WLAN Node Composition and Configuration
This topic gives an overview of the composition and configuration of a WLAN node. The Node Composition section describes the node composition by mapping the layers and functionalities of a WLAN node with corresponding helper objects. The Node Configuration section describes different configuration parameters related to the node, physical layer (PHY), medium access control (MAC) layer, application layer (APP), channel, and mesh that facilitates transmissions and receptions.
Node Composition
WLAN system-level simulation begins by creating nodes using the
hCreateWLANNodes
helper function. This function creates a
set of WLAN nodes, each consisting of the APP, MAC, PHY, and channel.
To model the APP functionality of a WLAN node,
hCreateWLANNodes
uses thehApplication
helper object.To model the MAC layer functionality of a WLAN node,
hCreateWLANNodes
uses thehEDCAMAC
helper object. To implement functionalities like round-robin scheduling, MAC queue management, power control algorithm, and rate control algorithms, thehEDCAMAC
helper object uses thehSchedulerRoundRobin
,hMACQueueManagement
,hPowerControlFixed
,hRateControARF
(autorate fallback (ARF) algorithm), andhRateControlFixed
(fixed-rate control algorithm) helper objects, respectively.To model the PHY transmitter and receiver,
hCreateWLANNodes
uses thehPHYTxAbstract
andhPHYRxAbstract
helper objects, respectively. To model interference,hCreateWLANNodes
uses thehInterference
helper object. ThehCreateWLANNodes
helper function creates a channel link quality model by using thehTGaxLinkQualityModel
helper object.To model the wireless channel,
hCreateWLANNodes
uses thehChannel
helper object.
This figure shows the WLAN node composition by mapping the APP, MAC, PHY, and channel functionalities of a WLAN node with the corresponding helper objects.
This table describes the functionalities of the helper functions and objects that are used in the WLAN system-level simulation.
Helper Function or Object or Class | Description |
---|---|
| Simulate wireless network. |
| Create a base class for nodes in a wireless network. |
| Create a WLAN node object consisting of APP, MAC, PHY
and channel and interference modeling. You can have multiple
interfaces, each with a corresponding PHY, MAC, and channel.
Add the interfaces by using the
|
hCreateWLANNodes | Create WLAN nodes with specified configuration parameters. |
| Create a WLAN APP object. |
| Create a WLAN enhanced distributed channel access (EDCA) MAC object. |
| Create a round-robin scheduler object. |
| Create a WLAN MAC queue management object. |
| Create a base class to implement a power control algorithm. This class defines an interface supported for power control. |
| Create a fixed transmit power selection object |
| Create a base class to implement a rate control algorithm. This class defines an interface supported for rate control. |
| Create an object providing functionality for the ARF algorithm . |
| Create a fixed-rate selection object. |
| Create a WLAN PHY receiver interface class. This interface class acts as a base class for all the PHY types. This class defines an interface to the PHY receiver. In this class, you can set the properties and methods to interact with the higher layers. |
| Create a WLAN abstracted PHY receiver object for PHY decoding. |
| Create a WLAN PHY receiver object for PHY decoding. |
| Create an object to model interference at the PHY. |
| Create a link quality model object. This model estimates the signal-to-interference noise ratio (SINR) for an 802.11ax SU link assuming perfect synchronization. |
| Create a WLAN PHY transmitter interface class. This interface class acts as a base class for all PHY transmitters. This class defines an interface to the PHY transmitter. In this class, you can set the properties and methods to interact with the higher layers. |
| Create an object for the WLAN abstracted PHY transmitter. The object creates a WLAN PHY transmitter object that supports these operations:
|
| Create an object for the WLAN PHY transmitter. The object creates a WLAN PHY transmitter object that supports these operations:
|
| Create an object for the WLAN channel. |
| Create a class to log and visualize statistics. This class implements the functionality to plot the statistics at the end of the simulation. |
To access the helper files, add the
mlWLANSystemSimulation
folder to the MATLAB®
path.
addpath(genpath(fullfile(pwd,'mlWLANSystemSimulation')));
Node Configuration
The WLAN node configuration includes configuring the APP traffic and node-related
parameters. To explore the APP, MAC, and PHY configuration, use the
hConfigurationHelp
helper function.
APP Traffic Configuration
To configure the APP layer at a node, configure the APP traffic fields in the
wlanTrafficConfig
structure. To configure multiple
applications in the network, follow these steps.
Replicate the
wlanTrafficConfig
structure.Configure each structure with the desired values of
SourceNode
andDestinationNode
fields.
This table defines the APP traffic configuration fields at a WLAN node.
Fields | Description | Valid Values | Default Value |
---|---|---|---|
| Name of the node that transmits the packet and at which the application is running | Character vector or string scalar that matches a valid node name |
|
| Name of the node to which the packet originated at
| Character vector or string scalar that matches a valid node name To configure broadcast traffic, set
this field to |
|
| Size of the generated application packets | Integer in the range [1, 2034] |
|
| Rate, in Kbps, at which the application packets are generated | Numeric scalar |
|
| Access category (AC) | Nonnegative integer in the range [0,3]
|
|
To view the APP traffic configuration fields of a WLAN node, enter this command at the MATLAB command prompt.
hConfigurationHelp('wlanTrafficConfig')
Node Parameters
This table defines the fields to configure WLAN node parameters.
