GSM WORLD

Hi,

I have some queries regarding the GSM.


What are the Layer1 and layer 2 functions?
How a data packet filters?
How the systems recognize whether the data packet is of data or control



signal?
What are the role of DLP at layer2?
What are the role of Length identifier and Fill bits?
Difference between A, B Abis and Bbis LAPDm frame format?


Regards,
Saurabh

Saurabh wrote:

Sounds like youve been set some homework for your Mobile and Data
Networks course... ;)

Could be wrong - but they seem too specific for someone who doesnt
understand GSM. Id have expected someone who is asking these questions
themselves would have been able to answer them. Theres too many
specifics of GSM dropped in there - if youre asking what the layer 2
functions are - how did you come up with the the question about the role
of DLP at layer 2?

D

Hi David,
Thanks for reply, but it is not my homework.
Well I am a student, it is true, during digging to GSM framework and
architecture I found it is little tough to understand. So post this
question list.


Saurabh

Hi David,
Thanks for reply, but it is not my homework.
Well I am a student, it is true, during digging to GSM framework and
architecture I found it is little tough to understand. So post this
question list.


Saurabh

Saurabh wrote:

Okay - my apologies then! Unfortunately I never took the GSM course at
uni, so Im unable to help you directly - hopefully youll get the
answers youre looking for.

D

Saurabh wrote:
Try this:-

http://ccnga.uwaterloo.ca/~jscouria/GSM/gsmreport.html

--
Ian Edwards

All those who believe in telekinesis, raise my hand.

Steven Wright

Ian Edwards wrote in message
news:PrhPf.62347$Fy4.9193@newsfe4-win.ntli.net...
Good suggestion.

Layer 1 = physical layer (radio in this case)

Layer 2 = logical layer (LAPDm) in this case.

Layer 3 = network layer (based on CCITT No 7.) but more complex to deal with
hand off etc. etc.

I suggest you have a look at X.21, X.25 or Q.701-7xx to get a feel for how
data protocols work - GSM is at the tough end, and a hard place to start.

Hi,

Perhaps I am referring the following books, but I am not getting clear
picture in detail.

1. Neil J. Boucher, The Cellular Radio Handbook, Second Edition,
Mendocino, California: Quantum Publishing, Inc.
2. George Calhoun, Wireless Access and the Local Telephone Network,
Norwood, Massachusetts: Artech House, Inc.
3. An Introduction to GSM: Siegmund M. Redl, Matthias K. Weber, Malcolm
W. Oliphant
4. GSM Switching, Services and Protocols: Jorg Eberspacher, Hans-Jorg
Vogel, and Christian Bettstetter

I will dig in specifications, hope will get something.
By the ways, thanks to all for support and suggestions.

Regards,
Saurabh