Sample Application

Figure 26 illustrates a sample xRAN application.

Figure 26. Sample Application

The sample application was created to execute test scenarios with features of the O-RAN library and test external API as well as timing. The sample application is named sample-app, and depending on configuration file settings can act as O-DU or simplified simulation of O-RU. The first O-DU should be run on the machine that acts as O-DU and the second as O-RU. Both machines are connected via ETH. The sample application on both sides executes using a constant configuration according to settings in corresponding config files (./app/usecase/mu0_10mhz/config_file_o_du.dat and ./app/usecase/mu0_10mhz/config_file_o_ru.dat) and uses binary files (ant.bin) with IQ samples as input. Multiple-use cases for different numerologies and different BW are available as examples. Configuration files provide descriptions of each parameter, and in general, those are related to M-plane level settings as per the O-RAN Fronthaul specification, refer to Table 2.

From the start of the process, the application (O-DU) sends DL packets for the U-plane and C-plane and receives U-plane UL packets. Synchronization of O-DU and O-RU sides is achieved via IEEE 1588.

U-plane packets for UL and DL direction are constructed the same way except for the direction field.

Examples of default configurations used with the sample application for v20.04 release provided below:

1 Cell mmWave 100MHz TDD DDDS:

• Numerology 3 (mmWave)

• TTI period 125 µs

• 100 MHz Bandwidth: 792 subcarriers (all 66 RB utilized at all times)

• 4x4 MIMO

• No beamforming

• 1 Component carrier

• Jumbo Frame for Ethernet (up to 9728 bytes)

• Front haul throughput ~11.5 Gbps.

12 Cells Sub6 10MHz FDD:

• Numerology 0 (Sub-6)

• TTI period 1000 µs

• 10 MHz Bandwidth: 624 subcarriers (all 52 RB utilized at all times)

• 4x4 MIMO

• No beamforming

• 12 Component carrier

• Jumbo Frame for Ethernet (up to 9728 bytes)

• Front haul throughput ~13.7Gbps.

1 Cell Sub6 100 MHz TDD

• Numerology 1 (Sub-6)

• TTI period 500 µs

• 100 MHz Bandwidth: 3276 subcarriers (all 273 RB utilized at all times)

• 4x4 MIMO

• No beamforming

• 1 Component carrier

• Jumbo Frame for Ethernet (up to 9728 bytes)

• Front haul throughput ~11.7 Gbps.

1 Cell Sub6 100 MHz TDD (Category B):

• Numerology 1 (Sub-6)

• TTI period 500 µs

• 100 MHz Bandwidth: 3276 subcarriers (all 273 RB utilized at all times). 8 UEs per TTI per layer

• 8DL /4UL MIMO Layers

• Digital beamforming with 32T32R

• 1 Component carrier

• Jumbo Frame for Ethernet (up to 9728 bytes)

• Front haul throughput ~23.5 Gbps.

3 Cell Sub6 100MHz TDD Massive MIMO (Category B):

• Numerology 1 (Sub-6)

• TTI period 500 µs

• 100 Mhz Bandwidth: 3276 subcarriers (all 273 RB utilized at all times). 8 UEs per TTI per layer

• 16DL /8UL MIMO Layers

• Digital beamforming with 64T64R

• 1 Component carrier for each Cell

• Jumbo Frame for Ethernet (up to 9728 bytes)

• Front haul throughput ~44 Gbps.

Other configurations can be constructed by modifying the config files (see app/usecase/)

One_way Delay Measurements:

There are 4 usecases defined that are based on cat a, numerology 0 and 20 MHz Bw:

Common to all cases the following parameters are needed in the usecase_xu.cfg files where x=r for ORU and x=d for ODU.

oXuOwdmNumSamps=8 # Run 8 samples per port

oXuOwdmFltrType=0 # Simple average

oXuOwdmRespTimeOut=10000000 # 10 ms expressed in ns (Currently not enforced)

oXuOwdmMeasState=0 # Measurement state is INIT

oXuOwdmMeasId=0 # Measurement Id seed

oXuOwdmEnabled=1 # Measurements are enabled

oXuOwdmPlLength= n # with 40 <= n <= 1400 bytes

For the ORU

oXuOwdmInitEn=0 #O-RU is always the recipient

For the ODU

oXuOwdmInitEn=1 #O-DU is always initiator

20 Corresponds to the Request/Response usecase with Payload Size 40 bytes

oXuOwdmMeasMeth=0 # Measurement Method REQUEST

21 Corresponds to the Remote Request usecase with Payload Size 512 bytes

oXuOwdmMeasMeth=1 # Measurement Method REM_REQ

22 Corresponds to the Request with Follow Up usecase with Payload Size 1024 bytes

oXuOwdmMeasMeth=2 # Measurement Method REQUESTwFUP

23 Corresponds to the Remote Request with Follow Up usecase with default Payload Size

oXuOwdmMeasMeth=3 # Measurement Method REM_REQ_WFUP