On Fri, Jan 7, 2011 at 8:51 AM, Nataraju A B <natarajuab.tech(a)gmail.com> wrote:
>
> Hi Andreas,
> Thanks for the speedy reply.
> The link which sent you is=3DA0definitely=3DA0useful. But the very basic= q=3D uestion I wanted to get a clarification was that, what is the drive behind =3D selection of burst time to be 577us.
> For example the audio frequency can range upto 4Khz. The sampling freq=3D uency should be 8Khz. If each sample is of 8 bit accuracy. This lead to 64K=3D bits of data. ...... =3DA0If we explore further on these lines we should be = =3D able to correlate to the time 577us for each burst.
> I wanted some more info these lines. What was/were the drives behind s=3D election of this burst time. Otherwise what are the other end requirements =3D 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(a)versatel.de> wr= ot=3D e:
>>
>> in addition:
>>
>> Traffic Multiframe Structures - The 26 traffic multiframe structur=3D e is
>> used to send information on the traffic channel. The 26 traffic >> multiframe structure is used to combine user data (traffic), slow<=3D br> >> control signaling (SACCH), and idle time period. The idle time per=3D iod
>> allows a mobile device to perform other necessary operations such =3D as
>> monitoring the radio signal strength level of a beacon channel fro=3D m
>> other cells. The time interval of a 26 frame traffic multiframe is=3D 6
>> blocks of speech coder data (120 msec).
>> (http://www.althos.com/tutorial/GSM-tutorial-f= =3D rame-structure.html)
>>
>> one encoded speech block lasts 20ms.
>>
>>
>> =3DA0 =3DA0 =3DA0 =3DA0576,92307692307692307692307692308us per slot<= br> >> =3DA0 =3DA0 =3DA0 =3DA04615,3846153846153846153846153846 per 8 slots= (1 fr=3D ame)
>> =3DA0 =3DA0 =3DA0 =3DA0120ms per 26 frames (6 speech blocks)
>>
>>
>>
>
>
>
> --
> Thanks,
> Nataraju A B