Tch fr/hr full rate, half rate channel coding

A business channel (TCH) contains coded voice or user data. It can be divided into full-rate business channels (TCH/F) and half-rate business channels (TCH/h, the two messages respectively contain information with a total rate of 22.8 and 11.4 kbit/s. The half rate channel can be obtained by using half of all time slots of the full rate channel. Therefore, a carrier can provide 8 full-speed or 16 half-rate business channels (or a combination of the two) and contain their own along-the-way control channels.

(1) voice service channels

Business channels carrying voice encoding are divided into full-speed voice service channels (TCH/FS) and half-rate voice service channels (TCH/HS ), the total rate is 22.8 and 11.4 kbit/s, respectively.

For full-speed voice encoding, the voice frame length is 20 ms, each frame contains 260 bits, and the net speed is 13 kbit/s.

(2) Data Service Channel

For full-rate or semi-rate channels, different rate adaption, channel coding and interweaving support transparent and non-transparent data services up to 9.6 kbit/s. The service channels used for different user data rates include:

9.6 kbit/s, full rate data service channel (TCH/f9.6)

4.8 kbit/s, full rate data service channel (TCH/f4.8)

4.8 kbit/s, half-rate data service channel (TCH/h4.8)

≤ 2.4 kbit/s, full rate data service channel (TCH/f2.4)

≤ 2.4 kbit/s, half-rate data service channel (TCH/h2.4)

Data service channels also support unrestricted digital bearer services with a net rate of 12 kbit/s.

In the GSM system, an additional channel, namely, TCH/8, is introduced to improve system efficiency. It has a low rate and is only used for signaling and short message transmission. If tch/h can be viewed as half of tch/F, TCH/8 can be viewed

If it is half of tch/F, TCH/8 can be viewed as 1/8 of tch/F. Tch/8 should be attributed to the range of the slow-track control channel (sacch.