5G NSA 驻网信令

由于5G NSA 是通过 4G走控制面信令，5G走数据用户面的双链接。相比较于4G来说

注册的log中首先能够看到是BS对手机进行了两次UECapabilityEnquiry，一次是请求上报4G的能力，第二次是请求上报5G NR的能力，详情如下：

5G NSA UECapabilityEnquiry

UE Capability上报分为：

PDCP-Parameters：PDCP层对应的UE Capability

RLC-Parameters：RLC层对应的UE Capability

MAC-Parameters：MAC层对应的UE Capability

Phy-Parameters：PHY层对应的UE Capability

RF-Parameters：RF（射频）相关的UE Capability

第一次Enquiry：

请求的是eutra的能力

Information：

UECapabilityInformation

第二次Enquiry：

其中NR对应上报NR的UE Capability，Eutra-NR对应上报MR-DC的UE Capability，Eutra对应上报LTE侧的UE Capability

第二次的Information ：

UECapabilityInformation中可以包含多个Container，每个Container可以包含NR，Eutra-NR 或者Eutra对应的UE Capability N78

在LTE的Attach accept Msg 后，会进行RRCConnectionReconfiguration，在RRCConnectionReconfigurationComplete后会激活默认EPS承载，在激活承载结束后，ULInformationTransfer 后会进行又一次RRCConnectionReconfiguration

准备进行4/5G的测量的RRC重配，包含4/5G的频点，A1和B1事件的门限。

Qcom 平台：

iRATAPNFallback specifies the priority of the APN entries in ims_apn_name_db[x].cAPNName to be

used for a specific RAT. Each RAT that is to be acknowledged by IMS must have an entry covered in

this NV.

 RAT = (iRATAPNFallback & 0x1F000) >> 12

 RAT:

 RAT_GPRS = 1

 RAT_EDGE = 2

 RAT_WCDMA = 3

 RAT_EHRPD = 4

 RAT_LTE = 5

 RAT_HSPA = 6

 RAT_W_HSPA = 7

 RAT_WLAN = 8

 RAT_IWLAN = 9

 RAT_LTENOVOPS = 10

 RAT_TDSCDMA = 11

 RAT_CDMA = 12

 RAT_NR = 13

 RAT_NR_NOVOPS = 14

First priority RAT = ( iPMRATAPNFallback & 0x0E00 ) >> 9

 Other priority RAT settings are currently not used.

 APN type enum:

 1 = IMS

 2 = Internet

 3 = emergency

 4 = RCS

 5 = UT

 6 = WLAN