SK Telecom just last month amped up its LTE network in Seoul to support blistering speeds of 300 Mbps, but the carrier is already tinkering with LTE-Advanced technologies that could double that speed in the future.
The South Korean operator is working with [company]Nokia[/company] Networks on new antenna technologies that effectively double the number of data streams sent from a cell tower to your device. Called 4×4 MIMO (multiple input-multiple output), the two companies claim they’re clocking speeds of 600 Mbps and they plan to demo the technology at Mobile World Congress in Barcelona next week.
You may already be familiar with the term MIMO because it’s a common feature in every LTE network and device today. Instead of sending a single signal from the tower, MIMO sends parallel streams, which are in turn picked up by two antennas on the device. By using four antennas instead of two at either end of the transmission, Nokia and [company]SK Telecom[/company] are able to double that capacity again.
Cool beans, right? Well, don’t get too excited.
4×4 MIMO is going to be a hard thing to pull off in a commercial network. Not only would it require device makers to pack four antennas into the limited space they have in their smartphones, but a 4×4 MIMO air link is quite delicate. When the going gets rough in today’s 4G systems, networks regularly downgrade connections from 2X2 MIMO to a single transmission path. Maintaining the proper radio frequency conditions to support a 4X4 MIMO link is going to be even more difficult, which is why the industry has been focusing its efforts on other LTE-Advanced technologies like carrier aggregation.
But I’ll be the last guy to tell SK Telecom what it can or can’t do. Ever since the dawn of 3G, SK has been on the cutting edge of wireless networking technologies, so if anyone is going to make a commercial case for 4×4 MIMO it’s probably our friendly operator in Korea. And if it works, it could be a big boon for the mobile industry because 4×4 MIMO would allow carriers to double the capacity of their networks without getting their hands on new spectrum.
SK looks to have a big presence at MWC. In addition to 4×4 MIMO demos with Nokia, SK will be showing off a very future-looking radio system with Samsung that claims to deliver 7.55 Gbps of throughput. The technology utilizes the millimeter waves, which lie higher frequencies than those used for cellular communications today. That millimeter wave technology is a big candidate for future 5G standards, though we’re still a while away from defining what exactly 5G is exactly.