LTE注⽹总体流程-⽇志分析
LTE⼊⽹流程分析，从开机上电搜⽹到注册到⽹络的过程
1.插卡开机上电
2.⼩区选择过程
1.搜索NAS请求的PLMN
2.扫描E-UTRA频带中的所有RF信道以到PLMN（UE可以通过使⽤存储在采集数据库中的信息来优化该搜索）
3.搜索最强的⼩区并读取系统信息以确定PLMN
4.确认⼩区选择标准都满⾜于⼩区(S准则)
5.驻扎在选择的⼩区上
2.1 PLMN选择张国荣 陈志朋
选择PLMN的时候会从SIM卡中读取，及配置⽂件中读取已有的PLMN信息，如RPLMN(上次驻留的PLMN),HPLMN(SIM卡中的HPLMN),EHPLMN(等价的HPLMN，可以在NV65602中配置)等,device_config配置。
// NAS reads PLMN information from SIM
21:18:51.828 reg_sim.c 1836 H CS RPLMN(1-1)
21:18:51.829 reg_sim.c 1576 H HPLMN(001-001)
21:18:51.829 reg_sim.c 2406 H Forbidden PLMN list (length = 4)
21:18:51.829 reg_sim.c 2410 H # MCC-MNC
21:18:51.829 reg_sim.c 2423 H 0 310-017
21:18:51.830 reg_sim.c 2031 H RPLMN RAT Search Order (UMTS-GSM)
2.2 扫频
使⽤频率扫描，UE选择⽤于驻留的频率/ EARFCN。
有两种类型的频率扫描：
1. System scan, also known as List Frequency scan (similar to Acq DB scan)
上层应提供EARFCN列表，请求带宽和双⼯模式到L1
2.Band scan, also known as Full Frequency scan
上层应提供频带索引和L1允许的带宽集
Log Analysis – System Scan
//Automatic service Request
11458 76:00:16:20.595reg_state.c1171HCM_SERVICE_REQ –AUTOMATIC
11491 89:00:16:20.600emm_reg_handler.c475HEMM: Received MMR_REG_REQ
//NAS sends service request to AS
11494 81:00:16:20.600emm_rrc_if.c310HEMM: Sent LTE_RRC_SERVICE_REQ
/
/RRC sends LTE_CPHY_START_REQ to ML1
11537 81:00:16:20.603lte_ml1_mgr_stm.c6923MLTE_CPHY_START_REQ
//LTE AS is initialized
11675 97:00:16:20.620lte_ml1_mgr_cphy_cnf_handlers.c976MLTE_CPHY_START_CNF
Status: 0
11680 89:00:16:20.620lte_ml1_mgr_stm.c12645LL1M: INACTIVE STATE ENTER
//ML1 initiates System Scan request
11704 153:00:16:20.620lte_ml1_sm_main.c1118HSM: Sys Scan Req module 1 num_sys 1
min_sys 0 early_abort 0 sys[0] band 13 earfcn 5230 bw 50
//RF tune request
11705 113:00:16:20.620lte_ml1_sm_main.c641HSM: RX cfg req freq 5230 BW 50 cell_id
65535
Log Analysis – Band Scan
//Acquisition database search (System Scan) is exhausted. No system found李婷个人资料
11497 89:00:47:21.166lte_rrc_csp.c3603HCSP: All entries tried in acq list
11498 81:00:47:21.166lte_rrc_csp.c9373HCSP: Exhausted acquisition list
//Initiate Band Scan
11506 89:00:47:21.166lte_rrc_csp.c2191XCSP: Sending 1 bands in band scan谁是凶手小胡是谁
11507 81:00:47:21.166lte_rrc_csp.c2210XCSP: Sent Band Scan Request
