The Application Of Adhoc Network On The Hydrological Supervision

With the high-speed development of information technology represented by network and computer technology since 21^st century, especially after the appearance of AdHoc network, the resource of water conservancy information are developed and applied deeply and widely. At the same time, the collection, transmission, storage and disposition of water conservancy information are carried out, improving the transmission effectiveness and accuracy of the information conditions of rain, flood, project, drought and disaster, which offered a scientific foundation to flood prevention and drought combat policy. Finally, a good effect on flood prevention has been gained in the most possibility.AdHoc network is a temporary self-control system without relying on any certain foundation facilities. It is also a monitoring site of water condition which is suitable for solving the problem which the preparative facilities can not be set up in the remote areas.In AdHoc network, the pause of chain-lines is caused by the continuous change of wireless channel and the expanding of network, which leads to the loss of the data package. This demands the agreement on the top-layer application can search the basic transmission one quickly and even the statement information of passageway. Meanwhile, according to the needs, it can also exchange the information between agreements on different layers, make decisions quickly and improve the successful ratio of receiving in a group way. In AdHoc network, the problem is solved which is how to set up the network conversation instantly to implement the transmission and communication among datum, voice, pictures and video information. According to SIP(Session Initiation Protocal) defined by IETF which is a session management protocol in order to support applications such as VoIP, Instant Message etc, this thesis first presents how a certain function of enrolled and agential services are inserted into a linking point of AdHoc network. The users' contact information is received by SIP itself. Thus, the service can be provided on the basis of SIP. In view of it, cross-layer design is adopted, which is compared with the thought of OSI and combines the characteristics of SIP with the particular routing protocol with that of AdHoc network. One of the methods on the basis of SIP is AODV(Ad-hoc On Demand Distance Vector) which is based on the AODV routing protocol and combins REGISTER broadcast of practical SIP to HELLO system of AODV to reduce the number of broadcast. The other method is ZRP on the basis of SIP, which combines REGISTER broadcast of SIP on the application layer to BRP of ZRP under the supporting of ZRP in order to reduce the redundancy of agreement sites, shorten the time of reflecting, save the limited resource of wireless network and achieve the purpose of optimizing a system.The combination of AdHoc network and water conservancy system is the improvement of the traditional water monitoring system with foundation facilities. And it is also connected with AdHoc network to finish the seamless connection of the fifferent structure network. This is an expansion of VOIP network in a certain occasion.