5G通信协议学习：CGI-InfoNR
– CGI-InfoNR
The IE CGI-InfoNR indicates cell access related information, which is reported by the UE as part of report CGI procedure.
CGI-InfoNR information element
– ASN1START
– TAG-CGI-INFO-NR-START
CGI-InfoNR ::= SEQUENCE {
plmn-IdentityInfoList PLMN-IdentityInfoList OPTIONAL,
frequencyBandList MultiFrequencyBandListNR OPTIONAL,
noSIB1 SEQUENCE {
ssb-SubcarrierOffset INTEGER (0…15),
pdcch-ConfigSIB1 PDCCH-ConfigSIB1
} OPTIONAL,
…,
[[
npn-IdentityInfoList-r16 NPN-IdentityInfoList-r16 OPTIONAL
]],
[[
cellReservedForOtherUse-r16 ENUMERATED {true} OPTIONAL
]]
}
– TAG-CGI-INFO-NR-STOP
– ASN1STOP
CGI-InfoNR field descriptions
noSIB1
Contains ssb-SubcarrierOffset and pdcch-ConfigSIB1 fields acquired by the UE from MIB of the cell for which report CGI procedure was requested by the network in case SIB1 was not broadcast by the cell.
cellReservedForOtherUse
Contains cellReservedForOtherUse field acquired by the UE that supports nr-CGI-Reporting-NPN from SIB1 of the cell for which report CGI procedure was requested by the network.
.
– PLMN-IdentityInfoList
The IE PLMN-IdentityInfoList includes a list of PLMN identity information.
PLMN-IdentityInfoList information element
– ASN1START
– TAG-PLMN-IDENTITYINFOLIST-START
1个小区被N个运营商共享，每个运营商可以配置属于自己的plmnId/gNodeBId/cellID.
对于小区被AB 2个运营商共享的场景，
-
case 1: 如果A和B共享TrackingAreaCode,racac, cellId等信息，则只需要一组PLMN-IdentityInfo。 PLMN-IdentityInfoList[0][0].plmnId = A, PLMN-IdentityInfoList[0][1].plmnId = B,
-
case 2: 如果A和B不共享TrackingAreaCode,racac, cellId等信息，则需要2组PLMN-IdentityInfo。 PLMN-IdentityInfoList[0][0].plmnId = A, PLMN-IdentityInfoList[1][0].plmnId = B.
-
其实case1 也可以用case 2表述， 如果这样表述， 则协议的plmn-IdentityList这一维列表可以改成PLMN-Identity， 看起来更容易理解。 为什么没有这样做？ 可能的原因是使用case 1的表述方式asn编码后的数据更少。当然，这种协议定义支持case 1这种asn 编码后数据更小的实现方式，也支持即便AB共享模式下也按照case 2的实现方式，但是基于运营商可能更希望定制自己的小区ID来考虑，使用case 2的实现方式更加灵活容易扩展。
-
所以PLMN-IdentityInfoList[0][0]必然是小区的主运营商。其余依次往下都是小区的从运营商。 虽然PLMN-Identity定义了maxPLMN * maxPLMN个，但是在填写的时候，总共能填写的PLMN数目还是maxPLMN个。
PLMN-IdentityInfoList ::= SEQUENCE (SIZE (1…maxPLMN)) OF PLMN-IdentityInfo
PLMN-IdentityInfo ::= SEQUENCE {
plmn-IdentityList SEQUENCE (SIZE (1…maxPLMN)) OF PLMN-Identity,
trackingAreaCode TrackingAreaCode OPTIONAL, – Need R
ranac RAN-AreaCode OPTIONAL, – Need R
cellIdentity CellIdentity,
cellReservedForOperatorUse ENUMERATED {reserved, notReserved},
…,
[[
iab-Support-r16 ENUMERATED {true} OPTIONAL – Need S
]]
}
– TAG-PLMN-IDENTITYINFOLIST-STOP
– ASN1STOP
PLMN-IdentityInfo field descriptions
cellReservedForOperatorUse
Indicates whether the cell is reserved for operator use (per PLMN), as defined in TS 38.304 [20]. This field is ignored by IAB-MT.
iab-Support
This field combines both the support of IAB and the cell status for IAB. If the field is present, the cell supports IAB and the cell is also considered as a candidate for cell (re)selection for IAB-node; if the field is absent, the cell does not support IAB and/or the cell is barred for IAB-node.
trackingAreaCode
Indicates Tracking Area Code to which the cell indicated by cellIdentity field belongs. The absence of the field indicates that the cell only supports PSCell/SCell functionality (per PLMN)…
– PLMN-Identity
The IE PLMN-Identity identifies a Public Land Mobile Network. Further information regarding how to set the IE is specified in TS 23.003 [21].
PLMN-Identity information element
– ASN1START
– TAG-PLMN-IDENTITY-START
PLMN-Identity ::= SEQUENCE {
mcc MCC OPTIONAL, – Cond MCC
mnc MNC
}
MCC ::= SEQUENCE (SIZE (3)) OF MCC-MNC-Digit
MNC ::= SEQUENCE (SIZE (2…3)) OF MCC-MNC-Digit
MCC-MNC-Digit ::= INTEGER (0…9)
– TAG-PLMN-IDENTITY-STOP
– ASN1STOP
PLMN-Identity field descriptions
mcc
The first element contains the first MCC digit, the second element the second MCC digit and so on. If the field is absent, it takes the same value as the mcc of the immediately preceding IE PLMN-Identity. See TS 23.003 [21].
mnc
The first element contains the first MNC digit, the second element the second MNC digit and so on. See TS 23.003 [21].
Conditional Presence Explanation
MCC This field is mandatory present when PLMN-Identity is not used in a list or if it is the first entry of PLMN-Identity in a list. Otherwise it is optionally present, Need S.
– MultiFrequencyBandListNR
The IE MultiFrequencyBandListNR is used to configure a list of one or multiple NR frequency bands.
MultiFrequencyBandListNR information element
– ASN1START
– TAG-MULTIFREQUENCYBANDLISTNR-START
MultiFrequencyBandListNR ::= SEQUENCE (SIZE (1…maxNrofMultiBands)) OF FreqBandIndicatorNR
– TAG-MULTIFREQUENCYBANDLISTNR-STOP
– ASN1STOP
– FreqBandIndicatorNR
The IE FreqBandIndicatorNR is used to convey an NR frequency band number as defined in TS 38.101-1 [15] and TS 38.101-2 [39].
FreqBandIndicatorNR information element
– ASN1START
– TAG-FREQBANDINDICATORNR-START
FreqBandIndicatorNR ::= INTEGER (1…1024)
– TAG-FREQBANDINDICATORNR-STOP
– ASN1STOP