Data Dissemination In Mobile Sink Wireless Sensor Networks

The wireless sensor networks topic has been a very important subject for researchers in the world for many decades until now,and it is still very attractive for more researching.Since the emerging of wireless sensor networks,many approaches and radical changes were proposed,and the wireless sensor networks got more advanced and complicated.The mobility was proposed for these networks,and the mobility could be assigned for the sinks(base stations),or to the wireless sensor nodes,or to both of them.There are many advantages of mobility in WSNs,and one of the main advantages is getting rid of or alleviating the hotspot problem,which happens mostly among the neighbour nodes of the immobile sink.The main objective of this dissertation is to address specific challenges of wireless networks with mobile sinks.The thesis contains two main protocols with four main contributions.The first proposed protocol is the Heuristic Data Dissemination protocol(HDD),and the second protocol is the sink-oriented tree-based data dissemination protocol.The first contribution of HDD is the Double Ring,and it addresses the problem of the frequent location updates of the sink mobility.Additionally,the Double Ring makes the interaction between the sensor nodes and mobile sinks easier and as a result,the network lifetime will be longer.The second contribution of HDD is addressing the problem of the data packet delivery delay,especially from the source sensor nodes to the mobile sinks.The main idea of HDD protocol is considering the whole data routing as a random process,and make the data forwarding under the control of four main values:direction value,transmission distance value,perpendicular distance value,and the residual energy value.HDD proposed many algorithms to accomplish this purpose and the results are good comparing to the state of art protocols.The second protocol is the sink-oriented tree-based data dissemination protocol,and the main part of this protocol represents the third and the fourth contributions.The third contribution is solving two problems.It addresses the problem of the frequent location updates of mobile sinks also but through a tree-based approach.The protocol also addresses the problem of the data packet delivery delay during data dissemination by a tree-based approach also.The fourth contribution of this protocol is the merged paths solution.The merged path solution addresses the high-energy consumption problem during data dissemination from source nodes to the mobile sinks,and the proposed solution for this problem is unique.The second protocol shows better performance comparing to the state of art protocols.The dissertation includes more details about these contributions.