手动实现community_louvain的代码

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mob64ca140761a4 2024-11-06 11:15:22

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LoraWAN源码学习(1)–通道选择详解

文章目录

LoraWAN源码学习(1)--通道选择详解

入网通道配置
收发通道配置
应用层设置通道/缺省通道接口

本篇代码以EU868为例。

入网通道配置

#define EU868_JOIN_CHANNELS       ( uint16_t )( LC( 1 ) | LC( 2 ) | LC( 3 ) )

EU868入网默认打开CH1/2/3(分别对应频点868.1/868.3/868.5MHz)。入网成功后，join accept消息中CFList对通道设置，需要说明的是CFList不会对默认通道做修改，设置通道分别是CH4~8 每个通道占用3个字节，单位：100Hz

手动实现community_louvain的代码_#define

手动实现community_louvain的代码_初始化_02

下面是join accept中CFList代码解析

//EU868默认3个通道
#define EU868_NUMB_DEFAULT_CHANNELS                 3

//CFList 支持修改的通道数，EU868默认最多5个通道
#define EU868_NUMB_CHANNELS_CF_LIST          5

void RegionEU868ApplyCFList( ApplyCFListParams_t* applyCFList )
{
    ChannelParams_t newChannel;
    ChannelAddParams_t channelAdd;
    ChannelRemoveParams_t channelRemove;

    // Setup default datarate range
    newChannel.DrRange.Value = ( DR_5 << 4 ) | DR_0; //设置数据速率范围 DR_0 ~ DR_5 

    // Size of the optional CF list
    if( applyCFList->Size != 16 ) //Lorawan规范中CFList是可选项，长度为16字节，具体的定义在【区域参数文档】中
    {
        return;
    }

    // Last byte is RFU, don't take it into account
    // EU868 的CFList设置通道不会修改默认通道EU868_NUMB_DEFAULT_CHANNELS
    for( uint8_t i = 0, chanIdx = EU868_NUMB_DEFAULT_CHANNELS; chanIdx < EU868_MAX_NB_CHANNELS; i+=3, chanIdx++ )
    {
        if( chanIdx < ( EU868_NUMB_CHANNELS_CF_LIST + EU868_NUMB_DEFAULT_CHANNELS ) )
    		 {
        	// Channel frequency
        	newChannel.Frequency = (uint32_t) applyCFList->Payload[i];//每个通道频率占用3个字节，单位：100Hz
        	newChannel.Frequency |= ( (uint32_t) applyCFList->Payload[i + 1] << 8 );
        	newChannel.Frequency |= ( (uint32_t) applyCFList->Payload[i + 2] << 16 );
        	newChannel.Frequency *= 100;

        	// Initialize alternative frequency to 0
        	newChannel.Rx1Frequency = 0;
        }
        else
        {
            newChannel.Frequency = 0;
            newChannel.DrRange.Value = 0;
            newChannel.Rx1Frequency = 0;
        }

        if( newChannel.Frequency != 0 )
        {
            channelAdd.NewChannel = &newChannel;
            channelAdd.ChannelId = chanIdx;

            // Try to add all channels
            RegionEU868ChannelAdd( &channelAdd );//频率不为0，添加通道
        }
        else
        {
            channelRemove.ChannelId = chanIdx;

            RegionEU868ChannelsRemove( &channelRemove );//频率为0，删除通道
        }
    }
}

收发通道配置

参数初始化
EU868与入网一样默认打开CH1/2/3(分别对应频点868.1/868.3/868.5`MHz)，且这3个通道必须开启

void RegionEU868InitDefaults( InitDefaultsParams_t* params )
{
    Band_t bands[EU868_MAX_NB_BANDS] =
    {
        EU868_BAND0,
        EU868_BAND1,
        EU868_BAND2,
        EU868_BAND3,
        EU868_BAND4,
    };

