The Problem With “Somewhere in the Building”
There is a particular kind of frustration that facilities managers know well. A piece of expensive equipment is supposed to be in bay 7. It is not in bay 7. It is not in bay 8 either. Someone checked it out three days ago, and the paper trail ends at a whiteboard. In a 400,000-square-foot distribution center, “somewhere in the building” is not a useful answer.
GPS, of course, is useless indoors – satellite signals have never cared much for reinforced concrete. Wi-Fi positioning gets you to a zone, roughly. Bluetooth Low Energy (BLE) tags are fine for low-density environments, but fall apart when you put a few thousand of them in a metal-dense warehouse and expect reliable reads. UWB – ultra-wideband – is genuinely impressive, hitting 10 to 20 centimeter accuracy, but it requires its own anchor infrastructure on top of whatever else you have built. Layering a second location network on top of a freshly deployed private 5G system is the kind of proposal that gets laughed out of a capex meeting.
Enter MC-RTT. Multi-Cell Round Trip Time is the 5G standard’s built-in answer to the location problem, and its pitch is simple: use the network you already have.
The Clever Part Is What It Does Not Need
Most cellular positioning techniques have a catch. Time Difference of Arrival, for instance, needs every base station in the grid to share a synchronized clock – tight synchronization, the kind that adds cost and complexity in real deployments. MC-RTT sidesteps this entirely. Each base station conducts its own two-way timing exchange with the device: the signal goes out, comes back, and the round-trip time is logged. The device’s own clock offset cancels out in the math. No shared synchronization required.
Triangulate those round-trip measurements from three or more base stations, and you have a position. A handheld scanner, an asset tag on a forklift, a mobile robot – anything with a 5G radio. No extra hardware. The same radios already moving data around the facility are running the location logic in the background.
MC-RTT was standardized in 3GPP Release 16 and further tightened in Release 17, bringing sub-meter accuracy under line-of-sight conditions within reach. That is not a lab claim either – research published in 2025 in the IEEE Internet of Things Journal found that Multi-RTT outperforms every other 5G NR indoor positioning method when the signal path is clear. Release 17 tooling is now showing up in commercial private network deployments, so this is no longer a future roadmap item.
| PRO TIP: Design for Location from Day One If you are planning or deploying a private 5G network, do not treat positioning as a feature to layer in later. The geometry of your small-cell placement determines the accuracy of MC-RTT. That means antenna placement decisions made today – height, spacing, coverage overlap – will either enable sub-meter location or cap it at something far less useful. Work with your network vendor to map anticipated asset-tracking zones before the radios go in the ceiling. Ask specifically which 3GPP Release your RAN equipment targets for positioning, and whether MC-RTT is enabled or requires a software unlock. The network is going in anyway – a little upfront planning is the difference between a location-capable deployment and one that needs a costly overlay later. |
Why Private 5G Is the Right Venue for This
MC-RTT technically works on public 5G networks too, but the geometry matters enormously. More base stations, closer together, with controlled placement – that is what drives accuracy. Public macro networks were never designed with indoor triangulation in mind. Private 5G networks are, by definition, designed for the specific environment they serve. A dense, small-cell grid in a manufacturing plant provides MC-RTT with the overlapping coverage geometry it needs to perform.
The private 5G market is not waiting around. SNS Telecom projects annual investment will grow at roughly 41% per year through 2028, eventually clearing $5 billion. The indoor 5G market, broadly valued at around $16.3 billion in 2024, is forecast to grow at a CAGR of 15.9% through 2034. Behind those numbers are factories, hospitals, logistics operators, and increasingly, commercial real estate owners – all of them asking the same question: now that I have a private network, what else can it do?
That question is exactly what vendors are positioning against. Nokia has deployed private wireless networks for 890 customers globally. Ericsson has baked precise positioning into its enterprise network stack. And in June 2025, Nokia and Andorix announced a partnership to bring private 5G – and the edge applications that run on top of it – to commercial, retail, and residential real estate properties across the US and Canada. Indoor navigation was explicitly named as a target use case. That is not a coincidence.
Where UWB Still Wins – and Why That Is Fine
There is no point pretending MC-RTT beats UWB on raw accuracy. In a controlled point-to-point setup, UWB at centimeter precision is still a different class of measurement. If you are doing robotic surgery guidance or submillimeter assembly work, the conversation ends there.
But most industrial location use cases do not need centimeters. They need to know which aisle something is in. Which zone. Which floor. Sub-meter 5G accuracy handles that – and does it on infrastructure the enterprise already owns and manages. One vendor, one management console, one ops team. The alternative is running a parallel UWB network alongside your 5G deployment, which means separate power, separate firmware, separate maintenance cycles, and a second vendor at the table when something breaks.
5G also handles one problem with location accuracy that other technologies like BLE and Wi-Fi do not: multipath. In a metal-dense industrial environment, signals bounce off racking, machinery, and moving equipment in unpredictable ways. Wider channel bandwidth – up to 100 MHz in sub-6 GHz 5G – helps the timing algorithm pick out the direct signal path from the reflected noise. That is where most indoor positioning systems quietly fail, and 5G is better equipped to deal with it.
The honest limitations still exist. Millimeter-wave 5G offers sharper timing resolution but struggles with penetration – more small cells, more capex. Native 5G asset tags are still more expensive and power-hungry than their BLE counterparts, and the device ecosystem is catching up rather than leading. These are real constraints, not dealbreakers, but they are worth factoring into the cost model before the project is approved.
What Is Coming Next – and It Is Not Just More Accuracy
3GPP Release 18 – branded 5G-Advanced – and it brings something genuinely new to positioning: AI assistance baked into the standard. Machine learning models trained on signal behavior will improve location accuracy in non-line-of-sight conditions, the scenarios where multipath reflections have always caused the most grief. That matters in practice because most real-world facilities are not open-plan line-of-sight environments – they are full of shelving, walls, machinery, and people.
Vertical positioning is also on the roadmap: floor-level differentiation in multi-story buildings. For anyone trying to track assets or personnel across a hospital campus or a multi-level distribution center, 5G closes the last major gap in location capability.
MC-RTT is not the end state – it is the foundation. Each release of the standard adds resolution, adds robustness, adds capability. Enterprises that build their private 5G networks with positioning in mind now will find that capability improving with software updates rather than infrastructure overhauls. That is a reasonable bet to make, especially when the network is going in anyway.
The underlying shift here is that location is becoming a network service rather than a separate system. That is a meaningful change in how enterprises think about their infrastructure spend – and for facilities managers who are tired of hearing “somewhere in the building,” it is long overdue.
What This Means for You
If you are a building owner: Indoor location capability is becoming a tenant expectation, particularly for logistics operators, healthcare systems, and manufacturers evaluating long-term leases. A private 5G network with MC-RTT positioning built in is not just an operational upgrade – it is an amenity that differentiates your asset. If you are already considering a private wireless deployment for connectivity alone, ask your integrator to scope positioning from the start. The incremental cost at design time is a fraction of what a retrofit or parallel system costs later. Done right, you are not just upgrading your building’s infrastructure – you are building a platform that tenants can run their operations on.
