connectUE

R2026b

Connect one or more UEs to gNB

Since R2023a

Syntax

connectUE(gnb,ue,Name=Value)

Description

connectUE(gnb,ue,Name=Value) connects one or more new radio (NR) user equipment (UE) nodes, ue, to a NR base station node (gNB), gnb. The function sets the connection configuration parameters using one or more optional name-value arguments. For example, BSRPeriodicity=5 sets the uplink (UL) buffer status reporting periodicity to 5 subframes. You can connect multiple UE nodes to a gNB node in a single connectUE function call, but these UE nodes must all use same connection parameter values specified in the name-value arguments. This feature also requires the Wireless Network Toolbox™ product.

Note

• When you use carrier aggregation, UE nodes initially connect to the gNB node on the primary carrier (the first configured carrier of the gNB node) using the connectUE function. After the UE nodes connect to the primary carrier, you can assign the secondary carriers to UE nodes using the addSecondaryCarrierOnUE function.

• When you connect more than 16 UE nodes to a gNB node using the connectUE object function, you must adjust the SRS transmission periodicity of the nrGNB object manually. For more information about this, see the SRSPeriodicityUE property.

Examples

Connect UEs to gNB

Create a default gNB node.

gnb = nrGNB;

Create two UE nodes positioned at [100 100 0] and [5000 100 0], with each one having a transmit power of 20 dBm.

ueArray1 = nrUE(Position=[100 100 0; 5000 100 0],TransmitPower=20); % In Cartesian x, y, and z 

Create two UE nodes positioned at [700 100 430] and [500 1000 657], with each one having a transmit power of 29 dBm.

ueArray2 = nrUE(Position=[700 100 430; 500 1000 657],TransmitPower=29);

Connect two UE nodes positioned at [100 100 0] and [5000 100 0] to the gNB node with the uplink (UL) buffer status reporting periodicity set to 5.

connectUE(gnb,ueArray1,BSRPeriodicity=5)

Connect two UE nodes positioned at [700 100 430] and [500 1000 657] to the gNB node with the UL buffer status reporting periodicity set to 16.

connectUE(gnb,ueArray2,BSRPeriodicity=16)

.Copyright 2022-2026 The MathWorks, Inc.

Create, Configure, and Simulate 5G Network

Initialize wireless network simulator.

networkSimulator = wirelessNetworkSimulator.init;

Create a gNB node with these specifications.

• Duplex mode — Time division duplex

• Channel bandwidth — 20 MHz

• Subcarrier spacing — 30 KHz

gnb = nrGNB(ChannelBandwidth=20e6,DuplexMode="TDD",SubcarrierSpacing=30e3);

Create a UE node with a transmit power of 20 dBm.

ue = nrUE(TransmitPower=20);

Add a random way point mobility model to the UE node.

addMobility(ue,BoundaryShape="rectangle")

Establish a connection between the UE and gNB nodes.

connectUE(gnb,ue)

Create a voice over Internet protocol (VoIP) application traffic pattern object.

traffic = networkTrafficVoIP;

Add the data traffic source to the gNB node. Set the destination node as the UE node.

addTrafficSource(gnb,traffic,DestinationNode=ue)

Add the gNB node to the wireless network simulator.

addNodes(networkSimulator,gnb)

Add the UE node to the wireless network simulator.

addNodes(networkSimulator,ue)

Specify the simulation time, in seconds.

simulationTime = 0.3;

Run the simulation for the specified simulation time.

run(networkSimulator,simulationTime)

Obtain the statistics for the gNB and UE nodes.

gnbStats = statistics(gnb);
ueStats = statistics(ue);

Configure CSI Report Configurations for UEs

Create a gNB node.

gnb = nrGNB;

Create four UE nodes and specify the UE positions.

uePositions = [300 0 3; 700 0 3; 1200 0 3; 3000 0 3];
UE = nrUE(Position=uePositions);

Create two CSI report configurations.

csiReportConfig1 = nrCSIReportConfig(CodebookType="type1SinglePanel",...
                                  CQITable="table2")

csiReportConfig1 = 
  nrCSIReportConfig with properties:

                     NSizeBWP: []
                    NStartBWP: []
                     CQITable: "table2"
                 CodebookType: "type1SinglePanel"
              PanelDimensions: [1 2 1]
           CQIFormatIndicator: "wideband"
           PMIFormatIndicator: "wideband"
                PRGBundleSize: []
                 CodebookMode: 1
    CodebookSubsetRestriction: []
                I2Restriction: []
                RIRestriction: []

