Massive MIMO is an increasingly important element of operators’ plans for LTE-Advanced Pro and for 5G, despite a lack of devices and mass market chipsets on the near horizon. But the tests are piling up, many of them in China, Japan and Korea – but Vodafone UK is claiming the first in Europe in the 2.6 GHz TDD band.
The unpaired spectrum is underused in Europe and many other regions, but will be an important source of affordable capacity for mobile data in future, and deployments in China, the US and elsewhere are creating a wide ecosystem for TD-LTE in the bands between 2.3 GHz and 2.6 GHz.
Vodafone ran its trial with Huawei on its commercial network in its Newbury, Berkshire headquarters, and it claimed significant improvements in spectrum efficiency and network capacity. The UK carrier is already deploying 4×4 MIMO commercially in some areas and is now testing 8×8 MIMO. Kye Prigg, head of mobile networks at the MNO, recently told FierceWireless Europe: “We’re very interested in MIMO and the efficiency gains that that could bring for us.”
This will be a common theme among MNOs, particularly in Europe, where financial constraints are pushing operators to squeeze as much capacity and performance out of their existing network assets before they embark on 5G.
Massive MIMO boosts efficiency by focusing the signal into a more precise set of layers, and can be combined with advanced beamforming. In pre-5G trials, some vendors and operators have experimented with arrays of up to 256 antennas – as ZTE and China Mobile have reported. But in the current generation of network upgrades, 8×8 will be as ‘massive’ as most get.
“These layers can bring more capacity than current 4G systems with the same bandwidth and massive MIMO is also capable of ‘full dimensional beamforming’, which means it can direct beams both horizontally and vertically,” Vodafone and Huawei commented.
“We’re not chasing the peak speeds. It’s not about shouting about 200, 300, or 400 megabits per second, it’s about getting the capacity where people need it,” Prigg said.