[srslte-users] Getting srsUE up and running

Wed Jul 27 12:12:55 UTC 2016

Yes, I understand this, it makes sense. My only issue is that I can't get srsUE to decode MIB correctly, and also if once it finally detects the correct BW it fails to synchronize - with all frequency scaling changed to maximum performance. 
Is there any way to hard-code MIB data so at least that part is taken care of? Or is this a bad idea, because if MIB decoding fails it means the radio connection is such low quality between the eNB and the UE that there is no way it's going to work? 

Cheers, 
Domi 

> From: "Ismael Gomez" <ismael.gomez at softwareradiosystems.com>
> To: "Tomcsányi," <domi at tomcsanyi.net>
> Cc: "srslte-users" <srslte-users at lists.softwareradiosystems.com>
> Sent: Wednesday, July 27, 2016 1:58:58 PM
> Subject: Re: [srslte-users] Getting srsUE up and running

> As I said before, in order to synchronize and decode the 20 MHz signal you'll
> need a true 4-core system (your processor is 2-core). Notice that generating a
> signal (what the eNodeB does) requires much less processing than decoding it
> (what the UE does), this is why with the eNodeB it is possible to generate the
> signal with the same laptop (probably not support high UL rates).

> On Wed, 27 Jul 2016 at 13:52 Tomcsányi, < domi at tomcsanyi.net > wrote:

>> Yes, it ran in 20 MHz mode, but I didn't do much of actual IP traffic, just an
>> attach.
>> So I rebooted my PC with SpeedStep and C states disabled, currently I'm having a
>> hard time decoding the MIB. It still detects random BW values (right now it
>> detected after many tries 1.4 MHz which is wrong again). I don't know what to
>> do, will keep trying to adjust the gain settings maybe I can find a good value
>> finally.

>> Cheers,
>> Domi

>>> From: "Ismael Gomez" < ismael.gomez at softwareradiosystems.com >
>>> To: "Tomcsányi," < domi at tomcsanyi.net >

>>> Cc: "srslte-users" < srslte-users at lists.softwareradiosystems.com >
>>> Sent: Wednesday, July 27, 2016 1:36:56 PM
>>> Subject: Re: [srslte-users] Getting srsUE up and running

>>> Hi Domi,
>>> were you able to run OAI eNodeB in 20 MHz mode? With that processor, srsUE
>>> should do full rate downlink in 10 MHz mode and support up to 35 Mbps. For 20
>>> MHz bw and to reach 75 Mbps downlink you'll need a true 4-core processor.

>>> On Wed, 27 Jul 2016 at 13:33 Tomcsányi, < domi at tomcsanyi.net > wrote:

>>>> Hi Ismael,

>>>> Thanks for the quick reply. I'm using an i7-6500U CPU @ 2.5GHz. I'll try to
>>>> disable frequency scaling and also set it to maximum performance, however I
>>>> find it weird that I was able to run a full eNodeB with OpenAirInterface5G
>>>> using the same hardware (laptop and B200) with the same frequency scaling
>>>> settings and phones were able to connect to it fine.
>>>> Also I asked my colleague who configured the eNB and it is set for 10 MHz
>>>> bandwidth.

>>>> I'll reboot now and disable frequency scaling in BIOS/EFI.

>>>> Cheers,
>>>> Domi

>>>>> From: "Ismael Gomez" < ismael.gomez at softwareradiosystems.com >
>>>>> To: "Tomcsányi," < domi at tomcsanyi.net >, "srslte-users" <
>>>>> srslte-users at lists.softwareradiosystems.com >
>>>>> Sent: Wednesday, July 27, 2016 1:26:01 PM
>>>>> Subject: Re: [srslte-users] Getting srsUE up and running

>>>>> Hi Domi,
>>>>> It looks like it's a CPU issue. Make sure the CPU frequency scaling is disabled
>>>>> and the frequency governor is set to "performance" (ie fixed to maximum MHz).
>>>>> Also make sure you don't run other background processes. What sort of CPU are
>>>>> you using?

>>>>> Do you have access to the enodeb to try with a lower BW, like 10 MHz?

