4G/LTE Mobile Network Test Bed

During the software development of mobile router, IOT gateway, it is essential to have 4G/LTE test bed in place.

LTE testbed In this post, I will cover three approaches to set up test bed for 4G/LTE test bed.

To have a cost effective, and easy to use 4G/LTE test bed is critical for software development when it comes to mobile router, IOT gateway software development. It could be also critical for hardware compliance testing as well.

In my lab at Cisco, there are three approaches:

  1. Using SIM card from carrier, and connect to live 4G/LTE network.
  2. Using the dedicated base state simulator (BSS)
  3. Using software defined radio (SDR) picoLTE

The above three ways, there are pros and cons as decribed below.

Using SIM card from carrier, and connect to live 4G/LTE network.

With this approach, you can buy SIM card from wireless carrier like AT&T, Verizon, T-Mobile. The SIM card is inserted into unit under test (UUT), it is ready for testing.

pros:

  1. Minimum effort to prepare.
  2. Very minimum initial cost to start. </ol> cons:
    1. It requires monthly payment even when it is not used.
    2. The network is not under fully controlled enviroment. Even though most time the carrier network should be up running, there is down time for sure. This will add up another variable. This could be a serious concern especially when the software is still under development.
    3. This is not suitable for performance testing.
    4. One SIM card is limited to the modem for the carrier only, i.e. it can NOT be used to test different model of modems.
    # Using the dedicated base state simulator (BSS) With this approach, you need buy the dedicated BSS from vendors such as [Rohde & Schwarz] (http://www.rohde-schwarz.com), [Anritsu] (http://www.anritsu.com). A test SIM card is used, typically RF cable will be used to feed radio signal to UUT. pros:
    1. The whole enviroment is under fully controlled, meaning it is stable and to be trusted.
    2. It typically provides ethernet port to feed traffic from device like IXIA, Spirent for performance testing.
    3. It can test various modems by changing the setup.
    4. It can do almost all kinds of testing.
    cons:
    1. BSS is very expensive, a basic setup box easily costs $70K. This is a lot investment!
    2. Typically one box can be used to test one UUT at one time, at most two UUTs.
    3. The setup is quite complicated.
    # Using software defined radio (SDR) picoLTE With this approach, you need purchase the dedicated SDR picoLTE from vendor like [Nutaq] (http://www.nutaq.com). A test SIM card is used. picoLTE will be acting as eNode, also with mme, PGW. The ethernet interface is provided so that it can be connected to corporate network for testing. pros:
    1. It is cost effective comparing to BSS (only cost 1/3 or half)
    2. It can test many UUT devices(e.g. 50) in the sametime.
    3. It runs under a controlled enviroment.
    4. The setup is relative easy. Mainly it needs to change the configuration file to change the radio frequency.
    cons:
    1. It can NOT be used for performance testing.
    Besides the above three approaches, there are other ways like using a low end eNode, then run MME, SGW, PGW software stack in another linux box. This would require more resources, but could be a good approach too if the company owns those software stack.