5G is fundamental for the economic development of the country. Yes, but why?

Because of its lower latency?

Because it will allow us to talk to the fridge and to know if the yogurt has expired?

To enable the circulation of self-driving cars or to allow remote surgical operations?

Let’s try to shed some light, let’s understand – beyond the hype – why the real “killer application” of the new mobile generation, for users, will probably not be any of those advertised so far.

5G, some technical elements

Let’s remember that the promise of the distinguishing features of 5G relates to a lower energy consumption for the same bits transmitted (which is ecologically commendable) coupled with higher “bandwidth” (throughput) with lower latency; all with greater capillarity and lower emissions.

To understand throughput with a simple analogy, think of a fireman’s hose and a straw: the throughput is the amount of water that comes out of the pipe per time unit. It depends on many factors such as the section of the hose, the water pressure and, last but not least, how much water per second the aqueduct is able to actually deliver to the hose.

Latency is a measure of how long it takes for the water molecule entering the pipe to exit on the other side.

2G

3G

3G HSPA+

4G – LTE-A

5G

Peak

0.3Mbps

7.2Mbps

42Mbps

150Mbps-1Gbps

1-10Gbps

Average(*)

0.1Mbps

1.5Mbps

5Mbps

15Mbps-50Mbps

50Mbps e oltre

Table 1 – Throughput (” bandwidth “) of the various standards (indicative values)

(*) without congestion

Standard

2G

3G

4G

5G

Latenza

300-1000ms

100-500ms

40-100ms

15-25ms

Table 2 – Latency (milliseconds) of the various standards (indicative values)

It is often said that 5G will have a latency of 1ms. This is a limit, under laboratory conditions that will not be experienced in practice.

We must also ask ourselves “latency to get where?”. In order for our bit inserted in the network in Rome to get out in Sao Paulo, Brazil, even at the speed of light and with few switching devices in between, requires over 100ms (Sao Paulo is far away!). So actually the latency will go from aprox 150ms with 4G to about 120 ms with 5G. It may seem a small reduction, but it’s actually a big gain.

If we consider that most of the contents and services that we usually access are not located on the opposite side of the world but in a datacenter near to us, we can understand that when accessing blog.quintarelli.it the latency will be nearly halved. If then we put a myriad of servers, with replicated content, in each city, then the latency could fall even beyond the values indicated in the table.

Low latency, for which business reason ?

What type of business would need such a low level of latency to justify such a large and widespread server infrastructure? Certainly not streaming video – it is not dramatic to wait 30milliseconds more for a movie to start – but for example interactive games that require fast reaction times (the reaction times of sportsmen vary between 100ms of a world record-breaking 100meter and 250ms of a “normal” professional). So a professional gamer connected to a 5G access would have an advantage over other professionals using 4G, a difference that could earn him the first step of the podium. (Of course, not all of us are professional gamers).

All this, provided that the rest of the network is carefully dimensioned and has no other bottlenecks (congestion) other than the access segment. And this is rarely the case.

While I’m writing, a simple ping command (which provides an estimate of round-trip latency) to a server located at the heart of the Italian network, from my PC reports a minimum value of 46ms and maximum of 68ms, with a variability of about 50%. (long live the smartworking! With so many people normally in the office contending the available network capacity, often the variability is larger).

There is then a further element to consider, that is where to put the application: let’s think about a virtual reality or augmented reality helmet: when the wearer turns his head, in order not to feel a motion sickness, it is important that the sliding of the images seen by the eye accompanies the sliding sensation determined by the vestibular apparatus in our inner ear. Having a low latency can be very useful to mitigate this annoying sensation.

The closer the application is to the viewer, the better.

Bringing applications as close as possible to users is a paradigm that is called edge computing. Some hypothesize to deploy myriads of small datacenters close to the antennas. But what would be the application that requires such low latency, staying within the operator’s business perimeter, in order to justify these investments? (that is to justify a sufficient number of users that pay something more than the traditional price in order to benefit from this latency reduction?).

The question is not trivial, especially if you consider that the most extreme level of edge computing is to put the computer in the user’s home. If the application was delivered from a home console connected with a cable (or an ultrawideband wireless link) to the helmet, it would be (with a few exceptions) even better than if the application was delivered from a server near the network border (near the radio access portion of the network). It’d be even better if the application was directly in the helmet.

So what is 5G really for?

Some TV commercials promote the image of 5G-enabled drones delivering cups of “frappuccinos” to our door, children entertaining themselves with dinosaur holograms popping up in the garden, advanced telemedicine, so much so that a surgeon can perform a surgery while waiting for a wedding, cars driving alone in the city and spectators watching basketball games circling their point of view around the players on the field.

