Research And Design Of Routing Algorithm For Underwater Sensor Networks

As a newly arisen network technique, underwater sensor networks (UWSNs) are products of global network technology popularization. So more and more attention is paid to the research of underwater sensor network, and scholars both at home and abroad have done a lot of in-depth research on it. Generally composed of underwater sensor nodes, autonomous underwater vehicles and surface stations that provide radio communication links to on-shore stations, UWSN is kind of underwater wireless communication networks. It illustrates a good prospect of application on long-term monitoring of marine environment information, pollution monitoring, disaster prevention, assisted navigation and positioning underwater, marine surveying, mine detection and underwater target detection, tracking and positioning.Due to the particularity of the underwater environment, such as long transmission delay, severe multi-path interference, strong environmental noise, limited available bandwidth of channel, all of these factors seriously interfere with data transmission rate, reliability of data communication, communication range, network throughput and energy consumption of UWSNs. So full consideration is required to give on node energy saving, maintaining a quick, correct and effective data transmission, extending the network life cycle when the routing protocols for underwater sensor networks are studied.The paper carries on research and design on routing algorithm for UWSNs. To increase energy-consumption efficiency and extend network lifetime, a time-slicing based routing algorithm (TSR) is proposed. We design a probability balanced mechanism, apply it to TSR, and propose a time-slicing based balanced routing algorithm (TSBR). To meet the requirement of further reducing node energy consumption and extending network lifetime, the theory of network coding is introduced to TSBR. So a time-slicing balanced routing algorithm based on network coding (TSBNC) comes into being. What the paper studies is listed as follows.1. The paper presents TSR by making a series of improvements on flooding protocol and. To avoid conflict, only when their own time-slices come, nodes begin to send data packet. In the process of routing establishment, nodes do not need to reply to their parents individually; instead they directly broadcast routing messages which incidentally can be the ACK to reply to their parents. In this way, more time and energy can be saved to quicken routing establishing process.2. The TSBR is put forward by bringing a probability balanced mechanism into TSR, and puts forward. In the process of routing tree establishment, this algorithm continually compares the number of child nodes of every neighbor node, and dynamically adjusts the number of child nodes of each sub-tree according to the designed probabilistic balancing mechanism, so that routing can achieve balance in probability, thus making energy expenditure of each node more balanced and the network life cycle longer.3. By introducing network coding theory into TSBR algorithm, we propose TSBNC. In this algorithm, all packets that every intermediate node receives are encoded to integrate redundant packets before they are forwarded. Thus it will cut down data bulk in transmitting, as well as further reduce node energy consumption, increase efficiency of network bandwidth utilization and effectively extend network life.At last, a testing experiment for TSBNC is processed to analyze and evaluate its performance. The results show that the proposed protocol can reduce the probability of nodes confliction, shorten the process of routing construction, balance energy consumption of each node and effectively extend network life cycle.