Data communication in wireless ad hoc, sensor and vehicular networks

自组织网络是由无线自治主机组成的多跳无线网络，其中每台主机都可以充当路由器来辅助来自其他节点的流量。传感器网络的应用主要是为了监测环境(如运动和火灾检测、化学物质、温度)或作为嵌入式系统。在车载自组织网络(VANET)中，车辆配备了无线设备，用于与其他车辆和路边单元进行通信。VANET允许车辆集成到智能交通系统(ITS)中。该研究计划集中在adhoc、传感器、执行器、机器人和车载网络的网络层，并采用跨层设计，考虑了现实的物理和介质访问协议以及功率效率。在数据通信问题中，如路由、地理广播、组播和广播(分别从源节点向一个目的节点、一个区域内的所有节点或多个目的节点发送消息)，其主要目标是在自组织网络中的节点之间成功地完成给定的通信任务。次要任务是最小化通信开销(因为无线通信中的带宽通常是有限的)和电池供电节点的功率消耗。传感器网络中还存在各种数据传播、数据收集、数据聚合、机器人辅助或自我放置和重新定位的问题。在VANET中，地理广播用于警告传播，而路由提供基于位置的服务。移动速度的高度变化性和间歇性连接给车载自组织网络中的数据通信协议的设计提出了独特的新挑战。本地化算法，节点根据本地知识做出决策，将提供可伸缩性，这是标准的集中式或分布式解决方案无法实现的。无信标算法不需要邻居知识和寻址节点移动性。简洁性也是我们的重要标准。从单位圆盘图到真实物理层的有用建模的并行推进，为所设计的协议提供了易管理性和接近应用级别。

Ad hoc networks are multi-hop wireless networks consisting of wireless autonomous hosts, where each host may serve as a router to assists traffic from other nodes. The applications of sensor networks are envisioned primarily for monitoring the environment (e.g. motion and fire detection, chemicals, temperature) or as embedded systems. In vehicular ad hoc networks (VANETs), vehicles are equipped with wireless devices for communication to other vehicles and to road side units. VANETs allow the vehicles to become integrated within an Intelligent Transportation System (ITS). This research plan concentrates on the network layer of ad hoc, sensor, actuator, robot, and vehicular networks, and applies a cross layering design, considering realistic physical and medium access protocols and power efficiency. In data communication problems, such as routing, geocasting, multicasting, and broadcasting (sending a message from a source node to one destination node, all nodes in a region, or several destination nodes, respectively), the primary goal is to fulfill a given communication task successfully between nodes in ad hoc network. The secondary task is to minimize the communication overhead (since bandwidth in wireless communication is typically limited) and power consumption by battery operated nodes. There are also a variety of data dissemination, data gathering, data aggregation, robot assisted or self placement and relocation issues in sensor networks. In VANETs, geocasting is used for warning dissemination while routing provides location based services. High variability of mobility speeds, and intermittent connectivity pose unique and new challenges for the design of data communication protocols in VANETs. Localized algorithms, where nodes make decisions based on local knowledge, will provide scalability, which is not achieved with standard centralized or distributed solutions. Beaconless algorithms do not require neighbor knowledge and address node mobility. Simplicity is also our important criterion. Parallel advance of useful modeling, from unit disk graphs to realistic physical layers, provides tractability and approaching application level for designed protocols.