GSM Network Interfaces | Um,A,Asub,Abis,B,C,D,E,F,G interface

GSM network interfaces-Um,A,Asub,Abis,B,C,D,E,F,G

This page of GSM tutorial covers GSM network interfaces which includes Um, A, Asub, Abis, B, C, D, E, F and G interfaces.

Figure-1 depicts all the GSM network interfaces between GSM subsystems. The table below describes the same GSM network interfaces.

GSM interface	Description with position
Um	It is the air interface used between MS and BTS.It carries the GSM bursts carrying data and control information. Also referred as Air interface.
A or Asub	It is used between BSC and MSC/VLR. It supports 2Mbps standard digital connection as per CCITT.
Abis	It is used between BTS and BSC. It supports two types of communication links viz. traffic channel at 64 kbps and signaling channel at 16 kbps.
B	It is used between MSC and VLR.
C	It is used between HLR and GMSC. Also between MSC and HLR.
D	It is used between HLR and VLR.
E	It is used between MSC and another MSC or G-MSC.
F	It is used between EIR and MSC and between EIR and G-MSC.
G	It is used between VLR and another VLR.