establishMAPCAgreement

R2026b

Establish multi-AP coordination agreement between APs

Since R2026b

Syntax

establishMAPCAgreement(apList)

establishMAPCAgreement(apList,MAPCScheme=mapcScheme)

Description

establishMAPCAgreement(apList) establishes coordinated time division multiple access (Co-TDMA) multi-access point coordination (MAPC) agreements between every pair of access points (APs) in the AP list. Once established, all APs in the list can function as both coordinating and coordinated APs. For more information about Co-TDMA, see How Does Co-TDMA Work?

establishMAPCAgreement(apList,MAPCScheme=mapcScheme) specifies the MAPC scheme mapScheme. Currently, the function supports only the Co-TDMA scheme.

Examples

Simulate Multi-AP Coordination with Co-TDMA

Coordinated time-division multiple access (Co-TDMA) is a technique that enables multiple Access Points (APs) to coordinate their transmissions, reducing interference and potentially improving overall throughput and latency. Simulate a wireless local area network (WLAN) with three APs capable of Co-TDMA and their associated stations (STAs). Both the APs and STAs are multi-link devices (MLDs). Configure the network, enable multi-AP coordination, run the simulation, and collect throughput and latency statistics at each node.

Create and Simulate Network

Set the seed for the random number generator to 1. The seed value controls the pattern of random number generation. The random number generated by the seed value impacts several processes within the simulation including backoff counter selection at the MAC layer and predicting packet reception success at the physical layer. To improve the accuracy of your simulation results, after running the simulation, you can change the seed value, run the simulation again, and average the results over multiple simulations.

rng(1,"combRecursive")

Specify the simulation time in seconds.

simTime = 1; % Units are in seconds

Initialize the network simulator.

networkSimulator = wirelessNetworkSimulator.init;

Create three AP MLDs and three STA MLDs. Configure each to operate on both the 5 GHz and 6 GHz bands.

% AP1 and STA1
apLinkCfg = wlanLinkConfig(BandAndChannel=[5 36; 6 1], ....
    BeaconInterval=50,TXOPLimit=[1 2 94 47],TransmissionFormat="EHT-SU", ...
    MCS=7,MPDUAggregationLimit=256);
apMLDCfg = wlanMultilinkDeviceConfig(Mode="AP",LinkConfig=apLinkCfg,StandardCapability="UHR");
ap1 = wlanNode(DeviceConfig=apMLDCfg,Position=[0 0 0]);

staLinkCfg = wlanLinkConfig(BandAndChannel=[5 36; 6 1],....
    BeaconInterval=50,TXOPLimit=[1 2 94 47],TransmissionFormat="EHT-SU", ...
    MCS=7,MPDUAggregationLimit=256);
staMLDCfg = wlanMultilinkDeviceConfig(Mode="STA",LinkConfig=staLinkCfg);
sta1 = wlanNode(DeviceConfig=staMLDCfg,Position=[-2 -2 0]);

% AP2 and STA2
apLinkCfg = wlanLinkConfig(BandAndChannel=[5 36; 6 1], ...
    BeaconInterval=50,TXOPLimit=[1 2 94 47],TransmissionFormat="EHT-SU", ...
    MCS=7,MPDUAggregationLimit=256);
apMLDCfg = wlanMultilinkDeviceConfig(Mode='AP',LinkConfig=apLinkCfg,StandardCapability="UHR");
ap2 = wlanNode(DeviceConfig=apMLDCfg,Position=[5 0 0]);

staLinkCfg = wlanLinkConfig(BandAndChannel=[5 36; 6 1], ...
    BeaconInterval=50,TXOPLimit=[1 2 94 47],TransmissionFormat="EHT-SU", ...
    MCS=7,MPDUAggregationLimit=256);
staMLDCfg = wlanMultilinkDeviceConfig(Mode="STA",LinkConfig=staLinkCfg);
sta2 = wlanNode(DeviceConfig=staMLDCfg,Position=[7 -2 0]);

