Vodafone NZ says it has a team investigating reports of interference to its mobile service in Alexandra with "high priority".
A Geekzone thread quotes multiple complaints from a local Facebook page - and also notes that Spark has just kicked off a 5G fixed wireless trial in the Central Otago town.
That, in turn, sparked comparisons with Telecom's "XT" 3G launch in 2009, when Vodafone took Spark's predecessor to the High Court on the verge of XT's launch. Vodafone sought an injunction on the grounds that XT was interfering with its already-up-and-running 3G network. The case was settled, with Telecom agreeing to spend an extra $1000 per cell site to install extra filtering technology to cut interference.
Vodafone has sent an optimisation team to Alexandra, but at this time is being careful not to point any fingers.
Spokeswoman Nicky Preston said: "We are investigating the connectivity issues being reported by a few customers in Alexandra as a high priority, to determine the root cause and solution. In the interim, we are asking impacted customers to manually select Vodafone as the network operator on their mobile device."
On Geekzone, user "J" posted: "This is not a beat-up, our business [account] has been with Vodafone for approx 15 years, and apart from these issues lately I have no complaints.
"There have been several threads on Alexandra local FB pages about frequent loss of connectivity.
"Phones receiving no signal and displaying a no-carrier message, Txt messages not being delivered till phones are restarted."
A spokeswoman for Spark said: "Our Spark 5G wireless broadband service in Alexandra is using 2600MHz spectrum, which is not a spectrum band that Vodafone uses in Alexandra. So it is very unlikely that any issues experienced by Vodafone customers are caused by the Spark 5G service."
Vodafone uses 700, 900, 1800 and 2100MHz spectrum in the area, Preston says.
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The XT interference case occurred at a time when Spark was using 850MHz for its 3G service and Vodafone 900MHz.
One wrinkle next to 2009 is that Spark is using Nokia Networks gear for its Alexandra 5G trial as it pursues a "multi-vendor" strategy in the face of the GCSB's ongoing ban against its 4G incumbent, Huawei. Nokia Networks is Vodafone NZ's longtime primary technology partner.
2degrees also has two of its own cell sites in the area, at Alexandra and Clyde, and there is at least one of its customers being caught up in the problems.
The telco could not immediately be reached for comment.