| /* |
| * Copyright (c) 2018, The OpenThread Authors. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. Neither the name of the copyright holder nor the |
| * names of its contributors may be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE |
| * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| * POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| /** |
| * @file |
| * This file implements the channel monitoring module. |
| */ |
| |
| #include "channel_monitor.hpp" |
| |
| #if OPENTHREAD_CONFIG_CHANNEL_MONITOR_ENABLE |
| |
| #include "common/code_utils.hpp" |
| #include "common/locator_getters.hpp" |
| #include "common/log.hpp" |
| #include "common/random.hpp" |
| |
| namespace ot { |
| namespace Utils { |
| |
| RegisterLogModule("ChannelMonitor"); |
| |
| const uint32_t ChannelMonitor::mScanChannelMasks[kNumChannelMasks] = { |
| #if OPENTHREAD_CONFIG_RADIO_915MHZ_OQPSK_SUPPORT |
| OT_CHANNEL_1_MASK | OT_CHANNEL_5_MASK | OT_CHANNEL_9_MASK, |
| OT_CHANNEL_2_MASK | OT_CHANNEL_6_MASK | OT_CHANNEL_10_MASK, |
| OT_CHANNEL_3_MASK | OT_CHANNEL_7_MASK, |
| OT_CHANNEL_4_MASK | OT_CHANNEL_8_MASK, |
| #endif |
| #if OPENTHREAD_CONFIG_RADIO_2P4GHZ_OQPSK_SUPPORT |
| OT_CHANNEL_11_MASK | OT_CHANNEL_15_MASK | OT_CHANNEL_19_MASK | OT_CHANNEL_23_MASK, |
| OT_CHANNEL_12_MASK | OT_CHANNEL_16_MASK | OT_CHANNEL_20_MASK | OT_CHANNEL_24_MASK, |
| OT_CHANNEL_13_MASK | OT_CHANNEL_17_MASK | OT_CHANNEL_21_MASK | OT_CHANNEL_25_MASK, |
| OT_CHANNEL_14_MASK | OT_CHANNEL_18_MASK | OT_CHANNEL_22_MASK | OT_CHANNEL_26_MASK, |
| #endif |
| }; |
| |
| ChannelMonitor::ChannelMonitor(Instance &aInstance) |
| : InstanceLocator(aInstance) |
| , mChannelMaskIndex(0) |
| , mSampleCount(0) |
| , mTimer(aInstance, ChannelMonitor::HandleTimer) |
| { |
| memset(mChannelOccupancy, 0, sizeof(mChannelOccupancy)); |
| } |
| |
| Error ChannelMonitor::Start(void) |
| { |
| Error error = kErrorNone; |
| |
| VerifyOrExit(!IsRunning(), error = kErrorAlready); |
| Clear(); |
| mTimer.Start(kTimerInterval); |
| LogDebg("Starting"); |
| |
| exit: |
| return error; |
| } |
| |
| Error ChannelMonitor::Stop(void) |
| { |
| Error error = kErrorNone; |
| |
| VerifyOrExit(IsRunning(), error = kErrorAlready); |
| mTimer.Stop(); |
| LogDebg("Stopping"); |
| |
| exit: |
| return error; |
| } |
| |
| void ChannelMonitor::Clear(void) |
| { |
| mChannelMaskIndex = 0; |
| mSampleCount = 0; |
| memset(mChannelOccupancy, 0, sizeof(mChannelOccupancy)); |
| |
| LogDebg("Clearing data"); |
| } |
| |
| uint16_t ChannelMonitor::GetChannelOccupancy(uint8_t aChannel) const |
| { |
| uint16_t occupancy = 0; |
| |
| VerifyOrExit((Radio::kChannelMin <= aChannel) && (aChannel <= Radio::kChannelMax)); |
| occupancy = mChannelOccupancy[aChannel - Radio::kChannelMin]; |
| |
| exit: |
| return occupancy; |
| } |
| |
| void ChannelMonitor::HandleTimer(Timer &aTimer) |
| { |
| aTimer.Get<ChannelMonitor>().HandleTimer(); |
| } |
| |
| void ChannelMonitor::HandleTimer(void) |
| { |
| IgnoreError(Get<Mac::Mac>().EnergyScan(mScanChannelMasks[mChannelMaskIndex], 0, |
| &ChannelMonitor::HandleEnergyScanResult, this)); |
| |
