1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/devices/wifi/minstrel-wifi-manager.cc Thu Aug 13 08:45:47 2009 +0200
1.3 @@ -0,0 +1,720 @@
1.4 +/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
1.5 +/*
1.6 + * Copyright (c) 2009 Duy Nguyen
1.7 + *
1.8 + * This program is free software; you can redistribute it and/or modify
1.9 + * it under the terms of the GNU General Public License version 2 as
1.10 + * published by the Free Software Foundation;
1.11 + *
1.12 + * This program is distributed in the hope that it will be useful,
1.13 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
1.14 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
1.15 + * GNU General Public License for more details.
1.16 + *
1.17 + * You should have received a copy of the GNU General Public License
1.18 + * along with this program; if not, write to the Free Software
1.19 + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
1.20 + *
1.21 + * Author: Duy Nguyen <duy@soe.ucsc.edu>
1.22 + *
1.23 + * Some Comments:
1.24 + *
1.25 + * 1) Segment Size is declared for completeness but not used because it has
1.26 + * to do more with the requirement of the specific hardware.
1.27 + *
1.28 + * 2) By default, Minstrel applies the multi-rate retry(the core of Minstrel
1.29 + * algorithm). Otherwise, please use ConstantRateWifiManager instead.
1.30 + *
1.31 + * http://linuxwireless.org/en/developers/Documentation/mac80211/RateControl/minstrel
1.32 + */
1.33 +
1.34 +
1.35 +
1.36 +#include "minstrel-wifi-manager.h"
1.37 +#include "wifi-phy.h"
1.38 +#include "ns3/random-variable.h"
1.39 +#include "ns3/simulator.h"
1.40 +#include "ns3/log.h"
1.41 +#include "ns3/uinteger.h"
1.42 +#include "ns3/double.h"
1.43 +#include "ns3/wifi-mac.h"
1.44 +#include "ns3/assert.h"
1.45 +#include <vector>
1.46 +
1.47 +NS_LOG_COMPONENT_DEFINE ("MinstrelWifiManager");
1.48 +
1.49 +
1.50 +namespace ns3 {
1.51 +
1.52 +NS_OBJECT_ENSURE_REGISTERED (MinstrelWifiManager);
1.53 +
1.54 +TypeId
1.55 +MinstrelWifiManager::GetTypeId (void)
1.56 +{
1.57 + static TypeId tid = TypeId ("ns3::MinstrelWifiManager")
1.58 + .SetParent<WifiRemoteStationManager> ()
1.59 + .AddConstructor<MinstrelWifiManager> ()
1.60 + .AddAttribute ("UpdateStatistics",
1.61 + "The interval between updating statistics table ",
1.62 + TimeValue (Seconds (0.1)),
1.63 + MakeTimeAccessor (&MinstrelWifiManager::m_updateStats),
1.64 + MakeTimeChecker ())
1.65 + .AddAttribute ("LookAroundRate",
1.66 + "the percentage to try other rates",
1.67 + DoubleValue (10),
1.68 + MakeDoubleAccessor (&MinstrelWifiManager::m_lookAroundRate),
1.69 + MakeDoubleChecker<double> ())
1.70 + .AddAttribute ("EWMA",
1.71 + "EWMA level",
1.72 + DoubleValue (75),
1.73 + MakeDoubleAccessor (&MinstrelWifiManager::m_ewmaLevel),
1.74 + MakeDoubleChecker<double> ())
1.75 + .AddAttribute ("SegmentSize",
1.76 + "The largest allowable segment size packet",
1.77 + DoubleValue (6000),
1.78 + MakeDoubleAccessor (&MinstrelWifiManager::m_segmentSize),
1.79 + MakeDoubleChecker <double> ())
1.80 + .AddAttribute ("SampleColumn",
1.81 + "The number of columns used for sampling",
1.82 + DoubleValue (10),
1.83 + MakeDoubleAccessor (&MinstrelWifiManager::m_sampleCol),
1.84 + MakeDoubleChecker <double> ())
1.85 + .AddAttribute ("PacketLength",
1.86 + "The packet length used for calculating mode TxTime",
1.87 + DoubleValue (1200),
1.88 + MakeDoubleAccessor (&MinstrelWifiManager::m_pktLen),
1.89 + MakeDoubleChecker <double> ())
1.90 + ;
1.91 + return tid;
1.92 +}
1.93 +
1.94 +MinstrelWifiManager::MinstrelWifiManager ()
1.95 +{}
1.96 +
1.97 +MinstrelWifiManager::~MinstrelWifiManager ()
1.98 +{}
1.99 +
1.100 +void
1.101 +MinstrelWifiManager::SetupPhy (Ptr<WifiPhy> phy)
1.102 +{
1.103 + uint32_t nModes = phy->GetNModes ();
1.104 + for (uint32_t i = 0; i < nModes; i++)
