蓝牙网格堆栈

蓝牙核心规范[1]包括用于低速无线个人面积网络的低能量版本，称为蓝牙低能量（BLE）或蓝牙智能。BLE堆栈包括：通用属性配置文件（GATT），属性协议（ATT），安全管理器协议（SMP），逻辑链路控制和适配协议（L2CAP），链路层（LL）和物理层（PHY）。添加到低能量设备标准的标准，生成少量数据，例如家庭自动化，医疗保健，健身和物联网（物联网）等应用中使用的通知警报。

这蓝牙Mesh Profile [2] defines the fundamental requirements to implement mesh networking solutions for BLE. The mesh stack is located on top of the Bluetooth Core Specification and consists of the: model layer, foundation model layer, access layer, upper transport layer, lower transport layer, network layer and bearer layer. Bluetooth mesh networking enables end-to-end communication in large-scale networks to support applications like smart lighting, industrial automation, sensor networking, asset tracking, and many other IoT solutions.

网格堆栈

该图显示了广告承载上的蓝牙网格堆栈。

核心堆栈

This example models these layers of the BLE core stack:

离散事件仿真

DES是一种模拟模拟系统的功能作为时域中的离散事件序列。每个事件发生在特定时间时代，随后标记系统中的状态。结果，模拟可以在时域中直接从事件跳转到事件。在此示例中使用DES的基本优势是：

检查支持包安装金宝app

％检查'蓝牙协议的“通信工具箱库”% support package is installed or not.comm金宝appsupportpackagecheck（'蓝牙');

多节点蓝牙网状网模型

此示例模拟蓝牙网状网络，具有21个节点。该模型输出网络的PDR以及物理，链路和网络层的发送，接收和丢包等不同的统计数据，以及可视化网络方案的绘图。建模包括：

要配置特定方案，请执行以下操作之一：

蓝牙节点

每个节点都被建模为具有网络堆栈的子系统，该网络堆栈包括蓝牙网格分组生成器和接收器，网络层，LL和PHY。

应用层

实现应用层以生成和接收应用程序流量。它分为两个子块：

Network layer

这network layer is modeled as a DES block. This block is responsible for transmitting the lower transport layer messages over the advertising bearer and relaying the mesh messages when the 'Relay' feature is enabled. When a network PDU is received, this block decodes the received PDU. If the PDU is decoded successfully, then the decoded information is passed to the lower transport layer.

您可以使用网络层块的掩模参数配置中继功能，网络发送间隔，网络传输计数，继电传输间隔和继电器重传计数。

链接层

链路层被建模为des块。此块维护用于LL广播公司和观察者角色的状态机。该块负责通过使用传输和接收网格广告数据包BlelladvertisingChannelpdu.andBlelladvertisingChannelpdu.Decode职能。

您可以使用链路层块的掩码参数配置扫描和广告间隔。

Physical layer

PHY功能包括：

会启动包传输通过发送一个你packet and Tx indication to the PHY Tx block. This block generates a waveform for the received LL packet by using thebleWaveformGenerator功能。它还使用配置的TX功率（假设TX增益为0）来缩放BLE波形的样本。产生的BLE波形通过共享信道发送。共享通道是通过使用Simevents组播队列建模的。

您可以使用PHY TX块的蒙版参数配置TX功率（DBM）。

这free-space path loss model is added to the transmitted BLE waveform as channel impairments. You can choose to enable or disable this impairment. In addition to this impairment model, the signal reception range can also be limited by using an optional range propagation loss model. To model any of these channel impairment options, the channel model must contain the position of both the sender and the receiver. The channel is modeled inside each receiving node, before passing the BLE waveform to the PHY Rx block.

You can configure channel impairments by using mask parameters of the BLE channel block.

该块对接收的BLE波形（假设RX增益为0）施加热噪声和干扰。热噪声通过使用使用Comm.Thermalnoise.函数噪声系数的配置值。通过添加干扰和实际信号的IQ样本来建模干扰。在施加热噪声和干扰后，PHY RX块解码得到的波形。如果LL数据包已成功解码，则将其传递给LL。

You can configure the noise figure (in dB) using mask parameters of the PHY Rx block.

Node position allocator (NPA)为网状网络分配节点的位置。此块支持线性，网格和列金宝app表位置分配策略。

VisualizerThis block is used to visualize the mesh network scenario in the simulation. You can configure this block to visualize the specified configuration. You can enable or disable visualization by using the mask parameters of this block.

仿真结果

这results obtained in this simulation are:

这PDR.is the ratio of number of received packets at the destination to the number of packets transmitted by the source and is given by:

此模型输出此多节点网状网络的PDR，并将其保存到名为的基础工作区变量PDR.。

This model outputs statistics of each node in the workspace variablestatisticsAtEachNode。每个节点捕获的统计数据是：

一个可视化表示的网格netw的阴谋ork scenario is shown in the simulation. You can see the statistics of each node by placing your cursor over it.

This example shows how to configure and simulate a multi-node Bluetooth mesh network by using DES. The mesh network model in this example outputs PDR as a workspace variable with a visual representation of the mesh network.

Further Exploration

要观察网络PDR中的变体，可以在网格包生成器，网络层，LL和PHY上改变配置参数。在这些仿真结果中，您可以看到网络层重复（NLR）对网络PDR的影响。

这NLR includes the repetitions of both the network messages and the relayed messages. The working principle of flood-based networks ensures that the message reaches the destination node. Therefore, it is important to retransmit the network and the relay messages. The number of NLR is dependent on the network configuration of the given network topology. Increasing the number of NLR ensures that the likelihood of the messages reaching the desired destination node is high. However, specifying a high value of the NLR can have adverse effects on the network performance parameters such as the overhead, energy consumption, and the duty cycle. As a result, it is essential to tune the value of NLR for a given network topology and achieve an efficient tradeoff between the PDR and network performance.

In the preceding figure you can see that the PDR increases with the NLR and decreases with the number of source nodes in the network. For a specific value of the NLR, the PDR value reaches 1 and thereafter it stabilizes. This specific value of the NLR might vary based on the network configuration parameters such as the total number of nodes, location of the nodes, number of source nodes, number of relay nodes, and so on. You can runHelperBerleshDespdrcalculation.通过使用三个源节点来重现这些结果。将源节点的数量设置为2和5以获取相应的结果。您可以为任何自定义网络场景运行模拟，并获得NLR的最佳值。

Apart from the NLR, the PDR varies with respect to multiple configuration parameters stated inHelperBerleshDespdrcalculation.。您可以通过改变任何这些参数来进一步探索网状网络模型。

附录

该示例使用这些功能：

该示例使用这些帮助程序：

References