From ebf676597b179e196eb27867725bf0ef7210b7aa Mon Sep 17 00:00:00 2001 From: Vadim Yanitskiy Date: Mon, 8 Jul 2019 10:14:10 +0700 Subject: trx_toolkit/fake_trx.py: basic TRXD version 0x01 support Since the new TRXD header format has been introduced, FakeTRX needs to be able to fill it correctly. In particular, the following: - Modulation, which can be determined from the burst length; - Training Sequence Code (and set), which needs to be detected by comparing the burst bits of L12TRX message against known training sequences (only GMSK and the default TS set for now); - C/I (Carrier-to-Interference ratio), which can be simulated later on, as instructed on the TRXC interface ('FAKE_CI'). The actual TRXD header version is stored in the instance of class DATAInterface. By default (at startup), legacy version 0 is used. The version negotiation is supposed to be performed on the TRXC interface, and to be implemented in a follow-up change. Different Transceivers may use different header versions, thus in FakeTRX.send_data_msg() we need to override the original version of the L12TRX message, and generate the corresponding PDU. Limitations: - NOPE / IDLE indications are not (yet) supported; - TSC detection: GMSK modulation only. Change-Id: I164f5ae4ce7694d6e324aab927a04e96d489ebd8 Related: OS#4006 --- src/target/trx_toolkit/burst_fwd.py | 2 +- src/target/trx_toolkit/data_if.py | 32 +++++++++++++++++++++++- src/target/trx_toolkit/fake_trx.py | 49 ++++++++++++++++++++++++++++++++++--- 3 files changed, 78 insertions(+), 5 deletions(-) (limited to 'src') diff --git a/src/target/trx_toolkit/burst_fwd.py b/src/target/trx_toolkit/burst_fwd.py index 164271fe..1d5dd7b8 100644 --- a/src/target/trx_toolkit/burst_fwd.py +++ b/src/target/trx_toolkit/burst_fwd.py @@ -84,4 +84,4 @@ class BurstForwarder: if tx_msg.tn not in trx.ts_list: continue - trx.send_data_msg(src_trx, tx_msg) + trx.send_data_msg(src_trx, rx_msg, tx_msg) diff --git a/src/target/trx_toolkit/data_if.py b/src/target/trx_toolkit/data_if.py index 027fd854..10df4383 100644 --- a/src/target/trx_toolkit/data_if.py +++ b/src/target/trx_toolkit/data_if.py @@ -4,7 +4,7 @@ # TRX Toolkit # DATA interface implementation # -# (C) 2017-2018 by Vadim Yanitskiy +# (C) 2017-2019 by Vadim Yanitskiy # # All Rights Reserved # @@ -29,9 +29,29 @@ from data_msg import * class DATAInterface(UDPLink): def __init__(self, *udp_link_args): + # Default header version (legacy) + self._hdr_ver = 0x00 + UDPLink.__init__(self, *udp_link_args) log.debug("Init TRXD interface (%s)" % self.desc_link()) + def set_hdr_ver(self, ver): + if not ver in DATAMSG.known_versions: + return False + + self._hdr_ver = ver + return True + + def match_hdr_ver(self, msg): + if msg.ver == self._hdr_ver: + return True + + log.error("(%s) Rx DATA message (%s) with unexpected header " + "version %u (!