% AP3 and STA3
apLinkCfg = wlanLinkConfig(BandAndChannel=[5 36; 6 1], ...
    BeaconInterval=50,TXOPLimit=[1 2 3 4],TransmissionFormat="EHT-SU", ...
    MCS=7,MPDUAggregationLimit=256);
apMLDCfg = wlanMultilinkDeviceConfig(Mode="AP",LinkConfig=apLinkCfg,StandardCapability="UHR");
ap3 = wlanNode(DeviceConfig=apMLDCfg,Position=[0 5 0]);

staLinkCfg = wlanLinkConfig(BandAndChannel=[5 36; 6 1], ...
    BeaconInterval=50,TXOPLimit=[1 2 94 47],TransmissionFormat="EHT-SU", ...
    MCS=7,MPDUAggregationLimit=256);
staMLDCfg = wlanMultilinkDeviceConfig(Mode="STA",LinkConfig=staLinkCfg);
sta3 = wlanNode(DeviceConfig=staMLDCfg,Position=[-2 7 0]);

Associate each STA with its AP. Use associateStations for each AP-STA pair.

associateStations(ap1,sta1)
associateStations(ap2,sta2)
associateStations(ap3,sta3)

Create three On-Off application traffic pattern objects.

trafficSource1 = networkTrafficOnOff(DataRate=10000,PacketSize=100);
trafficSource2 = networkTrafficOnOff(DataRate=10000,PacketSize=100);
trafficSource3 = networkTrafficOnOff(DataRate=10000,PacketSize=100);

Configure traffic between the APs and STAs using the addTrafficSource function.

addTrafficSource(ap1,trafficSource1,DestinationNode=sta1,AccessCategory=2)
addTrafficSource(ap2,trafficSource2,DestinationNode=sta2,AccessCategory=2)
addTrafficSource(ap3,trafficSource3,DestinationNode=sta3,AccessCategory=2)

Establish an MAPC agreement for the Co-TDMA scheme between each pair of APs: ap1, ap2, and ap3. This enables any of these APs to initiate Co-TDMA operation.

establishMAPCAgreement([ap1 ap2 ap3],MAPCSchemes="Co-TDMA");

Add the nodes to the simulator, and set up performance monitoring by using thehelperPerformanceViewer helper function.

nodes=[ap1 sta1 ap2 sta2 ap3 sta3];
addNodes(networkSimulator,nodes)
perfViewer = helperPerformanceViewer(nodes,simTime);

Run the Simulation.

run(networkSimulator,simTime)

Check the throughput for each AP and latency for each STA.

% Throughput for each AP
throughput_ap1 = throughput(perfViewer,ap1.ID)

throughput_ap1 = 
9.9880

throughput_ap2 = throughput(perfViewer,ap2.ID)

throughput_ap2 = 
3.4760

throughput_ap3 = throughput(perfViewer,ap3.ID)

throughput_ap3 = 
9.0424

% Average receive latency for each STA
latency_sta1 = averageReceiveLatency(perfViewer,sta1.ID)

latency_sta1 = 
4.7124e-04

latency_sta2 = averageReceiveLatency(perfViewer,sta2.ID)

latency_sta2 = 
0.0013

latency_sta3 = averageReceiveLatency(perfViewer,sta3.ID)

latency_sta3 = 
0.0248

Input Arguments

apList — List of APs

vector of wlanNode objects

List of APs, specified as a vector of wlanNode objects. The DeviceConfig property of each node must be a wlanMultilinkDeviceConfig object with the Mode property set to "AP" and the StandardCapability property set to "UHR".

Note

When you set the value of the StandardCapability property of the wlanMultilinkDeviceConfig to "UHR", specify the value of theTransmissionFormat property of the wlanLinkConfig object as any value other than "auto" for all transmissions from the link.

mapcScheme — MAPC scheme

"Co-TDMA" (default)

MAPC scheme, specified as "Co-TDMA".

Note

To enable Co-TDMA operation between APs, the wlanLinkConfig object for at least one access category (AC) must have aTXOPLimit property with a nonzero value. Additionally, ensure that the TXOPLimit value for AC VI is nonzero.

Algorithms

How Does Co-TDMA Work?

