Remove the paragraph about writing to the Free Software Foundation's
mailing address. The FSF has changed addresses in the past, and may do
so again. In 2021 this is not useful, let's rather have a bit less
boilerplate at the start of source files.
Change-Id: I73be012c01c0108fb6951dbff91d50eb19b40c51
There are two ways to implement frequency hopping:
a) The Transceiver is configured with the hopping parameters, in
particular HSN, MAIO, and the list of ARFCNs (channels), so the
actual Rx/Tx frequencies are changed by the Transceiver itself
depending on the current TDMA frame number.
b) The L1 maintains several Transceivers (two or more), so each
instance is assigned one dedicated RF carrier frequency, and
hence the number of available hopping frequencies is equal to
the number of Transceivers. In this case, it's the task of
the L1 to commutate bursts between Transceivers (frequencies).
Variant a) is commonly known as "synthesizer frequency hopping"
whereas b) is known as "baseband frequency hopping".
For the MS side, a) is preferred, because a phone usually has only
one Transceiver (per RAT). On the other hand, b) is more suitable
for the BTS side, because it's relatively easy to implement and
there is no technical limitation on the amount of Transceivers.
FakeTRX obviously does support b) since multi-TRX feature has been
implemented, as well as a) by resolving UL/DL frequencies using a
preconfigured (by the L1) set of the hopping parameters. The later
can be enabled using the SETFH control command:
CMD SETFH <HSN> <MAIO> <RXF1> <TXF1> [... <RXFN> <TXFN>]
where <RXFN> and <TXFN> is a pair of Rx/Tx frequencies (in kHz)
corresponding to one ARFCN the Mobile Allocation. Note that the
channel list is expected to be sorted in ascending order.
NOTE: in the current implementation, mode a) applies to the whole
Transceiver and all its timeslots, so using in for the BTS side
does not make any sense (imagine BCCH hopping together with DCCH).
Change-Id: I587e4f5da67c7b7f28e010ed46b24622c31a3fdd
One can confuse TRX control interface with libosmoctrl's one.
TRX toolkit is not using libosmoctrl, and will never do. But,
in order to avoid this confusion, and potential confusion of
DATA interface, let's call them 'TRXC' and 'TRXD' in logging.
Change-Id: I67b1e850094cf8e279777c45c7544886be42a009
It makes much more sense to read data from socket in handle_rx(),
instead of expecting a buffer with received data from caller.
Change-Id: I83479c60c54e36a2a7582714a6043090585957ae
There are multiple advantages of using Python's logging module:
- advanced message formatting (file name, line number, etc.),
- multiple logging targets (e.g. stderr, file, socket),
- logging levels (e.g. DEBUG, INFO, ERROR),
- the pythonic way ;)
so, let's replace multiple print() calls by logging calls,
add use the following logging message format by default:
[%(levelname)s] %(filename)s:%(lineno)d %(message)s
Examples:
[INFO] ctrl_if_bts.py:57 Starting transceiver...
[DEBUG] clck_gen.py:87 IND CLOCK 26826
[DEBUG] ctrl_if_bts.py:71 Recv POWEROFF cmd
[INFO] ctrl_if_bts.py:73 Stopping transceiver...
[INFO] fake_trx.py:127 Shutting down...
Please note that there is no way to filter messages by logging
level yet. This is to be introduced soon, together with argparse.
Change-Id: I7fcafabafe8323b58990997a47afdd48b6d1f357
This toolkit has branched out into several different tools for
TRX interface hacking, and creating a virtual Um-interface
(FakeTRX) is only one of its potential applications.
Change-Id: I56bcbc76b9c273d6b469a2bb68ddc46f3980e835
Oliver Smith
Vadim Yanitskiy
Alexander Couzens