| Summary: | 碩士 === 國立交通大學 === 資訊科學與工程研究所 === 97 === The IEEE 802.11p/1609 standards define the WAVE Independent basic service set (WIBSS) for vehicular ad-hoc networks to carry out vehicle-to-vehicle (V2V) communication. However, the design of a WIBSS cannot utilize the multi-channel property of an 802.11p/1609 network. To make use of these channels, an extra protocol is needed to negotiate and synchronize the channel used among nodes, which may complicate the design of the MAC layer.
These observations motivated us to find an easy-to-implement solution for it.In this thesis, we first observed the performances of several common routing protocols (such as, AODV and DSDV) in 802.11p/1609 networks using simulations. From our simulation results, we concluded that transmitting/broadcasting control messages of routing protocols in WAVE Basic Service Sets (WBSSs) is inefficient for routing protocols. To solve this problem, we propose a framework that transmits/broadcasts routing control messages using WSMs while data are still transmitted in WBSSs. Based on this framework, we further propose two MAC-layer WBSS-creating schemes to realize multi-hop data forwarding in WBSS-based networks. We compare the performances of 802.11p/1609 networks using these two WBSS-creating schemes with those of 802.11a networks.
Our simulation results show that the performances of routing protocols under 802.11p/1609 networks can be the same as those over 802.11a networks as long as in 802.11p/1609 networks routing control messages can be transmitted using WSMs. Because 802.11p/1609 networks only use a half of link bandwidth to transmit data, the bandwidth that can be used to transmit data is a half of the bandwidth that can be used in 802.11a networks. However, due to the multi-channel design WBSS-based V2V networks, can outperform 802.11a ad-hoc networks in several conditions.
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