Our view of security in communications infrastructure is changing, with a demand for security and availability when it’s needed becoming more widespread. In recent years, we have been exposed to terrorist attacks in Stockholm, cyber attacks on infrastructure, and storms. Municipalities whose IT systems have been inaccessible, shops whose cash register systems have not worked for days.
Such scenarios put both our systems and the work to develop more secure infrastructure systems in a new light. It’s easy to wake up on a sunny morning and feel that our communication networks are working perfectly. But it’s when the wind is blowing when the pressure is on and communications are not allowed to fail that we can test whether the communications networks have what it takes.
Wireless beyond the public networks
Public networks are in most cases fast, accessible, and well dimensioned. During the terrorist attack in Stockholm five years ago, the mobile networks’ voice traffic crashed while the data traffic worked. It was probably 3G that failed, while 4G, which is more spectrum-efficient, was able to cope. That is one reason why we need to develop the mobile networks and phase out 3G in favor of 4G and 5G.
But no matter how well operators build out public networks, it is difficult to combine the revenue streams in public networks with a network sized for every kind of chaos that can occur. And predicting where the next accident or disaster will take place is of course impossible.
The private network approach
Private networks have the disadvantage that they are expensive to build and have a limited range of use, but they have the advantage that they can be built without connection to the internet or public networks. And just connecting to public networks or the internet is, unfortunately, always having a potential back door open. The weak link in the chain. Another weak link is that public networks cannot control the amount of traffic or calculate for disaster scenarios, something you can do in a private radio network. Whether it is the transmission of speech between two firemen in a private radio network or pumping stations in a water supply system that have to talk to each other, these systems can be dimensioned for chaos from the start. So from both cybersecurity and an availability perspective, private radio networks are ideal.
Isn´t 5G the savior?
As we move into the future and build the infrastructure of the future, new challenges arise. With 5G, we will be able to control vehicles via mobile networks, perform operations remotely, and do all sorts of exciting things. But the networks have to be sized for extremely high demands. The new technology will have to be able to deal with huge issues in terms of cybersecurity, availability, and capacity, so there will be incredibly high demands on our operators, which I am sure they will be able to handle.
5G is a journey that has only just begun. Remote machines are a vision of the future that we are starting to test. Recently I wrote an article about Skogforsk’s testing of 5G in a private 5G network. For Skogforsk’s solution to work, it requires a combination of high definition video, high data transfer speeds, and low latency, something that the tests show works best when there are transmissions with line of sight. The tests proved the old thesis that there is a correlation between antenna mast height and how far you can reach with the signal. The problem with the terrain is that there are both trees and high mountains that prevent the signal from reaching unobstructed everywhere. Mast heights are not enough, as private 5G networks at 3.5-3.7 GHz have difficulty getting past the natural obstacles.
The importance of real-time transmission is because much of the machine is controlled by hydraulics. Hydraulics have a natural delay. When operating the machine using the regular controls, this is not a problem for the operator. But using a link with an uneven data flow, problems will arise. The solution at Skogforsk is not unique in terms of the need for real-time transmission. This is a need you will find in pretty much every similar remote control application using a wireless network. In a normal vehicle, it is easier to build other types of electronic systems that can anticipate the situation ahead. A system that can calculate what the next scene might be. This is something that cannot be done with a forestry machine. The problem here is that when the crane continues in the same path at the last value, it continues until a new value is received. If there are long delays, problems can arise. Since the crane is about 8 meters long and can rotate at a fairly high speed, a lot can happen at the tip of the crane in a fraction of a second.
The winning combo
Here, a combination of own radio network on UHF or VHF and 5G can be a solution. 5G on 3.5 GHz is good in the forest, but at the edges of the coverage, the own radio network can ensure the transmission of the critical control signals while 5G can serve image streams and other less critical systems.
Narrowband with integrity
Another source of problems is interference with other systems. Communications in wireless networks are subject to interference. In large networks such as mobile networks, noise from many different sources can be experienced. This is described in something called Shannon-Hartley’s theorem. Noise can be that generated by other transmitters on other frequency bands, and both that arising from overlapping base station deployments. Different types of noise thus degrade signal levels. One way to maximize the amount of error-free digital data that can be transmitted over a communications channel is to use a narrowband signal with minimal channel bandwidth and channel separation. Since noise is spread across the spectrum, narrow bands result in lower noise levels, so working with a narrowband channel means minimizing the risk of interference from neighboring channels. So there is a huge advantage here with private radio networks, radio modems for example, which use a very small amount of licensed spectrum.
Like building your shelter
With a private radio network, critical parts of applications, or critical parts of our society, can continue to function day in and day out. In a way, private radio networks are like building shelters to use in the event of a crisis. But believe me, it’s considerably better to have a shelter to go to if needed even if we hope they never need to be used.