A MANET Delay Guaranteed Protocol—DGCOP

As an emerging technology,Mobile Ad Hoc Network(MANET)can provide users with communication services without relying on any physical infrastructure.Because of the convenience of MANET,there are more and more data types transmitted by MANET,which requires higher transmission quality of MANET.For example,when transmitting audio and video data,MANET is required to ensure the real-time transmission.Because of the mobility of MANET nodes,the network topology will change unpredictably over time,which makes it more difficult to guarantee the delay of data transmission in MANET.In this paper,a MANET delay guaranteed cross-layer optimization protocol(DGCOP)is proposed.The main contributions of this work are summarized as follows:1.A set of delay guaranteed mechanisms is proposed to solve the problem of unstable transmission delay due to topology changes in MANETs.It includes pre-allocation mechanism,dynamic time slot resource scheduling mechanism and dynamic delay task allocation mechanism.The pre-allocation mechanism is based on the constructed node queue model,which predicts the remaining time for packets to reach the destination and initially determines whether the user’s demand can be met.The dynamic time slot resource scheduling mechanism is based on the user’s expected delay and the size of the business flow to the current node,calculates the number of slots required,and dynamically requests or releases slots to reduce resource wastage.The dynamic delay task allocation mechanism is used to respond to unexpected situations in the network and dynamically adjust the user’s expected delay on some nodes,which is complementary to the dynamic time slot resource scheduling mechanism.The experimental results show that this set of mechanisms can provide delay guaranteed service for data transmission and produce a lower packet loss ratio during node movement.2.An Access Control Self-Adaption(ACSA)queue scheduling mechanism is designed at the link layer.This mechanism is used to cope with the situation of resource scarcity in the network,to adjust the priority of some packets in one step,and to forward or discard this packet in advance to provide more transmission opportunities for other packets and stabilize the data transmission delay.The experimental results show that the protocol can complete the data transmission task on time and the packet loss ratio is no more than 15% when the user’s expected queuing delay to be no less than 70 ms.3.A Delay Guaranteed Cross-layer Optimization Protocol,DGCOP protocol,is designed to provide a cross-layer optimization framework for MANET delay guaranteed techniques.In this paper,the Optimized Link State Routing Protocol(OLSR)is chosen as the base protocol at the network layer,and the Dynamic-Time Division Multiple Access(D-TDMA)protocol is chosen as the base protocol at the link layer.protocol.In this paper,we modify them accordingly.The cross-layer signaling format of DGCOP,the maintenance table format of DGCOP and the interaction logic of DGCOP with the network and link layers are designed in this paper.Finally,the above mechanisms are implemented accordingly.4.This paper verifies the effectiveness of the proposed DGCOP protocol based on the OPNET network simulation software.The simulation results show that the DGCOP protocol can provide quality delay guaranteed services for data in MANET.