1.105 + {
1.106 + WifiMode mode = phy->GetMode (i);
1.107 + AddCalcTxTime (mode, phy->CalculateTxDuration (m_pktLen, mode, WIFI_PREAMBLE_LONG));
1.108 + }
1.109 + WifiRemoteStationManager::SetupPhy (phy);
1.110 +}
1.111 +
1.112 +WifiRemoteStation *
1.113 +MinstrelWifiManager::CreateStation (void)
1.114 +{
1.115 + return new MinstrelWifiRemoteStation (this);
1.116 +}
1.117 +
1.118 +Time
1.119 +MinstrelWifiManager::GetCalcTxTime (WifiMode mode) const
1.120 +{
1.121 +
1.122 + for (TxTime::const_iterator i = m_calcTxTime.begin (); i != m_calcTxTime.end (); i++)
1.123 + {
1.124 + if (mode == i->second)
1.125 + {
1.126 + return i->first;
1.127 + }
1.128 + }
1.129 + NS_ASSERT (false);
1.130 + return Seconds (0);
1.131 +}
1.132 +
1.133 +void
1.134 +MinstrelWifiManager::AddCalcTxTime (WifiMode mode, Time t)
1.135 +{
1.136 + m_calcTxTime.push_back (std::make_pair (t, mode));
1.137 +}
1.138 +
1.139 +MinstrelWifiRemoteStation::MinstrelWifiRemoteStation (Ptr<MinstrelWifiManager> stations)
1.140 + :m_stations (stations),
1.141 + m_nextStatsUpdate (Simulator::Now () + stations->m_updateStats),
1.142 + m_col (0),
1.143 + m_index (0),
1.144 + m_maxTpRate (0),
1.145 + m_maxTpRate2 (0),
1.146 + m_maxProbRate (0),
1.147 + m_packetCount (0),
1.148 + m_sampleCount (0),
1.149 + m_isSampling (false),
1.150 + m_sampleRate (0),
1.151 + m_sampleRateSlower (false),
1.152 + m_currentRate (0),
1.153 + m_shortRetry (0),
1.154 + m_longRetry (0),
1.155 + m_retry (0),
1.156 + m_err (0),
1.157 + m_txrate (0),
1.158 + m_initialized (false)
1.159 +{}
1.160 +
1.161 +MinstrelWifiRemoteStation::~MinstrelWifiRemoteStation ()
1.162 +{}
1.163 +
1.164 +void
1.165 +MinstrelWifiRemoteStation::CheckInit(void)
1.166 +{
1.167 + if (!m_initialized)
1.168 + {
1.169 + m_minstrelTable = MinstrelRate(GetNSupportedModes ());
1.170 + m_sampleTable = SampleRate(GetNSupportedModes (), std::vector<uint32_t> (m_stations->m_sampleCol));
1.171 + InitSampleTable ();
1.172 + RateInit ();
1.173 + m_initialized = true;
1.174 + }
1.175 +}
1.176 +
1.177 +void
1.178 +MinstrelWifiRemoteStation::DoReportRxOk (double rxSnr, WifiMode txMode)
1.179 +{
1.180 + NS_LOG_DEBUG("DoReportRxOk m_txrate=" << m_txrate);
1.181 +}
1.182 +
1.183 +void
1.184 +MinstrelWifiRemoteStation::DoReportRtsFailed (void)
1.185 +{
1.186 + NS_LOG_DEBUG("DoReportRtsFailed m_txrate=" << m_txrate);
1.187 +
1.188 + m_shortRetry++;
1.189 +}
1.190 +
1.191 +void
1.192 +MinstrelWifiRemoteStation::DoReportRtsOk (double ctsSnr, WifiMode ctsMode, double rtsSnr)
1.193 +{
1.194 + NS_LOG_DEBUG ("self="<<this<<" rts ok");
1.195 +}
1.196 +
1.197 +void
1.198 +MinstrelWifiRemoteStation::DoReportFinalRtsFailed (void)
1.199 +{
1.200 + UpdateRetry ();
1.201 + m_err++;
1.202 +}
1.203 +
1.204 +void
1.205 +MinstrelWifiRemoteStation::DoReportDataFailed (void)
1.206 +{
1.207 + CheckInit();
1.208 +
1.209 + m_longRetry++;
1.210 +
1.211 + NS_LOG_DEBUG ("DoReportDataFailed " << this << "\t rate " << m_txrate << "\tlongRetry \t" << m_longRetry);
1.212 +
1.213 + /// for normal rate, we're not currently sampling random rates
1.214 + if (!m_isSampling)
1.215 + {
1.216 + /// use best throughput rate
1.217 + if( m_longRetry < m_minstrelTable[m_txrate].adjustedRetryCount)
1.218 + {
1.219 + ; ///< there's still a few retries left
1.220 + }
1.221 +
1.222 + /// use second best throughput rate
1.223 + else if (m_longRetry <= (m_minstrelTable[m_txrate].adjustedRetryCount +
1.224 + m_minstrelTable[m_maxTpRate].adjustedRetryCount))
1.225 + {
1.226 + m_txrate = m_maxTpRate2;
1.227 + }
1.228 +
1.229 + /// use best probability rate
1.230 + else if (m_longRetry <= (m_minstrelTable[m_txrate].adjustedRetryCount +
1.231 + m_minstrelTable[m_maxTpRate2].adjustedRetryCount +
1.232 + m_minstrelTable[m_maxTpRate].adjustedRetryCount))
1.233 + {
