5G an overview

by Balhau

Much as been said about the new kid in town. Yes, you got it, the fifth generation technology standard for broadband cellular networks or 5G in short. It has been marketed as a revolutionary technology. From what we see in the news it is like god himself descended to earth. New revolutionary applications are awaiting in the corner, at least its what we are made to believe. Miracles are promised in healthcare industry.

Here we can see some miracles of 5G formalized.

  • Telehealth
  • Large Data Files
  • Real-Time Remote Monitoring
  • Sensor Innovation

The article finishes with

5G will make these technologies function in ways that 3G or 4G LTE couldn’t.

Yes I agree. 3G or 4G were not ideal to fulfill this. But I will say more, nor is 5G.

How dare you? You may say! Yeah, fair question. So lets start first by talking about what is 2G,3G,4G and 5G.

To understand better the differences between the several broadband cellular network standards it may help to check this article. Here we can see that on each new iteration we migrated to a higher range of the electromagnetic spectrum.

So what? You may say. It turns out that reality is not only roses and champagne. Higher frequencies enable us to exploit higher data transfer rates but at a price, a costly one. In this article we can see that

The trade-off for speed at mmWave frequencies is limited range. Testing of 5G service range in mmWave has produced results approximately 500 meters from the tower, meaning a huge propagation of MIMO-enabled antenna arrays would be required for pure standalone 5G deployment. In addition, the inability of millimeter wave signals to penetrate obstructions further limits the range potential because these obstructions would need to be factored into network designs for mobile users.

I would like to highlight the 500 meters range as a not so small detail. Compare this to the 4G standard that operates in the 32km range and you can start to figure out some issues with 5G. Going back to the previous picture we now have the following for the range

This means the following scenario regarding cell tower distribution

Which means that for the same area the amount of towers would increase by a lot. The density will be so high that the investment will only make sense in places of dense population. But even there it will be costly. And that because there is another factor inability of millimeter wave signals to penetrate obstructions. Yes another for fuck sake moment. So even if it makes sense in an economical standpoint to distribute all these cell towers it may not work as expected because it is dependent on the obstructions it may find.

Now lets look at the hypothesis we assumed to end up with a viable 5G setup

  • High dense population (to justify the investment in cellular infrastructure), or the economical argument.
  • High number of cell towers distributed
  • Amount of obstructions in the acceptable range (something to investigate)

By looking at theses assumptions some questions arise immediately. What about not so dense areas? Will lack 5G? But if not does it make sense to put 5g infrastructure everywhere? If not where do we will have 5G and where not? What about 5G fairness? Will we end up in a highly asymmetrical scenario in which some have, others don't, access to 5g?

Now back to reality. We are in 2021 (at time of writing) and lots of places in our country (Portugal) don't have access to optical fiber network and where a significant part of the ISP provide very low and unstable internet access. Another question. Can 5G help here? Maybe I'm wrong but I'm skeptical here as well. And this is the reason.

Cell towers with lower broadband capacity also put lower pressure on the underlying network infrastructure. This means that they consume a factor K of the underlying network capacity

When we increase the broadband capacity of the antennas we are also, by consequence, putting theoretically more pressure in the underlying infrastructure. I say theoretically because more availability does not imply immediately more usage. However have good reasons if bigger data transfers will be available people will find creative ways of using it.

This leads to another interesting point. Generalized internet connection access can actually become worse if the investment in the underlying infrastructure does not follow the increase of adoption and use of high data transfer rates by people using 5G solutions. This in turn leads to the increase of, yet, another issue. The fairness of internet access. Currently due to market incentives people don't have an equal and fair access to internet. Those close to the big cities will have usually better internet connection than those in small ones. The reason is because there is simply no financial interest in invest in small areas. They do however concur in terms of network infrastructure. Which means that without proper planning and oversight from regulatory entities the problem of fairness and equal access opportunity can became even more present. Actually this is not only a theoretical issue. While european ftth coverage looks in the right path we also know that some of these metrics can be misleading due some number engineering made by the ISPs. For instance some geographical areas report optic fiber coverage but then the connections into the households are not being done. 5G and FTTH are indeed two distinct problems and we should make an effort to avoid mixing the problems of each other. They are, however, correlated. Both end up being used as a mean to connect people through internet.

The choosen topology, driven by the investments done, will impose a set of tradeoffs. These tradeoffs are what is being discussed here. I argue that most of the investment should be done towards the use of optical fiber networks and 5G should be a very secondary way of increasing broadband where it makes sense. 5G should not be a global primary strategy as an infrastructure solution to connect people through the internet. This role should be done by optic fiber technology and that should be the main focus.

While some may think this to be a non issue, the possibility for bad tradeoff choices can be a reality, as highlighted in this huawei article

Given the cost of FTTH deployment in rural areas, we understand that some operators might be tempted by alternative broadband technologies like Fixed Wireless Access (FWA) or satellite, which can be faster and cheaper to deploy. However, neither FWA nor satellite can match the performance of full fibre networks. We also see the risk that what could be considered as a tempting temporary solution ends up being long-term infrastructure, creating a new digital divide between some rural areas and the rest of a given territory that benefits from full fibre connectivity. The slow and complex delivery of permits as well as the amount of red tape are familiar hurdles for all operators rolling out fibre. It seems that the situation is improving: The new Broadband Cost Reduction Directive will address these issues and hopefully overcome these obstacles.

Here FWA mean, in practical terms, 4g/5g wireless technology.