srsRAN_4G software suite includes a virtual radio which uses the ZeroMQ networking library to transfer radio samples between applications. Therefore, in order to confirm the facilities of EPC, I will describe the simple procedure for building these virtual eNodeB and UE instead of the real devices. Note that the RF plugin is disabled and the ZeroMQ library is built into the virtual eNodeB and UE.
Please refer to the following for building srsRAN 4G UE / RAN with ZeroMQ.
- srsRAN 4G - https://docs.srsran.com/projects/4g/en/latest/
The specification of the VM that have been confirmed to work is as follows.
| OS | CPU (Min) | Memory (Min) | HDD (Min) | GCC version |
|---|---|---|---|---|
| Ubuntu 22.04 | 1 | 2GB | 10GB | 11 (default) |
| Ubuntu 24.04 | 1 | 2GB | 10GB | 11 (downgrade from 13) |
2GB or more memory is required to build.
- Install the required libraries including ZeroMQ
- Clone srsRAN_4G
- Build srsRAN 4G UE / RAN by disabling RF plugins
- Create configuration files of eNodeB
- Create the configuration file of UE
- Create the configuration file of NR-UE
- Note for ensuring that packets pass through UE-RAN-UPF path
- Issues
- Confirmed Version List
- Sample Configurations
- Changelog (summary)
# apt install build-essential cmake libfftw3-dev libmbedtls-dev libboost-program-options-dev libconfig++-dev libsctp-dev libzmq3-dev
If building srsRAN_4G on Ubuntu 24.04, downgrade the gcc version from the default 13 to 11.
First, install gcc-11 and g++-11 in addition to the packages installed above.
# apt install gcc-11 g++-11
Then, use update-alternatives tool to be able to switch between gcc-11 and 13.
# update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-11 11 --slave /usr/bin/g++ g++ /usr/bin/g++-11
# update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-13 13 --slave /usr/bin/g++ g++ /usr/bin/g++-13
Finally, switch to using gcc-11.
# update-alternatives --config gcc
There are 2 choices for the alternative gcc (providing /usr/bin/gcc).
Selection Path Priority Status
------------------------------------------------------------
* 0 /usr/bin/gcc-13 13 auto mode
1 /usr/bin/gcc-11 11 manual mode
2 /usr/bin/gcc-13 13 manual mode
Press <enter> to keep the current choice[*], or type selection number: 1
update-alternatives: using /usr/bin/gcc-11 to provide /usr/bin/gcc (gcc) in manual mode
Confirm that gcc version has been switched to 11.
# update-alternatives --config gcc
There are 2 choices for the alternative gcc (providing /usr/bin/gcc).
Selection Path Priority Status
------------------------------------------------------------
0 /usr/bin/gcc-13 13 auto mode
* 1 /usr/bin/gcc-11 11 manual mode
2 /usr/bin/gcc-13 13 manual mode
Press <enter> to keep the current choice[*], or type selection number: ^C
# gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/11/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none:amdgcn-amdhsa
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 11.4.0-9ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-11/README.Bugs --enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++,m2 --prefix=/usr --with-gcc-major-version-only --program-suffix=-11 --program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-plugin --enable-default-pie --with-system-zlib --enable-libphobos-checking=release --with-target-system-zlib=auto --enable-objc-gc=auto --enable-multiarch --disable-werror --enable-cet --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none=/build/gcc-11-ZcnBzW/gcc-11-11.4.0/debian/tmp-nvptx/usr,amdgcn-amdhsa=/build/gcc-11-ZcnBzW/gcc-11-11.4.0/debian/tmp-gcn/usr --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu --with-build-config=bootstrap-lto-lean --enable-link-serialization=2
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 11.4.0 (Ubuntu 11.4.0-9ubuntu1)
# git clone https://github.com/srsran/srsRAN_4G.git
Configure that RF plugins is disabled to directly link the ZeroMQ library into the virtual eNodeB and UE.