1.234 + m_txrate = m_maxProbRate;
1.235 + }
1.236 +
1.237 + /// use lowest base rate
1.238 + else if (m_longRetry > (m_minstrelTable[m_txrate].adjustedRetryCount +
1.239 + m_minstrelTable[m_maxTpRate2].adjustedRetryCount +
1.240 + m_minstrelTable[m_maxTpRate].adjustedRetryCount))
1.241 + {
1.242 + m_txrate = 0;
1.243 + }
1.244 + }
1.245 +
1.246 + /// for look-around rate, we're currently sampling random rates
1.247 + else
1.248 + {
1.249 + /// current sampling rate is slower than the current best rate
1.250 + if (m_sampleRateSlower)
1.251 + {
1.252 + /// use best throughput rate
1.253 + if (m_longRetry < m_minstrelTable[m_txrate].adjustedRetryCount)
1.254 + {
1.255 + ; ///< there are a few retries left
1.256 + }
1.257 +
1.258 + /// use random rate
1.259 + else if (m_longRetry <= (m_minstrelTable[m_txrate].adjustedRetryCount +
1.260 + m_minstrelTable[m_maxTpRate].adjustedRetryCount))
1.261 + {
1.262 + m_txrate = m_sampleRate;
1.263 + }
1.264 +
1.265 + /// use max probability rate
1.266 + else if (m_longRetry <= (m_minstrelTable[m_txrate].adjustedRetryCount +
1.267 + m_minstrelTable[m_sampleRate].adjustedRetryCount +
1.268 + m_minstrelTable[m_maxTpRate].adjustedRetryCount ))
1.269 + {
1.270 + m_txrate = m_maxProbRate;
1.271 + }
1.272 +
1.273 + /// use lowest base rate
1.274 + else if (m_longRetry > (m_minstrelTable[m_txrate].adjustedRetryCount +
1.275 + m_minstrelTable[m_sampleRate].adjustedRetryCount +
1.276 + m_minstrelTable[m_maxTpRate].adjustedRetryCount))
1.277 + {
1.278 + m_txrate = 0;
1.279 + }
1.280 + }
1.281 +
1.282 + /// current sampling rate is better than current best rate
1.283 + else
1.284 + {
1.285 + /// use random rate
1.286 + if (m_longRetry < m_minstrelTable[m_txrate].adjustedRetryCount)
1.287 + {
1.288 + ; ///< keep using it
1.289 + }
1.290 +
1.291 + /// use the best rate
1.292 + else if (m_longRetry <= m_minstrelTable[m_txrate].adjustedRetryCount +
1.293 + m_minstrelTable[m_sampleRate].adjustedRetryCount)
1.294 + {
1.295 + m_txrate = m_maxTpRate;
1.296 + }
1.297 +
1.298 + /// use the best probability rate
1.299 + else if (m_longRetry <= m_minstrelTable[m_txrate].adjustedRetryCount +
1.300 + m_minstrelTable[m_maxTpRate].adjustedRetryCount +
1.301 + m_minstrelTable[m_sampleRate].adjustedRetryCount)
1.302 + {
1.303 + m_txrate = m_maxProbRate;
1.304 + }
1.305 +
1.306 + /// use the lowest base rate
1.307 + else if (m_longRetry > m_minstrelTable[m_txrate].adjustedRetryCount +
1.308 + m_minstrelTable[m_maxTpRate].adjustedRetryCount +
1.309 + m_minstrelTable[m_sampleRate].adjustedRetryCount)
1.310 + {
1.311 + m_txrate = 0;
1.312 + }
1.313 + }
1.314 + }
1.315 +}
1.316 +
1.317 +void
1.318 +MinstrelWifiRemoteStation::DoReportDataOk (double ackSnr, WifiMode ackMode, double dataSnr)
1.319 +{
1.320 + m_isSampling = false;
1.321 + m_sampleRateSlower=false;
1.322 +
1.323 + CheckInit ();
1.324 +
1.325 + m_minstrelTable[m_txrate].numRateSuccess++;
1.326 + m_minstrelTable[m_txrate].numRateAttempt++;
1.327 +
1.328 + UpdateRetry ();
1.329 +
1.330 + m_minstrelTable[m_txrate].numRateAttempt += m_retry;
1.331 + m_packetCount++;
1.332 +
1.333 + if (GetNSupportedModes () >= 1)
1.334 + {
1.335 + m_txrate = FindRate ();
1.336 + }
1.337 +}
1.338 +
1.339 +void
1.340 +MinstrelWifiRemoteStation::DoReportFinalDataFailed (void)
1.341 +{
1.342 + NS_LOG_DEBUG ("DoReportFinalDataFailed m_txrate=" << m_txrate);
1.343 +
1.344 + m_isSampling = false;
1.345 + m_sampleRateSlower=false;
1.346 +
1.347 + UpdateRetry ();
1.348 +
1.349 + m_minstrelTable[m_txrate].numRateAttempt += m_retry;
1.350 + m_err++;
1.351 +
1.352 + if (GetNSupportedModes () >= 1)
1.353 + {
1.354 + m_txrate = FindRate ();
1.355 + }
1.356 +}
1.357 +
1.358 +void
1.359 +MinstrelWifiRemoteStation::UpdateRetry (void)
1.360 +{
1.361 + m_retry = m_shortRetry + m_longRetry;
