LTE's theoretical maximum download speed will increase to 450 Mbps next year -- but the upgrade will be out of reach for most users, as many mobile operators simply don't have enough radio spectrum.
The broadband speed users get depends on a myriad of different factors, but in the network it all starts with the amount of spectrum their operator uses. Future increases will be fueled by a technology called carrier aggregation, which lets operators treat up to three radio channels in different frequency bands as if they were one.
This month, chip maker Qualcomm and network equipment manufacturer Ericsson have been doing their best to let the world know speeds at up to 450 Mbps will be possible next year, with product launches, interoperability tests and a demo with Australian network operator Telstra.
The demonstration used 60 MHz of spectrum made up of three separate 20 MHz LTE channels in the 2600 MHz, 1800 MHz and 700 MHz bands. That the mobile operators need 20 MHz in each of three bands to get to 450 Mbps makes the technology an option for only a select few.
For example, because spectrum in the U.S. is often licensed in 10 MHz chunks, North American subscribers are unlikely to see 450 Mbps anytime soon, according to Malik Saadi, practice director at ABI Research. In Europe, LTE penetration is still low, so mobile operators are more focused on migrating subscribers to regular LTE. The first to get 450 Mbps will instead be users in Asia, Saadi said.
Ericsson and Qualcomm are more upbeat, and think there is potential in North America and Europe as well. But the bulk of the deployments will use carrier aggregation at slower speeds, according to Peter Carson, senior director of marketing at Qualcomm. Speeds of 300 Mbps or even 375 Mbps are within reach of many more mobile operators, and that's still a big step for users.
The upgrade isn't just about really high speeds when users are close to a base station.
"The great thing about carrier aggregation is that it improves performance across the whole coverage area. That's one of the main reasons for using it," said Thomas Norén, vice president and head of product area Radio at Ericsson.
The ability to download data faster because of the higher speeds is also good for battery consumption and network congestion, according to Carson.
The network equipment and modems coming out next year will be able to mix and match LTE TDD (Time-Division Duplex) and LTE FDD (Frequency-Division Duplex), which gives mobile operators more flexibility. The former uses one channel for both uploads and downloads, with traffic alternating between the two directions, while the latter uses separate channels for download and upload traffic.
Sign up for CIO Asia eNewsletters.