Design And Implementation Of TD-ITE Base Station Self-healing Function

With the development of LTE and the increasing demands of users,the complexity of mobile cellular networks is increasing.In many cases,network maintenance requires the qualified experts to perform corresponding maintenance work and the cost of network equipment maintenance is increasing.In order to cope with the complexity of the network,and to avoid the increase in capital expenditure,3GPP has been developing SON functions.Self-healing mechanism is a large part of the SON content,the purpose is automatically to detect the communication equipment problems and solve the problems.Then,the communication equipments can work properly and avoid the impact on the user experience,reducing operating costs.In this paper,the self-healing function of TD-LTE base station is selected as the research topic.Aiming at the problems in peacetime,the self-healing scheme of three different problems of base station is designed.The main contents can be summarized as follows:(1)Design for Detecting and Recovering Sleeping Cell in LTE Systems.In order to detect the sleeping cell and recovering it,this paper proposes a scheme to detect the cell which may be a sleeping cell basing on detecting the change of RRC connections and the GTP-U messages in and out the eNodeB.Then eNode B sends the cell ID to OMC and OMC bases on KPI of neighbor cell UE handover conditions to judge whether the cell is a sleeping cell or not and then the eNodeB is automatic to recover the sleeping cell.Conducted practical tests based on the actual networks,the result shows that the schemes can effectively detect the sleeping cell and recover it.(2)Application Scheme of RRU Ring Network in eNode B.In the scheme,the application scenario and network layout of RRU ring networking are introduced.RRU ring network can be divided into working within a eNodeB and working between two eNodeB.When a link broken occurs,the RRU ring network can quickly detect the link broken and start the self-healing process.The self-healing process of RRU ring working between two eNodeB send message through the OMC to the opposite end of the eNodeB to complete self-healing process.Finally,the effectiveness of the RRU ring networking is verified through practical networking.(3)The 1588 clock part of the eNodeB is designed.First introduced the 1588 clock source,and then introduced 1588V2 protocol,according to the 1588V2 protocol that the eNodeB's 1588 master clock and 1588 slave clock is designed.The eNodeB's 1588 master clock needs to add external GPS clock information.First through the soft lock master clock frequency,and then read the GPS TOD information to adjust the 1588 clock time information.When the e NodeB acts as a slave clock station,it monitors the external 1588 synchronization packet,analyzes the time stamp,calculates the time offset between the master clock and the slave clock,writes time stamp and offset into the slave clock eNodeB.Then the slave clock can output correct 1PPS to lock VCO so that the slave clock can be synchronized with the master clock.The BMC algorithm is designed for the eNodeB's slave clock.When some external clock source is lost,the network can not be affected by the clock synchronization and the device can work normally.Finally,the effectiveness of the scheme is verified by using several eNodeB as master clock and slave clock to making synchronization network.