Vodafone New Zealand is in court trying to get an injunction to prevent rival-operator Telecom NZ launching their new "XT" service, which is scheduled to come online on May 13th.

The operators, who run a virtual duopoly on New Zealand mobile telephony, are both in the process of upgrading their networks, but Vodafone reckons that XT's decision to deploy UMTS technology at 850MHz is causing unacceptable interference to their existing deployments at 900MHz, and the company has gone to court to prevent the switch-on.

European operators are looking forward to being able to deploy UMTS at 900MHz, as the increased range should allow for greater coverage and the restriction to 2.1GHz is simply a legacy of old-style spectrum licensing.

Vodafone NZ also has a 3G network, using W-CDMA and operating at 2.1GHz, but has started deploying W-CDMA at 900MHz to take advantage of the increased range - something that Telecom's XT network, running at 850MHz, will also enjoy.

None of that should be a problem - both companies have sufficient bandwidth and should have allocated guardbands to prevent interference - but Vodafone reckons Telecom NZ's XT network (which is already widely tested) has been interfering with Vodafone customers and wants the plug pulled before it's too late.

Telecom NZ respond that they are operating within the rules, and that the whole thing is just FUD* on the part of Vodafone. That could be true, but if the interference is genuine then it could also point to a failure of W-CDMA at lower frequencies or at least a problem with the size of the guard bands, something that European operators should be watching for with interest. ®

* Fear, Uncertainty & Disinformation - always a good way to knock the opposition.

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