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I have a very basic question related to S1 setup and SIB1.

+7 votes

I saw S1 Setup Request message. It contains CSGID list parameter. And if I see SIB1 content which contains CSG- Identity only (one CSG-Id). So I want to ask what is the reason eNB can send a list of supported CSGs in S1SetupRequest message to MME and in SIB1 only one CSG-Identity is mentioned ?

posted Jul 9, 2013 by Vimal Kumar Mishra

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Let me understand your question -
Can S1Setpup Request can contain multiple CSG-ID answer is yes. This is the format of the message
Message Type
Global eNB ID
eNB Name
Supported TAs
>Broadcast PLMNs
>>PLMN Identity
Default paging DRX
CSG Id List

Now where SIB1 is coming into picture, probably not able to understand your question. Please elaborate.
I want to say when an eNB comes up it initiates s1 connection with MME. In S1 Connection Request message it sends CSG Id list. From S1 Connection Request message it seems it can support multiple CSG. But if I check SIB1 info it has provision to support only one CSG. so my question is that where are remaining CSG ? or is it a concept of primary and secondary CSG, where SIB1 broadcast only primary and no need of broadcasting others one ?
Understood the doubt, i never though in this direction. Let me search the reason may be TS 36.331

2 Answers

+1 vote

Hello Vimal,

The S1 setup is the ENB level message and one ENB can support 3 cells. Where as the SIBs are cell secific broadcasts. Thats why in SIB 1 you have only one CSG ID where as in S1 Setup you have CSG ID list.

answer Sep 24, 2014 by anonymous
–2 votes

Refer to TS36301, TS36321, and TS36331.

answer Jul 10, 2013 by anonymous
Similar Questions
+3 votes

int main()
    char ptr[]= {'a','b','c','0','e'};
    char str[]= "abc0e";
    printf("\nptr = %s\t len = %d\n",ptr, strlen(ptr));
    printf("\nstr = %s\t len = %d\n",str, strlen(str));
    return 0;

Output : ptr = abc0e len = 6
str = abc0e len = 5

Why the length for ptr is 6 ? Can someone please explain it ?

+2 votes

What is the eNB behavior in-case MME is not responding to S1 setup request message (ie. MME is not sending S1 setup failure or success).