Why TDM time slot time duration is 577us ??

[Nataraju A B]

Hi Andreas,

Thanks for the speedy reply.
The link which sent you is definitely useful. But the very basic question I
wanted to get a clarification was that, what is the drive behind selection
of burst time to be 577us.

For example the audio frequency can range upto 4Khz. The sampling frequency
should be 8Khz. If each sample is of 8 bit accuracy. This lead to 64K bits
of data. ......  If we explore further on these lines we should be able to
correlate to the time 577us for each burst.

I wanted some more info these lines. What was/were the drives behind
selection of this burst time. Otherwise what are the other end requirements
led to selection of this burst time and in turn TDMA frame hierarchy.

Thanks,
Nataraju A B

On Fri, Jan 7, 2011 at 7:01 PM, Andreas.Eversberg <
Andreas.Eversberg at versatel.de> wrote:

> in addition:
>
> Traffic Multiframe Structures - The 26 traffic multiframe structure is
> used to send information on the traffic channel. The 26 traffic
> multiframe structure is used to combine user data (traffic), slow
> control signaling (SACCH), and idle time period. The idle time period
> allows a mobile device to perform other necessary operations such as
> monitoring the radio signal strength level of a beacon channel from
> other cells. The time interval of a 26 frame traffic multiframe is 6
> blocks of speech coder data (120 msec).
> (http://www.althos.com/tutorial/GSM-tutorial-frame-structure.html)
>
> one encoded speech block lasts 20ms.
>
>
>        576,92307692307692307692307692308us per slot
>        4615,3846153846153846153846153846 per 8 slots (1 frame)
>         120ms per 26 frames (6 speech blocks)
>
>
>
>


-- 
Thanks,
Nataraju A B
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