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eta004
2018-02-15, 10:00 PM
Hello,

IN CASE OF MOCN - Multi-Operator CORE NETWORK SHARING ........we will have multiple PLMN IDs in SIB1 and only 1cell identity as given below .

In this case, how can we conclude ECGI from SIB1 alone?

ie how can we conclude the cellidentity belongs to which PLMN ID (In this case 3 PLMN Ids)
Any help is highly appreciated.

Sample:

SEQUENCE BCCH-DL-SCH-Message {


CHOICE BCCH-DL-SCH-MessageType {


BCCH-DL-SCH-MessageType = c1 (0 dec, 0x0)


CHOICE BCCH-DL-SCH-MessageType_c1 {


BCCH-DL-SCH-MessageType_c1 = systemInformationBlockType1 (1 dec, 0x1)


SEQUENCE SystemInformationBlockType1 {


SEQUENCE SystemInformationBlockType1_cellAccessRelatedInfo {


SEQUENCE PLMN-IdentityInfo {


SEQUENCE PLMN-Identity {


MCC-MNC-Digit = 3 (0x3)


MCC-MNC-Digit = x (0x1)


MCC-MNC-Digit = x (0x0)


MCC-MNC-Digit = 1 (0x1)


MCC-MNC-Digit = x (0x2)


MCC-MNC-Digit = 0 (0x0)


}


cellReservedForOperatorUse = notReserved (1 dec, 0x1)


}


SEQUENCE PLMN-IdentityInfo {


SEQUENCE PLMN-Identity {


MCC-MNC-Digit = 3 (0x3)


MCC-MNC-Digit = y (0x1)


MCC-MNC-Digit = y (0x0)


MCC-MNC-Digit = 8 (0x8)


MCC-MNC-Digit = y (0x3)


MCC-MNC-Digit = y (0x0)


}


cellReservedForOperatorUse = reserved (0 dec, 0x0)


}


SEQUENCE PLMN-IdentityInfo {


SEQUENCE PLMN-Identity {


MCC-MNC-Digit = 3 (0x3)


MCC-MNC-Digit = z (0x1)


MCC-MNC-Digit = z (0x2)


MCC-MNC-Digit = 5 (0x5)


MCC-MNC-Digit = z (0x3)


MCC-MNC-Digit = z (0x0)


}


cellReservedForOperatorUse = notReserved (1 dec, 0x1)


}


TrackingAreaCode = '1F12'H


CellIdentity = '0011111101011100101101000011'B


cellBarred = notBarred (1 dec, 0x1)


intraFreqReselection = allowed (0 dec, 0x0)


csg-Indication = FALSE (0 dec, 0x0)


}
oswe
2018-02-16, 08:47 PM
I understand you need to use cellId present also in SIB1 (not physical cellId)
apparently this cellId has 28bits of which the first 20 is eNodeBId
then with you plmn+ECI you can identify in case of mocn





Hello,

IN CASE OF MOCN - Multi-Operator CORE NETWORK SHARING ........we will have multiple PLMN IDs in SIB1 and only 1cell identity as given below .

In this case, how can we conclude ECGI from SIB1 alone?

ie how can we conclude the cellidentity belongs to which PLMN ID (In this case 3 PLMN Ids)
Any help is highly appreciated.

Sample:

SEQUENCE BCCH-DL-SCH-Message {


CHOICE BCCH-DL-SCH-MessageType {


BCCH-DL-SCH-MessageType = c1 (0 dec, 0x0)


CHOICE BCCH-DL-SCH-MessageType_c1 {


BCCH-DL-SCH-MessageType_c1 = systemInformationBlockType1 (1 dec, 0x1)


SEQUENCE SystemInformationBlockType1 {


SEQUENCE SystemInformationBlockType1_cellAccessRelatedInfo {


SEQUENCE PLMN-IdentityInfo {


SEQUENCE PLMN-Identity {


MCC-MNC-Digit = 3 (0x3)


MCC-MNC-Digit = x (0x1)


MCC-MNC-Digit = x (0x0)


MCC-MNC-Digit = 1 (0x1)


MCC-MNC-Digit = x (0x2)


MCC-MNC-Digit = 0 (0x0)


}


cellReservedForOperatorUse = notReserved (1 dec, 0x1)


}


SEQUENCE PLMN-IdentityInfo {


SEQUENCE PLMN-Identity {


MCC-MNC-Digit = 3 (0x3)