But are these the applications of 5G? Searching online you will find interesting ideas for less extreme use than TV advertising. I comment some of them:

  • “5G will make life easier for robots, that is, the world called the Internet of Things. Things, from traffic lights to the fridge at home, always connected to the network. The goal of 5G is basically to propose in mobility all those essential features present in fixed networks, but with a latency even lower than cable connections”.
    Traffic lights and refrigerators in mobility. But then are we sure that they need all this large bandwidth and that 20ms less are decisive to decide to switch from green to yellow or to tell us that the yogurt is running out?
  • “…will also allow musicians, singers and artists who are in different places to interact in a single show”.

    A reduced latency, accompanied by low-latency interfacing circuits of musical instruments, will probably allow people to play musical instruments together remotely. The task is not trivial and also depends to some extent on the type of music played, but this is a use case that seems likely, even if it is not yet the killer application of 5G.

  • “This connection will be important in the medical field for the new connected ambulances that will be able to give a lot of information to the hospital even before the patient arrives. Planned uses are in telemedicine and rehabilitative robotics with the possibility to use IoT devices and remote control”.

    Of course we are talking about all those ambulances that will have on board diagnostic imaging systems (CT, MRI) that must transmit many Gigabytes in a few seconds, yesssss….. because certainly to provide saturation informations and ECG requires just a few bytes and during the lockdown we all got used to make video conferences… Likewise for physiotherapeutic rehabilitation: clearly some believe that the electromechanical machines (that today are found only in specialized centers), if used at home, need much more than the 50Mbps that a current LTE can give and you can not do without a latency as low as hundred meter professional runner latency to be able to control the patient is bending a knee.

  • “In the field of security and video surveillance will be used high resolution camera with 5G support, installable in stations and crowded places”.

    4K video requires about 16Mbps, 8K video (7680 × 4320) will realistically require about 40-50Mbps. Nothing a decent landline access can’t support. Of course, you can’t watch it if you’re not at home.

  • It will be also usefulin tourism and journalism, the latter thanks to 5G will be able to provide more timely images and news in every part of the city”.

    Which, as we know, is the core problem of journalism today…

  • “5G also brings benefits to self-driving cars, as they will be able to communicate in real time with the road infrastructure and obtain important information for road safety and security”.

    One wonders how autonomous cars are doing today. Do we really need that latency reduction to signal positions and obstacles? Even assuming that this is indeed the case, that a very reduced latency is absolutely necessary, then wouldn’t it make more sense to make direct connections between cars, without passing through a network that, however, adds some latency?

    As you know, I am very skeptical about the concrete possibility of having cars autonomously whizzing through the cities because of safety problems related to an uneven and above all unmonitored environment. A differrent story are highways that are homogeneous and very well supervised environments. We will probably see autonomous driving on the highway, probably with reserved lanes and more than intervehicular communication we may need a lot of mobile bandwidth to be able to work or entertain ourselves during our travels.

  • “Even smart homes will benefit from 5G, all objects in the home will be able to communicate with each other, receive information from the outside and be controlled remotely from a single device”.

    What is it that can’t be done today with fixed network access and wifi? (hoping that the device that remotely controls our home belongs to us…) Are we sure that the complexity of Narrowband-IoT (NB IoT) and the 5G version will prevail over wifi and bluetooth? It seems to me that the probability that this will happen in the short to medium term is quite low, unless some black swan gives the necessary impulse.

  • “An ultra-performing network, will be fundamental for the transition to the Internet of things, i.e. to ensure the development of applications and services for the Smart City based on sensors (for example for traffic control, waste collection, urban lighting, logistics)”.

    In 20 milliseconds, many cars pass through street intersections and a lot of waste is thrown. If a lamp burns, then, we really know first!

  • “The new, very fast 5G mobile networks will also help improve safety on the roads. In addition to allowing more data to be transferred in the same unit of time, they have a much lower latency and a reduced error rate: if one data packet in a thousand is “lost” with 4G, with 5G you get up to one in a million. It is these last two aspects that will make the electronic security systems of cars more effective, which will “dialogue” with each other in real time and with the certainty that the information arrives”.

    About the latency I mentioned above; about the loss of packets, as people who deal with networks know, network protocols (TCP) have control mechanisms to ensure applications that all transmitted packets arrive. This aspect, therefore, is already insurable to current technologies.

  • “The productive world will be revolutionized through the full digitalization of production facilities – the so-called Industry 4.0 – and the development of precision agriculture”.