1.362 + m_shortRetry = 0;
1.363 + m_longRetry = 0;
1.364 +}
1.365 +
1.366 +Ptr<WifiRemoteStationManager>
1.367 +MinstrelWifiRemoteStation::GetManager (void) const
1.368 +{
1.369 + return m_stations;
1.370 +}
1.371 +
1.372 +WifiMode
1.373 +MinstrelWifiRemoteStation::DoGetDataMode (uint32_t size)
1.374 +{
1.375 + UpdateStats ();
1.376 + if (!m_initialized)
1.377 + {
1.378 + CheckInit ();
1.379 +
1.380 + /// start the rate at half way
1.381 + m_txrate = GetNSupportedModes () / 2;
1.382 + }
1.383 + return GetSupportedMode (m_txrate);
1.384 +}
1.385 +
1.386 +WifiMode
1.387 +MinstrelWifiRemoteStation::DoGetRtsMode (void)
1.388 +{
1.389 + NS_LOG_DEBUG ("DoGetRtsMode m_txrate=" << m_txrate);
1.390 +
1.391 + UpdateStats ();
1.392 + return GetSupportedMode (0);
1.393 +}
1.394 +
1.395 +uint32_t
1.396 +MinstrelWifiRemoteStation::GetNextSample ()
1.397 +{
1.398 + uint32_t bitrate;
1.399 + bitrate = m_sampleTable[m_index][m_col];
1.400 + m_index++;
1.401 +
1.402 + /// bookeeping for m_index and m_col variables
1.403 + if (m_index > (GetNSupportedModes () -2))
1.404 + {
1.405 + m_index =0;
1.406 + m_col++;
1.407 + if (m_col >= m_stations->m_sampleCol)
1.408 + {
1.409 + m_col = 0;
1.410 + }
1.411 + }
1.412 + return bitrate;
1.413 +}
1.414 +
1.415 +uint32_t
1.416 +MinstrelWifiRemoteStation::FindRate ()
1.417 +{
1.418 + NS_LOG_DEBUG ("FindRate " << "packet=" << m_packetCount );
1.419 +
1.420 + if ((m_sampleCount + m_packetCount) == 0)
1.421 + {
1.422 + return 0;
1.423 + }
1.424 +
1.425 +
1.426 + uint32_t idx;
1.427 +
1.428 + /// for determining when to try a sample rate
1.429 + UniformVariable coinFlip (0, 100);
1.430 +
1.431 + /**
1.432 + * if we are below the target of look around rate percentage, look around
1.433 + * note: do it randomly by flipping a coin instead sampling
1.434 + * all at once until it reaches the look around rate
1.435 + */
1.436 + if ( (((100* m_sampleCount) / (m_sampleCount + m_packetCount )) < m_stations->m_lookAroundRate) &&
1.437 + ((int)coinFlip.GetValue ()) % 2 == 1 )
1.438 + {
1.439 +
1.440 + /// now go through the table and find an index rate
1.441 + idx = GetNextSample ();
1.442 +
1.443 +
1.444 + /**
1.445 + * This if condition is used to make sure that we don't need to use
1.446 + * the sample rate it is the same as our current rate
1.447 + */
1.448 + if (idx != m_maxTpRate && idx != m_txrate)
1.449 + {
1.450 +
1.451 + /// start sample count
1.452 + m_sampleCount++;
1.453 +
1.454 + /// set flag that we are currently sampling
1.455 + m_isSampling = true;
1.456 +
1.457 + /// bookeeping for resetting stuff
1.458 + if (m_packetCount >= 10000)
1.459 + {
1.460 + m_sampleCount = 0;
1.461 + m_packetCount = 0;
1.462 + }
1.463 +
1.464 + /// error check
1.465 + if (idx >= GetNSupportedModes () || idx < 0 )
1.466 + {
1.467 + NS_LOG_DEBUG ("ALERT!!! ERROR");
1.468 + }
1.469 +
1.470 + /// set the rate that we're currently sampling
1.471 + m_sampleRate = idx;
1.472 +
1.473 + if (m_sampleRate == m_maxTpRate)
1.474 + {
1.475 + m_sampleRate = m_maxTpRate2;
1.476 + }
1.477 +
1.478 + /// is this rate slower than the current best rate
1.479 + m_sampleRateSlower = (m_minstrelTable[idx].perfectTxTime > m_minstrelTable[m_maxTpRate].perfectTxTime);
1.480 +
1.481 + /// using the best rate instead
1.482 + if (m_sampleRateSlower)
1.483 + {
1.484 + idx = m_maxTpRate;
1.485 + }
1.486 + }
1.487 +
1.488 + }
1.489 +
1.490 + /// continue using the best rate
1.491 + else
1.492 + {
1.493 + idx = m_maxTpRate;
1.494 + }
1.495 +
1.496 +
1.497 + NS_LOG_DEBUG ("FindRate " << "sample rate=" << idx);
1.498 +
1.499 + return idx;
1.500 +}
1.501 +
1.502 +void
1.503 +MinstrelWifiRemoteStation::UpdateStats ()
1.504 +{
1.505 + if (Simulator::Now () < m_nextStatsUpdate)
1.506 + {
1.507 + return;
1.508 + }
1.509 +
1.510 + NS_LOG_DEBUG ("Updating stats="<<this);
