Research Of The Content Dissemination Mechanism In Opportunistic Networks Based On Information And Energy Collaborative Technologies

The key and difficult research of the opportunistic network is how to design some effective strategies to control the content dissemination between energy-limited nodes,based on the dynamic topology,unconnected environment and limited energy of the network.And users can collect the environmental energy or receive the wireless energy signals for the subsequent wireless information transmission(WIT)and wireless energy transfer(WET),when the information and energy collaborative technology(IECT)is applied to the network.Therefore,the IECT can be used in the opportunity network to provide extra energy for the energy-limited network by connecting energy from nature,which is good for sustainable communication between nodes.Moreover,it can coordinate energy balance between nodes,reduce the number of death nodes,and further improve the overall performance of the network by utilizing mobile node contact opportunity for wireless energy transfer.In the background,this thesis launched the research of the content dissemination mechanism in the opportunistic network based on the IECT,including:(1)The existing routing and forwarding mechanism of delay-tolerant content and delay-sensitive content in opportunistic networks is studied,and the advantage and disadvantage is analyzed.Besides,a simple network system based on the IECT is introduced and some primary characteristics of it is illustrated.Finally,some significant problems that need to study of the content dissemination of opportunistic networks based on the IECT are discussed.(2)Applying the IECT to the process of delay-tolerant content dissemination,the energy transfer behavior and the content transfer behavior and the different transmitted power of them are defined in the thesis.Then,the time-social relation intensity and the energy-social relation intensity are defined,according to the historical information opportunity connection record and the historical energy relation record.Considering the moving behaviors,the content transfer behavior and the energy transfer behavior,a new routing forwarding strategy is proposed named time and energy social strength based content dissemination algorithm,based the two social relation intensity.Besides,the simulation results show that the strategy can effectively reduce content dissemination delay and the number of content copies and death nodes and improve the overall performance of the network for the delay-tolerance content dissemination.(3)Using the IECT in the process of delay-tolerant content dissemination,the energy collection process is analyzed,and the forwarding behavior based on energy is defined appropriately.According the forwarding behavior based on energy threshold,the social relationship between nodes and the wireless communication link,the successfully forwarding probability of the content is defined.After modelling the contents dissemination process,an optimization to minimize the content dissemination is proposed with the constraint of slot resource fairness,based on the dynamic allocation scheme of slot resource.According to this optimization problem,the branch and bound method is utilized and a new algorithm named the target oriented search algorithm is proposed.Finally,the simulation results indicate that the new algorithms can effectively decrease the dissemination delay of the delay-sensitive content.