I am in Seattle this week for FYUZ, the TIP event and if there is one acronym on every 6G slide from the vendors and the US operators, it is ISAC. AT&T called integrated sensing and communication "the big shiny object in 6G" from the stage, as Mobile World Live reported on November 4, and Samsung, Ericsson and the rest of the usual suspects have a keynote, a demo or a birds of a feather session on it before the show closes on Thursday. Having spent a career watching each generation of cellular get designed around one headline use case, I have seen this movie before.
ISAC, in plain terms, is the use of the signals a base station already radiates to detect objects that are not connected to the network, the way a radar does. The echoes of the downlink reference signals, received by the same base station (monostatic) or by a neighbouring one (bistatic), are processed to extract the range, speed and direction of a drone, a vehicle, a crowd, etc... 3GPP added a sensing channel model in Release 19 and published in June 2026 the Release 20 study (TR 38.765) on base station sensing of drones in FR1, reusing the CP-OFDM waveform, while SA2 drafted the architecture in TR 23.700-14. Full ISAC is a 6G affair, Release 21 and later, which is why AT&T wants a limited version on 5G Advanced rather than wait, and why Ericsson told Fierce Network in July it expects small scale deployments within two years, the Los Angeles Olympics of 2028 being the stated target.
This is where my skepticism comes from. 2G was designed for digital voice, and texting, an afterthought squeezed into the signalling channel, became the killer app and the most profitable bits the industry has ever carried. 3G was sold on video calling and push to talk, and what actually paid, modestly, was MMS (I ran the product team that shipped the first commercial MMSC at Logica, so I remember how modestly). 4G was architected around IMS and VoLTE, and the application that filled the pipes was video from YouTube and Netflix, which no operator designed for and none monetized. 5G was built around network slicing and the enterprise connectivity products it was supposed to enable, and seven years in, the only 5G product with a revenue line of its own is fixed wireless access, a service that was in nobody's keynote in 2018, as I wrote here and here. In each generation, the standard was optimized for the use case the industry wanted, and the market picked another one that the standard merely tolerated.
What is different this time is who is doing the pushing. The US Department of Defense's FutureG office calls ISAC a "mission-first priority" against drone swarms (Tom Rondeau, July 2026) and awarded Cohere Technologies 28 million dollars to turn commercial cell sites into drone detectors, Ericsson Federal demonstrated drone detection in Plano in February with the same office on the press release, and Verizon's trial with Samsung at a soccer fan event in Dallas and its FCC experimental licence in 4.8 to 4.9 GHz, reported by Light Reading in September, both point at NTIA's Mission 6G 28 showcase at the Los Angeles Olympics, an initiative NTIA describes as industry led, industry planned and industry funded. Ericsson Federal's CEO put it plainly to Mobile World Live in October: sensing gives the US military a reason to invest in commercial cellular infrastructure beyond connectivity.
In my mind, read backwards, that sentence describes a national air defence sensor layer built on operator capex, with the requirements set in Washington and the bill presented to the operators and, eventually, their subscribers. The industry is not naive about it; AT&T's own speaker said on stage that some assume defence money will fly in through the window, and asked the right question, which is, outside defence and public safety, who pays the bill? Nobody at FYUZ had an answer beyond "new revenue streams", which is the same answer slicing got in 2018.
Because ISAC reuses the radio, the pitch is that sensing comes almost for free. It does not. Monostatic sensing means listening for an echo while the base station is transmitting, which today's TDD massive MIMO radios do not do; it requires a separate, isolated receive panel or self interference cancellation, in other words new hardware at the cell site, and the Release 20 work on base station monostatic sensing exists precisely because that architecture is not in the field. Second, every resource given to sensing is taken from communication: beam time swept across empty sky instead of pointed at subscribers, denser reference signals, wider bandwidth and longer integration windows to resolve speed, and transmissions in idle periods where energy saving would have switched the carrier off. The ISAC panel at FYUZ said as much; the test vendor on stage described sensing as blanking out resource blocks stolen from the operator, and the operator's own 3GPP delegate explained that the exposure layer needs checks and balances on every request precisely because sensing is resource intensive and cannot be an always-on API. Third, processing: the sensed data runs to terabytes, the result is worthless unless the processing sits close enough to the radio to make a decision in time, and one panelist expects purpose-built analog silicon at the cell site because the sensing runs continuously across a lot of spectrum, which he conceded will require a lot of additional money. ABI Research makes the same point, sensing is a continuous processing workload, unlike connectivity, with no revenue model to cover it. Fourth, everything above the radio is new: an exposure layer with its northbound API, about 75% specified and due in March 2027 according to the delegate, a new sensing function in the packet core to translate an external request (area, time window, detection or tracking) into the right set of base stations, the RAN procedures to go with it, roaming between networks when the requested area crosses them, and consent, since the delegate conceded that people who are not the operator's subscribers get sensed. Fifth, the one that gets no slide time, liability: a network that tracks objects that never attached to it, "operationally invisible" in Cohere's words, will be treated by regulators, courts and customers as a surveillance system, in Europe before anywhere else.
The comparison the ISAC slides never show is with what already exists. Drone detection is a market of 2 billion dollars in 2026 growing to 6 billion by 2034 according to Fortune Business Insights, radar being the largest segment, RF detection the cheapest and optical the fastest growing, and products like Dedrone's fuse all three with recognition models that tell a drone from a bird or a balloon, which an echo at 3.5 GHz cannot. Cameras with facial, scene and object recognition are deployed at scale in stadiums, airports, ports and borders, and the EU has a 250 million euro border management call for exactly this. These sensors are purpose built, mature, specialized, and what they lack, connectivity, backhaul and compute for inference, is what operators are good at providing. The operator opportunity in my mind is to connect, backhaul and host these sensors at the edge, not to rebuild a mediocre radar out of a radio designed for throughput.
In my opinion, the technology works, the AT&T and Verizon trials show it, and for a stadium, a port or a military base with a federal customer paying, a few hundred sites will carry sensing. That is a managed service for a handful of government buyers, which ABI Research itself now frames as ISAC sold inside a private network or edge platform rather than as a mainstream 6G feature, with commercialization after 2030. It is not a reason to design the 6G air interface, the radios and the baseband around sensing, and it is certainly not a reason for operators to fund national security infrastructure on their balance sheets while the government keeps the spectrum and sets the requirements. If the killer app of 6G follows the pattern of the last four generations, it will be something the standard tolerates rather than something it was designed for, and the sensing hardware will sit at the cell site the way the IMS cores sat in the data centres, waiting for a use case. Will the Pentagon pay the full price of the sensor network it is asking for, or will it, as is now customary, leave the bill with the subscribers?
