Design And Optimization Of Software Defined Mobile Ad Hoc Network Media Access Control Protocol

In recent years,Mobile Ad Hoc Network(MANET)has been widely used in many fields such as crisis response,military applications,Internet of Vehicles,and home or office networks.In the MANET network,nodes make communication decisions independently in a distributed manner,which will make the centralized management of the network difficult.And users are no longer satisfied with basic data transmission,but expect high-level information processing and customized services.Some scholars combined Software Defined Network(SDN)and Mobile Ad Hoc Network to solve the above problems,and proposed a new network architecture of Software Defined Mobile Ad Hoc Network(SDMANET).In SDMANET networks,SDN centralized control is challenged by inherent problems such as the low data rate of MANET network channels,limited network bandwidth and complex network environment.Therefore,the SDMANET link protocol also needs to be designed and optimized for the new network architecture.Based on the existing SDMANET network architecture,this paper divides the network into a basic network layer and a control layer through control channels and data channels,and focuses on the media access control protocol of the two channels.Both protocols use the idea of Software Defined Media Access Control(SDMAC),and use applications to control the timing of nodes obtaining wireless media to send data,so as to achieve a more flexible way to coordinate message transmission in the network.The main work of this paper is as follows:Firstly,in order to cope with the continuous changes of network topology and improve the stability of the network,this paper proposes a Software Defined Control Channel MAC(SDCC-MAC)protocol in the control channel.In this protocol,the controller determines the nodes that can access the control channel according to the service characteristics and network topology,and allocates time slots for its calculation of the number of time slots through the idea of queuing theory.At the same time,the agreement also reserves competitive time slots to provide emergency plans for network emergencies.Secondly,in order to improve the data plane channel utilization and network throughput,and reduce network control overhead,This paper proposes a Software Defined Data Channel MAC(SDDC-MAC)protocol in the data channel.It is a crosslayer design MAC protocol in which the controller provides a time slot allocation scheme based on service flow planning.The protocol performs centralized time slot allocation based on service flow and global view,which solves the problem of hidden terminals and exposed terminals.By adding a pre-allocation strategy and consistency detection method,the protocol significantly optimizes the access protocol’s performance such as delay and packet loss rate in large-scale scenarios.Finally,this article uses Riverbed simulation software to model the proposed protocol and uses the RYU controller as the SDN controller platform.By designing different simulation scenarios,the performance of SDCC-MAC protocol and SDDCMAC protocol was verified.The simulation results show that the method proposed in this paper is suitable for complex node movement and large-scale network scenarios,and can effectively improve the network delivery rate and throughput.