An Access Protocol for Urgent Traffic in Wireless Networks Enhanced with Ad Hoc Networking

摘要

The communications environment is currently well organized. Still, it is not easy to handle requirements for urgent communications in a disaster. In a large-scale disaster, it is highly probable that communications functions will be hampered, making access to communication links itself difficult. There is a need for studies directed at assuring robustness and reliability in the emergency communications system. This paper proposes an access protocol for wireless networks in which the centralized control hierarchical network and the horizontal connection ad hoc network are combined. The routing method in which a terminal that cannot directly communicate with the base station (BS) sends urgent data to the BS through neighboring terminals, and an access control protocol for multihopping, are described. In the proposed scheme, the terminal monitors communications in neighboring nodes and dynamically generates a route based on the number of hops to the BS. Evaluations show that the percentage of terminals that can reach the BS by multihopping involving a few hops is significantly improved. It is also shown that the terminal knows the number of hops to the BS in the proposed method, which makes it possible to predict the throughput and the delay time, which is a property suited to urgent communications.