Spark says it has switched on 5G wireless broadband services for a "limited number" of invited business and consumer customers in Alexandra, Central Otago, using gear from Nokia to get around the GCSB's Huawei ban.
It says five other "heartland towns" will get 5G by Christmas.
With its limited trial, Spark steals some of the thunder from Vodafone, which is set for a full commercial launch in December, with 100 cell sites upgraded to 5G across Auckland, Wellington, Christchurch and Queenstown.
Read more:
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• 5G phone overheats - should you freak out about radiation?
• The real reason Spark boss Simon Moutter loves 5G
• Vodafone reveals wider 5G rollout
Spark says it will begin upgrading its mobile network to 5G from July next year, following a "multivendor strategy" (read: Cisco and Ericsson rather than Huawei), while 2degrees has yet to set a timetable.