| Recently,the development of increasingly frequent maritime activities,like military,business and scientific research and so on,drives the demand of raising utility for maritime wireless communication networks.However,due to the unpredictable disruption and difficulty to maintain the facility in maritime environment,too many challenges have to be overcome,and the imperatives for building a maritime wireless communication networks are diminishing transmission delay to meet users’ demand and energy conservation to maintain facility run.For these problems,this paper investigates a joint sleeping scheduling and opportunistic transmission scheme in delay-tolerant maritime wireless communication networks to.find a better tradeoff between the energy consumption and the delay.First,a plain delay-tolerant maritime wireless communication networks focusing on delay is modeled,whose validity is confirmed via an algorithm.After that,this paper builds a more complicated delay-tolerant maritime wireless communication networks,in which,specifically,a delay tolerant networking(DTN)node deployed in the ocean receives/transmits data from/to vessels within its communication range.The DTN node is energy-limited and can harvest the renewable energy from the environment.To further save the energy,a long-term energy minimization problem is formulated with the optimization of sleeping scheduling and opportunistic transmission.In order to solve this problem,Lyapunov optimization(LO)is utilized first to reformulate this problem as a multi-objective problem of energy and delay minimization and then the multi-objective problem is solved by convex optimization in each time slot.The proposed online scheduling optimization algorithm does not need to know arrival data as well as harvest energy in advance.Moreover,both mathematical analyses and simulation results demonstrate that the LO and proposed algorithm have satisfactory performances for delay-energy tradeoff problem. |
