5g信令流程详解

zhen658

中移2.6G频率基础信息配置

D4

D5

D6

D1

D2

D3

D7

D8

D4

D5

D6

D1

D2

D3

D7

D8

[img=41,360]blob:https://www.txrjy.com/cb85e5c3-3bed-45cf-b5f0-bab9eb29b33c[/img]

2515MHz

[img=41,108]blob:https://www.txrjy.com/bd95225f-8ddf-46c1-999d-4409e45c597a[/img][img=41,119]blob:https://www.txrjy.com/7a871f15-ad4d-45c5-86d2-ec72f028077e[/img]

2575MHz

2615MHz

Cell:60MHz

Cell freq:2544.9MHz

Ssb freq : 2523.75MHz

Ssb GSCN : 6309

Cell:100MHz

Cell freq:2565MHz

Ssb freq : 2524.95MHz

Ssb GSCN : 6312

[img=41,360]blob:https://www.txrjy.com/9f5fbe18-605b-4b13-a5e9-85354137af71[/img]

2675MHz

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中移2.6G频率基础信息配置-60M&100M小区SSB对齐

D4

D5

D6

D1

D2

D3

D7

D8

D4

D5

D6

D1

D2

D3

D7

D8

[img=41,360]blob:https://www.txrjy.com/7b8552f1-1218-4f26-9ea6-485cd8acbfec[/img]

2515MHz

[img=41,108]blob:https://www.txrjy.com/82e6c69c-c62a-4df9-96b0-6622c4db2d1d[/img][img=41,119]blob:https://www.txrjy.com/7886d28c-5b99-4cb5-8424-a99b01f7187d[/img]

2575MHz

2615MHz

Cell:60MHz

Cell freq:2545.02MHz

Ssb freq : 2524.95MHz

Ssb GSCN : 6312

Cell:100MHz

Cell freq:2565MHz

Ssb freq : 2524.95MHz

Ssb GSCN : 6312

[img=41,360]blob:https://www.txrjy.com/5c9eb4f8-e99f-433e-89e6-92cb930b4fee[/img]

2675MHz

正在载入…

空口前台关键信令[接入] 简介

[img=212,405]blob:https://www.txrjy.com/999bea19-e579-45f6-86af-09446c8402c6[/img][img=187,247]blob:https://www.txrjy.com/a8c9e0b1-fba9-45b1-9681-cfdf9a4c0704[/img]

LTE接入流程

[img=142,59]blob:https://www.txrjy.com/1eaebb9a-2cb0-4718-87a8-78e735a7b138[/img][img=161,74]blob:https://www.txrjy.com/edf5f4a0-c71f-48e0-ac17-7f82e03d02e6[/img]

NR-B1测量控制

[img=127,69]blob:https://www.txrjy.com/89f1ba14-e3fd-49c3-baa4-ad0c5456dfb6[/img][img=139,95]blob:https://www.txrjy.com/7ee66084-8666-48d8-b472-b311664f9cde[/img]

LTE侧-MR[B1]

[img=198,57]blob:https://www.txrjy.com/845b3488-f194-487a-bc8b-67e6cc2079d9[/img][img=160,60]blob:https://www.txrjy.com/f8e771a6-36c3-4e2c-a011-a22aef49e1d2[/img]

辅小区添加CFG

[img=139,72]blob:https://www.txrjy.com/a60ed422-6b0f-407f-9eb1-e0f44f909fe7[/img]



[img=138,46]blob:https://www.txrjy.com/517ccdb5-98fa-452d-b68f-db2c140cfc80[/img]

4G侧5G测量对象移除

[img=168,74]blob:https://www.txrjy.com/e0d7624b-3f78-44a9-bbb6-16ffc0bed2d4[/img][img=94,46]blob:https://www.txrjy.com/cba660e4-7881-4a8c-ba9e-d8803960e5e1[/img]

NR侧-MR[A2/A3]

[img=168,108]blob:https://www.txrjy.com/8582e70e-aa25-4a1c-a5c5-d8800e3f43d2[/img][img=130,56]blob:https://www.txrjy.com/ff41d27e-2a31-4ebd-9fad-5e89d1745b1c[/img]

NSA初始接入和空闲态转连接态整体信令流程

[img=41,360]blob:https://www.txrjy.com/5c9eb4f8-e99f-433e-89e6-92cb930b4fee[/img]

正在载入…

[img=159,400]blob:https://www.txrjy.com/791c4597-31aa-4034-bd33-b90091b31cc2[/img][img=138,46]blob:https://www.txrjy.com/517ccdb5-98fa-452d-b68f-db2c140cfc80[/img]

