Energy-Efficient Multi-User Routing In A Software Defined Multi-Hop Wireless Network

Software-defined networking(SDN)is an innovative architecture,and the main idea of SDN is to separate control plane and data plane to realize the separation of data and control.SDN designs a logical controller to manage and program the network based on the global view,providing more efficient management,better performance,and higher flexibility for the network.Therefore,applying the SDN concept in a multi-hop wireless network(MWN)can overcome the challenges of MWN.Compared with the traditional multi-hop wireless network,Software-defined multi-hop wireless networking(SDMWN)can monitor the location,remaining energy,current bandwidth and other related information of mobile devices in real time,so as to ensure the quality of service more effectively.In order to realize the data transmission between non adjacent devices in SDMWN,it is necessary to design an efficient multi-user routing algorithm,so as to meet the needs of efficient and reliable communication and improve the utilization of network resources.In this paper,we mainly study the constrained minimization routing for multiple users and propose an energy-efficient global routing algorithm for SDMWN,which is able to get transmission paths for several users at the same time to minimize the global energy consumption with the premise of satisfying the QoS required by users.In the research of routing algorithm,only the impact of delay constraint on data transmission is often considered.However,combined with the actual application scenario,the amount of data and the acceptable transmission delay are different when users transmit data.If the size of data is small,the transmission time will be relatively small.On the contrary,if the size of data is large,the transmission time will be longer.In this case,the mobility of nodes in the transmission process may affect the stable transmission of data.Therefore,according to the size of data transmitted by users,the impact of other constraints on data transmission should be considered in the routing algorithm,this paper proposes that: for the transmission request with small amount of data,only single constraint minimization based on delay is considered;for the transmission request with large amount of data,multi-constraint minimization based on delay and link break rate is considered.In this paper,the multi-user constraint minimization problem is decomposed into a combination of multiple single user constraint minimization problems,so as to reduce the difficulty of solution.Therefore,there are two steps to solve the above problems: in the first step,the K-Lagrange algorithm,which combines the constraint routing algorithm based on Lagrange relaxation and K-Dijkstra idea,can obtain the candidate path set of each user in polynomial time,in which each candidate path set contains K least energy consumption paths satisfying the user's service quality;in the second step,an improved heuristic genetic algorithm is proposed,which is used to select a path from each user's candidate path set and combine them to get a routing scheme with the lowest global total energy consumption and no duplication of transmission nodes.According to the number of constraints of K-Lagrange algorithm,the above methods can be named KLG algorithm and MKLG algorithm.They can be applied to two application scenarios : single constraint energy consumption minimization routing and multi constraint energy consumption minimization routing.KLG algorithm can solve the single constraint energy consumption minimization problem of multi-user with small amount of transmission data and MKLG algorithm can solve the multi-constraint energy consumption minimization problem of multi-user with large amount of transmission data.The simulation results show that the proposed KLG algorithm and MKLG algorithm have the ability to obtain the approximate optimal solution with lower time cost and has better solution efficiency and performance.