    switch( params->Type )
    {
        case INIT_TYPE_INIT:
        {
            // Initialize bands
            //初始化bands, 结构为 { DutyCycle, TxMaxPower, LastJoinTxDoneTime, LastTxDoneTime, TimeOff }
            //实际使用组根据通道Channels[x].Band选择，例如通道0中Band=1，EU868_LC1中定义如下：
            //{ Frequency [Hz], RX1 Frequency [Hz], { ( ( DrMax << 4 ) | DrMin ) }, Band }
            //#define EU868_LC1     { 868100000, 0, { ( ( DR_5 << 4 ) | DR_0 ) }, 1 }
            memcpy1( ( uint8_t* )NvmCtx.Bands, ( uint8_t* )bands, sizeof( Band_t ) * EU868_MAX_NB_BANDS );

            // Channels
            NvmCtx.Channels[0] = ( ChannelParams_t ) EU868_LC1;//通道参数设置
            NvmCtx.Channels[1] = ( ChannelParams_t ) EU868_LC2;
            NvmCtx.Channels[2] = ( ChannelParams_t ) EU868_LC3;

            // Initialize the channels default mask
            NvmCtx.ChannelsDefaultMask[0] = LC( 1 ) + LC( 2 ) + LC( 3 ); //缺省使能通道，这3个通道必须开启
            // Update the channels mask
            RegionCommonChanMaskCopy( NvmCtx.ChannelsMask, NvmCtx.ChannelsDefaultMask, 1 );//使用缺省使能通道 更新使能通道
            break;
        }
	...
        case INIT_TYPE_RESTORE_DEFAULT_CHANNELS:
        {
            // Restore channels default mask
            NvmCtx.ChannelsMask[0] |= NvmCtx.ChannelsDefaultMask[0];//这里只是从新使能缺省通道，缺省通道之外的通道不受影响
            break;
        }
        default:
        {
            break;
        }
    }
}

上边只是协议栈针对每个区域初始化的配置，实际上lorawan每次发射前会调用RegionNextChannel()选择发射的信道及根据上次发射时长和发送占空比(DutyCycle)计算发射关闭时间(dutyCycleTimeOff)，还是以EU868为例。

LoRaMacStatus_t RegionEU868NextChannel( NextChanParams_t* nextChanParams, uint8_t* channel, TimerTime_t* time, TimerTime_t* aggregatedTimeOff )
{
    uint8_t nbEnabledChannels = 0;
    uint8_t delayTx = 0;
    uint8_t enabledChannels[EU868_MAX_NB_CHANNELS] = { 0 };
    TimerTime_t nextTxDelay = 0;

    if( RegionCommonCountChannels( NvmCtx.ChannelsMask, 0, 1 ) == 0 )//计算使能的信道数，为0则恢复默认通道
    { // Reactivate default channels
        NvmCtx.ChannelsMask[0] |= LC( 1 ) + LC( 2 ) + LC( 3 );
    }

    TimerTime_t elapsed = TimerGetElapsedTime( nextChanParams->LastAggrTx );
    if( ( nextChanParams->LastAggrTx == 0 ) || ( nextChanParams->AggrTimeOff <= elapsed ) )
    {
        // Reset Aggregated time off
        *aggregatedTimeOff = 0;

        // Update bands Time OFF
        // 根据NvmCtx.Bands参数计算 发送延时时间【详细计算源码单独一篇讲解】
        nextTxDelay = RegionCommonUpdateBandTimeOff( nextChanParams->Joined, nextChanParams->DutyCycleEnabled, NvmCtx.Bands, EU868_MAX_NB_BANDS );

        // Search how many channels are enabled
        // 获取所有使能的通道，enabledChannels[]存放使能通道的索引，nbEnabledChannels返回使能通道的个数
        nbEnabledChannels = CountNbOfEnabledChannels( nextChanParams->Joined, nextChanParams->Datarate,
                                                      NvmCtx.ChannelsMask, NvmCtx.Channels,
                                                      NvmCtx.Bands, enabledChannels, &delayTx );
    }
...
    if( nbEnabledChannels > 0 )
    {//如果有使能的通道，则随机选择一个，立即发送
        // We found a valid channel
        *channel = enabledChannels[randr( 0, nbEnabledChannels - 1 )];//在使能通道数组中随机返回获取一个 使能通道索引

