The transmission delay of realtime video packet mainly depends on the sensing time delay(short-term factor) and the entire frame transmission delay(long-term factor).Therefore,the optimization problem in the spectrum ...The transmission delay of realtime video packet mainly depends on the sensing time delay(short-term factor) and the entire frame transmission delay(long-term factor).Therefore,the optimization problem in the spectrum handoff process should be formulated as the combination of microscopic optimization and macroscopic optimization.In this paper,we focus on the issue of combining these two optimization models,and propose a novel Evolution Spectrum Handoff(ESH)strategy to minimize the expected transmission delay of real-time video packet.In the microoptimized model,considering the tradeoff between Primary User's(PU's) allowable collision percentage of each channel and transmission delay of video packet,we propose a mixed integer non-linear programming scheme.The scheme is able to achieve the minimum sensing time which is termed as an optimal stopping time.In the macro-optimized model,using the optimal stopping time as reward function within the partially observable Markov decision process framework,the EHS strategy is designed to search an optimal target channel set and minimize the expected delay of packet in the long-term real-time video transmission.Meanwhile,the minimum expected transmission delay is obtained under practical cognitive radio networks' conditions,i.e.,secondary user's mobility,PU's random access,imperfect sensing information,etc..Theoretical analysis and simulation results show that the ESH strategy can effectively reduce the transmission delay of video packet in spectrum handoff process.展开更多
Micro-film is a product from the development of mobile media technology based on the network media, and the short and typical screen expression ability and effect are its forms of contents. Different from the communic...Micro-film is a product from the development of mobile media technology based on the network media, and the short and typical screen expression ability and effect are its forms of contents. Different from the communication way of traditional advertising, micro-film advertising has the characteristics of both social networking and video communication. With the creative characteristics of micro-film advertising, the conamunication way of video advertising has been started. In this paper, through the introduction to the advantages of micro-film advertising communication and combining with the development of micro-film in the new period, the application of aesthetic ideas to micro-film advertising is further explored, and then the striking expression effect caused by micro-film advertising is introduced.展开更多
基金supported by the National Natural Science Foundation of China under Grant No.61301101
文摘The transmission delay of realtime video packet mainly depends on the sensing time delay(short-term factor) and the entire frame transmission delay(long-term factor).Therefore,the optimization problem in the spectrum handoff process should be formulated as the combination of microscopic optimization and macroscopic optimization.In this paper,we focus on the issue of combining these two optimization models,and propose a novel Evolution Spectrum Handoff(ESH)strategy to minimize the expected transmission delay of real-time video packet.In the microoptimized model,considering the tradeoff between Primary User's(PU's) allowable collision percentage of each channel and transmission delay of video packet,we propose a mixed integer non-linear programming scheme.The scheme is able to achieve the minimum sensing time which is termed as an optimal stopping time.In the macro-optimized model,using the optimal stopping time as reward function within the partially observable Markov decision process framework,the EHS strategy is designed to search an optimal target channel set and minimize the expected delay of packet in the long-term real-time video transmission.Meanwhile,the minimum expected transmission delay is obtained under practical cognitive radio networks' conditions,i.e.,secondary user's mobility,PU's random access,imperfect sensing information,etc..Theoretical analysis and simulation results show that the ESH strategy can effectively reduce the transmission delay of video packet in spectrum handoff process.
文摘Micro-film is a product from the development of mobile media technology based on the network media, and the short and typical screen expression ability and effect are its forms of contents. Different from the communication way of traditional advertising, micro-film advertising has the characteristics of both social networking and video communication. With the creative characteristics of micro-film advertising, the conamunication way of video advertising has been started. In this paper, through the introduction to the advantages of micro-film advertising communication and combining with the development of micro-film in the new period, the application of aesthetic ideas to micro-film advertising is further explored, and then the striking expression effect caused by micro-film advertising is introduced.
