Hi Harald,
On 16.07.2011 15:51, Harald Welte wrote:
We have two nanoBTS-Booster 1800 here at the university. If for some reason the Ericsson RBS is not working it should be possible to lend you the two bossters for the time of the camp. We also have a splitter and combiner. I will test the splitter/combiner in combination with a booster at the GPN end of this month.
As it turns out, I have not yet managed to get the Motorola BTSs working, despite putting lots of time into it. There are many reasons, but basically the Motorola BSS is _extremely_ different from normal GSM BSS
So while I might still get it to work, I doubt it, and it would be better to pursue different plans now.
We can certainly bring together a sufficient number of nanoBTS units to fill all our ARFCN. The problem now is the coverage<-> capacity problem, i.e. I don't want 6 BTSs with small coverage area, but rather something like 2 or 3 sites (max) with each 2 or 3 BTSs.
Have you meanwhile tested your splitter/combiner/booster setup? does it work?
The original plan was to test the setup at the GPN. But stupid me forgot to order the RJ69 connectors :-( Last week I was finally able to try the multi TRX setup with two nanoBTS, but without success. TRX 0 worked well but TRX 1 was not working for some reason. I think the problem is the initialization of TRX 1. The nanoBTS are pretty new: Equipment_Version='165g029_73' Software_Version='168a352_v142b30d0'
Unfortunately I didn't had the time to investigate the issue further. Maybe tomorrow I have some time.
What I can really easily re-use from the Motorola BTS are 2x hybrid combiner/duplexer units, i.e. something that has the following ports:
- 1 antenna output, bidirectional, 7/16" socket
- 2 PA Tx inputs, SMA
- 1 Rx antenna output, N-type
So if you don't have a similar setup, we could use those together with two nanoBTS with a Rx LNA and a Rx splitter.
I have six of those hybrid combiner/duplexers.
I have two "SPLIT2P-SMA" from "Global Professional" [1]. My Idea was to use these two units with one naoBTS-Booster like shown here: [2]
Your idea sounds good too, but would require some RX LNA.
I _might_ also get the Rx LNA + splitter of the Motorola BTSs to work, but those are less stand-alone and I'm not certain about it.
What do you have in terms of antennas?
We have two omnidirectional antennas from PROCOM: CXL 1800-3 More information: [3]
Also, when would you be able to provide the equipment to me? I would want to put everything together + test it well ahead of the camp, probably around August 1st.
Ok, I will see what I can do.
Best regards Konrad Meier
[1] http://www.globalprofessional.co.uk/acatalog/Splitter_mod.html [2] http://lab.ks.uni-freiburg.de/attachments/download/260/setup.png [3] http://www.procom.dk/eng/Page_menu/Products/Base_Station_Antennas/1.3_-_2.0_...