1.511 +
1.512 + m_nextStatsUpdate = Simulator::Now () + m_stations->m_updateStats;
1.513 +
1.514 + Time txTime;
1.515 + uint32_t tempProb;
1.516 +
1.517 + for (uint32_t i =0; i < GetNSupportedModes (); i++)
1.518 + {
1.519 +
1.520 + /// calculate the perfect tx time for this rate
1.521 + txTime = m_minstrelTable[i].perfectTxTime;
1.522 +
1.523 + /// just for initialization
1.524 + if (txTime.GetMicroSeconds () == 0)
1.525 + {
1.526 + txTime = Seconds (1);
1.527 + }
1.528 +
1.529 + NS_LOG_DEBUG ("m_txrate=" << m_txrate << "\t attempt=" << m_minstrelTable[i].numRateAttempt << "\t success=" << m_minstrelTable[i].numRateSuccess);
1.530 +
1.531 + /// if we've attempted something
1.532 + if (m_minstrelTable[i].numRateAttempt)
1.533 + {
1.534 + /**
1.535 + * calculate the probability of success
1.536 + * assume probability scales from 0 to 18000
1.537 + */
1.538 + tempProb = (m_minstrelTable[i].numRateSuccess * 18000) / m_minstrelTable[i].numRateAttempt;
1.539 +
1.540 + /// bookeeping
1.541 + m_minstrelTable[i].successHist += m_minstrelTable[i].numRateSuccess;
1.542 + m_minstrelTable[i].attemptHist += m_minstrelTable[i].numRateAttempt;
1.543 + m_minstrelTable[i].prob = tempProb;
1.544 +
1.545 + /// ewma probability
1.546 + tempProb = ((tempProb * (100 - m_stations->m_ewmaLevel)) + (m_minstrelTable[i].ewmaProb * m_stations->m_ewmaLevel) )/100;
1.547 +
1.548 + m_minstrelTable[i].ewmaProb = tempProb;
1.549 +
1.550 + /// calculating throughput
1.551 + m_minstrelTable[i].throughput = tempProb * (1000000 / txTime.GetMicroSeconds());
1.552 +
1.553 + }
1.554 +
1.555 + /// bookeeping
1.556 + m_minstrelTable[i].prevNumRateAttempt= m_minstrelTable[i].numRateAttempt;
1.557 + m_minstrelTable[i].prevNumRateSuccess = m_minstrelTable[i].numRateSuccess;
1.558 + m_minstrelTable[i].numRateSuccess = 0;
1.559 + m_minstrelTable[i].numRateAttempt = 0;
1.560 +
1.561 + /// Sample less often below 10% and above 95% of success
1.562 + if ((m_minstrelTable[i].ewmaProb > 17100) || (m_minstrelTable[i].ewmaProb < 1800))
1.563 + {
1.564 + /**
1.565 + * retry count denotes the number of retries permitted for each rate
1.566 + * # retry_count/2
1.567 + */
1.568 + m_minstrelTable[i].adjustedRetryCount = m_minstrelTable[i].retryCount >> 1;
1.569 + if (m_minstrelTable[i].adjustedRetryCount > 2)
1.570 + {
1.571 + m_minstrelTable[i].adjustedRetryCount = 2 ;
1.572 + }
1.573 + }
1.574 + else
1.575 + {
1.576 + m_minstrelTable[i].adjustedRetryCount = m_minstrelTable[i].retryCount;
1.577 + }
1.578 +
1.579 + /// if it's 0 allow one retry limit
1.580 + if (m_minstrelTable[i].adjustedRetryCount == 0)
1.581 + {
1.582 + m_minstrelTable[i].adjustedRetryCount = 1;
1.583 + }
1.584 + }
1.585 +
1.586 +
1.587 + uint32_t max_prob = 0, index_max_prob =0, max_tp =0, index_max_tp=0, index_max_tp2=0;
1.588 +
1.589 + /// go find max throughput, second maximum throughput, high probability succ
1.590 + for (uint32_t i =0; i < GetNSupportedModes (); i++)
1.591 + {
1.592 + NS_LOG_DEBUG ("throughput" << m_minstrelTable[i].throughput << "\n ewma" << m_minstrelTable[i].ewmaProb);
1.593 +
1.594 + if (max_tp < m_minstrelTable[i].throughput)
1.595 + {
1.596 + index_max_tp = i;
1.597 + max_tp = m_minstrelTable[i].throughput;
1.598 + }
1.599 +
1.600 + if (max_prob < m_minstrelTable[i].ewmaProb)
1.601 + {
1.602 + index_max_prob = i;
1.603 + max_prob = m_minstrelTable[i].ewmaProb;
1.604 + }
1.605 + }
1.606 +
1.607 +
1.608 + max_tp = 0;
1.609 + /// find the second highest max
1.610 + for (uint32_t i =0; i < GetNSupportedModes (); i++)
1.611 + {
1.612 + if ((i != index_max_tp) && (max_tp < m_minstrelTable[i].throughput))
1.613 + {
1.614 + index_max_tp2 = i;
1.615 + max_tp = m_minstrelTable[i].throughput;
1.616 + }
1.617 + }
1.618 +
1.619 + m_maxTpRate = index_max_tp;
