KNOW HOW MIMO’s Massive role in 5G As the 2020 target for commercial 5G deployments approaches, we stand at the brink of a technological revolution that will dramatically change the way in which man and machine communicate, says Alex Wang, managing director of 5G Solutions at ZTE. T he dawning of this new era of communications has the potential to completely transform the way people live, work and get around, with the next wave of applications for the Internet of Things (IoT) utilising 5G connectivity to deliver a whole new world of interaction between humans and technology. Thanks to the emerging popularity of the smart home, the exponential growth of connected devices has been apparent for several years now, but the mobility that 5G can deliver is what will take the IoT to the next level of reach and potential. Machina Research predicts that the number of connected devices globally will top 25 billion in the first five years of 5G being commercially available, generating more than two zettabytes of data. Acting as the glue that holds the IoT together will be the telecommunications network. Creating and underpinning a network that is capable of handling these astronomical quantities of data poses the biggest challenge yet for operators, who must find a way to deliver the kind of ubiquitous connectivity that will enable the next generation of smart cities, factories and hospitals. While the 5G network will be built upon a foundation that is made up of many different technologies, it is clear that ensuring innovation in the base station matches developments elsewhere in the network will be key – especially when it comes to getting the necessary increases in network capacity without using too much spectrum. Building on the multiple- input multiple-output (MIMO) technology that is currently used to maximise capacity for Wi-Fi and LTE, Massive MIMO is one such innovation that will not only help deliver the connectivity that is required, but also allow operators to meet exponentially increasing 42 | May 2017 data demands while still using their existing sites and spectrum. By using more than 100 antennas within the same traditional base station space, Massive MIMO is able to transmit significantly more independent data streams between systems and user equipment, easing the pressure on the spectrum and making transmission much more efficient. In tests conducted by ZTE, the throughput of a Massive MIMO base station can be six to eight times that of a traditional two-antenna base station. Massive MIMO can also bring significant improvements in network coverage by accurately tracking users and utilising 3D beamforming, which is advantageous in denser urban environments. Smart city applications are where Massive MIMO really comes into its own. In the complex wireless environments that are emerging in major population centres across the globe, the use of virtual cells in Massive MIMO deployments transforms the mobile network by making it more user centric. In this scenario, users accessing the network are assigned a ‘virtual cell’ comprised of several physical cells in the geographic area that co-ordinate to deliver the best connection at any given time. As the user physically moves around the network – taking the bus or walking to work, for example – the physical cells change but the virtual cell remains the same, ensuring that the user will have excellent coverage and service delivery with seamless handovers. This represents a sea change for how end users access the network – instead of the customer’s device having to find the best network access point every time the user moves around, the network finds the device. Delivering on the concept In ZTE’s case, it is continuing to take the Massive MIMO concept into the field with its Pre5G solutions, which act as a bridge between the existing 4G LTE network and the future promise of 5G. Nearly three years on from ZTE’s first preliminary commercial tests on massive MIMO base stations and the birth of the Pre5G concept, operators are looking for solutions that will help them take the next big step towards commercial 5G deployment. In recent trials with Telefónica, for example, ZTE undertook a programme to assess the performance of Massive MIMO in hotspot and indoor coverage scenarios, delivering six-fold increases in both network capacity and cell-edge data rate compared to traditional LTE macro base stations. The trail also demonstrated its viability for driving new applications such as Virtual Reality and high-definition video streaming on mobile devices, showing how big a role Massive MIMO will have in delivering on the potential of 5G. This live test was the first of its kind in Europe, and the technology is evolving with the market. Developments such as the incorporation of both time division duplexing and frequency division duplexing into Massive MIMO systems will see the technology move forward by boosting coverage and further enhancing spectrum efficiency. Building the foundations The market for 5G is still developing but it will undoubtedly be huge, with ABI Research projecting that mobile broadband operators will see 5G revenues of $247 billion in 2025. While these lofty predictions are still some distance away, the building blocks for 5G are being laid in 2017 by technologies such as Massive MIMO and these are the innovations that will be the true key to unlocking the potential of an always connected society and enabling what many are calling the Fourth Industrial Revolution.