= expected %u), ignoring..." + % (self.desc_link(), msg.desc_hdr(), + msg.ver, self._hdr_ver)) + return False + def recv_raw_data(self): data, _ = self.sock.recvfrom(512) return data @@ -49,6 +69,11 @@ class DATAInterface(UDPLink): "from R:%s:%u" % (self.remote_addr, self.remote_port)) return None + # Make sure the header version matches + # the configured one (self._hdr_ver) + if not self.match_hdr_ver(msg): + return None + return msg def recv_trx2l1_msg(self): @@ -64,6 +89,11 @@ class DATAInterface(UDPLink): "from R:%s:%u" % (self.remote_addr, self.remote_port)) return None + # Make sure the header version matches + # the configured one (self._hdr_ver) + if not self.match_hdr_ver(msg): + return None + return msg def send_msg(self, msg, legacy = False): diff --git a/src/target/trx_toolkit/fake_trx.py b/src/target/trx_toolkit/fake_trx.py index 928333f6..de0e6ff0 100755 --- a/src/target/trx_toolkit/fake_trx.py +++ b/src/target/trx_toolkit/fake_trx.py @@ -35,9 +35,11 @@ import re from app_common import ApplicationBase from burst_fwd import BurstForwarder from transceiver import Transceiver +from data_msg import Modulation from clck_gen import CLCKGen from trx_list import TRXList from fake_pm import FakePM +from gsm_shared import * class FakeTRX(Transceiver): """ Fake transceiver with RF path (burst loss, RSSI, TA, ToA) simulation. @@ -98,18 +100,21 @@ class FakeTRX(Transceiver): TOA256_BASE_DEFAULT = 0 RSSI_BASE_DEFAULT = -60 + CI_BASE_DEFAULT = 90 def __init__(self, *trx_args, **trx_kwargs): Transceiver.__init__(self, *trx_args, **trx_kwargs) - # Actual ToA / RSSI / TA values + # Actual ToA, RSSI, C/I, TA values self.toa256_base = self.TOA256_BASE_DEFAULT self.rssi_base = self.RSSI_BASE_DEFAULT + self.ci_base = self.CI_BASE_DEFAULT self.ta = 0 - # ToA / RSSI randomization threshold + # ToA, RSSI, C/I randomization thresholds self.toa256_rand_threshold = 0 self.rssi_rand_threshold = 0 + self.ci_rand_threshold = 0 # Path loss simulation (burst dropping) self.burst_drop_amount = 0 @@ -137,6 +142,17 @@ class FakeTRX(Transceiver): rssi_max = self.rssi_base + self.rssi_rand_threshold return random.randint(rssi_min, rssi_max) + @property + def ci(self): + # Check if randomization is required + if self.ci_rand_threshold is 0: + return self.ci_base + + # Generate a random C/I value in required range + ci_min = self.ci_base - self.ci_rand_threshold + ci_max = self.ci_base + self.ci_rand_threshold + return random.randint(ci_min, ci_max) + # Path loss simulation: burst dropping # Returns: True - drop, False - keep def sim_burst_drop(self, msg): @@ -152,14 +168,41 @@ class FakeTRX(Transceiver): return False + def _handle_data_msg_v1(self, src_msg, msg): + # TODO: NOPE indications are not (yet) supported + msg.nope_ind = False + + # C/I (Carrier-to-Interference ratio) + msg.ci = self.ci + + # Pick modulation type by burst length + bl = len(src_msg.burst) + msg.mod_type = Modulation.pick_by_bl(bl) + + # Pick TSC (Training Sequence Code) and TSC set + if msg.mod_type is Modulation.ModGMSK: + ss = TrainingSeqGMSK.pick(src_msg.burst) + msg.tsc = ss.tsc if ss is not None else 0 + msg.tsc_set = ss.tsc_set if ss is not None else 0 + else: # TODO: other modulation types (at least 8-PSK) + msg.tsc_set = 0 + msg.tsc = 0 + # Takes (partially initialized) TRX2L1 message, # simulates RF path parameters (such as RSSI), # and sends towards the L1 - def send_data_msg(self, src_trx, msg): + def send_data_msg(self, src_trx, src_msg, msg): + # Override header version + msg.ver = self.data_if._hdr_ver + # Complete message header msg.toa256 = self.toa256 msg.rssi = self.rssi + # Version specific fields + if msg.ver >= 0x01: + self._handle_data_msg_v1(src_msg, msg) + # Apply optional Timing Advance if src_trx.ta is not 0: msg.toa256 -= src_trx.ta * 256 -- cgit v1.2.3