1.620 + m_maxTpRate2 = index_max_tp2;
1.621 + m_maxProbRate = index_max_prob;
1.622 + m_currentRate = index_max_tp;
1.623 +
1.624 + if (index_max_tp > m_txrate)
1.625 + {
1.626 + m_txrate= index_max_tp;
1.627 + }
1.628 +
1.629 + NS_LOG_DEBUG ("max tp="<< index_max_tp << "\nmax tp2="<< index_max_tp2<< "\nmax prob="<< index_max_prob);
1.630 +
1.631 + /// reset it
1.632 + RateInit ();
1.633 +}
1.634 +
1.635 +void
1.636 +MinstrelWifiRemoteStation::RateInit ()
1.637 +{
1.638 + NS_LOG_DEBUG ("RateInit="<<this);
1.639 +
1.640 + for (uint32_t i = 0; i < GetNSupportedModes (); i++)
1.641 + {
1.642 + m_minstrelTable[i].numRateAttempt = 0;
1.643 + m_minstrelTable[i].numRateSuccess = 0;
1.644 + m_minstrelTable[i].prob = 0;
1.645 + m_minstrelTable[i].ewmaProb = 0;
1.646 + m_minstrelTable[i].prevNumRateAttempt = 0;
1.647 + m_minstrelTable[i].prevNumRateSuccess = 0;
1.648 + m_minstrelTable[i].successHist = 0;
1.649 + m_minstrelTable[i].attemptHist = 0;
1.650 + m_minstrelTable[i].throughput = 0;
1.651 + m_minstrelTable[i].perfectTxTime = m_stations->GetCalcTxTime (GetSupportedMode (i));
1.652 + m_minstrelTable[i].retryCount =1;
1.653 + m_minstrelTable[i].adjustedRetryCount =1;
1.654 + }
1.655 +}
1.656 +
1.657 +void
1.658 +MinstrelWifiRemoteStation::InitSampleTable ()
1.659 +{
1.660 + NS_LOG_DEBUG ("InitSampleTable="<<this);
1.661 +
1.662 + m_col = m_index = 0;
1.663 +
1.664 + /// for off-seting to make rates fall between 0 and numrates
1.665 + uint32_t numSampleRates= GetNSupportedModes () - 1;
1.666 +
1.667 + uint32_t newIndex;
1.668 + for (uint32_t col = 0; col < m_stations->m_sampleCol; col++)
1.669 + {
1.670 + for (uint32_t i = 0; i < numSampleRates; i++ )
1.671 + {
1.672 +
1.673 + /**
1.674 + * The next two lines basically tries to generate a random number
1.675 + * between 0 and the number of available rates
1.676 + */
1.677 + UniformVariable uv (0, numSampleRates);
1.678 + newIndex = (i + (uint32_t)uv.GetValue ()) % numSampleRates;
1.679 +
1.680 + /// this loop is used for filling in other uninitilized places
1.681 + while (m_sampleTable[newIndex][col] != 0)
1.682 + {
1.683 + newIndex = (newIndex + 1)%GetNSupportedModes ();
1.684 + }
1.685 + m_sampleTable[newIndex][col] = i+1;
1.686 +
1.687 + }
1.688 + }
1.689 +}
1.690 +
1.691 +void
1.692 +MinstrelWifiRemoteStation::PrintSampleTable ()
1.693 +{
1.694 + NS_LOG_DEBUG ("PrintSampleTable="<<this );
1.695 +
1.696 + uint32_t numSampleRates= GetNSupportedModes ();
1.697 + for (uint32_t i=0; i < numSampleRates; i++)
1.698 + {
1.699 + for (uint32_t j=0; j < m_stations->m_sampleCol; j++)
1.700 + {
1.701 + std::cout << m_sampleTable[i][j] << "\t";
1.702 + }
1.703 + std::cout << std::endl;
1.704 + }
1.705 +}
1.706 +
1.707 +void
1.708 +MinstrelWifiRemoteStation::PrintTable ()
1.709 +{
1.710 + NS_LOG_DEBUG ("PrintTable="<<this);
1.711 +
1.712 + for (uint32_t i=0; i < GetNSupportedModes (); i++)
1.713 + {
1.714 + std::cout << "index(" << i << ") = " << m_minstrelTable[i].perfectTxTime<< "\n";
1.715 + }
1.716 +}
1.717 +
1.718 +} //namespace ns3
1.719 +
1.720 +
1.721 +
1.722 +
1.723 +
2.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
2.2 +++ b/src/devices/wifi/minstrel-wifi-manager.h Thu Aug 13 08:45:47 2009 +0200
2.3 @@ -0,0 +1,255 @@
2.4 +/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
2.5 +/*
2.6 + * Copyright (c) 2009 Duy Nguyen
2.7 + *
2.8 + * This program is free software; you can redistribute it and/or modify
2.9 + * it under the terms of the GNU General Public License version 2 as
2.10 + * published by the Free Software Foundation;
2.11 + *
2.12 + * This program is distributed in the hope that it will be useful,
2.13 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
2.14 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
2.15 + * GNU General Public License for more details.
