Spark, New Zealand’s second largest mobile operator, expanded its 4.5G network to the town of Queenstown, with five mobile towers delivering peak download speeds of more than 400Mb/s.

The operator, with a 38 per cent market share, said the upgrade puts the network slightly ahead of available devices, with no current modems or phones compatible with the entire range and combination of 4.5G features. However, it noted most new high-end smartphones can handle many 4.5G features, making them three- to five-times faster than regular 4G.

Spark plans to deliver 4.5G service to ten more towns in the next 12 months.

The launch in Queenstown follows single-tower deployments in 2016 covering limited areas in the Auckland suburb of Silverdale and Christchurch central business district.

Queenstown, surrounded by mountains and Lake Wakatipu, is a major tourism destination in New Zealand.

Spark COO Mark Beder said 4.5G is an important part of the operator’s strategy because it helps prepare for a 5G future today: “Because 4.5G combines a range of radio spectrum and uses it more efficiently, we can provide more capacity and speeds to our customers, allowing them to do more,” he said.

The company’s 4.5G network uses carrier aggregation, tapping a range of spectrum bands including recently acquired 2.3GHz spectrum, 4×4 multiple-input and multiple-output (MIMO) and 256 quadrature amplitude modulation, which improves the efficiency of radio transmissions.