   Constant properties:
                       Tables: [1×1 struct]

csiReportConfig2 = nrCSIReportConfig(CodebookType="eType2",...
                                  CQITable="table2")

csiReportConfig2 = 
  nrCSIReportConfig with properties:

                            NSizeBWP: []
                           NStartBWP: []
                            CQITable: "table2"
                        CodebookType: "eType2"
                     PanelDimensions: [1 2 1]
                  CQIFormatIndicator: "wideband"
                  PMIFormatIndicator: "wideband"
                        CodebookMode: 1
           CodebookSubsetRestriction: []
                       RIRestriction: []
                ParameterCombination: 1
    NumberOfPMISubbandsPerCQISubband: 1

   Constant properties:
                              Tables: [1×1 struct]

Assign csiReportConfig1 CSI report configuration to UE1 and UE3

connectUE(gnb, [UE(1),UE(3)], CSIReportConfig = csiReportConfig1);

Warning: Configuration of panel dimensions is not supported. The panel dimensions is set to [Ng N1 N2] "[1  1  1]".

Assign csiReportConfig2 CSI report configuration to UE2 and UE4.

connectUE(gnb, [UE(2), UE(4)], CSIReportConfig = csiReportConfig2);

Warning: Configuration of panel dimensions is not supported. The panel dimensions is set to [Ng N1 N2] "[1  1  1]".

Input Arguments

gnb — gNB node

nrGNB object

gNB node, specified as an nrGNB object.

ue — UE node

nrUE object | vector of nrUE objects

UE node, specified as an nrUE object or a vector of nrUE objects.

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Example: connectUE(gnb,ue,BSRPeriodicity=5) sets the uplink (UL) buffer status reporting periodicity to 5 subframes.

BSRPeriodicity — UL buffer status reporting periodicity

5 (default) | 1 | 10 | 20

Uplink (UL) buffer status reporting periodicity, specified as one of these options, in number of subframes. One subframe equals one millisecond.

• 1

• 5

• 10

• 20

• 32

• 40

• 80

• 128

• 160

• 320

• 640

• 1280

• 2560

• Inf

Data Types: double

CSIReportPeriodicity — CSI-RS reporting periodicity

positive integer

Channel state information reference signal (CSI-RS) reporting periodicity, specified as a positive integer. Units are in slots. If you do not specify CSIReportPeriodicity, the function uses the value of CSI-RS transmission periodicity, as determined by the gNB object. The UE nodes report the rank indicator (RI), the precoding matrix indicator (PMI), and the channel quality indicator (CQI) based on measurements taken from the CSI-RS. For more information about the CSI-RS transmission periodicity, see the Algorithms section.

• For FDD, the CSI-RS reporting periodicity must be greater than or equal to the CSI-RS transmission periodicity.

• For TDD, the CSI-RS reporting periodicity must also be a multiple of the length of DL-UL pattern.

Data Types: double

FullBufferTraffic — Configuration of full buffer traffic for UE

"off" (default) | "on" | "UL" | "DL"

Configuration of full buffer traffic for a UE, specified as one of these options.

• "off" — Disable the full buffer traffic in both the UL and DL directions.

• "on" — Enable the full buffer traffic in both the UL and DL directions.

• "UL" — Enable the full buffer traffic in the UL direction.

• "DL" — Enable the full buffer traffic in the DL direction.

You can use this name-value argument as an alternative to the addTrafficSource object function for setting up traffic during connection configuration.

When using the full buffer traffic, the system always attempts to send the maximum transport block size possible, given the allocated resources and channel measurements.

Data Types: char | string

RLCBearerConfig — RLC bearer configuration

nrRLCBearerConfig object

RLC bearer configuration, specified as an nrRLCBearerConfig object or a vector of nrRLCBearerConfig objects. If you do not enable the full buffer traffic and fail to specify this name-value argument, the objects uses the default configuration of an nrRLCBearerConfig object.

Note

If you set the FullBufferTraffic argument to "on", the connectUE object function ignores the RLC bearer configuration you specify.

