13 February 2018

GSM channel types

GSM channels help to maintain the GSM network. It also helps GSM mobile phones connect to the GSM network and maintain the connection. 

This article is very helpful in GSM network and also to learn more details about the different types of channels used in GSM system and how to work. 

The figure below mentions all the channels used in GSM. 

There are two main types of GSM channel : (i) Traffic channel (ii) Control channel

The following logical channels are defined in GSM :

TCH : Traffic channel. 

TCH/F : Full rate traffic channel.

TCH/H : Half rate traffic channel.

BCCH : Broadcast control channel for describing the current control channel structure.
BCCH is a point to multi point channel ( BSS to MS ).

SCH : Synchronization channel for the MS.

FCCH : Frequency correction channel.

CCCH : Common control channel. 

PCH : Paging channel terminating call announcement.

AGCH : Access grant control channel.

RACH : Random access control channel for access requests, response to call announcement, location update etc.

DCCH : Dedicated control channel. 

SACCH : Slow associated control channel for TCH in-band signaling for link monitoring.

SDCCH : Standalone dedicated control channel for signaling exchanges during call setup, registration / location updates.

FACCH : Fast associated control channel for time-critical signaling over the TCH for handover signalling.

Notes : For more detailed information about these channels click on the respective channel name.