8.1 KiB
DISCLAIMER : This page is under complete review and update, thanks for your patience
Configuration Overview:
-
Non Standalone (NSA) configuration : initial Control Plane established between UE and RAN eNB, then User Plane established between UE and gNB, Core network is 4G based supporting rel 15
-
Commercial UE: Oppo Reno 5G
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OAI Software Defined gNB and eNB
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eNB RF front end: USRP (ETTUS) B200 Mini or B210
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gNB RF front end: USRP (ETTUS) B200 Mini or B210 (N310 will be needed for MIMO and wider BW's)
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5G TDD duplexing mode
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5G FR1 Band n78 (3.5 GHz)
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BW: 40MHz
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Antenna scheme: SISO
SW Repository / Branch
https://gitlab.eurecom.fr/oai/openairinterface5g/tree/develop
Architecture Setup
The scheme below depicts our typical setup:
The photo depicts the FR1 setup part of the scheme above:
Build / Install
General guidelines for building : See https://gitlab.eurecom.fr/oai/openairinterface5g/blob/develop/doc/BUILD.md#building-ues-enodeb-and-gnodeb-executables
- EPC
for reference: https://github.com/OPENAIRINTERFACE/openair-epc-fed/blob/master-documentation/docs/DEPLOY_HOME.md
- eNB
sudo
- gNB
sudo
Configuration Files
Each component (EPC, eNB, gNB) has its own configuration file.
These config files are passed as arguments of the run command line, using the option -O <conf file>
Some config examples can be found in the following folder:
https://gitlab.eurecom.fr/oai/openairinterface5g/-/tree/develop/targets/PROJECTS/GENERIC-LTE-EPC/CONF
These files have to be updated manually to set the IP addresses and frequency.
1- In the eNB configuration file :
- look for MME IP address, and update the ipv4 field with the IP address of the EPC server
////////// MME parameters:
mme_ip_address = ( { ipv4 = "**YOUR_EPC_IP_ADDR**";
ipv6 = "192:168:30::17";
active = "yes";
preference = "ipv4";
}
);
- look for S1 IP address, and update the 3 fields below with the IP address of the eNB server
NETWORK_INTERFACES :
{
ENB_INTERFACE_NAME_FOR_S1_MME = "eth0";
ENB_IPV4_ADDRESS_FOR_S1_MME = "**YOUR_ENB_IP_ADDR**";
ENB_INTERFACE_NAME_FOR_S1U = "eth0";
ENB_IPV4_ADDRESS_FOR_S1U = "**YOUR_ENB_IP_ADDR**";
ENB_PORT_FOR_S1U = 2152; # Spec 2152
ENB_IPV4_ADDRESS_FOR_X2C = "**YOUR_ENB_IP_ADDR**";
ENB_PORT_FOR_X2C = 36422; # Spec 36422
};
2- In the gNB configuration file :
- look for MME IP address, and update the ipv4 field with the IP address of the EPC server
////////// MME parameters:
mme_ip_address = ( { ipv4 = "**YOUR_EPC_IP_ADDR**";
ipv6 = "192:168:30::17";
active = "yes";
preference = "ipv4";
}
);
- look for X2 IP address, and update the 4 fields with the IP address of the eNB server (notice : even if -in principle- S1 MME is not required for gNB setting)
///X2
enable_x2 = "yes";
t_reloc_prep = 1000; /* unit: millisecond */
tx2_reloc_overall = 2000; /* unit: millisecond */
target_enb_x2_ip_address = (
{ ipv4 = "**YOUR_ENB_IP_ADDR**";
ipv6 = "192:168:30::17";
preference = "ipv4";
}
);
NETWORK_INTERFACES :
{
GNB_INTERFACE_NAME_FOR_S1_MME = "eth0";
GNB_IPV4_ADDRESS_FOR_S1_MME = "**YOUR_ENB_IP_ADDR**";
GNB_INTERFACE_NAME_FOR_S1U = "eth0";
