By Wednesday afternoon, pings to California through IUSN showed 95% packet loss. They also showed 10-20 second latency, a sign of some serious network management problems. But by getting up really early, Tim managed to make the project's first blog post from Niue. A few hours later, via Telecom's private network, we got our first e-mail from IUSN telling us that they run a lot of US-style 900 MHz broadband equipment all over Niue and it was too bad that we didn't coordinate with IUSN and New Zealand's infrastructure consultant before we arrived. Their attitude seemed to be that Niue's spectrum is unregulated and they grabbed it first. They claimed that they needed no license, but still took issue with us referring to their system as "unlicensed". At that point, I gave up trying to make sense of their communications.
Silly us. We had been told our client had a license for GSM900. We had coordinated with the government regulator and with the state-owned telco. How foolish of us, not getting permission from some US-based non-profit we had never heard of, not consulting with some advisor from some other government and not expecting to see a ton of US-market ISM-900 gear in ITU region 3, stomping all over the GSM uplink band. We told IUSN that we were surprised to see ISM-900 equipment in Niue, since it is generally illegal outside of North America, and that we were surprised, license or not, that the official regulator had no specific technical information about what they were doing.
So here's the 900 MHz spectrum plan for Niue, as we now understand it:
880-890: Telecom Niue's AMPS WLL downlink, 7 kW EIRP, 2 sites
890-915: GSM900 uplink , up to 1 W EIRP, potentially hundreds of sites
903-928: IUSN's 900 MHz network, 6 W EIRP, ~20 sites
935-960: GSM900 downlink, up to 50 W EIRP, 1 site
IUSN was worried that GSM900 downlink would interfere with their ISM-900 stuff. That was unlikely from the start. ISM-900 radios are designed for unlicensed operation, so they need to tolerate high-power near-band interferers, like public service radios and cell towers. The fact that IUSN's network could coexist with Telecom's scorching hot AMPS sites meant that we were unlike to cause any new problems. But we also knew that ISM-900 gear jams the GSM900 uplink, since they overlap in the 902-915 MHz range ... which is why that stuff is illegal in most of the world. And we could see that cell phones themselves might disrupt IUSN's network, if there were ever enough of them out there. We recommended, as an immediate measure, that IUSN retune their links to avoid operating below 915 MHz within 3 km of the GSM site, at least to the greatest degree possible, and that GSM avoid the 902-915 MHz range. To our knowledge the Niue GSM system does avoid 902-915 MHz, but we never got a response from IUSN. And we don't need one now, since we turned over operation of the GSM site to Telecom Niue when we left.
On Thursday evening, IUSN was already reporting 900 MHz link failures. Our GSM gear was still in Auckland. Powerful stuff, huh?