LTE侧系统消息解读

[img=139,72]blob:https://www.txrjy.com/a60ed422-6b0f-407f-9eb1-e0f44f909fe7[/img][img=123,92]blob:https://www.txrjy.com/b97fec91-59cc-410b-94ad-38beefb0a66a[/img][img=116,216]blob:https://www.txrjy.com/e6b8d084-fc1c-46c8-89f4-c17f9f659707[/img][img=161,278]blob:https://www.txrjy.com/e72c562f-7934-430a-b8f0-bca9fe3eafa3[/img][img=198,57]blob:https://www.txrjy.com/845b3488-f194-487a-bc8b-67e6cc2079d9[/img][img=452,91]blob:https://www.txrjy.com/951b1d50-c2d6-45c1-a3ef-f306ee957d4d[/img][img=285,121]blob:https://www.txrjy.com/5478e644-8774-4f22-8c29-62bfa6b07abe[/img][img=127,69]blob:https://www.txrjy.com/89f1ba14-e3fd-49c3-baa4-ad0c5456dfb6[/img]

Lte读取到的sib1消息主要检查以下内容：

1、小区支持的PLMN列表：[右侧的示例信令标示站点为46000/46007的双PLMN基站]

2、小区的频段信息：

[右侧信令标示band3]

[img=108,90]blob:https://www.txrjy.com/91ea8f49-bc29-45af-95c6-33d225d24cf7[/img][img=125,50]blob:https://www.txrjy.com/410ea774-ba31-44b5-97a9-47df636d61f4[/img]

Lte读取到的sib2消息主要检查以下内容：

additionalGroupInfo-R15是否存在：目前LTE版本为3.70.20开启endc策略.upperlayerIndication开关=yes的时候，sib2消息带有该内容，ENDC手机解析该内容显示5G图标。

[img=139,95]blob:https://www.txrjy.com/7ee66084-8666-48d8-b472-b311664f9cde[/img][img=159,48]blob:https://www.txrjy.com/cd6f2892-6e81-48e1-82b3-26159a1638f0[/img][img=44,28]blob:https://www.txrjy.com/7b7ec255-1cb4-4486-84f5-90caac94e588[/img][img=46,28]blob:https://www.txrjy.com/c1c4261d-213c-4d8f-9ea1-ef08fa7dd3a2[/img][img=72,65]blob:https://www.txrjy.com/ff8343d5-a385-4125-9323-0cb45f9cab40[/img][img=72,65]blob:https://www.txrjy.com/483e38d9-49aa-46c3-89ab-8101d56a0667[/img][img=72,65]blob:https://www.txrjy.com/1ab67236-0a47-49d8-ad18-0ae03bc0f1f4[/img][img=168,74]blob:https://www.txrjy.com/e0d7624b-3f78-44a9-bbb6-16ffc0bed2d4[/img]

[img=159,400]blob:https://www.txrjy.com/3756d623-76b0-4af2-a2d3-5e997808a2c8[/img]

LTE侧RRC Connection Setup Complete选网

[img=266,329]blob:https://www.txrjy.com/332d5a06-6adb-4365-9089-592fa08e2a19[/img][img=248,167]blob:https://www.txrjy.com/a5e08456-4e78-4a94-b011-e97fb6cb632c[/img]

手机上报的RrcConnectionSetupComplete消息里的selectedPLMN-Identity字段告诉基站PLMN的选网信息，基站把相应的attachREQ信息转发到对应的核心网。

[右边信令标示本次选网为PLMNID=2，结合sib1消息，PLMNID=2对应的是46007的网络]

[img=72,65]blob:https://www.txrjy.com/497e3bb1-b5e2-4d14-b8b1-bfd9fefce67d[/img]

[img=159,400]blob:https://www.txrjy.com/a242152f-4438-4f70-96af-8489829cf690[/img]

LTE 两次UE能力识别过程

[img=248,167]blob:https://www.txrjy.com/a5e08456-4e78-4a94-b011-e97fb6cb632c[/img][img=117,110]blob:https://www.txrjy.com/ad2fd41f-da12-4463-bae8-8b5db94a8f31[/img][img=210,167]blob:https://www.txrjy.com/a9fe7824-8150-4b0b-8251-e74a042f147b[/img][img=65,62]blob:https://www.txrjy.com/68e72e00-7dff-452c-8b76-4ea4b21f4f14[/img][img=222,98]blob:https://www.txrjy.com/79fac61f-8875-4323-b5d1-f79e7ef11e3a[/img][img=312,82]blob:https://www.txrjy.com/26434988-98ee-4778-974b-c34382e784f2[/img][img=117,99]blob:https://www.txrjy.com/5ebb918c-be5e-4f17-882d-6088573eb02a[/img][img=151,195]blob:https://www.txrjy.com/4f67ea13-159c-4793-b9ed-09e136baf0f7[/img][img=168,108]blob:https://www.txrjy.com/8582e70e-aa25-4a1c-a5c5-d8800e3f43d2[/img][img=127,69]blob:https://www.txrjy.com/89f1ba14-e3fd-49c3-baa4-ad0c5456dfb6[/img][img=278,244]blob:https://www.txrjy.com/04ff9680-8254-4ef9-8c92-2f5efe6d13d2[/img][img=91,79]blob:https://www.txrjy.com/db95bf59-9f47-4878-9bcc-af25cf88745d[/img]

