Research On Data Gathering And Routing Protocol In Wireless Networks

Advances in wireless communications and integrated circuits have enabled the development of small, smart and inexpensive wireless sensor devices. We envision that these sensor nodes will be embedded into a multitude of human-carried devices in the very near future. A large number of these mobile devices can be dynamically networked together and form wireless sensor networks (WSNs).In wireless sensor networks, due to the limitation of communication radius, normally data delivery between each pair of nodes should be done by means of multi-hop forwarding and as a result, data gathering and routing protocol play key roles in WSNs. However, because of the characteristics of wireless sensor networks, traditional data gathering and routing protocols can not be applied. Therefore, data gathering and routing protocols become hot topics. Although now there are some achievements, they have various limitations and only apply to specific scenarios. More research should be done for more generic and comprehensive data gathering and routing solutions. This paper analyzes the characteristics of WSN (wireless sensor network), VANET (vehicular ad hoc network) and DTMSN(delay tolerant mobile sensor network) recent years. Based on the summary as well as the characteristics of WSN, comprehensive research has been done on relevant existing routing protocols and there are some achievements and contributions as follows:1. The author presents an agenda based routing protocol, ARP, which uses people's agenda and their social relationships to conduct routing. Since people have varying social roles in the real world, some people may more popular and interact with sink nodes more often than others in the network. Thus in ARP, human is ranked based on their popularity and routing decision is made according to two key variables, which are transmission rankings and communication probabilities of sensor nodes respectively. Moreover, ARP also employs the message survival time to decide message's transmission or dropping for minimizing transmission overhead. The author evaluates the effectiveness of ARP by simulations and compare its performance with previous schemes under a mobility model which combines both the social activities and the geographic movements. Simulation results show that, ARP achieves a relatively longer network lifetime and higher message delivery ratio with lower transmission overhead and data delivery delay than both flooding and LABEL schemes.2. The author presents an efficient event delivery algorithm called Distributed Group Mobility Adaptive Event Delivery (GMED) for Delay Tolerant Mobile Sensor Networks (DTMSN). GMED is to establish group-based event delivery model by effectively finding and then taking advantage of the groups generated during sensor nodes moving, and then lead to improved event delivery performance: On one hand, Inter-Group delivery will be achieved by multi-replica delivery based on its delivery probability to the sink– probability of deliver certain event to the sink successfully. On the other hand, Intra-Group delivery will be performed by single-replica delivery through established transmission path because each node has stable neighbor sets inside group. Meanwhile, delivery priority and dropping strategy will be based on event priority in the queue management. Furthermore, redundant replica control mechanism is also introduced to optimizing replica management as well as minimizing network overload. Simulation results have shown that the proposed GMED event delivery scheme not only achieves a relatively long network lifetime but also the higher message delivery ratio with the lower transmission overhead and data delivery delay than other DTMSN data delivering approaches.3. In this paper, the author presents a distributed cluster-based (DCB) algorithm for a long-lived sensor network. DCB achieves good performance in terms of network lifetime by using a efficient energy saving mechanism, which can balance the energy load to the proper nodes. Simulation results show that DCB outperforms HEED in terms of networks lifetime.