CustomContext — Custom UE context

structure

Since R2024b

Custom UE context, specified as a structure. Use this name-value argument to specify any custom information regarding a UE node, which you can then use for your custom scheduling logic. The CustomContext property of UEContext, a property of the nrScheduler class, reflects the specified value for the corresponding UE node. The connectUE call, invokable for each UE node, utilizes the CustomContext name-value argument to provide each UE with a unique context structure, enabling variation in fields or identical fields with distinct values.

Data Types: struct

CSIReportConfig — CSI report configuration

nrCSIReportConfig

Since R2026a

CSI report configuration, specified as an nrCSIReportConfig object. Use this name-value argument to configure CSI report configuration for the UE. You can configure the same CSI report configuration for multiple UEs, but configuring multiple CSI report configurations for a single UE is not supported.

You can only configure these properties of the nrCSIReportConfig object for the UE:

Property	Supported Property Value
CQITable	"table2"
CodebookType	"type1SinglePanel" "type2" "etype2"
CQIFormatIndicator	"wideband" and "subband" Note Built-in schedulers, such as "RoundRobin", "BestCQI", and "ProportionalFair", do not use subband-level channel quality indicator (CQI) measurements. Instead, they use wideband CQI measurements. However, custom schedulers can use subband-level CQI measurements for scheduling.
PMIFormatIndicator	"wideband" and "subband"
SubbandSize	4 8 16 32 Note The allowed values for SubbandSize depend on the NumResourceBlocks of nrGNB, according to TS 38.214. When the bandwidth part (BWP) size is greater than or equal to 24 PRBs, you can configure subband-based reporting for CQI and PMI. The system does not support sub-band measurements with multi-user (MU) multiple-input multiple-output (MIMO).
CodebookMode	1 2
CodebookSubsetRestriction	[] Binary vector
I2Restriction	[] Binary vector
RIRestriction	[1 1 1 1 0 0 0 0] for 'type1SinglePanel' Supports only up to rank 4. Only single codeword is supported.
NumberOfBeams	2 3 4
PhaseAlphabetSize	4 8
ParameterCombination	Integer from 1 to 8

Algorithms

CSI-RS and sounding reference signal (SRS) configuration

The gNB node automatically sets the connection parameters related to CSI-RS and sounding reference signal (SRS). The gNB node transmits a full bandwidth CSI-RS for downlink (DL) channel measurements. All the UE nodes connected to the gNB node use this full bandwidth CSI-RS. The minimum value of CSI-RS transmission periodicity is 10 slots. For the frequency division duplex (FDD) mode, the CSI-RS transmission periodicity is 10 slots. The CSI-RS transmission periodicity for the time division duplex (TDD) mode is a multiple of the length of the DL-uplink (UL) pattern, in slots. For UL channel measurements, the gNB node reserves one symbol for the sounding reference signal (SRS) for every L slots across the entire bandwidth. The minimum value of L is 5. For FDD, the value of L is 5. For TDD, L is a multiple of the length of the DL-UL pattern, in slots. The gNB node configures the UE nodes to share the reserved SRS by varying the comb offset, cyclic shift, or transmission time. The gNB uses both a comb size and maximum cyclic shift of 4. As a result, the gNB node can configure up to 16 connected UE nodes to transmit SRS with periodicity as L slots. If more than 16 UE nodes connect, the scheduler increases the SRS transmission periodicity for each UE to the next multiple of L to accommodate more UE nodes.

References

[1] 3GPP TS 38.104. “NR; Base Station (BS) radio transmission and reception.” 3rd Generation Partnership Project; Technical Specification Group Radio Access Network.

[2] 3GPP TS 38.101-1. “NR; User Equipment (UE) radio transmission and reception; Part 1: Range 1 Standalone.” 3rd Generation Partnership Project; Technical Specification Group Radio Access Network.

Version History

Introduced in R2023a

R2026a: Configure CSI reporting parameters

The CSIReportConfig name-value argument of the connectUE function enables you to configure CSI reporting parameters. Specify CSIReportConfig as an nrCSIReportConfig object with the CQITable property set to 'table2'.

R2026a: Moved to 5G Toolbox and requires Wireless Network Toolbox

Starting in R2026a, this feature is available in 5G Toolbox™ and also requires a Wireless Network Toolbox license. In prior releases, the feature is available through the Communications Toolbox™ Wireless Network Simulation Library add-on.

R2024b: Includes support for custom UE context

You can now specify the custom UE context as a structure using the customUE name-value argument of the connectUE object function.