers from the candidate list. Two main protocols that are proposed in the proposed open framework include the vehicular P2P messaging protocol and the somecast protocol. The vehicular P2P messaging protocol provides the communication mechanism for Telematics service discovery among Telematics central server, users and service providers using our proposed Telematics Service Markup Language (TSML). The proposed service discovery protocol using the somecast protocol consists of service provider search phase, service provider selection phase and service provider subscription phase to achieve service discovery. We also exhibit the performance merits of the proposed C-TP2P Telematics service discovery framework in this paper.

The 802.11p standard has been recently standardized to provide Wireless Access in Vehicular Environments (WAVE). A multi-channel architecture is envisioned to concurrently support both time-sensitive safety-related applications and value-added informative and entertainment services. According to the WAVE specifications, an alternating channel access scheme allows single-radio devices to tune into a common frequency during the control channel (CCH) interval, to exchange safety and control packets, and to subsequently switch to one of the available service channels (SCHs) for non-safety related data exchange. Broadcasting of short-lived packets is largely expected to be used on the CCH to deliver periodic status updates from vehicles and network initialization information. This paper investigates the joint impact of different packet generation patterns and contention window sizes on the delivery of broadcast packets on the CCH by accounting for WAVE channel switching under different traffic load conditions, data rate and packet size values.

This paper spotlights key design features of a novel Gigabit Wireless Mesh MAC protocol (GWM-MAC) for a new class of high-throughput backbone broadband wireless mesh networks operating in 60-80 GHz. The proposed protocol is based on the Spatial TDMA channel access scheme and defines several operating modes. The protocol is designed to serve the needs of a heavy-loaded backbone mesh network with a volatile traffic. GWM-MAC is suitable for transmitting data flows via multihop paths as well as for broadcasts and single-hop communications. For multihop flows-oriented communications the granted-to-requested ratio maxmin resource allocation criterion is utilized allowing fair schedules building in case of the large number of flows with significantly varying resource needs. The proposed protocol is very flexible and can be dynamically configured to serve the actual network needs.