2.16 + *
2.17 + * You should have received a copy of the GNU General Public License
2.18 + * along with this program; if not, write to the Free Software
2.19 + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
2.20 + *
2.21 + * Author: Duy Nguyen <duy@soe.ucsc.edu>
2.22 + */
2.23 +
2.24 +
2.25 +
2.26 +#ifndef MINSTREL_WIFI_MANAGER_H
2.27 +#define MINSTREL_WIFI_MANAGER_H
2.28 +
2.29 +#include "wifi-remote-station-manager.h"
2.30 +#include "wifi-mode.h"
2.31 +#include "ns3/nstime.h"
2.32 +#include <vector>
2.33 +
2.34 +
2.35 +
2.36 +/**
2.37 + * \author Duy Nguyen
2.38 + * \brief Implementation of Minstrel Rate Control Algorithm
2.39 + *
2.40 + * Porting Minstrel from Madwifi and Linux Kernel
2.41 + * http://linuxwireless.org/en/developers/Documentation/mac80211/RateControl/minstrel
2.42 + */
2.43 +
2.44 +
2.45 +namespace ns3 {
2.46 +
2.47 +
2.48 +/**
2.49 + * A struct to contain all information related to a data rate
2.50 + */
2.51 +struct RateInfo{
2.52 +
2.53 + /**
2.54 + * Perfect transmission time calculation, or frame calculation
2.55 + * Given a bit rate and a packet length n bytes
2.56 + */
2.57 + Time perfectTxTime;
2.58 +
2.59 +
2.60 + uint32_t retryCount; ///< retry limit
2.61 + uint32_t adjustedRetryCount; ///< adjust the retry limit for this rate
2.62 + uint32_t numRateAttempt; ///< how many number of attempts so far
2.63 + uint32_t numRateSuccess; ///< number of successful pkts
2.64 + uint32_t prob; ///< (# pkts success )/(# total pkts)
2.65 +
2.66 + /**
2.67 + * EWMA calculation
2.68 + * ewma_prob =[prob *(100 - ewma_level) + (ewma_prob_old * ewma_level)]/100
2.69 + */
2.70 + uint32_t ewmaProb;
2.71 +
2.72 + uint32_t prevNumRateAttempt; ///< from last rate
2.73 + uint32_t prevNumRateSuccess; ///< from last rate
2.74 + uint64_t successHist; ///< aggregate of all successes
2.75 + uint64_t attemptHist; ///< aggregate of all attempts
2.76 + uint32_t throughput; ///< throughput of a rate
2.77 +};
2.78 +
2.79 +/**
2.80 + * Data structure for a Minstrel Rate table
2.81 + * A vector of a struct RateInfo
2.82 + */
2.83 +typedef std::vector<struct RateInfo> MinstrelRate;
2.84 +
2.85 +/**
2.86 + * Data structure for a Sample Rate table
2.87 + * A vector of a vector uint32_t
2.88 + */
2.89 +typedef std::vector<std::vector<uint32_t> > SampleRate;
2.90 +
2.91 +
2.92 +class MinstrelWifiManager : public WifiRemoteStationManager
2.93 +{
2.94 +
2.95 +public:
2.96 + static TypeId GetTypeId (void);
2.97 + MinstrelWifiManager ();
2.98 + virtual ~MinstrelWifiManager();
2.99 +
2.100 + virtual void SetupPhy (Ptr<WifiPhy> phy);
2.101 +
2.102 + /// for estimating the TxTime of a packet with a given mode
2.103 + Time GetCalcTxTime (WifiMode mode) const;
2.104 + void AddCalcTxTime (WifiMode mode, Time t);
2.105 +
2.106 +private:
2.107 + friend class MinstrelWifiRemoteStation;
2.108 + virtual class WifiRemoteStation *CreateStation (void);
2.109 +
2.110 + typedef std::vector<std::pair<Time,WifiMode> > TxTime;
2.111 +
2.112 + TxTime m_calcTxTime; ///< to hold all the calculated TxTime for all modes
2.113 + Time m_updateStats; ///< how frequent do we calculate the stats(1/10 seconds)
2.114 + double m_lookAroundRate; ///< the % to try other rates than our current rate
2.115 + double m_ewmaLevel; ///< exponential weighted moving average
2.116 + uint32_t m_segmentSize; ///< largest allowable segment size
2.117 + uint32_t m_sampleCol; ///< number of sample columns
2.118 + uint32_t m_pktLen; ///< packet length used for calculate mode TxTime
2.119 +
2.120 +};
2.121 +
2.122 +class MinstrelWifiRemoteStation : public WifiRemoteStation
2.123 +{
2.124 +public:
2.125 + MinstrelWifiRemoteStation (Ptr<MinstrelWifiManager> stations);
2.126 +
2.127 + virtual ~MinstrelWifiRemoteStation ();
2.128 +
2.129 +protected:
2.130 +
2.131 + /**
2.132 + * when packet is successfully received
2.133 + * see wifi-remote-station-manager.h for more documentation
2.134 + */
2.135 + virtual void DoReportRxOk (double rxSnr, WifiMode txMode);
2.136 +
2.137 + /// when RTS timeout expires
2.138 + virtual void DoReportRtsFailed (void);
2.139 +
2.140 +
2.141 + /**
2.142 + *
2.143 + * Retry Chain table is implemented here
2.144 + *
2.145 + * Try | LOOKAROUND RATE | NORMAL RATE
2.146 + * | random < best | random > best |
2.147 + * --------------------------------------------------------------
2.148 + * 1 | Best throughput | Random rate | Best throughput
2.149 + * 2 | Random rate | Best throughput | Next best throughput
2.150 + * 3 | Best probability | Best probability | Best probability
2.151 + * 4 | Lowest Baserate | Lowest baserate | Lowest baserate
