November 2019 - Data Center | 5G Networks

The Edge & Edge Data Centers: Gaining Clarity - doteditorial

Béla Waldhauser, Leader of the eco Competence Group Data Center Infrastructure, grapples with the definition of edge data centers and envisages the environment that will evolve at the edge of 5G networks.

dotmagazine - On the Edge

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When we talk about current innovations and the future expansion of Internet infrastructure, there’s no way to get around having a discussion about the edge. Networks want to get closer to the edge, 5G will offer high-speed data transfer at the edge, and that data (or at least some of it) will be analyzed and processed at the edge. And this last activity will take place in what we now call edge data centers.

But while there is no way to avoid talking about the edge and all that is happening and will happen there, there is still no clear definition of what an edge data center is. So, allow me to take a look at what makes a data center an edge data center, giving some definition to a currently somewhat fuzzy buzzword.

What is an edge data center?

An edge data center is – generally speaking – a smaller kind of data center. It might be a very small computing unit next to a 5G antenna, or it could be one or two racks – but it could also extend to a room with 100 to 200 KW, and more IT power. This means that, while size can be an important element in defining the edge data center, it is certainly not enough in itself. By homing in on function and purpose, we can gain a clearer picture of what an edge data center is – or can be.

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1. Low latency

These are all scenarios in which the reaction speed is decisive for the success (and safety) of service provision. When it comes to smart cities and connected cars – and maybe, in the future, autonomous driving – we are talking about the need for the system to make a decision within milliseconds. 

The main purpose of edge data centers, first of all, is simply to reduce latency – that is, any delays in transmitting data. This is very important if we are talking about connected cars, autonomous driving, Smart City, or Industry 4.0 (i.e., the management of factories with smart computing power). 

This is simply not possible if you transfer data from one city to another (where a centralized data center is located) and back again, because if a car needs to stop, it can’t wait that long for a response. This almost real-time speed of reaction can be only guaranteed if we have 5G and an edge data center in close proximity.

The same is true for Industry 4.0: In an autonomous factory where the machines are doing their job by themselves, potentially with the support of artificial intelligence, very low latency is also a must.

So this means that location – proximity to the end user or device – is a key piece of what we might call the “edge-data-center puzzle”. Where will we find edge data centers in our digital future? In cities, they could be housed in the basements of houses. In scenarios like Agriculture 4.0, they might be attached to the machines themselves. Edge data centers can be installed in antenna towers, or in wind turbines, or can be placed in containers wherever they are needed. In the Industry 4.0 factory, there may be a larger edge data center – spanning to several hundred square meters and several hundred KW – which is needed in order to provide the computing power for the production plant. This latter example exemplifies why size alone is not the defining factor for an edge data center. Diversity and adaptability are key attributes, a fact which is expanded upon in two articles “Edge Data Centers – Offering Both Global and Very Local Services” by Jörgen Venot from the Data Center Group, and “Adapting Data Center Design to Diverse National Requirements” by Marc Fröse from RTIX Everywhere.

2. Filtering out the unwanted data

In addition to the scenarios mentioned above, where the edge data center provides low-latency reaction times, edge data centers are also important when we consider the billions of things connected to the Internet of things (IoT) – where the amount of data is so massive that it doesn't make sense to transfer all of it to big data centers or into the cloud.

In this context, a major purpose of an edge data center is simply one of filtering – to sort out important data, and then transfer the important data that you want to keep, store, and analyze. This next step will then be undertaken in bigger data centers – for example, the large colocation data centers found in large metropolitan regions and digital hubs like the Frankfurt-Rhine-Main area. The types of tailored digital infrastructure solutions that enable the enactment of such a step is explored further in the article “Build Your Own Internet: Making Interconnection Easy”, written by DE-CIX's Joanna Hahn.

5G and the edge

So, what are other implications of developments at the edge from an infrastructure perspective? First of all, one of the main focuses is 5G. We will need thousands of antennas in order to make 5G available to the general population. This comes down simply to frequency. The frequency band for 5G is completely different to 4G and LTE. And because of this, the coverage of one 5G antenna is much, much smaller than 4G or LTE. On the other hand, much more data can be transmitted simultaneously, and the latency decreases substantially: the latency in the air – which means from any mobile device to the antenna – is only one millisecond for 5G, compared to 20 or 30 milliseconds for 4G or LTE.

So, a 5G antenna has many advantages. But the one disadvantage is that we need much more of them in order to provide the service to everybody.

Next, we need to get fiber to all the antennas. Older infrastructure like copper cables will need to be replaced. And given the greater density of antennas demanded by 5G, a great deal more fiber will need to be laid in most areas – both regional and metropolitan – to bring them online. Here, Stefan Kreibig from innexio offers some interesting insights into the workings of fiber-optic networks, and on their ambitious plans to bring fiber to a million homes, in his article “One Million FTTH Connections – Data Volumes Pose the Biggest Challenge”.

Impact of the edge data center on existing data center business models

Bearing in mind the nascent potential of a 5G-enabled edge, it is clear that edge data centers will become increasingly important for certain industry or service-based sectors. However, this will not diminish the need for other types of large, centralized data centers – rather the reverse. The consequence of the scenarios mentioned above will be a huge amount of additional data generated, and a portion of this data needs to be stored and analyzed. (For more on this topic, see the article “The DE-CIX Digital Triangle for Edge Interconnection” by DE-CIX’s COO Ivo Ivanov, on the interplay of 5G, IoT, and AI as the enabler for innovation at the edge.) In my opinion, we will have a continued and growing demand for large data centers, simply due to economies of scale when it comes to data processing and storage. The need for and the rollout of edge data centers will therefore further increase this demand on the large data centers. Current trends suggest that the amount of data being generated is doubling every 18 to 24 months.

