5G is looming, but network innovations are needed far more urgently
The path to 5G
In all the excitement about 5G, it is easy to forget that the most intensive innovations of 2016-2020 will go on in "4.5G" – in Release 13 and 14, of course, but more importantly in the way the carriers and their vendors reinvent their cellular networks with new approaches like virtualization and HetNet, in the desperate bid to keep up with capacity, coverage and efficiency demands.
Nokia’s Bell Labs’ R&D unit published a report this week warning that the capacity of mobile and Wi-Fi networks is not growing nearly quickly enough to satisfy the rise in that demand, especially when it comes to content and video. Of course, such a conclusion, coming from an equipment vendor, is predictable and self-serving, but nonetheless, Bell Labs’ figures are compelling.
It calculates that, by 2020, Wi-Fi and cellular networks, taken together, will be able to carry just 81 per cent of the projected mobile content traffic, leaving almost one-fifth of demand unsatisfied. "Network operators will need to accelerate their path to 5G and cloud technologies, such as network functions virtualization (NFV) and software-defined networking (SDN), and adopt new business models to address the demand gap," Nokia said.
And its warnings did not even take account of new sources of traffic such as IoT growth. This will not put a significant load on capacity – IoT devices will account for about 2% of mobile traffic by 2020, says Bell Labs – but will add to signalling and management burdens, with Nokia predicting that there will be between 20bn and 46bn connected IoT devices by 2020 (though cellular will be less than 10% of those, between 1.6bn and 4.6bn). And after 2020, it sees a rise in higher bandwidth IoT use cases such as video surveillance and body-worn cameras.
At this point, the world will be moving towards “life automation” with billions of interconnected smart objects, robots and sensors exchanging data in real time, said Bell Labs chief and Nokia CTO Marcus Weldon. "This new digital era will produce a dramatic shift in demand, challenging mobile operators to achieve the highest performance at the lowest cost per bit while supporting extensive personalization," he said.
“Life automation” really is an issue for 5G, and it is questionable whether MNOs will play a significant role in that – but for now, those operators still have huge data challenges, and the challenges of keeping up with data demand, reducing cost per bit, and supporting personalization are all very real today.
C-RAN starts to become real
That is driving accelerated trials and deployments of new architectures into LTE networks. Some interesting examples have surfaced just this week, which highlight some of the most important RAN (radio access network) technologies that will help operators avoid the capacity shortfall envisaged by Bell. Among these are centralized and virtualized RANs, ultra-dense HetNets (especially indoors) and new evolutions of active antennas.
Nokia itself was talking this week about a trial of C-RAN (the ‘C’ can be centralized or cloud, depending on the operator’s access to long-haul fibre for fronthaul and to cloud server capacity). It has been working with China Mobile, the frontrunner in these architectures, on a trial in the 6,000-seat Beilun Stadium in Ningbo, as part of the operator’s roadmap towards full Cloud-RAN. The companies said they achieved a 62 per cent improvement in uplink rates on the TD-LTE network, compared to usual performance in high traffic areas, by adopting an approach in which the signals from up to six cells were monitored, and the best four combined to communicate with the smartphone. During peak usage times, devices were receiving data at speeds of 12Mbps or more, with power efficiency improved by one-third.
“We have shown that centralized RAN technology can eliminate the 4G network strain typically caused at large events,” said Wang Yong, assistant to the general manager at Ningbo Mobile, part of China Mobile Group. Nokia’s C-RAN technology can be deployed as a software upgrade to its Flexi Multiradio 10 base station.
Nokia rival Huawei has been showing off some other key components of evolved LTE architectures, which also look forward to 5G. These include a small cell HetNet deployment which reached gigabit 4G speeds in Singapore, and its active antenna unit (AAU), which is being deployed to enhance macro network performance around the world.
In Singapore, MNO StarHub said it reached 1Gbps speeds in an indoor trial of a Huawei LTE-Advanced HetNet in Marina Bay, and plans to offer the technology to consumers as soon as it has compliant devices.
StarHub CTO Mock Pak Lum said: "There is more we can do to get better mileage out of our existing wireless spectrum. We are closely tracking the development of this new small cell solution to help us enhance network quality quickly and cost efficiently, providing customers with much faster data speeds even within buildings and in crowded areas."
Indoor coverage and capacity are the major challenges for operators as enterprises go mobile-first and consumers use mobile data devices at home and in workplaces and leisure venues. Starhub plans to deploy its HetNet in 40 commercial buildings, hospitals and malls by the end of this year.
Another technology where Huawei is very prominent is active antenna, which incorporates radios into the antennas and supports flexible beamforming and spectrum bands. The concept has been slow to take off, but Huawei is confident it is reaching its tipping point now, and claims commercial deployments in 100 networks.
One of the most recent is by Finnish Shared Network (SYV), a joint venture between TeliaSonera Finland and smaller cellco DNA, which has deployed Huawei’s AAUs in to improve network quality and speeds in the northern region of the country.
The venture is in the process of rebuilding the legacy networks of its two parents in the northern area with AAU as a central part of the bid for reduced opex, greater energy efficiency and better performance.
Antti Jokinen, CEO of SYV, said in a statement: “SYV selected the Huawei AAU solution because it helps the company deploy efficient networks with lower operational costs, while providing an optimal MBB user experience. In addition to good performance and lower costs, AAU solutions also reduce the number of external equipment deployed. This demand is underlined when operating in a pristine and indigenous natural landscape, such as in Lapland, as well as in locations, where the presence of a top quality, modern network needs to be experienced, but not seen.”
The era of “massive deployment” of AAU, which is part of its GigaRadio range, is here, claims Huawei, allowing for rapid deployment on poles and walls and for flexible multimode, multiband networks. Yang Chaobin, CMO marketing officer of Huawei wireless networks. "The AAU solution is designed to address site construction issues in the MBB era. Its massive deployment by global operators has ushered in a new era for base stations and has mapped out an evolutionary path for future radio frequency units."
The company claims large scale live deployments in Latin America, Europe, Africa, the Middle East, the South Pacific and China, though of course it remains virtually excluded from tier one network contracts in the US.
Rising importance of TDD
These C-RAN and active antenna trials and deployments reflect the rising importance of TDD spectrum in carriers’ LTE expansion. China Mobile’s massive TD-LTE roll-out may originally have been driven by necessity – it was only initially awarded TDD spectrum for 3G and 4G, and it needed to migrate quickly from its underperforming TD-SCDMA 3G technology.
But it has made a major virtue out of that necessity, putting itself at the heart of a TD-LTE ecosystem which is now going global as operators look to unpaired spectrum to meet their rising capacity needs. Often underused and undervalued, TDD bands in 2.3 GHz, 2.5/2.6 GHz and even 3.5 GHz are becoming important elements of second-stage LTE roll-outs, which are driven by capacity rather than coverage.
Nokia is highlighting another example – Hutchison’s Hi3G subsidiary in Sweden is about to deploy TD-LTE-Advanced in its unpaired 2.6 GHz Band 38 spectrum, and will complete its first build-outs, starting in Gothenburg, this quarter.
“We are working with Nokia to tap the potential of TD-LTE-A in order to deliver a truly memorable service experience to our subscribers,” said Jorgen Askeroth, CTO at 3 Sweden. “In doing so, we are proud to launch one of western Europe’s first TD-LTE-A deployments on band 38.” Such network innovations, both in spectrum and architecture, will come thick and fast now, as the operators drag their eyes away from the sparkle of 5G over the horizon, and deal with the urgent need to improve capacity and efficiency right now with 4G.
Copyright © 2016, Wireless Watch
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