3 Jan
2022
3 Jan
'22
11:30 a.m.
Number of symbols in a burst =3D 156.25 symbols, and burst time 156.25 x
3.69... =3D 576,92=ECs
Number of symbols in TDMA frame is 8 x 156.25 =3D 1250 symbols,
Number of symbols in Multiframe is 26 x 1250 symbols.
On Fri, Jan 7, 2011 at 8:51 AM, Nataraju A B <natarajuab.tech(a)gmail.com> wr=
ote:
Hi Andreas,
Thanks for the speedy reply.
The link which sent you is=A0definitely=A0useful. But the very basic ques=
tion I
wanted to get a clarification was that, what is the drive behind sel=
ection of burst time to be 577us.
For example the audio frequency can range upto 4Khz.
The sampling frequen=
cy should be 8Khz. If each sample is of 8 bit accuracy. This
lead to 64K bi=
ts of data. ...... =A0If we explore further on these lines we should be abl=
e to correlate to the time 577us for each burst.
I wanted some more info these lines. What was/were the
drives behind sele=
ction 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@vers=
atel.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.
=A0 =A0 =A0 =A0576,92307692307692307692307692308us per slot
=A0 =A0 =A0 =A04615,3846153846153846153846153846 per 8 slots (1 frame)
=A0 =A0 =A0 =A0120ms per 26 frames (6 speech blocks)
--
Thanks,
Nataraju A B