# cd srsRAN_4G
# mkdir build
# cd build
# cmake ../ -DENABLE_RF_PLUGINS=OFF
# make -j`nproc`
# cd srsRAN_4G/srsenb
# cp enb.conf.example ../build/srsenb/enb.conf
# cp rr.conf.example ../build/srsenb/rr.conf
# cp rb.conf.example ../build/srsenb/rb.conf
# cp sib.conf.example ../build/srsenb/sib.conf
Then, edit according to your environment.
# cd srsRAN_4G/srsue
# cp ue.conf.example ../build/srsue/ue.conf
Then, edit according to your environment.
When used as 5G NR-UE with ZeroMQ support, it can connect to srsRAN_Project 5G RAN with ZeroMQ.
For 5G NR-UE configuration, get UE config of ZeroMQ-based Setup as the original file.
Also, see here for how to build this RF simulated gNodeB.
# cd srsRAN_4G/build/srsue
# wget <link of "UE config">
For reference, ue_zmq.conf on 2023.12.07 is as follows.
[rf]
freq_offset = 0
tx_gain = 50
rx_gain = 40
srate = 23.04e6
nof_antennas = 1
device_name = zmq
device_args = tx_port=tcp://127.0.0.1:2001,rx_port=tcp://127.0.0.1:2000,base_srate=23.04e6
[rat.eutra]
dl_earfcn = 2850
nof_carriers = 0
[rat.nr]
bands = 3
nof_carriers = 1
max_nof_prb = 106
nof_prb = 106
[pcap]
enable = none
mac_filename = /tmp/ue_mac.pcap
mac_nr_filename = /tmp/ue_mac_nr.pcap
nas_filename = /tmp/ue_nas.pcap
[log]
all_level = info
phy_lib_level = none
all_hex_limit = 32
filename = /tmp/ue.log
file_max_size = -1
[usim]
mode = soft
algo = milenage
opc = 63BFA50EE6523365FF14C1F45F88737D
k = 00112233445566778899aabbccddeeff
imsi = 001010123456780
imei = 353490069873319
[rrc]
release = 15
ue_category = 4
[nas]
apn = srsapn
apn_protocol = ipv4
[gw]
netns = ue1
ip_devname = tun_srsue
ip_netmask = 255.255.255.0
[gui]
enable = false
Then, edit according to your environment.
The following SST/SD values are in decimal notation. For example, SST=0x1 and SD=0x010203 are expressed in decimal as follows.
[slicing]
enable = true
nssai-sst = 1
nssai-sd = 66051
Make the following settings on UE to ensure that packets pass through UE-RAN-UPF path.
# ip route del default
# ip route add default dev tun_srsue
Then, for example when run iPerf3 client on UE, do the following.
# iperf3 -B <UE IP address> -c <IP address of iperf3 server>
In this case, in order to ensure that the traffic goes through tun_srsue interface, UE must not directly connect to the same network as the IP address to which iPerf3 server binds.
Note. According to this, srsUE is not intended to be used in high-throughput scenarios. It seems that srsUE is useful for confirming the functionality of 4G/5G core networks.
- If you're having an issue with a registration request from NR-UE with
[slicing]section in the configuration to Open5GS, this might be helpful.
I simply confirmed the operation of the following versions.
| Version | Commit | Date | Issues |
|---|---|---|---|
| 23.11+ | ec29b0c1ff79cebcbe66caa6d6b90778261c42b8 |
2024.02.01 | 1 |
| 23.11 | eea87b1d893ae58e0b08bc381730c502024ae71f |
2023.11.23 | 1 |
| 23.04.1 | fa56836b14dc6ad7ce0c3484a1944ebe2cdbe63b |
2023.06.19 | 1 |
- Open5GS 5GC & srsRAN 5G with ZeroMQ UE / RAN Sample Configuration
- free5GC 5GC & srsRAN 5G with ZeroMQ UE / RAN Sample Configuration
- [2025.05.11] Added instructions for building on Ubuntu 24.04.
- [2024.03.25] Updated a list of confirmed versions.
- [2023.12.02] Updated a list of confirmed versions.
- [2023.10.10] Added a list of confirmed versions.
- [2023.08.10] Added 5G NR-UE configuration file.
- [2023.05.06] Initial release.