5g network identity - detailed explanation of 5g Guti

5G-GUTI yes AMF Temporary identification information of the globally unique identifier assigned to the user ,3GPP and non-3gpp share ,AMF It can be reallocated at any time 5G-GUTI to UE.

–5G-GUTI structure ：

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5G-GUTI structure :
<5G-GUTI> =<GUAMI> <5G-TMSI>

GUAMI Can identify one or more AMF, When GUAMI Uniquely identify one AMF when ,5G-TMSI The only one AMF The only one in the world UE; When GUAMI Identify multiple AMF when ,AMF Distribution is needed 5G-GUTI when , Not with yourself share GUAMI Of AMF The distribution of 5G-GUTI repeat , Guarantee 5G-GUTI Uniqueness .5GC Now I understand that the former is generally the case ,GUAMI A unique logo AMF.

GUAMI structure ：
<GUAMI> := <MCC> <MNC> <AMF Region ID> <AMF Set ID> <AMF Pointer>
 MCC Mobile Country Code  Mobile country number , China is  460
 MNC Mobile Network Code ： Mobile network number  
 AMF Identifier  AMF Region ID + AMF Set ID+AMF Pointer ：
 AMF Region ID 8 bit AMF  Area identification , identification  AMF  Responsible area ;
 AMF Set ID 10 bit AMF  Group   identification , Unique identification  AMF  In the area   A group of  AMF
 AMF Pointer 6 bit AMF  Pointer identification , identification  AMF  Group   Internal  1  One or more AMF
 
  common  24 bit  Fixed bit length .

–4-5G GUTI The mapping relationship ：

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AMF Region ID+AMF Set ID common 18 individual bit , One of them is high 16 individual bit And
4G MME Of MMEGI 16 individual bit 、 2/3G Of LAC Of 16 individual bit share 16 individual bit Space , Cannot be reused .

–5G-S-TMS:

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5G-S-TMS yes GUTI Abbreviation , Used for multiple signaling processes related to wireless , Such as paging and service requests .
structure :
<5G-S-TMSI> := <5G-TMSI>

–5G-GUTI Analysis examples

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1. 5G AMF The distribution of GUTI

AMF region：dec 8,8bit：0000,1000,hex 08
AMF set ID：dec 401,10bit：0110,0100,01,hex 644
AMF point id：dec 1,6bit：000001,hex 1

mapping 4G Of EPS-GUTI：
EPS-GUTI=MCC+MNC+MMEGI+MMEC+M-TMSI
MMEGI 16bit：0000,1000,0110,0100,hex 08 64,dec 2148
MMEC 8bit:0100,0001,hex 41,dec 65

2. Old 4G EPS-GUTI

MMEGI：1038; 040E; 0000,0100,0000,1110
MMEC：10; 0A; 0000,1010

mapping 5G-GUTI：

8bit; 0000,0100; 4; 04; AMF region
10bit; 0000111000; 56; 38; AMF set ID
6bit; 00,1010; 10; 0A; AMF point id

3. get 16 Base number GUAMI Information 04 0e 06

translate ：
0000,0100,0000,1110,0000,0110
5G:
8bit; 0000,0100; 4; AMF region ID
10bit; 0000,1110,00; 56; AMF set ID
6bit; 00,0110; 6; AMF pointer ID
4G:
16bit; 0000,0100,0000,1110; 1038; MMEGI
8bit; 0000,0110; 6; MMEC