As a geographically wide-reaching, resilient, and highly used segment of RF spectrum, the decision to hand over swathes of C-band from SATCOM to 5G was controversial. Some satellite operators welcomed the news, while others voiced concerns at the decision’s impact on services being provided by SATCOM, especially within broadcast where its resilience is often relied upon.
After many long discussions, the decision was reaffirmed — the licensed use of 3.7-3.98 GHz was assigned and auctioned off for telecom’s use. In response, the satcom industry readjusted its services and looked to create mitigation tools and products to prevent RF interference. There were concerns around the impact of 5G cells on the satcom ground segment. Would there be an increase in cases of RFI? Would it be possible to identify the cause?
In recent years, SATCOM’s management of RFI has grown in sophistication, with monitoring and identification tools available to quickly identify issues and resolve them appropriately. Additionally, filtering products have been developed to mitigate the impact of 5G signals on satcom’s use of C-band; not only to prevent the loss of services caused by the lack of spectrum, but also to reduce the detrimental impact on the remaining services which operators are still able to deliver.
Anecdotally, there have been early instances of 5G causing issues with RF signals for neighboring users. This isn’t exclusive to 5G having an impact on satcom; there have been instances in which 5G has caused interference within the telecom industry, with mobile operators impacting on each other’s services.
Much of this interference seems to be location based; C-band users within Europe have shared many instances of RF interference in regions where 5G rollout has started. For many, instances of RF interference between the industries are unsurprising. RFI is a very familiar issue within satcom, and many have raised attention to the challenges surrounding its management across communications industries.
With many suggesting that the running of this should be managed by regulators, is the current regulatory situation thorough enough to cope with the increasing rollout?
Regulatory bodies across the world have taken different approaches when managing the sharing of spectrum. In many countries, a ‘negotiate and agree’ type system has been instated which has resulted in interference cases being solved by the communications operators themselves. Unfortunately, this method is not effective and is leaving many decisions to good will and best practice.
One of the more successful approaches has been that of the US’s FCC. The FCC has defined how to determine whether satcom is being impacted negatively by 5G and there is a clear procedure to follow if a fault is found. In the U.S., the mobile operator is required to solve any issues highlighted by RF users in SATCOM.
By providing the mobile operator with details, such as which tower or signal levels are causing RFI, the telecom provider must mitigate the effects.
Additionally, the FCC has taken an active role in managing the handover of spectrum to the mobile industry. It facilitated the auction of spectrum and, with the money gained from the sales, established a project to provide ground segment equipment to SATCOM users within areas of 5G.
Not only is FCC compensating the incumbent satellite operator spectrum rights holders for expediting their efforts to hand over spectrum to mobile operators, but they are also reimbursed the actual cost of doing so, and reconciling all remaining C-band services in grandfathered earth stations.
This seems to be having a good impact on the number of RFI instances being recorded; the FCC’s active role is helping to upgrade networks without passing down the associated costs to the ground segment.
Unfortunately, this proactive approach to spectrum management is not common. Each country has its own regulator, and no other is providing the same amount of regulation and support as the FCC. Could this be why we are hearing of many RFI instances caused by 5G in Europe?
We know that the coverage of 5G is going to be wide, and therefore it is hugely important that the rollout is handled correctly. There are huge benefits in regulators taking an active approach to spectrum management; without legislation and regulation, the process of managing incidents is left to operators themselves.
This is not an efficient method of dealing with such instances; what happens when operators disagree on the cause of the RFI? Will the region regulator have the capacity to review and oversee each case?
Another important question to ask is whether regulators are supporting satcom users to adjust to working alongside the telecom industry. A coordinated approach would prevent issues associated with RFI, and in turn reduce the number of incidents requiring attention.
Ultimately, the focus of communications is to deliver seamless connectivity to users. It is in no industry’s interest for its services to be disrupted. Small steps could be taken by regulators to mitigate these problems and it is frustrating to see many stalling on the matter.
A Coordinated Approach To Spectrum
At SIG, we have highlighted the need for a coordinated approach to spectrum for years. Spectrum is finite and we must respect that we are not its only users; poor use of RF can have a severe impact on neighboring users.
SATCOM has developed many solutions for identifying, monitoring, and mitigating RFI and is technologically prepared to identify RF issues being delivered by a new source. However, this is not enough to manage the cohesive use of spectrum. It is imperative that regulators take on an active role in spectrum management; it is not good enough to manage C-band auctions and simply move on once the spectrum has been sold.
The challenge has already been made difficult due to how spectrum has been assigned; in terms of spectrum, there are now two industries working very closely aside one another with very different technical characteristics and power levels. Managing industries with separate needs and expectations from their use of spectrum is going to take coordination;
there must be clear regulation in place to dictate who is responsible to mitigate instances of RF interference.
As we progress with the rollout of 5G, it is clear that its benefits will bring a range of opportunities for users. However, it is important that we harness our knowledge in RF management to ensure that there are suitable regulatory systems in place to allow users of RF to have confidence in implementing RF technology into their networks.
Author Helen Weedon is the Managing Director of the Satellite Innovation Group.