Integration with Air Interface Emulators

E2E testing of handover test scenarios are usually difficult to simulate and test. It can be made practical only by using Air Interface Emulators (aka Signal Attenuators), still with a laborious process. Handover test scenarios can now be automated using XGP with a direct integration of a programmable attenuator via USB or LAN connectivity. XG device can establish the connection between the attenuator and XGP core (Distributed execution framework) which enables the simulation of handover test scenarios for automated testing.

What is a Programmable Air Interface Emulator?

Air Interface Emulators enables the possibility of testing mobile radio base stations and mobile stations in the Lab environment via the air interface. It allows emulating a fading signal (even loss of signal) over a distance or under different atmospheric conditions. Air Interface Emulators is a device that can be used efficiently in wireless communication testing to emulate a variety of specific wireless network handover scenarios.

Engineers get the opportunity to test the performance and the functionality of the wireless devices and networks in a controlled environment. Programmable Air Interface Emulator can be programmed to simulate various scenarios such as handovers between base stations or different network configurations.

How does it work?

Air Interface Emulators uses semiconductor switches to change different attenuators (1 dB, 2 dB, 4 dB, 8dB etc.) into the signal path with the range of 0 to 95 dB to mimic the signals exchanged between the mobile device and the network. The control unit of the attenuator allows engineers and developers to configure these parameters according to their testing requirements. Programmable attenuators can be controlled via various interfaces such as USB, LAN, RS-232 etc.

What kind of E2E tests can be performed?

XGP interfaced with an Air Interface Emulator can automate testing many handover scenarios.

  • Different mobile radio handover scenarios (inter cell, inter system, etc.)
  • SRVCC test scenarios
  • Feeding a source of disturbance (e.g., for bit error rate tests)

With the scripting capabilities of XGP, complex test cases can be automatically executed, which might have taken significant manual effort otherwise. The script allows dynamic ramping up/down of the attenuation values on channels independently and simultaneously, which allows to perform simulations of different movements through radio environments.

XGP supports certain brands of Air Interface Emulators (Attenuators) out of the box. Please check with our support team regarding connecting the type of attenuator you use in your lab environment.

Integration with Air Interface Emulators


Take a look at a sample test:

import sys
import os
import sequential_runner
from xgdriver.module_driver import ModuleDriver

ModuleDriver.set_scenario_name('SRVCC VoLTE 01 Caller A')

xg = ModuleDriver(sys.argv[1])

msisdn_b = os.environ.get('MSISDN_B')
party_B_device = os.environ.get('PARTY_B')[0:11]
party_B_m_s = os.environ.get('PARTY_B')[-5:]

# Attach to LTE
xg.attach_to_lte()

# Check LTE Registration Status
xg.check_lte_status()

# Enable IMS
xg.config_ims_en()

# Check IMS Registration
xg.check_ims_en()

# Check LTE Registration Status
xg.check_lte_status()

# attenuator command
os.system("mts -d 11.242.52.96 -p 4001 -b 1 2 -a 60 35 -t 2 25")

# Check network status - Cs
xg.check_cs_status()

# Call MSIDN
xg.dial(str(msisdn_b))

# Check Call Active
xg.check_call_active()

# Hang Call
xg.hang_call()

# wait for 60 sec
xg.wait(60)

# change the attenuator config to default
os.system("mts -d 11.242.52.96 -p 4001 -b 1 2 -a -70 -35 -t 5 5")


Sample usage of the test step:

Set the channel 1 and 2 in the attenuator to 60 dB and 35 dB respectively. Attenuation value to be reduced by 25 over 5 seconds.

os.system("mts -d 10.241.52.96 -p 4001 -b 1 2 -a 60 35 -t 2 25")