This change introduces the following classes:
- DATADump - basic class, which contains methods to generate
and parse the a message header, and some constants.
- DATADumpFile - a child class, which contains methods to
write and parse DATA messages from capture files.
Usage example:
# Open a capture file
ddf = DATADumpFile("capture.bin")
# Parse the 10th message
msg = ddf.parse_msg(10)
msg.fn = 100
msg.tn = 0
# Append one to the end of the capture
ddf.append_msg(msg)
Change-Id: I1b31183bd7bcca94de089847ee0b2f4ec88a7f1d
Previously, it was expected that burst length should be equal
to 148. Let's also handle EDGE bursts and use GSM constants.
Change-Id: Iab13dd06f175556137c5e25d2cbddb9bea403b09
The DATAMSG API, that was introduced and extended a few commits
before, provides all required methods to create, validate,
generate and parse DATA messages. Let's use it now.
Change-Id: Ibc99126dc05d873c1ba538a5f4e74866de563f56
This change introduces a new method for both types of messages
called 'desc_hdr', that generates human-readable header
description.
Examples:
TRX -> L1: fn=571353 tn=1 rssi=-108 toa=-0.53
L1 -> TRX: fn=1777477 tn=3 pwr=161
Change-Id: Iafe63e39ad68f4ff373ae098424d76ca9f83c8fc
One L1 -> TRX message carries one to be transmitted burst encoded
as regular bits (0 or 1). One TRX -> L1 message carries one
received burst encoded as unsigned soft-bits (0..254).
This shall be noted during message encoding and decoding process.
Also, we shall distinguish between GSM and EDGE bursts.
Change-Id: I909b7a4dc70e8c632987bde07f00281a6595c4cb
This change introduces three new classes:
- DATAMSG - abstract class, defines common fields and methods
for any message on DATA interface, e.g. frame and timeslot
numbers, bit conversation methods, etc.
- DATAMSG_L12TRX - a child of DATAMSG, defines a message
coming from L1 to TRX.
- DATAMSG_TRX2L1 - a child of DATAMSG, defines a message
coming from TRX to L1.
Both child classes could be used to generate DATA messages from
known fields (i.e. fn, tn, etc.), and parse them back from
already encoded DATA messages.
Change-Id: Id1c72f0b18fb128acc74d0cd899fb7aab7bd8790
Previously there were multiple definitions of some common GSM
constants in different modules. Let's share them.
Change-Id: Id6cdfbc6e8688755a0df7e44daa512c9afa7dad2
This change introduces a new tool, which could be used to sniff a
single connection between L1 and TRX in both directions, filter
captured bursts by direction, timeslot and/or frame number, and
finally write them to a binary file for further analysis.
Sniffing capability is based on Scapy framework, so it should
be installed in order to run this tool. Please also note,
that sniffing requires root access. For details, see:
https://github.com/secdev/scapyhttps://scapy.readthedocs.io/en/latest/
Usage example:
sudo ./trx_sniff --frame-count 30 --timeslot 2 -o /tmp/bursts
This command will capture 30 frames on timeslot number 2, and
write them to a binary file. The format of this file is based
on TLV (Tag Length Value), that wraps each burst:
... |-TAG (byte)-|-LEN (byte)-|-BURST (LEN bytes)-| ...
TAG 0x01 - a message coming from L1 to TRX
TAG 0x02 - a message coming from TRX to L1
Change-Id: I6e65e1d657574cc3e67bc7cdb1c01ef6bf08ecde
Since both TA and AGC loops should be implemented in transceiver,
this TODO is meaningless. Let's drop it.
Change-Id: I84979712e2a1b849acaee53d5cd50de4e1e357c2
As there is no any order relation between logical channels, it's
better to use the linuxlist API instead of talloc array.
Change-Id: I5a78582c77ed1ab33817d240e065dc4cd4708199
Previously, when resetting or deleting a timeslot, we did not
deactivate the logical channels, relaying on talloc hierarchical
nature. This approach may cause some problems, e.g. on embedded
systems with emulated talloc API.
Change-Id: I8c34c793df87bd8c79b7bf1f05b949faf10520e8
Let's assume that a logical channel, which was already in use,
is activated again for a new connection. As we don't reset the
state variables, such as burst masks or ciphering data, it may
cause an unexpected behaviour.
In order to avoid this, let's always reset the logical channel
state after deactivation.
Change-Id: I91e736a97cb05b167614cb488a00d847a9a859e0
Initially it was expected that a TCH transmit queue could contain
TCH and FACCH primitives only. But there are also SACCH primitives,
which are also being stored there.
So, let's drop the assertations from the sched_prim_dequeue_tch(),
and return NULL if nothing was found.
Change-Id: Iae37057d35883c09a76f0612e52c2d14d9ff91cb
This change implements the A5/X ciphering support transparently
for the logical channel handlers. In other words, a DL burst is
deciphered before being passed to a handler, and an UL burst is
ciphered before being sent to transceiver.
The implementation mostly relays on the libosmocore's A5 API.
Change-Id: Ib53418d8c0f394fdece09cf5cc240887cb0bb5af
Having a possibility to preprocess UL burst before sending to
transceiver is required for the further ciphering support
integration and probably some other tasks.
Change-Id: Ia6eead5d4f51d7c0bf277b9d5ebb0a74676df567
Previously, the L1CTL_CRYPTO_REQ message contained only a ciphering
algorithm and actual Kc key to be used. The key length was
calculated manually using the MSGB API.
