AW: Order of functions to transmit and receive using layer1 - baseband-devel

14 Mar 2011

hi,

...
      I was wondering how to transmit and receive using
layer1.  I have 
 been reading some of the gsm specs.   I have been looking around in the 
...
  source code a lot, and there many functions that are
used for transmit 
...
  and receive.  Which are the right few to use? 
there are only two types of data between L1 and L2: data frames and
channel request burst. all the other functions control the radio and the
channel in which to communicate. the layer 1 is controlled by the radio
ressource protocol (gsm48_rr.c). in order to understand the channel
multiplexing, you should read GSM TS 05.02.

...
  Is there any way to send
 a text message to a different phone by simulating a base station? 
osmocom is not (yet) able to control baseband hardware to act as a BTS.

...
  Do I 
 need two phones or one phone to transmit and receive as a base station?  

in order to have more than a BCCH, you need two phones. one phone is not
able to send and receive at a time. continuouly transmission is required
for other phones to find a cell.

...
  Is there any way to make a half duplex base station on
a BCCH channel 
 with only one subscriber phone at a time, and what would that entail 
 code-wise? 
you can limit the number of active calls by limiting the number of
channels on the BTS, but you cannot limit the number of phones camping
on the BTS.

...
  Would it be legal to run a very low power base station
in  the USA on a different unused cellular band/frequency?

you need to check the FCC for laws and test licenses.

...
  I have a lot of 
 free time since I do school at home and I could probably help develop 
 some new parts of the osmocom-bb project if you want me to.  I know C, 
...
  some x86 assembly, and a few other languages.  I have
also had practice 
...
  fixing compile-time errors, and bugs in code.  I
apologize if this is 
 too many questions. You don't have to answer them all if you don't want
to.

if you are really interested. you should start reading with TS 04.08.
this is what i did. it describes all the three "layer 3" protocols. 

Thank you for helping,
Calvin E. Balke