# LimeSDR with srsenb
**URL:** https://discourse.myriadrf.org/t/limesdr-with-srsenb/7432
**Category:** RAN Forum
**Created:** [27 November 2021 01:37 UTC](https://discourse.myriadrf.org/t/limesdr-with-srsenb/7432 "2021-11-27T01:37:58Z")
**Posts on this page:** 14
**Page:** 1
### Author:  [@nemanja](https://discourse.myriadrf.org/u/nemanja)
#### Post date: [27 November 2021 01:37 UTC](https://discourse.myriadrf.org/t/limesdr-with-srsenb/7432/1 "2021-11-27T01:37:58Z")
Hi,
I have found it difficult to run srsenb on Ubuntu 20.04.
I am getting error showed on the image attached.
As shown on image I can see LimeSDR listed but uhd\_find\_devices returns “No UHD Devices Found”.
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### Author:  [@andrewback](https://discourse.myriadrf.org/u/andrewback)
#### Post date: [30 November 2021 13:50 UTC](https://discourse.myriadrf.org/t/limesdr-with-srsenb/7432/2 "2021-11-30T13:50:06Z")
> [@nemanja](#):
>
> As shown on image I can see LimeSDR listed but uhd\_find\_devices returns “No UHD Devices Found”.
That’s because a LimeSDR is not a USRP, hence cannot be used by UHD in this way.
This application note shows how to configure is to use SoapySDR with LimeSDR hardware:
[https://docs.srsran.com/en/latest/app\_notes/source/pi4/source/index.html](https://docs.srsran.com/en/latest/app_notes/source/pi4/source/index.html)
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### Author:  [@nemanja](https://discourse.myriadrf.org/u/nemanja)
#### Post date: [27 November 2021 17:38 UTC](https://discourse.myriadrf.org/t/limesdr-with-srsenb/7432/3 "2021-11-27T17:38:48Z")
Hi,
I have two runtime issues when running srsenb:
1. Couldn’t open: enb.conf
2. Soapy selects wrong device
Srsepc works fine.
Please find attached snapshot.
Any idea how to fix that?
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### Author:  [@nemanja](https://discourse.myriadrf.org/u/nemanja)
#### Post date: [2 December 2021 18:10 UTC](https://discourse.myriadrf.org/t/limesdr-with-srsenb/7432/4 "2021-12-02T18:10:03Z")
Thansk for your answer it works fine with SoapySDR.
Now I can run SoapySDRUtil --probe and see LimeSDR USB device.
Issue that remains is that I can not see my private network when I search it with my mobile phone (Samsung Galaxy S20+).
Could you tell me how to know if I connected antennas to the right connector?
I connected following antennas: TX1\_1, TX2\_1, RX1\_H, RX2\_H.
When I run srsENB with:
sudo srsenb ~/.config/srsran/enb.conf --expert.lte\_sample\_rates=true --rf.dl\_earfcn 1934
DL EARFCN is set to 1934 because I am in Europe and LTE is on 1800MHz.
I can see that Rx and Tx antennas are set to LNAL and BAND1, please find snapshot attached.
How LNAL and BAND1 are mapped to the LimeSDR USB antenna connectors?
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### Author:  [@nemanja](https://discourse.myriadrf.org/u/nemanja)
#### Post date: [16 December 2021 22:51 UTC](https://discourse.myriadrf.org/t/limesdr-with-srsenb/7432/5 "2021-12-16T22:51:34Z")
I have finally menaged to attach with Samsung Galaxy UE to my private network but connection is very unstabile.
In order to configure EPC, ENB to work with LimeSDR I have followed srsRAN Documentation, Release 21.10 (section: 5.2 COTS UE).
Could you tell me how this issue can be fixed?
