[vikas bhatnagar]

hi all,

my doubt is how channels and frames like sacch,facch n ctrl frames decodes with their proper bit structure at both uplink and downlink end .

[Pix]

If all the equipments are following the same 3GPP standards, there is no reason they cannot decode those channels correctly.

[vikas bhatnagar]

hi pix,thx 4 reply but my doubt was like in rach frame has 8 bits inwhich 5 for random no and rest 3 for connection cause like this can u explain me about others like faach and sdcch …
althoug how decoding of frames can be done ………..
pls help me out for the confusion.

[pix]

Vikas,

you are confusing a physical channel (RACH) and a message (CHANNEL REQUEST).
The RACH carries the CHANNEL REQUEST.
CHANNEL REQUEST is a 8-bits message (as you said).

FACCH is a physical channel. But it contains only 1 bit. So the message is either 0 or 1. If it’s = 1, then the content of the TCH should be decoded as signalling message (such as HO COMMAND)

SDCCH is a physical channel. It can carry many different messages (immediate assignment, etc…) you’ll find a description of each of them on the 3GPP website.

[Author]

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