1) GSM traffic channel (TCH)

GSM TCH may be either full rate or half rate and may carry either digitized speech or user data.

(a) Full rate TCH:

• Full rate speech channel (TCH/FS): This channel carries user speech which is digitized at a raw data rate if 13kbps. With GSM channel coding added to the digitized speech, this channel carries 22.8kbps.

• Full rate data channel for 9600 bps(TCH/F9.6): This channel carries raw user data which is sent at 9600bps. With additional forward error correction coding applied by GSM standard the 9600bps data is sent at 22.8kbps.

• Full rate data channel for 4800bps(TCH/F4.8) This channel carries raw user data which is sent at 4800bps. With additional forward error correction coding applied by GSM standard the 4800bps data is sent at 22.8kbps.

• Full rate data channel for 2400bps (TCH/F2.4) This channel carries raw user data which is sent at 2400bps. With additional forward error correction coding applied by GSM standard the 2400bps data is sent at 22.8kbps.

(b) Half rate TCH:

• Half rate speech channel (TCH/HS): This channel has been designed to carry digitized speech which is sampled at half rate of 6.5kbps. with GSM channel coding added to the digitized speech the half rate speech channel will carry data at 11.4kbps.

• Half rate data channel for 4800bps (TCH/H4.8): This channel carries raw user data which is sent at 4800bps. With additional forward error correction coding applied by GSM, this channel will carry data at 11.4kbps.

• Half rate data channel for 2400bps (TCH/H2.4) : This channel carries raw user data which is sent at 2400bps. With additional forward error correction coding applied by GSM, this channel will carry data at 11.4kbps.