For the sake of simplicity and due to some performance limitations,
fake_trx.py does not generate TRXD NOPE indications for osmo-bts-trx
on its own. It's actually trxcon sending NOPE.req (empty Tx PDUs)
when it has nothing to send, and fake_trx.py simply converting them.
In a follow-up change [1] we remove trxcon's internal clock module,
making the Uplink burst scheduling being driven by Downlink bursts
with the respective TDMA Fn/Tn values. Given that fake_trx.py is
currently dropping bursts received for inactive timeslots, we would
get NOPE.req only for a single timeslot, the one being currently
active. This would break several testcases in ttcn3-bts-test.
Remove SETSLOT based burst filtering, so that trxcon would still be
able to generate NOPE.req for all, active and inactive timeslots.
Downlink bursts for inactive timeslots are discarded anyway.
Change-Id: Ia42550d5c2d8b49efbdf8ef0ce46b26afd1c464e
Related: [1] Ic8a5b6277c6b16392026e0557376257d71c9d230
Related: OS#5500
By default, powering on/off a parent transceiver (child_idx=0) will
automatically power on/off its child transceivers (if any). This
behavior is desirable for the BTS, but not for the MS Transceivers.
Additional MS Transceivers are going to be used by ttcn3-bts-test
for spawning multiple DCCH components in parallel. We don't want
situations when one component powers off transceivers of the other
DCCH components - they must be independent.
Change-Id: I0cd6bac616273bed0e246ad48edc44fff484c589
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
I intentionally do not use 'Downlink' and 'Uplink' terms in this project
because both MS and BTS transmit and receive on the opposite directions.
A burst coming from demodulator may be a Downlink or an Uplink burst
depending on the context, so we definitely need more precise terms.
Back then when I started to work on TRX toolkit, I decided to use the
'TRX2L1' and 'L12TRX' for receive and transmit directions respectively.
Now I find them hard to read, so let's replace them with 'Rx' and 'Tx'.
Change-Id: I688f24a3c09dd7e1cc00b5530ec26c8e8cfd8f7c
Related: OS#4006, SYS#4895
This reverts commit 6e1c82d298.
Unfortunately, solving one problem it introduced even more regressions.
Change-Id: If29b4f6718cbc8af18fe18a5e3eca3912e8af01e
Related: OS#4658
In order to reflect the UL/DL delay caused by the premature burst
scheduling (a.k.a. 'fn-advance') in a virtual environment, the
Transceiver implementation now queues all to be transmitted bursts,
so they remain in the queue until the appropriate time of transmission.
The API user is supposed to call recv_data_msg() in order to obtain
a L12TRX message on the TRXD (data) inteface, so it gets queued by
this function. Then, to ensure the timeous transmission, the user
of this implementation needs to call clck_tick() on each TDMA
frame. Both functions are thread-safe (queue mutex).
In a multi-trx configuration, the use of queue additionally ensures
proper burst aggregation on multiple TRXD connections, so all L12TRX
messages are guaranteed to be sent in the right order, i.e. with
monolithically-increasing TDMA frame numbers.
Of course, this change increases the overall CPU usage, given that
each transceiver gets its own queue, and we need to serve them all
on every TDMA frame. According to my measurements, when running
test cases from ttcn3-bts-test, the average load is ~50% higher
than what it used to be. Still not significantly high, though.
Change-Id: Ie66ef9667dc8d156ad578ce324941a816c07c105
Related: OS#4658, OS#4546
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
The previous approach was based on threading.Timer, so on each clock
iteration one thread spawned another new thread. So far it worked
well, but such frequent spawning involves an additional overhead.
After this change, CLCKGen.start() allocates and starts a new thread,
that periodically sends clock indications and sleep()s during the
indication intervals. The CLCKGen.stop() in its turn terminates
that thread and frees the memory.