I connected very good antennas with 38dBi:
[https://www.aliexpress.com/item/1005002756942513.html?spm=a2g0s.9042311.0.0.45b64c4d1EUkid](https://www.aliexpress.com/item/1005002756942513.html?spm=a2g0s.9042311.0.0.45b64c4d1EUkid)
Here is my configuration:
#####################################################
[rf]
#dl\_earfcn = 3350
tx\_gain = 80
rx\_gain = 40
device\_name = soapy
#device\_args = auto
device\_args = rxant=LNAH,txant=BAND1
#####################################################
[mme]
mme\_code = 0x1a
mme\_group = 0x0001
tac = 0x0007
mcc = 901
mnc = 70
mme\_bind\_addr = 127.0.1.100
apn = srsapn
dns\_addr = 8.8.8.8
encryption\_algo = EEA0
integrity\_algo = EIA1
paging\_timer = 2
request\_imeisv = false
---
### Author:  [@andrewback](https://discourse.myriadrf.org/u/andrewback)
#### Post date: [20 December 2021 09:38 UTC](https://discourse.myriadrf.org/t/limesdr-with-srsenb/7432/6 "2021-12-20T09:38:53Z")
Two things which may help are a duplexer and external reference clock.
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### Author:  [@nemanja](https://discourse.myriadrf.org/u/nemanja)
#### Post date: [20 December 2021 10:00 UTC](https://discourse.myriadrf.org/t/limesdr-with-srsenb/7432/7 "2021-12-20T10:00:29Z")
I’m very unsatisfied with LimeSDR. I will probbubly try with another hardware solution.
I’m able to connect UE to LimeSDR-srsENB 1 out of 10 times.
In other cases in can’t see network or it can’t attach.
I have also added additional power supply (9V 3A), but it hasn’t improved stability.
Software srsRAN run withaout any errors but it is very difficult to attach.
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### Author:  [@andrewback](https://discourse.myriadrf.org/u/andrewback)
#### Post date: [21 December 2021 15:05 UTC](https://discourse.myriadrf.org/t/limesdr-with-srsenb/7432/8 "2021-12-21T15:05:13Z")
Without a duplexer the performance may be severely compromised, since you have a wideband SDR with no filtering _and_ the base station transmit signal coupling back into receive. This would be precisely the same with any SDR that does not integrate RF front-end filtering.
Same goes with external reference clock and ideally this would be GPS locked or maybe an OCXO.
A wideband SDR with no external reference or RF front-end + software does not equal an LTE base station. You may be lucky and get good results, e.g. of the on-board oscillator is not far off and the antennas set up such to minimise Tx-\>Rx coupling, but it’s not guaranteed. Stability issues can also sometimes result from O/S issues, e.g. process scheduling and USB.
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### Author:  [@nemanja](https://discourse.myriadrf.org/u/nemanja)
#### Post date: [21 December 2021 20:11 UTC](https://discourse.myriadrf.org/t/limesdr-with-srsenb/7432/9 "2021-12-21T20:11:24Z")
Could you recommend me duplexer for RF filtering?
I find this one:
> **[29.71US $ 32% OFF|LTE, OAI, SRSLTE duplexer BAND1 BAND3 BAND5 BAND7 supports...](https://www.aliexpress.com/item/4000186272193.html?spm=a2g0o.productlist.0.0.57975996YffHEC&algo_pvid=ff6ba59f-8520-469c-911c-1ce53d723879&algo_exp_id=ff6ba59f-8520-469c-911c-1ce53d723879-0&pdp_ext_f=%7B%22sku_id%22:%2210000000691990753%22%7D)**
>
> Smarter Shopping, Better Living! Aliexpress.com
Also please give me a suggestion for external reference clock?
I am not experienced in ti.
