Update TX card selection logic

1. Now only cards with near-maximum RX packet counter will be used in RSSI filtering.
2. Python code cleanup

.pylintrc

@@ -0,0 +1,2 @@
+[TYPECHECK]
+ignored-classes=Section

Makefile

@@ -63,6 +63,10 @@ bdist: all_bin
 
 check:
 	cppcheck --std=c++11 --library=std --library=posix --library=gnu --inline-suppr --template=gcc --enable=all --suppress=cstyleCast --suppress=missingOverride --suppress=missingIncludeSystem src/
+
+pylint:
+	pylint --disable=R,C wfb_ng/*.py
+
 clean:
 	rm -rf env wfb_rx wfb_tx wfb_tx_cmd wfb_keygen dist deb_dist build wfb_ng.egg-info wfb-ng-*.tar.gz _trial_temp *~ src/*.o
 

wfb_ng/conf/master.cfg

@@ -22,7 +22,11 @@ radio_mtu = 1445          # Used for mavlink aggregation and for tunnel packets
 tunnel_agg_timeout= 0.005 # aggragate tuntap packets if less than radio_mtu but no longer than 5ms
 mavlink_agg_timeout = 0.1 # aggragate mavlink packets if less than radio_mtu but no longer than 100ms
 mavlink_err_rate = True   # If true then inject RX error rate else absolute values
-tx_sel_delta = 3          # hysteresis for antenna selection, [dB]
+
+tx_sel_rssi_delta = 3     # hysteresis for antenna selection by RSSI, [dB]
+tx_sel_counter_abs_delta = 3   # hysteresis for antenna selection by RX packet counter
+tx_sel_counter_rel_delta = 0.1 # default is max(3 packets or 10% of packets from the best antenna)
+
 tx_rcv_buf_size = 2097152  # UDP SO_RCVBUF. Set 0 to use net.core.rmem_default. Increase in case of non-cbr data stream
                            # This should not be greater than net.core.rmem_max
 

wfb_ng/latency_test.py

@@ -19,13 +19,12 @@
 #
 
 import sys
-import time
 import struct
 import os
 from twisted.python import log
 from twisted.internet import reactor, defer, task
 from twisted.internet.protocol import DatagramProtocol
-from twisted.trial import unittest
+
 from .common import df_sleep, abort_on_crash, exit_status
 
 

wfb_ng/mavlink_protocol.py

@@ -21,13 +21,13 @@
 import struct
 import time
 
-from . import call_and_check_rc, ExecError
+from . import call_and_check_rc
 from .mavlink import MAV_MODE_FLAG_SAFETY_ARMED, MAVLINK_MSG_ID_HEARTBEAT, mavlink_map
 
 from zope.interface import implementer
 from twisted.python import log
-from twisted.internet import reactor, defer, utils, interfaces
-from twisted.internet.protocol import Protocol, DatagramProtocol, Factory
+from twisted.internet import defer, interfaces
+from twisted.internet.protocol import Protocol, Factory
 
 
 def unpack_mavlink(msg_id, mbuf):

wfb_ng/proxy.py

@@ -18,9 +18,6 @@
 #   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 #
 
-import struct
-import os
-
 from contextlib import closing
 from twisted.python import log
 from twisted.internet import reactor, defer

wfb_ng/server.py

@@ -27,12 +27,10 @@ import time
 import struct
 import gzip
 
-from base64 import b85encode
 from itertools import groupby
 from twisted.python import log, failure
-from twisted.python.logfile import LogFile
 from twisted.internet import reactor, defer, main as ti_main, threads, task
-from twisted.internet.protocol import ProcessProtocol, Protocol, Factory
+from twisted.internet.protocol import ProcessProtocol, Factory
 from twisted.protocols.basic import LineReceiver, Int32StringReceiver
 from twisted.internet.serialport import SerialPort
 
@@ -114,7 +112,9 @@ class StatsAndSelectorFactory(Factory):
 
         # Select antenna #0 by default
         self.tx_sel = 0
-        self.tx_sel_delta = settings.common.tx_sel_delta
+        self.tx_sel_rssi_delta = settings.common.tx_sel_rssi_delta
+        self.tx_sel_counter_rel_delta = settings.common.tx_sel_counter_rel_delta
+        self.tx_sel_counter_abs_delta = settings.common.tx_sel_counter_abs_delta
 