    Indeed in the business market there could be an interest in 5G for IIoT (Industrial IoT), unlike the residential market. The 5G will allow a higher communication density up to one sensor per square meter, that is one million sensors per square kilometer compared to the 50 thousand allowed by the best NB IoT technologies. We must also bear in mind that in the industrial field wired network technologies are very expensive (PROFINET cables and switches cost one order of magnitude more than the non-industrial equivalents) and introduce rigidity in installations that could be more flexibly realized and reconfigured using wireless connections. (examples 1, 2, 3, 4)

Be careful! I’m not saying that 5G doesn’t help, but that the “killer applications” that are proposed today (which often include “life saving” arguments, because on those you can’t squeeze investments), with the notable exception of the business market and IIoT, are generally trivial and almost certainly destined not to materialize.

Figure 1 – Piazza Maggi, Milan

This does not mean that a new network infrastructure should not be built, on the contrary! The first motivation for a new infrastructure is that it must precede the demand and enable it: the new infrastructure will serve a demand that is not there today. Einaudi, a very famous italian economist and politician, said that markets expresses demands, not needs, meaning they express immediate requirements and not long-term needs.

Also from this point of view the idea of pooling investments to co-invest in a 5G network infrastructure seems reasonable.

The networks they are a changin’

The “mobile” networks (which are not mobile: it is people who are mobile, not the networks) work by emitting signals that fade as you move away from the antenna, so that phones and antennas have to transmit with increasing power to be able to communicate, like two people talking to each other by moving away from each other. Or, another solution, is to place many more antennas that will be much closer to the user so that they will be able to communicate with lower power; the lower the power, the the larger the number of antennas that are needed. This is what has happened with mobile telephony: at every stage of evolution from GSM to UMTS (or 3G) to HSDPA (or 3.5G) to LTE (or 4G) emissions decrease and antenna density increases.

Consequently, the wireless access segment (the part from the user to the antenna) tends to become shorter: from the many kilometers of GSM (with low bandwidth) to a few tens of meters with Wi-Fi and 5G (which provide a lot of bandwidth).

With 5G, in Italy we will have hundreds of thousands of small antennas, with very low emissions (also because we have the lowest emission constraints in the world). In the future we will find them at the base of many buildings and they will provide us ubiquitously performances similar to Wi-Fi, wherever we go.

To each of these antennas we will need to feed some bandwidth with a network connection hookup (usually fixed). For this reason it is of obvious the importance of the presence of fixed networks, whether they are via the “old cable TV” as in some European countries or telephone networks with optical fibers. But it is good to overcome also this conceptual differentiation. The network is always and only one: it serves to carry data of any type. It does not matter if it was born for the telephone (copper pair) or for TV (cable networks) or if it is made with optical fibers.

Such a high density of antennas means that each antenna will be used by fewer people. If an antenna covers a radius of two kilometers, all users in a small town will connect to it. If an antenna covers a twenty meter radius, only the few people in that building will connect to it.

The transmission capacity available from an antenna is shared with the people who connect to it. In the case of the small town, it will be shared among many people; in the second case it will be shared among very few people so that each individual in the second scenario will have much more bandwidth available than their peers in the first scenario. Increasing the capillarity of the antennas helps to reduce emissions and increase the performance available to users.

Lower emissions thanks to 5G

It seems a counter-intuitive thing: lower electromagnetic emissions with more antennas; higher capacity with lower emissions. An example helps to clarify: imagine a room with forty people and two of them talking with a megaphone. The noise pollution will be very high and the overall capacity of the room will be just one conversation. If everyone whispers, the noise pollution will be minimal and the overall capacity will be twenty simultaneous conversations.

Ultimately, the network is not what we are used to think it is: a single object managed by an operator. Instead, it is a mix of different types of routes, with different technologies, much likey a road network.

From the point of view of the user, in the future there will not be a great distinction between fixed network and wireless network. The fixed network will have a very high capillarity and at its edge there will be an antenna. If located inside a house, it will still be a Wi-Fi managed independently by the most sophisticated users, if it will be located outside of the house it will instead be a 5G network managed by an operator.

A mental image of networks

Let’s picture circles to imagine service boundaries of an operator.

Today there is a circle that reaches the users’ home, the fixed network, to which a Wifi access point is connected; it can be right next to each side of the circumference, depending on whether it is provided and managed by the operator (inside the circle) or installed directly by the user (outside the circle). Outside this circle there are the user’s devices, from PCs to smart refrigerators (!?) to TVs connected to disks to store documents, photos and movies (and managing their complexity).

