Will 5G solve the fibration of Europe?
Mobile operators boasts about the fantastic speeds 5G will deliver for mobile communication. One question that keeps popping up is if 5G would not be a better choice than fiber to the home. Why spend a lot of money digging and laying fibre into the ground when 5G can get you there at lower cost?
Well. Let me first say that there is nothing wrong with wireless communication. Except stability, reliability and availability of bandwidth.
Wireless works for most of us most of the time and we certainly make use of it both at home and when on the move thanks to smartphones.
But nobody can seriously claim that the mobile networks have delivered anywhere near the bandwidths they boasted about for 3G or 4G. Radio is a shared medium that suffers immensely by all the obstacles of buildings, trees, hills, number of clients trying to use it at the same time and so on. Mobile communication is a complement not a replacement.
In terms of reliability and capacity there is no question about the advantage of fiber networks. Fiber can provide uncompressed video for the best possible TV-signal and reliable, ultra-fast Internet access. More importantly, fiber opens the path for new welfare services, such as e-health that will improve services to citizens but that also requires the reliability only fiber can provide.
A fiber connection will not fail you. A wireless connection will.
With wireless communication there are some laws of physics at play. It's not that complicated.
- The more data you want to transmit during a second of time - the higher the bandwidth - the higher the radio frequency needs to be.
- The higher the frequency the more difficult it is to get through materials such as wood and concrete.
- The higher the frequency the more power is needed to get the signal to travel longer distance from the antenna.
To get a proper 5G signal indoors will therefore be much more challenging than what 4G is today, and lots of people already have problem with getting a good 4G service indoors. Furthermore, since the mobile operators aren't allowed to roast people like a microwave owen, there are limits to how powerful the signal from the antenna can be and thus, any kind of barrier will reduce the signal strength significantly.
5G works at frequencies up to 28Ghz. This is needed to reach the bandwidth goals 5G is boasting about. But at 28Ghz the wavelength is millimeter sized. Current mobile networks operate at frequencies below 3Ghz so there is quite a difference. Popular home WiFi networks are at 2.5Ghz or 5Ghz today and most of us know what problems we have to get between floors and reach everywhere in our homes with just plain standard WiFi.
At 28Ghz the problems will be much worse.
So the marketing of 5G, boasting about 10Gbit/s speeds is a hoax. You will not be anywhere close to that with your mobile device if its truly mobile. Perhaps it you stand still in perfect unobstructed close vicinity of a 5G antenna with proper uplink. Not anywhere else.
5G also includes variants - even frequencies at below 1Ghz - which would have an easier task getting through walls and other obstacles, but at these frequencies the use-case is really to talk with sensors or other low-volume data sources - perhaps reading temperature gauge or controlling a door lock much like the use cases of LoRa networks today for IoT. So this is not the option for high speed Internet.
The future 5G will require antennas every few hundred meters to make an acceptable coverage outdoors and even more densely indoors or in urban areas.
The really funny part though is that 5G will DEPEND on fiber to supply enough bandwidth.
To build a 5G network dense enough to deliver higher speeds you need get fiber connections to every street corner or building roof antenna location - antennas everywhere.
So if you do have to spend a lot of money digging and laying fibre into the ground to build 5G you should also take the chance to connect every home and every business in the area with fiber at the same time. The additional cost is negligible once the backhoe starts digging up the street. In fact, you should start building the fiber network already now. Why wait for 5G that still is very unproven and hardly even deployed in experimental networks?
In an article in Swedish technology magazine Ny Teknik the professor of radio systems as Lund technical Fredrik Tufvesson said "Mobile communication is a good complement. However fibre will - for the foreseeable future - have higher capacity. Don't wait for 5G"
I couldn't agree more.
Correction: It has been pointed out by experts that some of my technical comments in this post were inaccurate while the overall conclusion is correct. What specturm (frequencey) that is used in 5G is not the determining factor of the resulting bandwidth, but rather the amount of bandwidth available in that frequency for example in relation to interference or use of adjacent frequencies. The capacity in 5G is better compared to earlier mobile technologies and the cost of antennas in the higher frequency ranges (15, 28Ghz) can be kept low which of course means that better coverage is possible without a significant cost increase due to more antennas. You still need to feed each such antenna locations with fiber. Experts comment that there might be a viable use-case for last-mile connection to consumers that are really unattractive from a fixed fiber point of view - such as extreme rural areas, islands or mountain regions where digging fiber into the ground may be extremely costly. Though such locations still require line of sight to be effective. Credit to Per Kangru and Mikael Abrahamsson for their feedback