NR Multicast Not Working

[JFrandon]

Hi All,

First of all I realize that I'm probably making a mistake somewhere but I can't figure out why.

I have the following simulation: omnetpp.ini

[General]
image-path=../../../images
output-scalar-file-append = false
sim-time-limit=20s
**.routingRecorder.enabled = false

############### Statistics ##################
output-scalar-file = ${resultdir}/${configname}/${repetition}.sca
output-vector-file = ${resultdir}/${configname}/${repetition}.vec
seed-set = ${repetition}
**.vector-recording = false

################ Mobility parameters #####################
# *

**.mobility.constraintAreaMaxX = 1000m
**.mobility.constraintAreaMaxY = 1000m
**.mobility.constraintAreaMinX = 0m
**.mobility.constraintAreaMinY = 0m
**.mobility.constraintAreaMinZ = 0m
**.mobility.constraintAreaMaxZ = 0m
**.mobility.initFromDisplayString = false

############### Number of Resource Blocks ################
**.numBands = 50 # this value should be kept equal to the number of RBs

############### Transmission Power ##################
**.ueTxPower = 26
**.eNodeBTxPower = 40
**.targetBler = 0.01
**.blerShift = 5  

############### IPv4 configurator config #################
*.configurator.config = xmldoc("./demo.xml")

#------------------------------------#
# Config Standalone
#
# Topology configuration for the exemplary scenario for NR Standalone deployment
#
[Config Standalone]
network = simu5g.simulations.NR.networks.SingleCell_Standalone
sim-time-limit=20s

############### e/gNodeB configuration #################
*.gnb.mobility.initialX = 450m
*.gnb.mobility.initialY = 300m

############## UE configuration ##################
*.numUe = 3

# connect the UE's NIC to the corresponding serving eNB
*.ue[*].macCellId = 1
*.ue[*].masterId = 1
*.ue[*].nrMacCellId = 1
*.ue[*].nrMasterId = 1

# UE position
*.ue[*].mobility.initialX = 450m
*.ue[*].mobility.initialY = 350m
#------------------------------------#

[Config UdpSend]
extends=Standalone

# one UDP application for each user
*.ue[*].numApps = 1

# the amount of UDP applications on server should be equal to (numUEs)*(ue[*].numApps) 
*.server.numApps = 1

#============= Application Setup =============
*.server.app[0].typename = "inet.applications.udpapp.UdpEchoApp"
*.server.app[0].localPort = 1000

*.ue[1..2].app[0].typename = "inet.applications.udpapp.UdpEchoApp"
*.ue[1..2].app[0].localPort = 1000

*.ue[0].app[0].typename = "ether_tic_toc.apps.udp_send.UdpSendApp"
*.ue[0].app[0].destAddress = "224.0.0.10" 
*.ue[0].app[0].destPort = 1000
#------------------------------------#

With the following network config: demo.xml

<config>
    <interface hosts='*' address='10.x.x.x' netmask='255.x.x.x'/>
    <multicast-group hosts="ue[*]" interfaces="cellular" address="224.0.0.10"/>
</config>

And ether_tic_toc.apps.udp_send.UdpSendApp is a UDP app that sends a single packet to the port and destination

But When I run it it crashes at LteAmc::existTxParams() with cRuntimeError("LteAmc::existTxparams(): Unrecognized direction")

Then I tried adding

**.usePreconfiguredTxParams = true
**.d2dCqi = 7
**.amcMode = "D2D"

to my config.ini But then it looks like the packet is never sent or received

I'm using the latest commit of Simu5G, INET 4.4.0 and Omnet 6

[giovanninardini]

Hello,

if I understood well, you would like to simulate downlink multicast transmissions. However, unfortunately at the moment Simu5G implements multicast transmissions for device-to-device transmissions only.

Giovanni

[JFrandon]

Not really.

In this scenario, I have 1 NRUe (ue[0]) sending a UDP packet to the other UEs (ue[1..2]). If I understand correctly that should be a device-to-device transmission.

I put this scenario together by copying simulations/LTE/d2d_multicast/ and porting it to an NR network

[giovanninardini]

Oh, I am sorry, I overlooked the UE acting as sender in your configuration.

You should probably also configure the UEs such that they are "registered" to the multicast group. Please try to change your demo.xml file as follows:

<config>
    <interface hosts='*' address='10.x.x.x' netmask='255.x.x.x'/>

    <!-- all D2D-capable UEs participate in the multicast group --> 
    <multicast-group hosts="ue[*]" interfaces="cellular" address="224.0.0.1"/>
</config>

[JFrandon]

I added those in but it still doesn't seem to be working (I edited the original post to show this change)

Are you able to reproduce this setup on your end ?

[giovanninardini]

I tried your configuration and I was able to make it work by changing the position of the UEs:

*.ue[0].mobility.initialX = 450m
*.ue[0].mobility.initialY = 350m
*.ue[1..2].mobility.initialX = 450m
*.ue[1..2].mobility.initialY = 360m

You set the same position for all the UEs, and apparently this makes the channel model compute an infinite value for the path loss, hence causing all packets to be dropped at the receivers.

[JFrandon]

Thanks for the solution, It works now