Then there is another circle, the “mobile network” one, which radius is smaller. It’s the network that powers the cellular radio stations located right inside the edge of the circle, inside the perimeter of the operator, to which users connect with their mobile devices.

Over time this second circle has expanded and with the 5G it will come close to the border of the first circle, so close that many users will find it more convenient to directly connect their devices, entrust the operator with the custody of their documents, photos and movies (without having to manage the complexity) reducing its management burden, often increasing the level of security and being able to have everywhere what would otherwise only be available at home / office.

These two circles, the fixed network and the mobile network have grown closer over time and will continue to do so with 5G; there is a large overlap in the surface area of the two circles. The more widespread the “fixed” network is developed, the more it will also contribute to the infrastructure for 5G.

The telephonist’s drama

Let’s go back to the use cases: many of those told, especially those that are presented as useful to save lives, suffer from what we could call “the telephonist’s drama”. I call it this way because i often perceive it when talking to many friends, very competent people, who work for telco operators who, being born as telephone operators, keep that imprinting in their DNA and seem to me they still are a bit conditioned by that way of thinking.

An example of a typical “telephone” way of thinking is that of value added services.

Let’s imagine a system to improve driving safety, based on a myriad of temperature and humidity sensors scattered along a mountain road so that a car that arrives that behind the blind curve can be informed there is a high risk of icing.

This is a typical use case in 5G narratives.

Let’s ask ourselves: did Vodafone or Telefonica put those sensors? If Vodafone put them, will they be accessible to cars connected to Telefonica’s network? And to those connected to Iliad’s ?

If we were in a monopoly situation, the problem would not arise: the same single operator puts the sensors and connects the cars.

But in a competitive situation, how can it be solved ? All mobile operators sign service interoperability agreements (and payment settling) whereby one operator gives the other access to the information of the sensors that he has placed in street X, a second operator gives access to the information for street Y to the first operator and then periodically they make a balance to see who owes the other how much money, after compensation.

You can bet that, while they are busy negotiating multiple bilateral service roaming agreements, someone will come along who will install sensors that will communicate via the Internet, taking away these possible services from the operators and making them over the top. And remunerating them with advertising, credit card or freemium models.

Does it recall something ?

In order to avoid a similar scenario, the operators should probably make a consortium and create a joint over the top service provider, presenting themselves on the market as a single integrated entity.

I doubt it will ever happen. Genetic imprinting is hard to die. Consider that in the 2020’s 5G WhitePaper issued by the NGMN Alliance (Alliance for Next Generation Mobile Networks, an association of operators, vendors, manufacturers and research institutes operating in the mobile phone industry) the word “Internet” appears only once (just once!), in the glossary, in the definition of “IIoT: Industrial Internet of things”.

What fate for 5G networks?

I have to make a major premise: the operators’ business cases to sustain the realization of widely spread 5G networks, with myriads of access points, are anything but obvious. It is likely that we will see a gradual roll-out, starting where the market can reward technology, i.e. in the business market, especially in industry.

As far as the residential market is concerned, the destiny of 5G use, for a growing user base, could lead to a reduction in the myriad of WiFi access points, now bought everywhere and by anyone, installed by anyone and uninspected for quantity and quality of their emissions. For many users 5G could greatly reduce their need of a fixed hookup to their homes, replacing the last meters of WiFi access with the last tens of meters of 5G.

TodayAs today, the way we use the network at home or on the move, are different: at home we have our files, backups, and our devices that (in general) we cannot access when we are on the move. A scenario like the one described could allow the members of a family to benefit from all their data in mobility, anywhere, as if they were at home. Perhaps this could be a killer app (that might be of interest to operators, though in a clash with OTT and device manufacturers who already provide these services, although with a looser billing relationship with the customer ).

However, there is a fundamental consideration that must be made: history teaches us that at home as at work, on the internet, people want to do more and more things in less and less time. So the traffic increases in a sensitive and inexorable way.

It is true that in nature there are no exponential curves that grow forever (sorry Mr. Kurzweil!), that all exponential curves sooner or later become logistic curves and flatten. There is certainly an asymptote of how much bandwidth a user can consume. My impression is that we are still very far from reaching it. This seems to be confirmed also by the recent actual usage data trends: the bandwidth used in Italy (and in the world at large) is still growing by ca. 50% per year with a comparable number of users.

As Alfonso Fuggetta said with a lucky expression, one cherry pulls the other, i.e. we start with simple things and then we make more and more, more and more complex, more and more requirements and more and more bandwidth. And at the same time our expectation of ever shorter reaction times increases.

Ultimately, for users, the killer app is still human impatience.