Let's avoid manual calculations here, as it may cause unexpected
behavior if the message structure is changed. Also, let's fill
the UL header with minimal information about a channel, which
is going to be encrypted.
Change-Id: I1813a188e755141241273479b17896415abcc3f1
Previously we used to compare two consecutive first primitives,
taken from a transmit queue. This approach may cause some delay,
which is critical for FACCH e.g. in case of handover.
Let's walk through a whole transmit queue to find a pair of
both FACCH frames, and only then decide what to do.
Change-Id: I925cca77bfaa255dd095bc882c901d41c9bc4633
Previously, each lchan handler used to obtain and delete primitives
from a timeslot's tranmit queue itself. This approach entails many
potential problems and bugs:
- The lchan handlers shall not do that by definition, they
should encode and decode frames according to GSM 05.03.
- In some cases (e.g. TCH), a single transmit queue may contain
primitives of different types (e.g. TCH, FACCH and SACCH). At
the same time, the lchan handlers don't care and don't even
know about each other. So, this could cause an unexpected
behaviour in some cases.
This change separates all primitive management routines,
providing a new API for obtaining and dropping them.
"Write programs that do one thing and do it well."
Change-Id: I29503ece51903784bc53541015285234471c8d15
It's good to write, keep and make the source code as much modular
as possible. So, Tte primitive management code was separated to
the 'sched_prim.c' and going to be extended in the near future.
Change-Id: Ifec8c9e4f2c95c72b00772688bcb5dc9c11d6de7
Both SACCH and FACCH messages have the same 23-byte length, both
are being queued together within a single transimt queue. So,
previously a SACCH frame could be picked by TCH burst handler,
and then sent as a FACCH frame. Let's fix this.
A FACCH primitive may have one of the TRXC_TCH* logical channel
types, while SACCH primitives have one of the TRXC_SACCH*.
Change-Id: Ia7090384f3ff74c9d94997265135acbceffa0ffe
Previously, we used to drop a frame if decoding wasn't successful.
This way, the higher layers didn't even know about that, so the
local counters and Measurement Reports were incomplete.
This change makes scheduler to forward L2 frames in any case,
setting the num_biterr for each of them. In case of decoding
error, a dummy (payload filled by 0x00) L2 frame will be sent.
Change-Id: I31011d8f3ca8b9a12474cd0bc653faed18391033
This change implements basic TCH/F lchan handlers for both data
reception and transmission. Only FACCH (signaling), FR and EFR
payloads are supported at the moment.
Change-Id: If6b0eaede2b484484d2a824e7219ff04483266a1
Previously, TCH frames coming from L1 were reordered to the RTP
format. Moreover, the implementation had a few problems:
- L1CTL is not the best place for such manipulations;
- payloads with other than FR codec were corrupted.
Let's use RTP-ordered payloads on the L1CTL interface,
performing TCH frame reordering at the firmware.
Please note, that actual FR reordering was moved to the firmware
as is, without any codec determination. This could be fixed in
a separate change.
Change-Id: I235a9f535c39d8e57f5d2c6566daeaf883aeef9e
There were some BTS specific variables, which are meaningless.
This change cleans them up, and also groups some measurement,
encryption, and AMR specific variables into sub-structures.
Change-Id: Ie753a7e3e7fa2b433d8319b3a05b85b8583d7be2
Since the 32e5641d, the gsm0503_rach_encode() is deprecated, and
the library provides new API with extended (11-bit) RACH support.
Change-Id: I1955fe46eebd173d6eddd1d47ee9f7318b9b4e2d
The time at which the phone is allowed to transmit a burst of
traffic within a timeslot must be adjusted accordingly to prevent
collisions with adjacent users. Timing Advance (TA) is the
variable controlling this adjustment. The TA value is normally
between 0 and 63, with each step representing an advance of
one bit period (approximately 3.69 microseconds).
As trxcon doesn't perform actual burst transmission, this value
needs to be forwarded to the transceiver, which will take care
about the timings.
Change-Id: Ia8c0848827ab2b4cd7cf1efe128b28d5c06ec84e
The 'SETMAXDLY' command is used on the BTS side to limit maximal
Time of Arrival for access bursts. As we don't receive RACH
bursts on the MS side, the command is useless.
The 'SETRXGAIN' command is used on the BTS side to set initial
receive gain value for TRX. On the MS side it's possible to set
that parameter via command-line options of TRX.
Change-Id: I3e61b4b48193004cdcb241cefabb44c12db93120
In order to get the transceiver more time to process bursts,
the L1 scheduler should process the frames and send the bursts
in advance (a few frames before), like OsmoBTS does. By default,
the advance value is 20 frames, but this can be adjusted using a
new command line option of trxcon '-f'.
Change-Id: Ic258a169f3554f931d6277e18ca060d029b77f32
This change introduces a new tool for sending existing bursts from
file or standard input either to L1 (OsmoBTS or OsmocomBB) or to
TRX (OsmoTRX and GR-GSM TRX).
Change-Id: I2c542583252d31daac466e6c7837317fda8a7020
Sometimes it's important to use different CTRL port, for example
when OsmoTRX is running at the same time. This change adds the
corresponding command line options and help message.
Change-Id: Ic6eeb69d9a1fc151eab2e63f3708e3d70e2e558b
Since 8c4f5457 in libosmocore there are some limitations on FSM
and FSM instance names. This change adjusts the names of both
l1ctl_fsm and trx_fsm instances.
Change-Id: Icaaac3f51bdcfe4f7723060179b8730c3a06529b