Hong Kong’s largest operator HKT and Chinese vendor Huawei said they have demonstrated LTE-Advanced service using tri-band carrier aggregation to achieve a theoretical peak download speed of 450Mb/s.

The companies claimed to have tested the world’s first three-component carrier (3CC) LTE-A carrier aggregation (CA) across three 20MHz blocks using Huawei’s IP-RAN technology.

HKT is rolling out its LTE-A 450Mb/s network and expects the network to be commercialised next year.

CA technology allows the combined use of fragmented spectrum resources to increase data throughput, but implementations today require fragmented spectrum resources be hosted by the same cell site. Huawei said that many commercial CA networks today have coverage holes due to coverage differences between LTE cell sites using different spectrum bands, which makes it difficult to combine LTE carriers on different bands.

To solve this problem, Huawei said it has developed inter-site CA that is able to combine carriers from more than one cell site to maximise the CA coverage area.

HKT’s test in Hong Kong integrated three 20MHz spectrum blocks to achieve a peak rate of 450Mb/s without modifying the current transmission network.

Peter Lam, HKT’s managing director of engineering, said the IP-RAN based CA technology will allow it to get the most from its frequency resources to further raise the bar to 450Mb/s. “This will enable HKT to provide more network capacity.”

HKT commercially launched 300Mb/s LTE-A last December by combining two 20MHz spectrum blocks.

Elsewhere, SingTel said in February it expects its 300Mb/s LTE-A service to cover the entire city-state by the end of March.

Japan’s largest mobile operator NTT DoCoMo was due to launch 225Mb/s LTE-A service at the end of March.

At the end of 2014 there were 49 LTE-A commercial networks globally. More than 100 LTE-A commercial networks are expected to be in use by the end of this year.