LTE Base Station

Projects LimeSDR
1

I would like to setup a LTE Base station using LimeSDR USB.

I am a newbie in SDRs. I am currently going through the various documentation provided by myriadRF. However, if you could answer some of the questions, it would be very helpful.

Questions

  1. Is a complete LTE Base Station feasible with 1 Linux PC (Intel Xeon 2.8 GHz, 8GB RAM), limeSDR, antenna & other related open source software ?
  2. Is a full-duplex Tx/Rx LTE Base station possible with LimeSDR ?
  3. Is additional duplexer required ?
  4. Which is the best combination of software to be used with lime SDR for base station (GNU radio , pothos, limesuite, OAI, osmocom, srsLTE) ?
  5. Can the output RF signal levels be controlled by configuration i.e. if the max. output is +10dBm for a given frequency, can I control it such that the output is -90 ~ -120 dBm ?

@andrew : Can you please provide some suggestions ?

TG

2

On the topic of 4G LTE it isnt quite as Plug-Compile-and-Play as other things with SDR but look into these i have heard good things about open air interface.

https://www.openairinterface.org/?page_id=2762 Demonstrated by https://limemicro.com/news/limesdr-software-defined-radio-applications-part-1-lte/

or possibly https://github.com/srsLTE/srsLTE

3

Thanks Maxwell!
Can you answer pts. 2,3 & 5 ?

4

Of course.

Yes.

If you want to use single antenna for Tx and Rx, then yes.
Band specific filters are recommended.

Would recommend srsLTE.

Yes, you can control Tx output power.

5

Thanks Zack for the concise answers!

6

Is there any particular Linux distro that is recommended for projects with limeSDR ? esp. with the complexity of a base-station. My question is from software compatibility and overall performance point of view. if I am not mistaken, Ubuntu seems to be a popular choice . Is Snappy Ubuntu Core better ?

7

Generally recommend Ubuntu classic for development and typical use.

Ubuntu Core is what you might use in a production network with many devices and where you want a minimal, locked-down O/S with device management etc. features.

8

Thanks Andrew!

9

Is any one aware if experimental (non-commercial) indoor LTE transmission at low power (<70 dBm) is allowed in India ?
How are other people (from India) who bought limeSDR for LTE femtocell (base station) dealing with the legal aspects ?

10

Please use Faraday cage and your lab should have experimental license from WPC

11

I am trying to setup LTE base station using srsLTE and limesdr mini. The issue is commercial phone as UE is unable to see the network created by srsenb. The transmission is happening in desired frequency(checked by separate setup consisting Hackrf One).
There are so many posts on commercial phones are unable to see network created by limesdr and srsLTE, but the solutions are not specific.

12

Thanks @tikiarya , Can you give the link for the Faraday cage (that you have tried) and the link for the exact license required ? Is this license for importing equipment or to run the indoor LTE base station non-commercially ? Also, what are the costs involved for the license ?

13

@tusharg21, could you set it up and test it ? I’m on a similar project, wanted to know if it’s possible.
Thanks,
Srinivas

14

@srinivas : I have not worked on it for quite some time. I will try to set it up next week.

1 Like
15

Can someone share good case verbose logs for
[1] srsenb
[2] srsepc
[3] limeSDR / SoapySDR
when the setup works as LTE Base Station ?

Also, can someone share the troubleshooting procedure if the srsLTE network does not appear in radio n/w scan on commercial mobile phones like Redmi or Samsung ?

16

before you got confuse do three little thing important.

  1. check your limeSDR with LimeQuickTest command if it fail in some freq avoid that freq than contact zack for RMA.
  2. Check You handphone what band they work (don’t laugh I made this mistake :kissing_closed_eyes:)
  3. try to lowering TX gain a little bit (you can find in enb.conf the default is 80 lowering to 70 or 65) and RX gain too.
    Try it its good for whole weekend work :grin:
    dont worry about anything else (you still need more week end work after You can see the network on your handphone ) combination of Soapy, limesuite and srsLTE for me like make a cake the recipe very easy to find but the result is difficult to predict ( I lost count how many time I reinstall my ubuntu and still no exact result in same sdr, same handphone, same table, same PC).
17

Thanks for your inputs @theboel.