Is it possible to connect a UE to a nrGNB in both download and upload links at the same time?

Hello all.

Is it possible to connect a UE to a nrGNB in both download and upload links at the same time?

In my scenario, I have to simulate UE connecting in both links at the same gNB or in different ones simultaneously, depending on some current evaluations.

In "NR Intercell Interference Modeling" and "Connect UEs to gNB" examples, I could see how to do this separately. But couldn't understand if and, if possible, how to do it.

Any clue?

[]'s.

Answer 1

[Saurav]

Hi @Hudson Romualdo,

In MATLAB's 5G Toolbox, the simulation framework is designed to handle both uplink and downlink transmissions when a gNB and a UE are connected. However, it is essential to ensure that both links are properly configured and invoked within the simulation script.

Configuration of Uplink and Downlink

1. Separate Configuration Objects: In scenarios where different settings are required for uplink and downlink, separate configuration objects may be necessary. This makes it possible to set parameters that are specific to each link.
2. Example for Better Understanding: Consider the example provided in MATLAB: “CreateConfigureAndSimulate5GNRNodesExample”. This example demonstrates how to set up and simulate 5G NR nodes effectively.

openExample('wirelessnetwork/CreateConfigureAndSimulate5GNRNodesExample')

3. Configuring Downlink:

• In the example, the following line of code adds a data traffic source to the gNB node, with the destination set as the UE node. This configuration is for the downlink:

addTrafficSource(gnb, traffic, DestinationNode=ue)

• Upon reviewing the ‘ueStats’ after executing the script, it is observed that only received packets and bytes are recorded, indicating a downlink configuration.

4. Extending to Uplink:

• To configure both downlink and uplink, an additional line of code is introduced:

addTrafficSource(gnb, traffic, DestinationNode=ue)
addTrafficSource(ue, traffic, DestinationNode=gnb) % This new line of code added

• This additional line configures the uplink by adding a traffic source to the UE node with the gNB as the destination. Running the script again and reviewing ueStats will now show both transmitted and received packets, confirming the configuration of both links.

By following these steps, the simulation can effectively model both uplink and downlink transmissions between the gNB and UE, providing a comprehensive view of the network's performance.

Hope this helps you in better understanding.

[Hudson Romualdo]

Thanks for answering me, @Saurav.

My first impression of this example was exactly the opposite. Since the UE is created with the "TransmitPower" method and "configureULPowerControl" that was used, I thought this example was about uploading from the UE to the gNB.

Reading the documentation for "addTrafficSource" we have: adds a data traffic source, trafficSource, to a new radio node (NR).

So, correct me if I'm wrong, in your example UE and gNB are communicating in both, upload a download links over mmWave (NR).

If not, do you know how to create them as mmWave channels?

And if I need, how can I create an upload link between UE and gNB with another frequency? (sub-6 GHz for example)