Research On QoS In Mobile Deterministic Network

With the rapid growth of communication demands,a large number of new applications have stringent quality-of-service(QoS)requirements and require that the network can provide high throughput and guaranteed QoS.In 2015,the IETF established a Working Group called Deter-ministic Network to discuss the feasibility of adding deterministic services to Internet.In 2017,Huawei also proposed the concept of Mobile Deterministic Network,to build a mobile commu-nication network that can provide guaranteed QoS for 5G.The relevant drafts state that QoS for mobile deterministic network must be end-to-end,deterministic and high-throughput.To im-prove the QoS performance of mobile deterministic network,this thesis do some researches on network architecture,switch scheduling argorithm and theoretical analysis of DCTCP through-put.Firstly,we study the network architecture of mobile deterministic network,aiming at solv-ing the end-to-end QoS problem in mobile deterministic network.The network architecture of the mobile deterministic network needs to be compatible with the 5G system architecture.But the existing 3GPP 5G system architecture solution does not involve the transport network and adopts a differentiated service-based QoS policy,which cannot provide end-to-end deter-ministic QoS service.Based on the 5G system architecture developed by 3GPP,we propose a multi-controller mobile deterministic network architecture,covering end-to-end 3GPP networks including radio access networks,transport networks and core networks.Together with the multi-controller architecture,new procedures for initial attachment and deterministic service request are also presented.Secondly,we study the scheduling algorithm of the switches to achieve the determinis-tic QoS performance in mobile deterministic network.As the core devices in a switching net-work,the input-queued(IQ)switches are important parts of mobile deterministic network.The scheduling problem of the IQ switches can be mainly divided into two directions:slot-based and frame-based,while both of them are faced with the problem that deterministic transmission and high resource utilization cannot be achieved at the same time.In this thesis,we designe a deterministic switch that adopts a new hybrid queue structure,a novel slot-based scheduling algorithm called Frame Reservation First(FRF).Simulation results show that our deterministic switch can not only reserve bandwidth and provide guaranteed QoS with very low bounded la-tency for some specified deterministic flows,but also share the unused reserved bandwidth to all best-effort traffic to maximize the utilization of bandwidth resources.At last,we theoretically analyze the throughput of the DCTCP protocol,to analyze the impact of packet size on the throughput in the mobile deterministic network edge cloud scenarios.Data center is the physical entity that runs the edge cloud application and the most widely used transport protocol in data center network is DCTCP protocol.At present,the theoretical analysis of the throughput of the DCTCP protocol is still in a blank state.In this paper,We theoretically analyze the throughput of DCTCP protocol and obtaine the theoretical result of the relationship between packet size and DCTCP throughput.Theoretical analysis and simulation results show that increasing the packet size can effectively improve the network throughput in the edge cloud scenario of mobile deterministic network.