2.152 + *
2.153 + * Note: For clarity, multiple blocks of if's and else's are used
2.154 + * After a failing 7 times, DoReportFinalDataFailed will be called
2.155 + */
2.156 + virtual void DoReportDataFailed (void);
2.157 +
2.158 + /// when receive a CTS, associated with an RTS
2.159 + virtual void DoReportRtsOk (double ctsSnr, WifiMode ctsMode, double rtsSnr);
2.160 +
2.161 + /// when an ACK, associated with a data pkt, is received
2.162 + virtual void DoReportDataOk (double ackSnr, WifiMode ackMode, double dataSnr);
2.163 +
2.164 + /// after calling ReportRtsFailed if NeedRtsRetransmission returns false
2.165 + virtual void DoReportFinalRtsFailed (void);
2.166 +
2.167 + /// after calling ReportDataFailed if NeedDataRetransmission returns false
2.168 + virtual void DoReportFinalDataFailed (void);
2.169 +
2.170 +
2.171 +private:
2.172 + virtual Ptr<WifiRemoteStationManager> GetManager (void) const;
2.173 +
2.174 + /**
2.175 + * returns the transmission mode for sending this packet
2.176 + * this function gets called when node is getting ready to send DATA
2.177 + * see wifi-remote-station-manager.h for more documentation
2.178 + */
2.179 + virtual WifiMode DoGetDataMode (uint32_t size);
2.180 +
2.181 + /// returns the transmission mode for sending RTS packet
2.182 + virtual WifiMode DoGetRtsMode (void);
2.183 +
2.184 + /// update the number of retries and reset accordingly
2.185 + void UpdateRetry (void);
2.186 +
2.187 + /// getting the next sample from Sample Table
2.188 + uint32_t GetNextSample (void);
2.189 +
2.190 + /// find a rate to use from Minstrel Table
2.191 + uint32_t FindRate (void);
2.192 +
2.193 + /// updating the Minstrel Table every 1/10 seconds
2.194 + void UpdateStats (void);
2.195 +
2.196 + /// initialize Minstrel Table
2.197 + void RateInit (void);
2.198 +
2.199 + /// initialize Sample Table
2.200 + void InitSampleTable (void);
2.201 +
2.202 + /// printing Sample Table
2.203 + void PrintSampleTable (void);
2.204 +
2.205 + /// printing Minstrel Table
2.206 + void PrintTable (void);
2.207 +
2.208 + /**
2.209 + * \param packet lenghth
2.210 + * \param current WifiMode
2.211 + * \returns calcuated transmit duration
2.212 + */
2.213 + Time CalcRatePacket (uint32_t, WifiMode);
2.214 +
2.215 + void CheckInit(void); ///< check for initializations
2.216 +
2.217 + Ptr<MinstrelWifiManager> m_stations;
2.218 +
2.219 + Time m_nextStatsUpdate; ///< 10 times every second
2.220 +
2.221 + MinstrelRate m_minstrelTable; ///< minstrel table
2.222 +
2.223 + SampleRate m_sampleTable; ///< sample table
2.224 +
2.225 + /**
2.226 + * To keep track of the current position in the our random sample table
2.227 + * going row by row from 1st column until the 10th column(Minstrel defines 10)
2.228 + * then we wrap back to the row 1 col 1.
2.229 + * note: there are many other ways to do this.
2.230 + */
2.231 + uint32_t m_col, m_index;
2.232 +
2.233 + uint32_t m_maxTpRate; ///< the current throughput rate
2.234 + uint32_t m_maxTpRate2; ///< second highest throughput rate
2.235 + uint32_t m_maxProbRate; ///< rate with highest prob of success
2.236 +
2.237 + int m_packetCount; ///< total number of packets as of now
2.238 + int m_sampleCount; ///< how many packets we have sample so far
2.239 +
2.240 + bool m_isSampling; ///< a flag to indicate we are currently sampling
2.241 + uint32_t m_sampleRate; ///< current sample rate
2.242 + bool m_sampleRateSlower; ///< a flag to indicate sample rate is slower
2.243 + uint32_t m_currentRate; ///< current rate we are using
2.244 +
2.245 + uint32_t m_shortRetry; ///< short retries such as control packts
2.246 + uint32_t m_longRetry; ///< long retries such as data packets
2.247 + uint32_t m_retry; ///< total retries short + long
2.248 + uint32_t m_err; ///< retry errors
2.249 + uint32_t m_txrate; ///< current transmit rate
2.250 +
2.251 + bool m_initialized; ///< for initializing tables
2.252 +
2.253 +
2.254 +};
2.255 +
2.256 +}// namespace ns3
2.257 +
2.258 +#endif /* MINSTREL_WIFI_MANAGER_H */
3.1 --- a/src/devices/wifi/wscript Wed Aug 12 12:07:25 2009 +0100
3.2 +++ b/src/devices/wifi/wscript Thu Aug 13 08:45:47 2009 +0200
3.3 @@ -63,6 +63,7 @@
3.4 'msdu-aggregator.cc',
3.5 'amsdu-subframe-header.cc',
3.6 'msdu-standard-aggregator.cc',
3.7 + 'minstrel-wifi-manager.cc',
3.8 ]
3.9 headers = bld.new_task_gen('ns3header')
3.10 headers.module = 'wifi'
3.11 @@ -113,6 +114,7 @@
3.12 'dcf-manager.h',
3.13 'mac-rx-middle.h',
3.14 'mac-low.h',
3.15 + 'minstrel-wifi-manager.h'
3.16 ]
3.17
3.18 if bld.env['ENABLE_GSL']: