Analyse And Application Research On Control Plane Protocol Stack Of TD-LTE System

The TD-LTE system control plane protocol stack,as the protocol specification for control signaling in TD-LTE systems,takes a very important role in the entire system.Therefore,the analysis and application of control plane protocols have always been one of the key research directions in the related research of TD-LTE systems.In this paper,we mainly do the following work on the basis of the research of control plane protocol stack: Firstly,after analyzing the attaching procedure,UE initiating service request procedure,paging procedure,VoLTE calling procedure and VoLTE called procedures in TD-LTE system,based on Initial UE message signaling,a wireless signal shielding method during the phase of network attachment is proposed.Secondly,because of the method cannot shield CSBD calling in TD-LTE system,this paper proposed a method of shielding the CSFB call based on the UE context management signaling.The main work of this paper is described as follows:(1)Based on the control plane protocol S1 signaling,a method of shielding wireless signals during the phase of network attachment is proposed.The method can implement signal shielding when the UE performs attaching,UE initiate service request,paging,and VoLTE calling procedure.The method firstly sets the shield user mobile phone number,and then obtain the corresponding international mobile subscriber identity IMSI information and the S-TMSI information of the shielded user mobile phone number.Next,through the S1 interface filtering out the initial UE message signaling,and extracted the user identity information in the initial UE message signaling.According to the data type in the signaling information element,compared the user information of the shielding user with the user information in the initialization user message.Blocking the signaling flow of the shielding user,so as to implement the shielded user's wireless signal shielding.(2)Based on the UE context management message in the control plane signaling,a method of shielding the user CSFB call in TD-LTE system is proposed.The method solves the problem that the first work of this paper cannot shield the CSFB call during the wireless signal shielding method in the network attachment phase.In the method after setting the shield user's mobile phone number information,then obtaining the corresponding user identity information(MME UE S1 AP ID)assigned by the mobility management entity(MME)to the user equipment(UE)in the S1 AP link.Finally,the UE context management signaling including Initial UE Context Response and UE Context Modification Response are filtered through the S1 interface.After extracting the MME UE S1 AP ID information in the signaling,and determining whether the user is the shielded user,change the shielded user original CSFB call signaling procedure,thereby shielding the shielded user's CSFB call.The shielding method proposed in this paper has the advantages of accurate shielding,no electromagnetic interference,and low UE energy consumption compared with traditional methods.The simulation results show that the method proposed in this paper has strongbenefits in UE energy consumption when shielding for a long time.The first method mentioned here,when compared with the traditional method,saves energy consumption up to33% at 30 min.When the time is longer,the advantage will be more obvious;The second method proposed,when the shielding duration is 200 s,the energy consumption of the UE in the proposed method is approximately 45%.With the increase of time,the reduction in energy consumption of the proposed method will further enhance.