What will be the story of ISAC?

I’ve had a weird habit of referencing songs in my telco blogs throughout my career. Rick Astley, Paul Simon, and now Leonard Cohen. I promise I was actually born in the 90s…

At the start of this year, integrated sensing and communication (ISAC) was barely on my radar. It still felt relatively niche and one of those technologies that people much smarter than I am were excited about, but which hadn't yet escaped into the wider telecoms conversation.

The story of ISAC has moved on pretty quickly since then.

There were already signs by the time MWC came around. Fierce Network came away from Barcelona remarking on how often wireless sensing had cropped up in conversations, while GSMA Intelligence subsequently said it was surprised ISAC hadn't received even more airtime given the level of operator and vendor interest. You couldn’t help by think “You were not there before”.

By DTW, I was hearing about it much more frequently.

Since then, Cohere has won a $28 million US government contract to develop an ISAC prototype for aerial surveillance using commercial cellular infrastructure. Samsung and Verizon have used 5G infrastructure to generate near-real-time crowd-density information at a major sporting event. Ericsson and Finnish public-safety operator Erillisverkot have demonstrated 5G-based detection and tracking of drones. And the standards work is getting more concrete too. In September, 3GPP progressed approved Release 20 work on ISAC for NR, while work on system architecture and security and privacy is also advancing.

ISAC is having a moment. So, what happens next?

Telecoms is very good at discovering an interesting technology, attaching it to every possible use case and all jumping on the buzzword bandwagon before we've quite figured out the nuts and bolts.

With MWC 2027 approaching, ISAC feels like a prime candidate. It feels like we're only halfway up the mountain.

The basic idea is actually quite good

For a technology with such a telecoms-y name, ISAC has a fairly easy pitch.

Mobile networks already fill the world around us with radio signals. Those signals interact with buildings, vehicles, people, drones and other objects. Analyse those interactions and the network can potentially detect where something is, how it is moving and what is happening in the physical environment around it.

In very simple terms, the network starts behaving a bit like a giant sensor.

That's quite cool. (I wonder what 18 year old me would think of that sentence….)

Compared with some of the more abstract promises attached to previous generations of mobile technology, you can immediately start imagining why it might be useful. A mobile network that can detect a drone approaching an airport or critical infrastructure makes sense. Using existing radio infrastructure to understand how crowds are moving around a stadium makes sense. There are potential applications in transport, industrial environments, public safety and network optimisation.

For once, there is a 6G proposition that doesn't immediately sound like something we could already do, BUT FASTER!.

So far, so good.

Are we all heading up the mountain?

We've seen this cycle plenty of times in telecoms.

A technology starts generating momentum. More vendors decide they need a position on it. Use cases multiply. Marketing gets there slightly ahead of commercial reality.

But, a scheme is not a vision.

Before long, every diagram contains a factory, an autonomous car, a drone and possibly someone wearing a VR headset. ISAC is in an interesting position because there is now enough happening around it for companies to credibly talk about it, but plenty of fundamental questions remain unresolved, including some very technical ones.

Take the waveform. Samsung and Ericsson see a route to delivering sensing using OFDM, the waveform technology already underpinning today's mobile networks. Recent demonstrations are useful evidence that you don't necessarily need to wait for a completely new 6G air interface before radio sensing becomes possible. Cohere has a different view. It is pushing Zak-OTFS, operating in the delay-Doppler domain, which it argues offers particular advantages for sensing and highly dynamic environments. Its US government-funded programme will incorporate both conventional OFDM and Zak-OTFS. There is a proper technical bunfight developing here (always wanted to use that word in a blog), just according to whose plan?

The eventual choices affect performance, network complexity, investment and ultimately what sort of sensing services operators can realistically deliver, but it also illustrates how early some of this still is. We're already starting to build a big narrative around ISAC while engineers, vendors, operators and standards bodies are still working through how it should work.

