5G Interference and What to Do About It
With the gradual introduction of 5G services among the countries of the world, ongoing discussion are happening on possible interference between 5G services and any existing telecommunication services.
So what is interference to begin with?
What is Interference?
interference happens whenever two separate services are using the same or similar frequency range. The fact is, the universe only operates at one frequency spectrum. So assuming service A is working on 5GHz and service B is also working on 5GHz, the data throughput of this two services both happening at 5GHz would mutually corrupt and mess the data that was sent.
In radios, we get a glimpse of how interference works when you tune to a frequency that is in between station. You receive transmission from both station, but they are mostly garbled and unintelligible.
But the effect of interference can be much more severe. Take for example a recent findings from this article. 5G interference will potentially put commercial airplanes at risk in the US. To give context, the US 5G spectrum is set to operates at the C-band range of 3.7–3.98GHz. Meanwhile the commercial flights in the US have their aircraft altimeters operating at 4.2–4.4GHz
This is considered to be too close for comfort. Any interference from the 5G signal would have disastrous effect. The solution is to implement RF filters that are able to have a “clean cut” between both frequency range, a separation band. a filter that has a high isolation and good throughput is needed for this task.
And that is in theory.
Points of Concern
the ongoing discussions is always considering this 2 points of concern.
Feasibility. Existing or ongoing research will need to be able to support the proposed solution to mitigate any interference from 5G services on other telecommunication services. There is no point if the proposed solution is “in theory”, and at the moment, being impossible to achieve. Questions that are ask may revolve around how easy it is to design the said solution, or even the material science behind the design.
Cost-effectiveness. Of course it is fully possible to revamp any of the services to adapt to the newly introduced 5G network. But is it really cost effective to begin with to thrash and redo all the infrastructure and equipment of the said service? Impact analysis has to be carried out to determine how wide-ranging the effect of a solution can be and how much modal has to be spent just to implement the solution. Simple saying, the more easier/cheaper the solution the better.
In many cases, applying a passive filter is the easiest solution to mitigate any interference. Because passive filters do not require any input power to operate it, it is usually easy to retrofit into pre-existing technology. Depending on the type or technology used, they could potentially be the cheapest solution too.
Take this image below as an example:
This image shows the Low Noise Block down-converter (LNB) and the Feed Horn of a satellite dish. To mitigate any interference that may be picked up by this satellite dish, a passive filter can be retrofitted in-between the LNB and the Feed Horn. This solution is a retrofitting solution that can be easily achieved without any damage or extra cost to the infrastructure.
For many Fixed-Satellite Services (FSS) which operates at C-band frequency range of 3.4Ghz — 4.2GHz, a solution such as this will be potentially needed across the world due to 5G operating at 3.7–3.98GHz. In this case, a C-band RF filter retrofitted will be a good solution.
The fact is this, interference will always be a challenge that needs to be overcome. With introduction of 5G, even more so. Perhaps even right now, filter technology is even more crucial for the many telecommunication services to be able to coexist in the same ecosystem.
In FILPAL, we design C-band filters as a retrofitting solution for 5G and FSS coexistence. Check it out at: https://www.filpal.com/bandpass-filters
Originally published at http://filpal.wordpress.com on May 29, 2022.