Research On Resource Management And Standardization Of IAB Under 5G Ultra-dense Networks

With the continuous emergence of various new services and applications of the mobile Internet and the Internet of Things,it will bring about a surge in data traffic and more than 50 billion terminal device connections.Ultra-dense networks intensive deployment of low-power small base stations in indoor and outdoor hotspots is an effective solution to the explosive growth of 5G mobile network data traffic.However,due to the intensive deployment of backhaul connections based on wired fiber and the high cost,in order to solve this problem,the Third Generation Partnership Project proposed an integrated access and backhaul(IAB)architecture.For 5G ultra-dense networks,the ultra-dense deployment of small cells and the mobility of IAB nodes will bring many problems to be solved.How to use limited resources to obtain greater network capacity and meet the needs of more users is an urgent problem to be solved.In addition,in the ultra-dense network,due to the large-scale deployment of mobile IAB nodes and the real-time changes in the network traffic,there will be lightly loaded nodes or nodes with no service objects,causing unnecessary power loss and interference to other nodes.In the high-speed moving train scenario,frequent switching between donor nodes will cause longer user service interruptions.In response to the above-mentioned challenges,in order to improve network throughput,reduce network energy consumption and reduce user interruption time,this thesis has carried out the following work:First of all,this thesis has carried out the research of resource allocation strategy based on static IAB under ultra-dense networks.Based on the IAB architecture that works in the in-band backhaul under the millimeter wave frequency band,a new resource allocation scheme is proposed,taking into account the co-frequency interference from adjacent IAB nodes and the next generation NodeB and different user rate requirements.Through the joint allocation of spectrum and power on the access and backhaul links,the network capacity can be maximized while the user rate requirements are met.The constructed optimization problem is transformed into a convex optimization problem through logarithmic approximation and first-order Taylor expansion,and the optimal solution is obtained through the proposed resource allocation scheme based on sequential convex programming.The simulation results show that the proposed resource allocation scheme is superior to other schemes in terms of fairness performance,throughput,and spectrum efficiency,and the network capacity is also improved a lot while ensuring user service quality.Then,this thesis carries out the research of handover strategy based on mobile IAB under ultra-dense networks.Aiming at the problem of excessively long user service interruption time caused by node migration,analysis is carried out from different perspectives,and two switching schemes are proposed to realize the enhancement of topology adaptation.The first solution is a handover mechanism between donors based on location prediction.In this solution,the prediction part and the control plane dual connection part are introduced.First perform location prediction;then,based on the prediction results,establish dual connections on the control plane to achieve user service interruption close to 0 milliseconds.The second solution is an inter-donor handover mechanism based on additional pre-notified signaling.After the migrating node receives the radio resource control reconfiguration message and before donor-CU1 sends the SN Status Transfer message,it is possible to add two signaling to make the UE ready for handover in advance s solution.The results show that the proposed topology adaptive enhancement scheme can greatly reduce the UE service interruption caused by the migration of mobile IAB nodes and greatly improve the user's service quality.Finally,this thesis carries out research on energy-saving strategies based on mobile IAB under ultra-dense networks.An energy saving scheme for mobile IAB nodes is proposed,including the deactivation mechanism of IAB nodes based on dormancy information and the activation mechanism of IAB nodes based on service overload or node congestion information.At the same time,two methods for node activation are proposed.The trigger modes are service overload trigger and node congestion trigger,which can more specifically determine whether to activate the IAB node,so as to realize the energy saving of the mobile IAB node.The simulation results show that the proposed energy saving scheme for IAB nodes has little effect on network throughput and can effectively reduce energy loss.