That doesn't mean companies shouldn't talk about it, of course, but it does mean there's a risk of the story getting ahead of the technology. Again.

For companies doing credible work in the space, there’s an opportunity to shape how the market understands ISAC before everyone else arrives and sticks the acronym on the side of the stand.

So what is the actual 'why'?

Forgive me if I inquire, but what is the ‘why’? “Network as a sensor” explains what the technology does reasonably well. However, it doesn't tell you which of its potential applications anyone urgently needs, and some of the current answers are much stronger than others.

Drone detection is probably the clearest example. There is an obvious problem. Airports, governments, defence organisations and operators of critical infrastructure already spend money trying to understand what is moving through the airspace around them. Conventional radar doesn't provide perfect coverage everywhere, particularly for small or low-flying objects. If mobile infrastructure that is already widely deployed can add another layer of sensing, the proposition isn't difficult to explain. There is a customer. There is a problem. There is existing spend. There are now live demonstrations attached to solving it.

Compare that with saying ISAC will enable smarter cities or richer digital twins. Maybe it will, but those are categories, not reasons to buy something.

Crowd sensing sits somewhere in between. The ability to understand movement without deploying additional cameras or requiring every person to carry a participating device is interesting. It also immediately opens another conversation about privacy, security and exactly what information a network should be able to infer about people who haven't actively connected to it.

There may also be a less sexy but potentially important “why” inside the network itself.

If sensing gives an operator a much richer picture of its physical and radio environment, can that information help the network operate better? Can it feed optimisation, automation or network digital twins? Does the strongest economic case eventually come from improving the network rather than selling a shiny new sensing service to somebody else?

Those stories are very different and lumping all of them together under “ISAC will unlock new 6G use cases” doesn't do any of them many favours.

There is a 5G hype hangover

The mobile industry, like my Dad when it came to securing Man Utd tickets growing up, is full of big promises.

5G delivered network improvements, but we also spent years being told it would transform manufacturing, healthcare, transport, entertainment, cities and practically everything else. Not a great deal of that has happened. Quite a lot of it remains stubbornly less transformed than the keynote slides suggested, and so the bar ought to be higher this time around.

That could work in ISAC's favour, because unlike plenty of early 5G promises, there is already something tangible to point at. The drone-detection work is real. So is the crowd-sensing trial. There is government money attached to the technology, standards work moving forward and enough disagreement over how it should ultimately be delivered to show there is something there. If anything, that uncertainty makes the story more interesting.

The mistake would be pretending ISAC is further along than it is. There is a big difference between showing that sensing over mobile infrastructure is possible and proving which applications will justify the investment at scale. The companies that handle that gap well should have more credibility than the ones rushing to declare that 6G has already solved another dozen industries.

What happens at MWC?

I wouldn't be surprised if ISAC is considerably more visible in Barcelona next year. That's partly because there is genuine momentum behind it, but it's also exactly the sort of technology the industry likes at MWC, one that is demonstrable, visual, futuristic enough to attract attention and broad enough for lots of companies to find themselves a role.

Which is why the communications battle around it is about to get harder. If ten companies are all talking about “network as a sensor”, who wins? If every booth has the same slide featuring drones, vehicles, factories and smart cities, being able to list more potential applications isn't thought leadership. The interesting stories will answer a much more basic question, which is Why this sensing capability, for this problem, now?

For some companies that may be drone detection and public safety. For others it might be improving the network itself. Others may have a play around transport, industry or entirely different applications. The winning ISAC narrative hasn't been decided yet. Neither have the companies most closely associated with the category outside the relatively small group already deeply involved in it.

MWC 2027 could be where some of that territory starts to get claimed. There are interesting technical debates happening underneath all of this, working demonstrations. and standards activity. Most crucially, there is real money beginning to appear.

The raw material for a good story is there. The companies that can connect credible technical work to a clear answer to “why should anyone care?” have a chance to shape one of the more interesting narratives on the road to 6G.

Everyone else can add another drone to the slide.