Separating 5G fact from hype: Is Massive MIMO a Solution or Dead End?


Despite only a “vision” with no definition or specs from ITU-R of fifth generation wireless networks (5G),  mobile vendors and wireless network operators continue to keep talking about 5G ready products and deployment — even if they’re not really even sure what 5G is yet.   In the last year, we have seen carriers announce “4.5G” and “Pre-5G” technology and island’s vying for the first 5G network. In reality, carriers are simply marketing 5G packages that include speeds that barely reach what is defined today as 4G.  

For the record, true 4G is LTE Advanced (see reference below), which only a few features have been deployed, like Carrier Aggregation. Almost all the “4G-LTE” deployments are really 3.5G. 

Karl Bode reported previously that the ITU-R declared no major wireless carrier was technically deploying 4G networks since none were capable of speeds over 100 Mbps.  Yet many wireless carriers simply ignored the declaration, with T-Mobile arguing their HSPA+ build was the “largest 4G network,” while Sprint, AT&T and Verizon also made “4G” part of marketing for their respective Mobile WiMax, HSPA+ and LTE networks.

To turn their hype into reality, carriers pressured the ITU-R to redefine 4G so that almost every current wireless network was deemed 4G.  Consequently, it’s looking more likely that over the next few years, the definition of 5G will be lowered to make sure that improved 4G networks are included in the definition of 5G.

ITU-R Status on 5G now called IMT-2020:

In early 2012, ITU-R embarked on a programme to develop “IMT for 2020 and beyond”, setting the stage for “5G” research activities that are emerging around the world.  As of June 19, 2015, ITU-R finally established the overall roadmap for the development of 5G mobile and defined the term it will apply to it as “IMT-2020.

With the finalization of its work on the “Vision” for 5G systems at a meeting of ITU-R Working Party 5D in San Diego, CA, ITU defined the overall goals, process and timeline for the development of 5G mobile systems. This ongoing 5G work plan is being done by ITU in close collaboration with governments and the global mobile industry.

The ITU-R Working Party 5D San Diego, CA meeting also agreed that the work should be conducted under the name of IMT-2020, as an extension of the ITU’s existing family of global standards for International Mobile Telecommunication systems (IMT-2000 and IMT-Advanced) which serve as the basis for all of today’s 3G and 4G mobile systems.

The next step is to establish detailed technical performance requirements for the radio systems to support 5G, taking into account the needs of a wide portfolio of future scenarios and use cases, and then to specify the evaluation criteria for assessment of candidate radio interface technologies to join the IMT-2020 family. The ITU-R Radiocommunication Assembly, which meets in October 2015, is expected to formally adopt the term “IMT-2020.” These new systems, set to become available in 2020, will usher in new paradigms in connectivity in mobile broadband wireless systems to support, for example, extremely high definition video services, real time low latency applications and the expanding realm of the Internet of Things (IoT).  

We think a huge segment of the IoT market will require cellular communications (mostly 3G or LTE, but NOT LTE Advanced or 5G).

“The buzz in the industry on future steps in mobile technology – 5G – has seen a sharp increase, with attention now focused on enabling a seamlessly connected society in the 2020 timeframe and beyond that brings together people along with things, data, applications, transport systems and cities in a smart networked communications environment,” said ITU Secretary-General Houlin Zhao. “ITU will continue its partnership with the global mobile industry and governmental bodies to bring IMT-2020 to realization.”

Ongoing ITU information on the development of IMT-2020 will be available here.

5G NORMA project to help define 5G radio architecture:

The 5G Infrastructure Public-Private Partnership (5GPPP) initiative has started the 5G NORMA (5G Novel Radio Multiservice adaptive network Architecture) project, set up to define the overall 5G mobile network architecture, including radio and core networks, needed to meet 5G multiservice requirements. The consortium is composed of 13 partners among leading industry vendors, operators, IT companies, small and medium-sized enterprises and academic institutions.

5G NORMA  will propose an end-to-end architecture that takes into consideration both radio access network (RAN) and core network aspects. The consortium will work over a period of 30 months from July, to meet the key objectives of creating and disseminating innovative concepts on the mobile network architecture for the 5G era.