Fields | Description | Valid Values | Default Value |
---|---|---|---|
| Name of the node | Character vector or string scalar If you do
not configure this field, the default format of this field
is |
|
| Position, in meters, of the node in Cartesian coordinates | Three-element vector of elements corresponding to the (x, y, z) point |
|
MAC, PHY, and Channel Configuration
To configure the MAC, PHY, and channel at a WLAN node, configure the fields in
the wlanNodeConfig
structure. To configure multiple nodes in
the network, you must replicate the wlanNodeConfig
structure.
Then, you can customize the node configuration fields for any node in the
network.
This table shows the configurable fields at the MAC layer of a WLAN node.
Fields | Description | Valid Values | Default Value |
---|---|---|---|
| Format used for frame transmission |
To configure this field, see the
|
|
| Channel bandwidth, in MHz |
|
|
| Modulation and coding scheme (MCS) index for transmitting the frame. To enable this field,
set |
|
|
| Number of space-time streams (STS) |
|
|
| Number of transmit chains used during the transmission |
|
|
| Flag to enable or disable MAC protocol data unit (MPDU) aggregation |
|
|
DisableAck | Flag to indicate that the transmitting node does not solicit acknowledgment for the data frame | logical |
|
| Maximum number of subframes that can be aggregated in the aggregate-MPDU (A-MPDU) | Integer in the range [1, 256] |
|
| Threshold length of the frame below which the node does not use request to send/clear to send (RTS/CTS) protection for data transmission To enable this field, set
the | Integer in the range [0, 65,536] |
|
| Flag to enable or disable the RTS/CTS exchange for data transmissions | logical |
|
| Retry limit for frames less than or equal to RTS threshold | Integer in the range [1, 255] |
|
| Retry limit for frames greater than the RTS threshold | Integer in the range [1, 255] |
|
| Non-HT rates, in Mbps, supported by all the nodes in the network to transmit control frames | Row vector of data rate values from the set {6, 9, 12, 18, 24, 36, 48, 54}. |
|
| Flag to indicate the use of 6 Mbps data rate for all
control frames, ignoring the values in the
| logical |
|
| Operating band and channel number | Cell array of a vector in the form {[x, y]}, where x is a frequency band of 2.4, 5, or 6 GHz and y is any valid channel number. The value of x can be 2.4, 5, or 6. The value of y can be any valid channel number. |
|
| Minimum value of the contention window range for each AC | Four-element row vector of elements that are integers in the range [1, 1023], where each element indicates a value of an AC |
|
| Maximum value of the contention window range for each AC | Four-element row vector of elements that are integers in the range [1, 1023], where each element indicates a value of an AC |
|
| Number of arbitrary interframe space (AIFS) slots for each AC | Four-element row vector of elements that are integers in the range [2, 15], where each element indicates number of AIFS slots for four ACs |
|
| Rate control algorithm |
|
|
| Power control algorithm |
|
|
| Maximum number of stations (STAs) that can be scheduled for a downlink (DL) multiuser (MU) transmission |
| 1 |
| Type of frame exchange sequence to be used in DL orthogonal frequency-division multiple access (OFDMA) MU transmissions |
| 1 |
| Flag to indicate whether a node is an access point (AP) |
To configure AP in a particular interface of the
node, set the element corresponding to the interface as
|
|
| Flag to indicate whether a node is a mesh node |
To enable mesh functionality in a particular
interface of the node, set the element corresponding to the
interface as |
|
This table shows the configurable fields at the PHY layer of a WLAN node.
Fields | Description | Valid Values | Default Value |
---|---|---|---|
| Transmit power, in dBm | Numeric scalar | 15 |
| Transmit gain, in dB | Numeric scalar | 1 |
| Receive gain, in dB | Numeric scalar |
|
| Energy detection threshold, in dBm | Numeric scalar |
|
| Receiver noise figure, in dB | A scalar number specifying the noise figure in dB |
|
This table shows the channel configuration fields at a WLAN node.
Fields | Description | Valid Values | Default Value |
---|---|---|---|
| Distance, in meters, beyond which the receiver ignores signal to reduce the simulation complexity | Numeric scalar |
|
| Flag to enable or disable free space pathloss | logical |
|
This table shows the mesh configuration fields at a WLAN node.
Fields | Description | Valid Values | Default Value |
---|---|---|---|
| Maximum number of hops allowed to forward a packet in the mesh network | Integer in the range [1, 255] |
|
To view the PHY, MAC, channel, and mesh configuration fields of a WLAN node, enter this command at the MATLAB command prompt.
hConfigurationHelp('wlanNodeConfig')
Related Topics
- Statistics Captured in WLAN System-Level Simulation
- 802.11ax Multinode System-Level Simulation of Residential Scenario Using MATLAB
- Get Started with WLAN System-Level Simulation in MATLAB
- MAC and PHY Layer Abstraction in System-Level Simulation
- Create and Visualize 802.11ax Multinode Residential Scenario
- Configure Uplink and Downlink Traffic at 802.11ax Access Point
- Visualize Node State Transitions in 802.11ax System-Level Simulation