| mTimer.StartAt(mTimer.GetFireTime(), Random::NonCrypto::AddJitter(kTimerInterval, kMaxJitterInterval)); |
| } |
| |
| void ChannelMonitor::HandleEnergyScanResult(Mac::EnergyScanResult *aResult, void *aContext) |
| { |
| static_cast<ChannelMonitor *>(aContext)->HandleEnergyScanResult(aResult); |
| } |
| |
| void ChannelMonitor::HandleEnergyScanResult(Mac::EnergyScanResult *aResult) |
| { |
| if (aResult == nullptr) |
| { |
| if (mChannelMaskIndex == kNumChannelMasks - 1) |
| { |
| mChannelMaskIndex = 0; |
| mSampleCount++; |
| LogResults(); |
| } |
| else |
| { |
| mChannelMaskIndex++; |
| } |
| } |
| else |
| { |
| uint8_t channelIndex = (aResult->mChannel - Radio::kChannelMin); |
| uint32_t newAverage = mChannelOccupancy[channelIndex]; |
| uint32_t newValue = 0; |
| uint32_t weight; |
| |
| OT_ASSERT(channelIndex < kNumChannels); |
| |
| LogDebg("channel: %d, rssi:%d", aResult->mChannel, aResult->mMaxRssi); |
| |
| if (aResult->mMaxRssi != OT_RADIO_RSSI_INVALID) |
| { |
| newValue = (aResult->mMaxRssi >= kRssiThreshold) ? kMaxOccupancy : 0; |
| } |
| |
| // `mChannelOccupancy` stores the average rate/percentage of RSS |
| // samples that are higher than a given RSS threshold ("bad" RSS |
| // samples). For the first `kSampleWindow` samples, the average is |
| // maintained as the actual percentage (i.e., ratio of number of |
| // "bad" samples by total number of samples). After `kSampleWindow` |
| // samples, the averager uses an exponentially weighted moving |
| // average logic with weight coefficient `1/kSampleWindow` for new |
| // values. Practically, this means the average is representative |
| // of up to `3 * kSampleWindow` samples with highest weight given |
| // to the latest `kSampleWindow` samples. |
| |
| if (mSampleCount >= kSampleWindow) |
| { |
| weight = kSampleWindow - 1; |
| } |
| else |
| { |
| weight = mSampleCount; |
| } |
| |
| newAverage = (newAverage * weight + newValue) / (weight + 1); |
| |
| mChannelOccupancy[channelIndex] = static_cast<uint16_t>(newAverage); |
| } |
| } |
| |
| void ChannelMonitor::LogResults(void) |
| { |
| #if OT_SHOULD_LOG_AT(OT_LOG_LEVEL_INFO) |
| const size_t kStringSize = 128; |
| String<kStringSize> logString; |
| |
| for (uint16_t channel : mChannelOccupancy) |
| { |
| logString.Append("%02x ", channel >> 8); |
| } |
| |
| LogInfo("%u [%s]", mSampleCount, logString.AsCString()); |
| #endif |
| } |
| |
| Mac::ChannelMask ChannelMonitor::FindBestChannels(const Mac::ChannelMask &aMask, uint16_t &aOccupancy) const |
| { |
| uint8_t channel; |
| Mac::ChannelMask bestMask; |
| uint16_t minOccupancy = 0xffff; |
| |
| bestMask.Clear(); |
| |
| channel = Mac::ChannelMask::kChannelIteratorFirst; |
| |
| while (aMask.GetNextChannel(channel) == kErrorNone) |
| { |
| uint16_t occupancy = GetChannelOccupancy(channel); |
| |
| if (bestMask.IsEmpty() || (occupancy <= minOccupancy)) |
| { |
| if (occupancy < minOccupancy) |
| { |
| bestMask.Clear(); |
| } |
| |
| bestMask.AddChannel(channel); |
| minOccupancy = occupancy; |
| } |
| } |
| |
| aOccupancy = minOccupancy; |
| |
| return bestMask; |
| } |
| |
| } // namespace Utils |
| } // namespace ot |
| |
| #endif // OPENTHREAD_CONFIG_CHANNEL_MONITOR_ENABLE |