But who is going to build and run these huge numbers of edge data centers in our digital future? Certainly, the mobile operators need to have a solution for this demand, because otherwise their 5G business will not succeed. Most of the incumbent big data center operators are unlikely to go into the edge market. But we already have players who have built their business case in this area, offering edge data center solutions. It is possible, for example, to purchase containers fully packed with racks, servers, power, and cooling, to place wherever needed, where you have power and fiber connectivity.

There are a growing number of companies who are specializing in such offers. Some of these solutions take the approach of combining edge functionality with sustainability concepts, an approach I will come back to later.

This means that 5G, while enabling all sorts of new connectivity scenarios and intelligent services, also offers great potential to the infrastructure industry through synergy effects. 5G opens up new business potential not only for mobile operators, but also for broadband fiber operators; not only for a new breed of edge data center operator, but also for colocation data center and cloud operators. It will drive innovation not only in intelligent services, but also in digital infrastructure for rapidly evolving connectivity demands. (See GasLINE CEO Wolfram Rinner’s article on the current demand for connectivity and what is needed to enable edge computing.)

Security, availability, and reliability of edge data centers

Coming back to the edge data center: one challenge for their deployment is the question of security. It seems clear that if personal data or important critical data (such as the data involved in autonomous driving) is stored or put through an edge data center, then the security level of that data center should be equivalent to the existing big data centers, simply because of the sensitive nature of this data. However, this raises the question of how it is possible to make these many small edge data centers as secure as one of the large high-security colocation data centers, hyperscalers, and so on. This is a question for which we do not yet have an ultimate answer. (On the topic of IT security, Gerd Simon in his article “Cyber Security: Dancing With Wolves” offers advice on undertaking a risk assessment and ensuring insurance coverage in the event of cyber attacks – which is, in principle, relevant for all kinds of business, including the providers of digital infrastructure.)

On the other hand, when considering reliability or redundancy and resilience, the demand for the availability we have in our big data centers is not the same as for edge data centers, because of the huge number of these edge data centers. If one of these edge data centers fails and the next one is just a kilometer or so away, it hardly matters. There is more than enough time to repair it and all the other edge data centers around the one which failed will take over the tasks. The key thing is that more than one edge data center is connected to one 5G antenna. So if one fails, the other one can take over. The same is true for smart factories, smart homes and even a smart city.

Sustainability in data centers – reducing the footprint

In discussions with politicians and industry decision makers, one of the main topics in relation to digital services and data centers is always sustainability. Certainly, power consumption for all kinds of data centers is increasing heavily year by year, driven by the demand of both private and business users.

As data center operators, we do whatever we can do in order to be more efficient in our data centers. But the demand is simply so huge that we will see a big increase in data center usage and therefore power consumption. As a consequence, our environmental obligation is to look at sustainability. (LuxConnect’s Christine De Ridder looks at the importance of energy efficiency & the need for infrastructure providers to also transform digitally in her article “Luxembourg – The Digital Nation in the Green Heart of Europe.” 

The eco Association in collaboration with NeRZ recently published a white paper on the re-use of waste heat generated by data centers for other purposes, such as the heating of office buildings and apartment blocks, and for vertical farming (see also my own article, “Heat Recovery from Data Centers: A Win-Win Situation”, which highlights some of the findings from the study). This is one way in which already highly energy-efficient data centers can further reduce their footprint, as well as becoming integrated in new energy-related value chains. Just one example: Telehouse Frankfurt is negotiating with an investor planning to build 1,200 apartments on the other side of the street, and we would like to provide the heat from our data center to these apartments. This is being discussed quite concretely, also with the local power supplier Mainova. The initial meetings have already taken place, and I hope that we will find a technical and commercial solution that will work for all parties.

To go back again to the idea of a small edge data center in the basement of a house: the waste heat from that unit could also be channeled into the house’s heating system. From a technical point of view, that works perfectly. But from a security point of view, it's very difficult to guarantee the security level that is required if personal data is transferred through such a unit. Once such issues are resolved, there is really huge potential for using synergies of size and location to design edge computing solutions in a sustainable manner.


Theoretical physicist Dr. Béla Waldhauser is Chief Executive Officer of Telehouse Deutschland GmbH and KDDI Deutschland GmbH. Previously he was responsible for the German operations of Global Switch, and prior to that TeleCity. Before this, he was Managing Director for Germany and Austria for Teleglobe. For several years, he has been Leader of the eco Competence Group "Data Center Infrastructure" and since 2011 Member of the Jury for the "German Data Center Prize" in conjunction with the annual "Future Thinking" congress. In 2014, he was invited by the German Federal Ministry of Education and Research, as an expert and as a member of the eco Association, to actively participate in establishing the new strategy platform for “ITC in Horizon 2020”. Dr. Waldhauser is also Spokesperson for the Alliance for Strengthening Digital Infrastructures in Germany, set up in early 2018 under the umbrella of eco to support Germany's development as a digital location.