The overall aim of the 30-month project is to propose an end-to-end architecture taking into account both the radio access network (RAN) and core networks. The project will seek to underpin Europe’s leadership position in 5G, breaking from the rigid legacy network paradigm. It will on-demand adapt the use of the mobile network (RAN and Core Network) resources to the service requirements, the variations of the traffic demands over time and location, and the network topology, which include the available front/backhaul capacity. The consortium envisions the architecture will enable unprecedented levels of network customisability to ensure that stringent performance, security, cost and energy requirements are met. It will also provide an API-driven architectural openness, fueling economic growth through over-the-top innovation.

The project partners, spread across six countries, include leading mobile operators (Orange, Deutsche Telekom, Telefonica), network vendors and IT companies (Nokia Networks, Alcatel-Lucent, ATOS), SMEs (Nomor Research, Azcom Technology) and Universities (King’s College London), Technische Universität Kaiserslautern, and Univerdidad Carlos III de Madrid).   More info on NORMA is here.

Massive MIMO for 5G

The next generation wireless networks need to accommodate 1000x more data traffic than contemporary wireless networks. Since the spectrum is scarce in the bands suitable for coverage, the main improvements need to come from spatial reuse of spectrum; many concurrent transmissions per unit area. This is made possible by the massive MIMO technology, where the access points are equipped with hundreds of antennas. These antennas are phase-synchronized and can thus radiate the data signals to multiple users such that each signal only adds up coherently at its intended user.

Over the last the couple of years, massive MIMO has gone from being a theoretical concept to becoming one of the most promising ingredients of the emerging 5G technology. This is because it provides a way to improve the area spectral efficiency (bit/s/Hz/area) under realistic conditions, by upgrading existing base stations. Many experts think that massive MIMO is a commercially attractive solutionsince 100x higher efficiency is possible without installing 100x more base stations.

Maybe not?   According to co-authors Jin Liu and Hlaing Minn, there are serious analog front end design challenges for Massive MIMO as noted in this just published IEEE ComSoc Technology News article.

More HYPE- does it ever end?

Telecom firm Ericsson is testing out a new 5G device on the streets of Stockholm, Sweden and Plano, Texas, the company says will revolutionize mobile technology.

5G technology will also tap into new high-frequency spectrum known as the millimeter waves, which today are unusable for mobile communications. However, in the future the spectrum could open up thousands of megahertz of new frequencies for wireless broadband use, thereby adding tremendous amounts of bandwidth to mobile networks.”

Much of the work being done on 5G has little do with raw speed. Researchers are trying to bring down the latency of the network—the delay users experience after clicking on a link and before a web page loads—cutting it down from 30 milliseconds today to less than a single a millisecond in the future. By reducing the network’s reaction time, researchers open the door for a whole new set of real-time applications. For instance, autonomous cars could communicate their intentions to other vehicles over the network instantaneously, allowing them to coordinate their speed and lane position or avoid potential accidents.

“This is not only yet another system for mobile broadband,” says Sara Mazur, Ericsson’s head of research. “The 5G system is the system that will help create a networked society.”

5G could be all of these different technologies, or it could wind up being only one or two of them. The fact is 5G doesn’t yet have an official definition, and won’t for several years, while the mobile industry and global regulators settle on a standard.  5G is viewed by some as a way of bridging the digital divide between poor and rich countries or big cities and rural towns. Still others want 5G to become the glue connecting every conceivable device and application to the Internet.

To this author 5G is all about vision, hype, and speculation.  We advise you to not believe ANY vendor or wireless network operator claims about their 5G network or products!


ITU defines vision and roadmap for 5G mobile development 

IMT Vision towards 2020 and Beyond

More on IMT2020 and Beyond

ICC 2015 Globecom Tutorial: 5G Evolution and Candidate Technologies

Cutting through the Hype: Will the real 4G (LTE-A) please stand up and tell us what 5G is?

Upcoming webinar:

5G: Separating hype from fact – understanding where the market really is at today,  July 8, 2015 at 2pm BST (9am EDT)