Co-TDMA operates in three phases.

1. Polling phase — The AP that currently owns the transmission opportunity (TXOP), known as the coordinating AP, initiates coordination by sending an initial control frame (ICF) to other APs. The intended APs that receive this ICF are coordinated APs. They respond with an initial control response (ICR) frame to indicate whether they wish to participate in TXOP sharing.

   All APs participating in a MAPC agreement attempt Co-TDMA operation. An AP starts a TXOP with an ICF buffer status report poll (BSRP) non-trigger-based (NTB) for polling if all of these are true:

   • Beacon Reception — The AP has received at least one beacon with a received signal strength indicator (RSSI) ≥ –72 dBm from any AP participating in the MAPC agreement.

   • Beacon Configuration — All APs participating in the MAPC agreement enable beacons.

   • AC VI TXOP — AC VI has a nonzero TXOP.

   • Data Traffic TXOP — The AC that handles data traffic has a non-zero TXOP.

   • TXOP Duration — The configured TXOP limit values provide sufficient duration for the polling phase, the estimated data frame exchange, and the estimated minimum allocation phase. The equations for these phases are:

     • T_polling = T_BSRP + T_MBA + (2×SIFS), where T_polling represents the total time for the polling phase, T_BSRP represents the time to transmit a Buffer Status Report Poll, T_MBA represents the time to transmit a multi-STA block ack (MBA), and SIFS represents the short interframe space.

     • T_DE = T_FES × N_FES, where T_DE represents the estimated data frame exchange time with the associated STAs, T_FES represents the time required for the next frame exchange sequence, and N_FES is the ratio of the total number of MPDUs waiting in the queue to the number of MPDUs that can fit in the next frame exchange sequence.

     • T_allocation = T_TimeMURTSCTS + T_TimeData100B, where T_allocation represents the estimated allocation phase time, T_TimeMURTSCTS represents the time required for multi-user request to send (MU-RTS) triggered TXOP sharing (TXS) and clear to send (CTS) exchange, and T_TimeData100B represents time required for a 100-byte data frame exchange sequence (including RTS transmission and CTS response) using non-high throughput at 6 Mbps.

   A coordinated AP evaluates the polling request and rejects the polling when either condition applies.

   • The AP has no frames to transmit.

   • The duration indicated in the Max TXOP allocation (under consideration) parameter of the ICF frame cannot accommodate at least one aggregated medium access control (MAC) protocol data unit (A-MPDU) containing one MPDU.

2. TXOP allocation phase — After collecting poll responses and completing frame exchanges with its own associated stations, the coordinating AP allocates the remaining time to a coordinated AP by sending an MU-RTS TXS trigger frame. The coordinated AP responds with a CTS, then utilizes the shared TXOP to perform frame exchanges with its associated stations.

   To allocate a TXOP to a coordinated AP, a coordinating AP must satisfy all of the following conditions:

   • The coordinating AP has finished its own scheduled transmissions.

   • The coordinated AP has requested TXOP sharing during the polling phase.

   • The coordinating AP has used at least 33% of its TXOP limit.

   • The remaining TXOP time is enough to perform a frame exchange sequence for at least a 100-byte data frame (including RTS/ CTS exchange).

3. TXOP return phase — If a coordinated AP completes its transmission before using its entire allocated TXOP, it can return the unused portion of the TXOP to the coordinating AP.

   When possible, a coordinated AP returns the TXOP to the user using these steps.

   1. The coordinated AP sends a TXOP Return Action frame to the coordinating AP, provided sufficient time remains to complete the transmission.

   2. If sufficient time remains, the coordinating AP then transmits a contention-free (CF) End frame to terminate the TXOP.

Note that all communication between APs uses a data rate of 24 Mbps, which is the highest mandatory basic rate for Non-HT modes. This applies to frames such as BSRP NTB, MU-RTS TXS, MAPC TXOP return, and their corresponding responses. The only exception is the CTS response to MU-RTS, which the standard restricts to 6 Mbps.

This diagram illustrates the Co-TDMA operation for two APs.

Version History

Introduced in R2026b