OpenBTS> chans
TN chan transaction UPFER RSSI TXPWR TXTA DNLEV DNBER
TN type id pct dB dBm sym dBm pct
0 SDCCH/4-0 1804303614 0.00 -61 33 15 -102 0.00
0 SDCCH/4-1 1804303619 0.00 -58 33 8 ----- ------
So at that moment there were two handsets on control channels at distances of roughly 7.5 km and 4.0 km, they were both transmitting at 2 W and the channels were error-free. Not bad for a prototype. We will try to do a software update later this evening to make the task of provisioning a little easier for the Telecom staff and continue to monitor performance as conditions allow.
And Tim's Xorcom box finally arrived, even though Tim himself is back in the UK. Installation has been a little more hairy than expected, but it is happening. When that is complete, Telecom Niue will be able to connect calls between OpenBTS and their wireline switch, which is one more step toward a public mobile network.
Yes, there are still problems and loose ends. This is a test network and nobody expects everything to be perfect at this point. We understand the problems. We have a plan. It might take a few weeks for everything to come together, but it will happen.
There are plenty of technical details that I'm leaving out for now. All of that will be released when it is ready. For now, I want to thank the people who have supported this project, especially Taiichi, Frank and the people at Telecom Niue and in the government. We look forward to working with you all as this project moves forward. And I thank those people of Niue who have show patience and offered kind words, because I know you outnumber those few who were cursing and blaming. Faka'aue lahi. We will do our best for you.
Fakaaue Lahi David, for this and I hope detailed future progress reports. So often in Niue such consumer consideration is ignored, not because of any malicious desire to keep people in the dark but simply because in Niue, the customer doesn't always know best. Your reports are a breath of fresh air. I am travelling now but I long for the day when I can fire up my iphone in my beloved home Liku. Please keep up the good work and the reports. www.markcross.nu
ReplyDeleteThanks David! I've greatly enjoyed the blog posts! Glad that every thing is up and running!
ReplyDeleteHi David, was eager to read about this project after you spoke of it at AnimalFarm. Good thing you got it done even with IUSN's many issues. One note though, I wouldn't use Ubiquity junk for anything important... people on the Motorola ML (like PDMNet, contact Paul there) are selling used Canopy 5.2/5.4/5.7 links for < 800$, those are very solid and have a working spectrum analyzer.
ReplyDeletePerformance-wise, the NS5s are doing OK if not for the interference, but Telecom Niue might move to Canopy in the future. That won't fix the immediate problem, though, since IUSN occupies or plans to occupy nearly *all* of the 5.2/5.3/5.4/5.7/5.8 bands -- for a network where no single link probably needs over 4 Mbs/s.
ReplyDeleteDears in Openbts teem
ReplyDeleteCongratulation for your good work
please can you explain the role of the two nanostations ? How you have connected USRP hardware to the antenna and wich cable ? and how the USRP are connected to the asterisk not in samme place (usb connection)?.
and please explain did you use the same frequecy for gsm antenna and nanostation??
Best Regards
NB:SORRY FOR MY BASIC QUESTIONS BUT IT IS IMPORTANT FOR THE GENERAL PUBLIC .
To answer your questions:
ReplyDelete(1) The two Nanostations form the link between the BTS unit at the TV tower and the Telecom office in Alofi.
(2) The BTS unit (USRP, power amplifiers, etc.) is connected to the antenna through a 200-foot run of LMR-600 coaxial cable, installed by Telecom.
(3) There are two Asterisk servers in this system, one inside the BTS unit at the TV tower and one in the telecom office. The Asterisk server inside the BTS is connected to the USRP via USB (within the BTS unit). These two Asterisk servers communicate over the Nanostation link.
(4) The mobile phone system uses the following frequencies and power levels:
* GSM downlink, 4 W (36 dBm) on ARFCN 31 (941.2 MHz), bandwidth 271 kHz, from the Sekena TV tower; 13 dBi antenna gives 79 W (49 dBm) effective power, directed to the southeast.
* GSM uplink, variable 5 mW to 2 W (7-33 dBm) on ARFCN 31 (896.2 MHz), bandwidth 271 kHz, from test phones in and around Alofi; antennas are roughly isotropic (0 dBi). These frequencies are active only when people are actually using mobile phones.
* Nanostation-5 802.11a data radios, 24 dBm on channel 43 (5.215 GHz), bandwidth 5 MHz, sites at TV tower and Telecom building; antennas are 14 dBi for 6.3 W (38 dBm) effective power along the link. According to documents submitted by IUSN, they are not using these frequencies.
Hi David, thanks for the work on the testing phase of our OpenBTS station. There are always lots of work to do, hope you will be back soon to do some more work.
ReplyDeleteRegards,
Frank Sioneholo
Mutalau, NIUE
Very impressive, well done.
ReplyDeleteI am interested in rough costs for the components if you have any option as there are a number of small communities where this could be very useful.
The nanostations and asterisk boxes are relatively insignificant except maybe setup for asterisk, but I am interested in the BTS unit costs
Did you link to a billing platform at all?
Great posts, your description of interaction with IUSN was laugh out loud funny.
ReplyDelete