>>>>> On Wed, 27 Jul 2016 at 13:21 Tomcsányi, < domi at tomcsanyi.net > wrote:

>>>>>> Hi all,

>>>>>> I'm sorry if this has been asked before on the list, but I couldn't find any
>>>>>> info about this using Google, so I'm turning to you:
>>>>>> I'm trying to connect srsUE to an LTE test network consisting of a commercial
>>>>>> eNB and MME. All my phones can see the network, connect to it etc. but with
>>>>>> srsUE I see the following:

>>>>>> root at LTE:~/srs/srsUE/build/ue/src# ./ue ue.conf
>>>>>> linux; GNU C++ version 4.8.4; Boost_105400; UHD_003.009.003-release

>>>>>> --- Software Radio Systems LTE UE ---

>>>>>> Reading configuration file ue.conf...
>>>>>> Using srsLTE version 001.002.000
>>>>>> Opening USRP with args: type=b200,recv_frame_size=9232,send_frame_size=9232
>>>>>> -- Detected Device: B200
>>>>>> -- Operating over USB 3.
>>>>>> -- Detecting internal GPSDO.... Found an internal GPSDO
>>>>>> -- Initialize CODEC control...
>>>>>> -- Initialize Radio control...
>>>>>> -- Performing register loopback test... pass
>>>>>> -- Performing CODEC loopback test... pass
>>>>>> -- Asking for clock rate 16.000000 MHz...
>>>>>> -- Actually got clock rate 16.000000 MHz.
>>>>>> -- Performing timer loopback test... pass
>>>>>> -- Setting master clock rate selection to 'automatic'.
>>>>>> -- Asking for clock rate 32.000000 MHz...
>>>>>> -- Actually got clock rate 32.000000 MHz.
>>>>>> -- Performing timer loopback test... pass
>>>>>> Setting frequency: DL=2685.0 Mhz, UL=2565.0 MHz
>>>>>> Searching for cell...
>>>>>> Found CELL ID: 1 CP: Normal , CFO: 1.8 KHz.
>>>>>> Trying to decode MIB...
>>>>>> - Cell ID: 1
>>>>>> - Nof ports: 2
>>>>>> - CP: Normal
>>>>>> - PRB: 100
>>>>>> - PHICH Length: Normal
>>>>>> - PHICH Resources: 1/6
>>>>>> - SFN: 0
>>>>>> MIB received BW=20 MHz
>>>>>> Initializating cell configuration...
>>>>>> Setting Sampling frequency 23.04 MHz
>>>>>> No space for SSS/CP detection. Realigning frame...
>>>>>> No space for SSS/CP detection. Realigning frame...
>>>>>> No space for SSS/CP detection. Realigning frame...
>>>>>> Timeout while synchronizing SFN
>>>>>> No space for SSS/CP detection. Realigning frame...
>>>>>> No space for SSS/CP detection. Realigning frame...
>>>>>> Timeout while synchronizing SFN
>>>>>> No space for SSS/CP detection. Realigning frame...
>>>>>> No space for SSS/CP detection. Realigning frame...
>>>>>> Timeout while synchronizing SFN
>>>>>> No space for SSS/CP detection. Realigning frame...
>>>>>> Timeout while synchronizing SFN
>>>>>> No space for SSS/CP detection. Realigning frame...
>>>>>> No space for SSS/CP detection. Realigning frame...
>>>>>> No space for SSS/CP detection. Realigning frame...
>>>>>> Timeout while synchronizing SFN
>>>>>> Timeout while synchronizing SFN
>>>>>> No space for SSS/CP detection. Realigning frame...
>>>>>> No space for SSS/CP detection. Realigning frame...

>>>>>> I'm using an USRP B200 with GPSDO (so not the MIMO capable B210 version) as you
>>>>>> can see. I'm pretty sure my ue.conf is in tact, basically just modified the
>>>>>> frequency and the USIM parts of it. I tried to mess around with the gain
>>>>>> settings since the whole setup is on my table, so not much gain is needed in my
>>>>>> opinion, but that didn't change much. It is weird though that MIB decoding
>>>>>> gives different results each time I start srsUE. The attached log you can see
>>>>>> shows 20 MHz of BW, but it also detects 10 MHz regularly.
>>>>>> Also sometimes it just says "Error receiveing from UHD: 30" and then I need to
>>>>>> unplug and plug in the USRP to get it working again.

>>>>>> I hope you can shed some on this for a newbie like me.

>>>>>> Cheers,
>>>>>> Domi
>>>>>> _______________________________________________
>>>>>> srslte-users mailing list
>>>>>> srslte-users at lists.softwareradiosystems.com
>>>>>> http://www.softwareradiosystems.com/mailman/listinfo/srslte-users
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