水产养殖参数无线测量网络的长生命周期研究

在水产养殖参数的无线测控网络中,测量节点能耗不均匀,个别节点由于能耗大过早失效,降低了网络的有效生命周期。该文对采用平面路由协议和低能量自适应分群分层路由协议(LEACH)的测控网络进行对比试验,发现采用LEACH协议网络的有效生命周期延长19%以上。在LEACH协议的水质参数测量网络中存在2个缺陷:一方面无线测控网络中每个簇的簇首功耗远远大于普通节点,LEACH协议通过等概率随机选择簇首部分改善了节点能耗的均衡性,但水产养殖参数监控中每个簇首功耗不同,为此在LEACH优化协议中依据节点剩余能量的多少选择簇首,使节点的剩余能量更趋均衡;另一方面水产养殖池中距离基站较远的节点容易提前失效,主要是因为监控面积大,簇首节点与基站采用单跳通信,远距离节点被选为簇首后向基站发送数据通信距离远,路径损耗采用多路径衰落信道模型,衰减指数为4。在优化协议中,对远距离簇首与基站通信采用双跳通信,使路径损耗采用自由空间信道模型,衰减指数为2。试验表明,无线传感网络有效生命周期延长了8%,各节点失效时间更趋接近。

Research on life cycle of wireless network for measuring environmental parameters in aquaculture

Abstract: There were the features of a large area and remote location in large-scale aquaculture farming. The communication cables were needed for wire communication, and it was difficult to promote because of expensive costs. In wireless measuring network, some individual nodes failed prematurely because of uneven energy consumption of the measuring nodes which were energized by a lithium battery. The effective life cycle of the wireless network was reduced due to the premature failure of the nodes. In the paper, the comparison test was implemented between the flat routing protocols and the low energy adaptive clustering hierarchical routing protocol (LEACH), and the results showed that the life cycle of wireless network adopted LEACH effectively extended 19% more than the wireless network adopted flat routing protocols. There were two weaknesses in the wireless network adopted LEACH protocol. Firstly, the cluster heads were selected randomly in LEACH protocol to keep a balance of energy in each node. The power consumptions of the cluster heads were far greater than the ordinary nodes, and the energy consumption in the cluster heads were different. The optimized LEACH protocol was adopted based on residual energy of the node to keep the balance of energy in each node. Secondly, in the conventional LEACH protocol, the nodes far from the base station were easier to fail prematurely in aquaculture, because the monitoring area was large and single hop communication was applied between the cluster head node and the base station. When the remote node was selected as the cluster heads, multi-path fading channel model was adopted in path loss, and the attenuation index was 4. In the optimized LEACH protocol, dual-hop communication was applied between the cluster heads and the base station. Free-space channel model was adopted in the path loss, and the attenuation index was 2. The effective life cycle of the wireless sensor network was extended by 8% by the optimized LEACH protocol.