Thanks,
Nemanja
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### Author:  [@andrewback](https://discourse.myriadrf.org/u/andrewback)
#### Post date: [23 December 2021 10:32 UTC](https://discourse.myriadrf.org/t/limesdr-with-srsenb/7432/10 "2021-12-23T10:32:14Z")
Numerous people have been successful using Leo Bodnar clocks:
[http://www.leobodnar.com/shop/index.php?main\_page=product\_info&cPath=107&products\_id=301](http://www.leobodnar.com/shop/index.php?main_page=product_info&cPath=107&products_id=301)
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### Author:  [@cassiano](https://discourse.myriadrf.org/u/cassiano)
#### Post date: [17 January 2022 18:37 UTC](https://discourse.myriadrf.org/t/limesdr-with-srsenb/7432/11 "2022-01-17T18:37:07Z")
I use LimeSDR for LTE with no problem it’s been a year, without duplexer and without GPSDO!
Let’s improve your network:
1- Give preference to [Open5GS](https://open5gs.org/) instead of SRSEPC; Open5GS is more stable to run over long durations, SRS developer himself says SRSEPC is for testing purposes only.
2- Use lower frequencies; LimeSDR has the highest power between 500 and 900MHz, I like to use it at 800MHz (B20) (EARFCN 6400)[use LNAL and BAND1] between 25 and 75PRBs… If you want to use high frequencies, high PRBs, you need to adjust the PPM offset (adjusting VCTCXO by LimeSuiteGUI can help) but better result; use GPSDO, but at high frequencies you will do better with an amplifier linear.
3 - Assuming you not have duplexer, increase your cellular device’s TX power (pusch), you can demand more power RF from your mobile by editing p0\_nominal\_pusch in your srsenb sib.conf file.
4- Use the maximum of 63 in your tx\_gain of srsenb.conf, above that you will get a saturated signal, in your rx\_gain use between 0-10 if your test is indoor.
5- Position your antenna 90 degrees apart to avoid arbitrary interference. Ex.: |\_
6- Adjust your time\_adv\_nsamples to get the most accuracy from your Timing Advance, if this is wrong you will have too many re-connections, as the delay is time-phased, For me it works well with value 60.
7 - If when connecting you don’t get internet, it’s because your firewall is blocking the sgw, so run: iptables -F && iptables -t nat -F && iptables -t mangle -F && echo 1 \> /proc/sys/net/ipv4/ip\_forward && iptables -t nat -A POSTROUTING -o enp4s0 -j MASQUERADE (replace enp4s0 for your interface)
for details on how to create a network with open5gs see: [https://open5gs.org/open5gs/docs/tutorial/01-your-first-lte/](https://open5gs.org/open5gs/docs/tutorial/01-your-first-lte/)
ps: My English was translated from Portuguese, so there may be inconsistencies. =)
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### Author:  [@nemanja](https://discourse.myriadrf.org/u/nemanja)
#### Post date: [17 January 2022 23:02 UTC](https://discourse.myriadrf.org/t/limesdr-with-srsenb/7432/12 "2022-01-17T23:02:42Z")
Thank you very much for suggestion.
I have try with OAI and srsRAN, but never with Open5GS.
OAI has some runtime error that I didn’t managet to fix.
I will setup Ubuntu 20 and try to run LimeSDR with Open5GS.
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### Author:  [@luis](https://discourse.myriadrf.org/u/luis)
#### Post date: [2 September 2024 02:43 UTC](https://discourse.myriadrf.org/t/limesdr-with-srsenb/7432/13 "2024-09-02T02:43:05Z")
Hi Nemanja:
I don´t know if you have tried this suggestion of LimeSDR and Open5GS.
Please if you can help because I am using OAI with LimeSDR for my thesis project about an LTE network. When I run the commands, the network is recognized on the phone, but it can not be able to attach. I am trying to check form the components of the OAI EPC, but I also want to have suggestions for that issue or try another option. I hope you answer soon please. I would appreciate a lot
Best wishes,
Luis
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### Author:  [@andrewback](https://discourse.myriadrf.org/u/andrewback)
#### Post date: [2 September 2024 12:48 UTC](https://discourse.myriadrf.org/t/limesdr-with-srsenb/7432/14 "2024-09-02T12:48:51Z")
My suggestion would be to use srsRAN instead of OAI and for use with LimeSDR hardware see:
[https://librecellular.org/](https://librecellular.org/)