第一次识别

[img=161,74]blob:https://www.txrjy.com/edf5f4a0-c71f-48e0-ac17-7f82e03d02e6[/img]

第一次上报

第二次识别

第二次上报

[img=452,91]blob:https://www.txrjy.com/951b1d50-c2d6-45c1-a3ef-f306ee957d4d[/img]

手机第一上报UE能力，携带en-DC-r15 = supported，标示手机支持ENDC能力。

基站识别改字段后进行第二次UE能力识别。

[右边信令我们主要关注手机上报的ENDC能力当中的频段组合]

[img=90,90]blob:https://www.txrjy.com/a4ddd885-1f0e-49d9-99cd-65e8df16ebe3[/img][img=81,75]blob:https://www.txrjy.com/9ed077ed-9e97-44e8-94cc-481a04020e19[/img][img=88,80]blob:https://www.txrjy.com/cc403d06-25d8-4686-97d1-2920ddad151e[/img][img=75,79]blob:https://www.txrjy.com/0b586fe2-8b8f-4f1c-9832-56fa2862f971[/img]

[左边信令频段组合有

Band3+N41

Band3+N77

Band3+N78

Band3+N79]

[img=159,400]blob:https://www.txrjy.com/0bd7ad7a-be91-4fc5-8922-24755dbf7682[/img]

LTE侧B1测量CFG下发

[img=147,204]blob:https://www.txrjy.com/cc38fde0-2733-4d3a-907e-ad25eda4d876[/img][img=151,215]blob:https://www.txrjy.com/a14275b1-1f54-4dfd-8684-bf80f914218f[/img][img=160,151]blob:https://www.txrjy.com/6b7068bc-4a0a-43ed-be41-43e4aa05c542[/img]



[img=312,82]blob:https://www.txrjy.com/26434988-98ee-4778-974b-c34382e784f2[/img]

测量对象

事件报告

测量ID

测量对象

measOBJ=1 1300[20Mhz]

measOBJ=2 504750[SSB]

事件报告

reportID =1 A3

reportID =2 A2

reportID =3 B1 [门限-140dBm]

测量ID

MEASID =1  measOBJ=1 + reportID =1[同频A3]

MEASID =2  measOBJ=1 + reportID =2[异系统A2]

MEASID =3  measOBJ=2 + reportID =3[异系统B1]

[手机拿到测量任务开启测量5G，满足MEASID=3的B1事件，上报NR的MR]

[img=159,400]blob:https://www.txrjy.com/f0fd49ea-107c-43a1-9cfb-9d5e3eeb299a[/img]

LTE侧辅小区添加CFG下发

[img=222,98]blob:https://www.txrjy.com/79fac61f-8875-4323-b5d1-f79e7ef11e3a[/img][img=224,309]blob:https://www.txrjy.com/d984d94a-6ec3-4b6a-bfcd-5cecef6adb01[/img][img=149,87]blob:https://www.txrjy.com/cee89277-1d19-4d62-9dec-8006244f76cb[/img][img=271,166]blob:https://www.txrjy.com/376d29fb-6085-453e-b02c-7c922a938519[/img]
[img=112,178]blob:https://www.txrjy.com/dd08528a-a316-4833-820b-61488ab540ac[/img][img=124,177]blob:https://www.txrjy.com/fa650a65-7e04-44fb-8b72-5f7a63fc28c1[/img]











[img=61,139]blob:https://www.txrjy.com/a41d8fc5-94c0-4ff8-b40c-fbafb54082ae[/img][img=203,238]blob:https://www.txrjy.com/6bb39d22-15ca-46ff-919c-a0dc071b2f56[/img][img=129,69]blob:https://www.txrjy.com/86d83d04-5d02-4589-b437-1b4fe0e3d025[/img]

辅小区添加的重配，内容很多，我们主要关注spCellConigCommon消息里的NR-SSB-FREQ和PCI信息；

测量控制中是否有A3的事件报告。

辅小区添加的重配置消息，如果手机校验不通过，高通手机不回复RRCReCFGComplete消息，直接发起RRC重建立请求，重建立的原因是CFG失败；海思终端回复RRCReCFGComplete消息，然后发起other原因的RRC重建立请求。

如果遇到类似的辅小区添加的CFG消息后发起重建，可以用正常的辅小区添加CFG小区去比对，从差异中判断是小区哪里的配置问题。

已知的几点重建问题原因：

1、LTE&NR DRB3的RLC模式不一致[AM/UM]

2、高通终端不支持上行256QAM

3、高通不支持2.6的SRS端口轮发

4、海思不支持SRS端口轮发

5、NSA手机LTE&NR制式线性功率超过26dBm

6、NSA手机上行只支持单流

[img=159,400]blob:https://www.txrjy.com/b906ddaf-5555-4678-83e0-9d768e1e1e90[/img]