11520 105:00:47:21.175rtr8600_lte.c866HRF LTE RX is tuned to band 13 and frequency 5230
2.3 ⼩区搜索
LTE⼩区搜索实际上就是PSS ( Primary Synchronization Signal ) / SSS ( Secondary Synchronization Signal)同步，实现UE对⼩区的识别和下⾏同步。
//搜索可⽤⽹络
17:33:26.156 reg_state.c 06955 ds1=REG= CM_NETWORK_LIST_REQ
解系统消息
// 设置BCH-PCCPCH来读取SIB
21:18:52.010 rrcsibproc.c 7392 H RRC_GET_SPECIFIC_SIBS_REQ cmd received
21:18:52.012 rrcllc.c 4749 H Sending CPHY_SETUP_REQ to L1 (PCCPCH)
21:18:52.063 rrcllc.c 24825 H Rcvd RRC_CPHY_SETUP_CNF from L1: 1
21:18:52.747 rrcsibproc.c 6503 H Sending GET_SPECIFIC_SIBS_CNF cmd整数包括什么
通过获取PSS / SSS / MIB，UE可以获得参考信号（RS）、位置（基于⼩区ID），并读取到DLSCH中的所有预定SIB
2.4 ⼩区选择
// 评估⼩区选择标准（S标准）WCDMA/L1过滤
21:18:52.750 l1mcmd.c 1223 H Received CELL_SELECTION_REQ
21:18:52.753 srchbch.c 1425 H 2*ecio=-5 2*squal=43 srxlv=18
21:18:52.753 rrcllc.c 27319 H Rcv’d RRC_CPHY_CELL_SELECTION_CNF
21:18:52.753 srchbch.c 1300 H CELL_SEL_CNF 2*sq 43,rxlv 18
21:18:52.753 srchbch.c 1469 H Cell Selection Succeed
2.5 ⼩区驻扎
// RRC⼩区选择过程声明驻扎成功
21:18:52.804 rrccsp.c 10034 H Camped on suitable cellID 0
3.注册过程
3.1 随机接⼊
RRC连接要建⽴，就要进⾏上⾏同步，也就是随机接⼊， 随机接⼊过程参考协议3GPP TS 36.300 10.1.5 Random Access Procedure。周杰强吻林心如
随机接⼊分为竞争和⾮竞争两种：
1） 基于竞争的随机接⼊的场景有： ①从RRC_IDLE状态接⼊②⽆线链路失败发起的接⼊③UE处于RRC_CONNECTED时有上⾏数据要发送；
2） 基于⾮竞争的随机接⼊场景有： ①切换过程的随机接⼊②UE处于RRC_CONNECTED时有下⾏数据到达
关于随机接⼊更详细的介绍可以参考此
3.2 RRC连接建⽴成功
3.3 RRC连接建⽴后发起Attach请求进⾏注册
可以通过过滤OTA消息，清楚的看到注册的信令流程
以下⽇志是NAS层的⽇志
读取配置文件失败17:33:53.904 msg_lib_encode_emm.c 01273 ds1Encoding Attach request
17:33:53.904 msg_lib_encode_esm.c 00550 ds1MSG_LIB: completed encoding PDN_CONNECTIVI
TY_REQ
//发起attach请求，attach msg中包含有PDN的信息，同时会激活PDN
17:33:54.302 emm_security.c 01057 ds1=EMM= Received AUTHENTICATION REQUEST message
//收到⽹络侧的鉴权请求
17:33:54.635 emm_security.c 01476 ds1=EMM= Sending AUTHENTICATION RESPONSE message //鉴权完成
17:33:55.003 emm_esm_handler.c 00616 ds1=EMM= Sending ATTACH_COMPLETE
//注册完成
17:33:55.006 emm_reg_handler.c 02911 ds1=EMM= sent MMR_REG_CNF
17:33:55.010 reg_state.c 07938 ds1=REG= CS_PS_SERVICE on HPLMN(460-0)
//获取到CS PS的服务
17:33:55.010 reg_send.c 00649 ds1=REG= CM_SERVICE_CNF
//注⽹流程完成