         # tcp sockets for UI
         self.ui_sessions = []
@@ -212,34 +212,53 @@ class StatsAndSelectorFactory(Factory):
                                  snr_min, snr_avg, snr_max) in stats_agg.items())
 
     def select_tx_antenna(self, stats_agg):
-        wlan_rssi = {}
+        wlan_rssi_and_pkts = {}
+        max_pkts = 0
 
-        for k, grp in groupby(sorted(((ant_id >> 8) & 0xff, rssi_avg) \
+        for k, grp in groupby(sorted(((ant_id >> 8) & 0xff, pkt_s, rssi_avg) \
                                      for ant_id, (pkt_s,
                                                   rssi_min, rssi_avg, rssi_max,
                                                   snr_min, snr_avg, snr_max) in stats_agg.items()),
                               lambda x: x[0]):
-            # Select max average rssi [dBm] from all wlan's antennas
-            wlan_rssi[k] = max(rssi for _, rssi in grp)
 
-        if not wlan_rssi:
+            grp = list(grp)
+            # Use max average rssi [dBm] from all wlan's antennas
+            # Use max packet counter per antenna from all wlan's antennas
+            rssi = max(rssi for _, pkt_s, rssi in grp)
+            pkts = max(pkt_s for _, pkt_s, rssi in grp)
+            max_pkts = max(pkts, max_pkts)
+            wlan_rssi_and_pkts[k] = (rssi, pkts)
+
+        if not wlan_rssi_and_pkts:
             return
 
-        cur_ant_rssi = wlan_rssi.get(self.tx_sel, -1000)
-        max_rssi, max_rssi_ant = max((rssi, idx) for idx, rssi in wlan_rssi.items())
+        # Select antennas with near-maximum RX packet counters only
+        tx_sel_counter_thr = max_pkts - max(self.tx_sel_counter_abs_delta, max_pkts * self.tx_sel_counter_rel_delta)
+        ants_with_max_pkts = set(idx for idx, (rssi, pkt_s) in wlan_rssi_and_pkts.items() if pkt_s >= tx_sel_counter_thr)
 
-        if max_rssi <= cur_ant_rssi + self.tx_sel_delta:
+        if not ants_with_max_pkts:
             return
 
-        log.msg('Switch TX antenna from %d to %d' % (self.tx_sel, max_rssi_ant))
+        new_max_rssi, new_tx_ant = max((rssi, idx) for  idx, (rssi, pkt_s) in wlan_rssi_and_pkts.items() if idx in ants_with_max_pkts)
+        cur_max_rssi = wlan_rssi_and_pkts.get(self.tx_sel, (-1000, 0))[0]
+
+        if new_tx_ant == self.tx_sel:
+            return
+
+        if self.tx_sel in ants_with_max_pkts and new_max_rssi - cur_max_rssi < self.tx_sel_rssi_delta:
+            # Already selected antenna with near-maximum RX packets counter
+            # and other antennas doesn't have significally large RSSI
+            return
+
+        log.msg('Switch TX antenna #%d -> #%d, RSSI %d -> %d[dB]' % (self.tx_sel, new_tx_ant, cur_max_rssi, new_max_rssi))
 
         for ant_sel_cb in self.ant_sel_cb_list:
             try:
-                ant_sel_cb(max_rssi_ant)
+                ant_sel_cb(new_tx_ant)
             except Exception:
                 log.err()
 
-        self.tx_sel = max_rssi_ant
+        self.tx_sel = new_tx_ant
 
     def process_new_session(self, rx_id, session):
         if self.logger is not None:

wfb_ng/tuntap.py

@@ -19,19 +19,19 @@
 #
 
 import os
-from . import mavlink
 import fcntl
 import struct
 
 from collections import deque
 from twisted.python import log, failure
-from twisted.internet import reactor, defer, abstract, main, task
+from twisted.internet import defer, abstract, main, task
 from twisted.internet.protocol import Protocol, connectionDone
 from pyroute2 import IPRoute
 from contextlib import closing
-from .conf import settings
+
 from .proxy import ProxyProtocol
 
+
 class TUNTAPTransport(abstract.FileDescriptor):
     TUN = 0x0001
     TAP = 0x0002