2G and 3G PS NETWORK Structure

2G and 3G PS NETWORK Structure

 

2G/3G Interfaces

GGSNàGnàSGSN  (for local traffic)

GGSNàGbàSGSN( for Roomer traffic)

RNCàIuPsàSGSN

SGSNàGràHLR

Inbound and Outbound

For OUTBOUND=SGW will be the other country

And PGW= will the local Operator

   Attach Request

The SIM applies secret GSM algorithms on the RAND and the secret key Ki to obtain the session key Kc and SRES
Update Location
The SGSN responds back tothe HLR.The HLR now responds backto the SGSN's UpdateLocation" message.Location Updating RequestThe mobile had initiated acombined attach,so the SGSN also updates the location information at the MSCVLR that will handle the voice call

Update LocationThe MSC also initiates an update at the HLR.Thesequence of actions here isidentical to that of the SGSN'sHLR updat
PDP Context Activation
PDP Context Activation(to obtainthe IP address for the device)
Access Point Name (APN) specified by the serviceprovider is passed as parameter
The SGSN initiates a DNSquery to find the GGSN corresponding to the APNspecified by the mobile
The DNS provides the GGSN IP address
(Create PDP Context Request) The SGSN routes the PDPcontext activation request tothe GGSN corresponding tothe APN.
Radius Authentication Request(The GGSN authenticates theGPRS subscription at theRADIUS server)
The GGSN now requests a DHCP server for an dynamic IP address for the GPRS mobile
The DHCP server provides the IP address.
The GGSN responds back tothe SGSN, indicatingcompletion of the PDP contextactivation procedure
Create PDP Context Response by the GGSN (The GGSN responds back tothe SGSN, indicatingcompletion of the PDP contextactivation procedure)

 

 

4G Interfaces

ENODB àS1MMEàMME (between ENODB and MME)

SGWà  S11à MME (between SGW and MME)

SGWàS₅-àPGW (between SGW and PGW) (for local traffic)

SGWàS₈-àPGW (between SGW and PGW)(for Roomer traffic)

SGWà S₄àSGSN (between SGW and SGSN )

MMEàS₃àSGSN(between MME and SGSN)