Change-Id: Ibe477eb0a1ee2193c1ff16452a407be7e858b2ef
Since fake_trx.py can handle multiple transceivers, it may be useful
to name transceivers. If transceiver has some name, it will appear
in logging messages, for example:
[INFO] transceiver.py:104 Init transceiver 'BTS@127.0.0.1:5700'
[INFO] transceiver.py:104 Init transceiver 'MS@127.0.0.1:6700'
[INFO] transceiver.py:104 Init transceiver '127.0.0.1:5700/1'
This change additionally assigns names to the both default
transceivers, and extends the '--trx' option with ability
to specify some name, for example:
--trx foo@127.0.0.1:5700 or --trx bar@127.0.0.1:5700/1
--trx ipv6@[2001:0db8:85a3:0000:0000:8a2e:0370:7334]:6700
Change-Id: I2f58f02e7819bb008b8aab1a8bf9e0adeb2e44ec
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
Since fake_trx.py can handle multiple transceivers, it makes sense
to print some info in logging messages about transceivers they
belong to. This acvieved by defining __str__() for Transceiver.
Some examples:
[DEBUG] ctrl_if_trx.py:83 (127.0.0.1:5700) Recv POWEROFF cmd
[INFO] ctrl_if_trx.py:85 (127.0.0.1:5700) Stopping transceiver...
[DEBUG] ctrl_if_trx.py:95 (127.0.0.1:5700/1) Recv RXTUNE cmd
[DEBUG] ctrl_if_trx.py:102 (127.0.0.1:5700/1) Recv TXTUNE cmd
[DEBUG] ctrl_if_trx.py:155 (127.0.0.1:5700/1) Ignore CMD SETTSC
[DEBUG] ctrl_if_trx.py:155 (127.0.0.1:5700/1) Ignore CMD SETPOWER
Change-Id: I1f706790a2da226f1418f89d2cfbb55baa6ea624
A BTS can (optionally) have more than one transceiver. In this case
additional (let's say child) transceivers basically share the same
clock source of the first transceiver, and being powered on / off
as soon as the first transceiver is powered on / off.
Change-Id: I7e97b7f32dde7ab74779133e9d7504f1d0fce60c
This change is a big step towards handling of multiple transceivers
in a single process, i.e. multiple MS and multiple BTS connections.
The old class hierarchy wasn't flexible enough, because initially
fake_trx was designed as a bridge between OsmocomBB and OsmoBTS,
but not as the burst router. There were two separate, but 90%
similar implementations of the CTRL interface, two variations
of each simulation parameter - one for UL, another for DL.
The following new classes are introduced:
- Transceiver - represents a single transceiver, that can be
used as for the BTS side, as for the MS side. Each instance
has its own CTRL, DATA, and (optionally) CLCK interfaces,
among with basic state variables, such as both RX / TX freq.,
power state (running or idle) and list of active timeslots.
- CTRLInterfaceTRX - unified control interface handler for
common transceiver management commands, such as POWERON,
RXTUNE, and SETSLOT. Deprecates both CTRLInterface{BB|BTS}.
- FakeTRX - basically, a child of Transceiver, extended with
RF path (burst loss, RSSI, TA, ToA) simulation. Implements
a custom CTRL command handler for CTRLInterfaceTRX.
The following classes were refactored:
- BurstForwarder - still performs burst forwarding, but now
it doesn't store any simulation parameters, and doesn't
know who is BTS, and who is MS. Actually, BurstForwarder
transforms each L12TRX message into a TRX2L1 message, and
dispatches it between running transceivers with matching
RX frequency and matching timeslot.
- FakePM - still generates random RSSI values, but doesn't
distinguish between MS and BTS anymore. As soon as a
measurement request is received, it attempts to find
at least one running TRX on a given frequency.
Please note that fake_trx.py still does handle only a single pair
of MS and BTS. No regressions have been observed. Both new and
refactored classes were documented.
Change-Id: Ice44e2b22566b3652ef6d43896055963b13ab185
Related: OS#3667
Vadim Yanitskiy
Oliver Smith
Vadim Yanitskiy