MCC-MNC-Digit = y (0x1)


MCC-MNC-Digit = y (0x0)


MCC-MNC-Digit = 8 (0x8)


MCC-MNC-Digit = y (0x3)


MCC-MNC-Digit = y (0x0)


}


cellReservedForOperatorUse = reserved (0 dec, 0x0)


}


SEQUENCE PLMN-IdentityInfo {


SEQUENCE PLMN-Identity {


MCC-MNC-Digit = 3 (0x3)


MCC-MNC-Digit = z (0x1)


MCC-MNC-Digit = z (0x2)


MCC-MNC-Digit = 5 (0x5)


MCC-MNC-Digit = z (0x3)


MCC-MNC-Digit = z (0x0)


}


cellReservedForOperatorUse = notReserved (1 dec, 0x1)


}


TrackingAreaCode = '1F12'H


CellIdentity = '0011111101011100101101000011'B


cellBarred = notBarred (1 dec, 0x1)


intraFreqReselection = allowed (0 dec, 0x0)


csg-Indication = FALSE (0 dec, 0x0)


}
eta004
2018-02-18, 08:51 PM
Hi,

Yes, but my concern is which of the given PLMN is related to the given Cell identity.
There are 3 PLMNs in SIB1, it can be of the same operator Say "Sprint " where there is no chance of MOCN or can be of ATT, Tmobile & Sprint in case of say
MOCN ...So which PLMN corresponds to the cell identity ?? Is it the 1st PPLMN reported or any other way b..sincw we have 3 PLMNs and 1 cell identity to get the ECGI.
crazyfind
2018-02-19, 12:35 AM
it will use the first one, which is the eNB belong to.
tanz
2018-02-19, 02:46 AM
Taking a guess here because i will need to confirm this; unless configured differently, Tracking Area Code and the Cell Identity are the same for both PLMNs, hence only one value comes in SIB1
eta004
2018-02-19, 02:59 PM
Can u please share any 3gpp specs in support of this statement..?


it will use the first one, which is the eNB belong to.
eta004
2018-02-19, 03:02 PM
I can confirm you that only 1 cell identity is reported in SIB1, as I can see only 1cell identity in all the log files even when there are multiple PLMNs in the SIB1.


Taking a guess here because i will need to confirm this; unless configured differently, Tracking Area Code and the Cell Identity are the same for both PLMNs, hence only one value comes in SIB1
wolverine
2018-02-19, 06:45 PM
Hi,

crazyfind is correct. See below..

From TS 36.300 E-UTRA and E-UTRAN Overall description (section 8.2)

E-UTRAN Cell Global Identifier (ECGI): used to identify cells globally. The ECGI is constructed from the
PLMN identity the cell belongs to and the Cell Identity (CI) of the cell. The included PLMN is the one given by
the first PLMN entry in SIB1, according to TS 36.331.
eta004
2018-02-19, 07:42 PM
Good !, that we confirmed.Thatz the answer I was waiting for. !:)



Hi,

crazyfind is correct. See below..

From TS 36.300 E-UTRA and E-UTRAN Overall description (section 8.2)

E-UTRAN Cell Global Identifier (ECGI): used to identify cells globally. The ECGI is constructed from the
PLMN identity the cell belongs to and the Cell Identity (CI) of the cell. The included PLMN is the one given by
the first PLMN entry in SIB1, according to TS 36.331.
oswe
2018-02-20, 07:41 PM
i also believe that.
i will confirm with some colleagues today.


Taking a guess here because i will need to confirm this; unless configured differently, Tracking Area Code and the Cell Identity are the same for both PLMNs, hence only one value comes in SIB1
rimeka
2018-03-01, 12:19 PM
Looking from the attach signaling flow, selectedPLMN-identity is sent by Ue on message RRCConnectionSetupComplete.
Ue may choose not only the first PLMN. I have tested before that Ue can attach to PLMN on the second list depend on the imsi number.



RRCConnectionSetupComplete-r8-IEs ::= SEQUENCE {
selectedPLMN-Identity INTEGER (1..maxPLMN-r11),
registeredMME RegisteredMME OPTIONAL,
dedicatedInfoNAS DedicatedInfoNAS,
nonCriticalExtension RRCConnectionSetupComplete-v8a0-IEs OPTIONAL
}
eta004
2018-03-02, 05:49 AM
Yes correct, but the cellidentity displayed in SIB1 is of first plmn id