        *time = 0;
        return LORAMAC_STATUS_OK;
    }

...
        return LORAMAC_STATUS_NO_CHANNEL_FOUND;
    }
}

获取可以发送的通道

发送通道未被使能
未入网情况下，入网通道未使能
数据速率不在范围内
发送占空比关闭时间TimeOff 不为0

static uint8_t CountNbOfEnabledChannels( bool joined, uint8_t datarate, uint16_t* channelsMask, ChannelParams_t* channels, Band_t* bands, uint8_t* enabledChannels, uint8_t* delayTx )
{
    uint8_t nbEnabledChannels = 0;
    uint8_t delayTransmission = 0;

    for( uint8_t i = 0, k = 0; i < EU868_MAX_NB_CHANNELS; i += 16, k++ )
    {//每一组通道 channelsMask[] 为 16bit
        for( uint8_t j = 0; j < 16; j++ )
        {
            if( ( channelsMask[k] & ( 1 << j ) ) != 0 )//通道第k组 j位 使能
            {
                if( channels[i + j].Frequency == 0 )
                { // Check if the channel is enabled
                    continue;
                }
                if( joined == false )
                {//没入网
                    if( ( EU868_JOIN_CHANNELS & ( 1 << j ) ) == 0 )
                    {//通道第k组j位 入网通道未使能
                        continue;
                    }
                }
                if( RegionCommonValueInRange( datarate, channels[i + j].DrRange.Fields.Min,
                                              channels[i + j].DrRange.Fields.Max ) == false )
                { // Check if the current channel selection supports the given datarate
                	//检查数据速率DR是否合法，每个通道的DR范围都有独立配置，如下两个通道范围均为 DR_0 ~ DR_5：
                	//{ Frequency [Hz], RX1 Frequency [Hz], { ( ( DrMax << 4 ) | DrMin ) }, Band }
                	//#define EU868_LC1      { 868100000, 0, { ( ( DR_5 << 4 ) | DR_0 ) }, 1 }
								//#define EU868_LC2      { 868300000, 0, { ( ( DR_5 << 4 ) | DR_0 ) }, 1 }
                    continue;
                }
                if( bands[channels[i + j].Band].TimeOff > 0 )
                { // Check if the band is available for transmission
                	//检查通道 TimeOff 如果不为0，则需要延时发送，不计入使能通道
                    delayTransmission++; //延时发送通道计数
                    continue;
                }
                enabledChannels[nbEnabledChannels++] = i + j; //
            }
        }
    }

    *delayTx = delayTransmission;
    return nbEnabledChannels;
}

应用层设置通道/缺省通道接口

LoRaMacStatus_t LoRaMacMibSetRequestConfirm( MibRequestConfirm_t *mibSet )
{
	...
        case MIB_CHANNELS_DEFAULT_MASK: {
            chanMaskSet.ChannelsMaskIn = mibSet->Param.ChannelsMask;
            chanMaskSet.ChannelsMaskType = CHANNELS_DEFAULT_MASK;

            if ( RegionChanMaskSet( LoRaMacRegion, &chanMaskSet ) == false ) {
                status = LORAMAC_STATUS_PARAMETER_INVALID;
            }
            break;
        }
        case MIB_CHANNELS_MASK: {
            chanMaskSet.ChannelsMaskIn = mibSet->Param.ChannelsMask;
            chanMaskSet.ChannelsMaskType = CHANNELS_MASK;

            if ( RegionChanMaskSet( LoRaMacRegion, &chanMaskSet ) == false ) {
                status = LORAMAC_STATUS_PARAMETER_INVALID;
            }
            break;
        }
	...
}

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