GNB_IPV4_ADDRESS_FOR_S1U = "**YOUR_ENB_IP_ADDR**";
GNB_PORT_FOR_S1U = 2152; # Spec 2152
GNB_IPV4_ADDRESS_FOR_X2C = "**YOUR_ENB_IP_ADDR**";
GNB_PORT_FOR_X2C = 36422; # Spec 36422
};
3- The frequency setting requires a manual update in the .C and in the gNB conf file:
In the C file openair2/RRC/LTE/rrc_eNB.c:3217
set the nrarfcn to the same value as absoluteFrequencySSB in the gNB config file, that is 641272 in the example below
C file :
MeasObj2->measObject.choice.measObjectNR_r15.carrierFreq_r15 =641272;
gNB config file :
# absoluteFrequencySSB is the central frequency of SSB
absoluteFrequencySSB = 641272;
dl_frequencyBand = 78;
# the carrier frequency is assumed to be in the middle of the carrier, i.e. dl_absoluteFrequencyPointA_kHz + dl_carrierBandwidth*12*SCS_kHz/2
dl_absoluteFrequencyPointA = 640000;
#scs-SpecificCarrierList
dl_offstToCarrier = 0;
# subcarrierSpacing
# 0=kHz15, 1=kHz30, 2=kHz60, 3=kHz120
dl_subcarrierSpacing = 1;
dl_carrierBandwidth = 106;
Run / Test
The order to run the different components is important:
1- first, CN
2- then, eNB
3- then, gNB
4- finally, switch UE from airplane mode OFF to ON
It is recommended to redirect the run commands to the same log file (fur further analysis and debug), using | tee **YOUR_LOG_FILE** especially for eNB and gNB.
It is not very useful for the CN.
The test takes typically a few seconds, max 10-15 seconds. If it takes more than 30 seconds, there is a problem.
- EPC (on EPC host):
for reference: https://github.com/OPENAIRINTERFACE/openair-epc-fed/blob/master-documentation/docs/DEPLOY_HOME.md
- eNB (on the eNB host):
Execute:
~/openairinterface5g/cmake_targets/ran_build/build$ sudo ./lte-softmodem -O **YOUR_ENB_CONF_FILE** | tee **YOUR_LOG_FILE**
for example:
~/openairinterface5g/cmake_targets/ran_build/build$ sudo ./lte-softmodem -O ../../../targets/PROJECTS/GENERIC-LTE-EPC/CONF/enb.band7.tm1.50PRB.usrpb210.conf | tee mylogfile.log
- gNB (on the gNB host)
Execute:
~/openairinterface5g/cmake_targets/ran_build/build$ sudo ./nr-softmodem -O **YOUR_GNB_CONF_FILE** | tee **YOUR_LOG_FILE**
for example:
~/openairinterface5g/cmake_targets/ran_build/build$ sudo ./nr-softmodem -O ../../../targets/PROJECTS/GENERIC-LTE-EPC/CONF/gnb.band78.tm1.106PRB.usrpn300.conf | tee mylogfile.log
Test Case
Test case description : UE attachement
Expected Logs to check
what logs and where to check, to ensure that your setup works fine (or not ...)
Required traces for debug
What info/traces/logs are needed for us to support the debug
Status of the interoperability
The following parts have been validated with FR1 COTS UE:
-
Phone accepts the configurtion provided by OAI eNB:
this validates RRC and X2AP -
Successful Random Access Procedure:
PRACH is correctly decoded at gNB
Phone correctly receives and decodes msg2 (NR PDCCH Format 1_0 and NR PDSCH)
msg3 is transmitted to gNB according to the configuration sent in msg2, and received correctly at gNB -
Successful path switch of user plane traffic from 4G to 5G cell (E-RAB modification message):
this validates S1AP -
Downlink traffic:
PDCCH DCI format 1_1 and correponding PDSCH are decoded correctlyby the phone
ACK/NACK (PUCCH format 0) are successfully received at gNB -
On going:
validation of HARQ procedures
Integration with higher layers to replace dummy data with real traffic -
Known limitations as of May 2020:
only dummy DL traffic
no UL traffic
no end-to-end traffic possible