Vodafone helps push Massive MIMO beyond its Asian stronghold

Massive MIMO has moved quickly from a science project to an important enabler of LTE network improvement and of 5G plans. Vodafone has been talking about its Massive MIMO work with Huawei, including testing a 64×64 antenna array, but its first real 5G commercial contract has gone to Ericsson.

The deal includes modernization of Vodafone’s UK network in the southern parts of the UK, cooperation on 5G trials and development, and some provisions for commercial 5G deployment when the time is right.

Vodafone UK will work with Ericsson on product validation, commercial deployment and professional services, it said. Arun Bansal, head of Europe and Latin America at Ericsson, said in a statement: “We are working with Vodafone UK to evolve its 4G network and test new 5G technologies. Together we will enable ubiquitous connectivity for their users that enable entirely new experiences, as well as monitoring and control of IoT in real time.”

Massive MIMO is a common theme, as well as new levels of carrier aggregation, as the MNO looks to boost speed, capacity and efficiency in its 4G network before it adds 5G into the mix.

Vodafone UK has been rolling out 4×4 MIMO for about two years and now has it live in 180 sites. It has recently deployed 64-element Massive MIMO, from Huawei, on two live sites to assess its performance. “It’s able to reuse the spectrum over and over again,” said Kye Prigg, head of mobile networks. “So instead of getting 140Mbps from your 20 MHz, what we’ve seen is around 500Mbps to 600Mbps aggregated throughput per sector. So the spectrum efficiency goes up by four to five times.” However, Prigg warned that Massive MIMO is currently an expensive option. “It is expensive technology. We are only going to put it in areas where it is needed.” These might include city downtown neighborhoods or sports venues.

Vodafone is certainly not the only operator which appears to have accelerated its journey to Massive MIMO, though its initial Ericsson deployments are thought not to be aiming for 64-element arrays. The high orders of MIMO – 64×64 and even 128×128 – have largely been the preserve of the Chinese vendors, Huawei and ZTE, so far, and both have trials and deployments of these architectures, mainly in Asia. Notably, Softbank has live 64×64 MIMO technology in a network in Tokyo and has worked on even larger arrays with both Chinese suppliers.

But Massive MIMO is set to break out of its initial east Asian borders. Another Vodafone subsidiary, Vodafone Turkey, recently demonstrated Massive MIMO at a basketball match, boosting downlink throughput by 13% at the final round of the EuroLeague tournament in Istanbul last month. This helped fans to share videos and pictures more easily.

The operator placed a 64×64 MIMO site at one corner of the stadium, using 2.6 GHz TDD spectrum, in addition to the existing macro cells. Vodafone said: “Massive MIMO technology, which is also set to become a key feature of 5G in future, provides higher capacity and throughput because is capable of doing ’full dimensional beamforming’, which means it can focus the mobile signal in beams that can be pointed horizontally and vertically to reach each customer.”

Almost 25% of data demand during the event was supported by the Massive MIMO cell, and this provided four times better spectrum efficiency than an FDD cell, according to the MNO. Its rival Turkcell has also recently conducted Massive MIMO trials.

Last week, UAE-based operator du said it has achieved “record breaking cell capacity” and speeds over 700Mbps using a single 20 MHz carrier with Massive MIMO. With three simultaneous carriers totaling 60 MHz, it was able to boost the figure to 2.1Gbps on a live du site with commercial handsets.

South-east Asia, however, remains the hotbed of Massive MIMO work and western operators are looking to tap into the expertise there, especially in China, Japan and South Korea, where there are live deployments. Sprint has recently tested 64×64 MIMO in Suwon, South Korea, working with one of its LTE vendors, Samsung Electronics America.

“The testing in South Korea is an important step towards deploying Massive MIMO in our US network where it will be a key element of LTE Plus as well as 5G,” said Günther Ottendorfer, Sprint’s COO – technology. “Massive MIMO is a tremendous differentiator for Sprint because it is easily deployed on 2.5 GHz spectrum due to the small form factor of the radios needed for a high frequency band. In lower frequency bands, wavelengths are much longer and therefore the radios require much larger, impractical form factors. This makes Massive MIMO an important tool for unleashing our deep 2.5 GHz spectrum holdings.”

During field testing, Samsung’s Massive MIMO systems, equipped with vertical and horizontal beamforming, reached peak speeds of 330Mbps per channel using 20 MHz of 2.5 GHz spectrum. Capacity per channel increased about four times, cell edge performance increased three times, and overall coverage area improved too, said the companies.

Sprint has deployed 8×8 arrays across its US network, and it wanted to compare the performance of that with Massive MIMO. Sprint and Samsung partnered to write the test cases and requirements, which included various scenarios involving multiuser and non-stationary usage. Both companies will use the results in preparation for commercial deployment of Massive MIMO in the US and other markets. Sprint expects to reach speeds of 3Gbps to 6Gbps per sector using 64×64 MIMO in 2.5 GHz spectrum along with carrier aggregation across 60 MHz, and 256QAM modulation.

Despite the Massive MIMO excitement, most operators are just moving towards 4×4 arrays, while a few are implementing 8×8, like Sprint. Two recent examples, in contrasting environments, were announced last week in France and Myanmar.

In France, SFR has worked with Huawei on a pre-commercial field verification of 4X4 MIMO on the operator’s live LTE-Advanced network. The test verified that the combination of 4×4 MIMO, two-way carrier aggregation and 256QAM could achieve a peak throughput of 628Mbps. CEO Michel Paulin said: “Today, SFR’s 4.5G network has achieved an average downlink throughput of 300Mbps in over 221 cities … We will further increase the average downlink throughput to 500Mbps by 2018.”

Meanwhile, Myanmar Post and Telecom (MPT) has adopted 4×4 MIMO for new LTE roll-outs in Yangon, Mandalay and Nay Pyi Taw. It plans to deploy LTE-Advanced capable of top speeds of 150Mbps in 47 townships across the three cities before extending it to
Bago, Taunggyi, Mawlamyine, Monywa and Patheingyi in July and to 20 other major cities the following month. The deployment is expected to cover all 30 major cities in the nation by November.

The state-owned MNO, which recently secured permission to use 1.8 GHz 2G spectrum for LTE, has partnered with Japan’s KDDI and Sumitomo for its mobile operations.

The Vodafone UK/Ericsson agreement:

In a memorandum of understanding, the two companies agreed to cooperate on:
4G evolution
5G radio non-standalone and standalone
5G site deployment scenarios
NR simulations: 3.5 GHz and mmWave
5G use-cases: business case study and proof of concept
Distributed cloud and network slicing proof of concept: end-to-end latency and cloud- optimized network applications
Collaboration with King’s College London
5G innovation: Technology Incubation Programme