Third-Party UWB Accessories in Apple's U2 Era: APIs, FiRa, Patents

What did Apple's second-gen UWB chip actually change?

Apple shipped its first UWB chip, the U1, in the iPhone 11 in 2019. The second generation arrived in September 2023 inside the iPhone 15 line, Apple Watch Series 9 and Ultra 2, and the USB-C charging case for AirPods Pro 2. Apple's stated improvement: up to 3x the range for Precision Finding, the arrow-and-distance screen that walks a user to a lost item or a friend in a crowd.

The radio underneath is standard IEEE 802.15.4z HRP UWB, 500 MHz wide channels at 6.5 and 8 GHz, which is exactly why third-party silicon can talk to it at all.

The strategic signal is not the phone, it is the charging case. When a company puts second-generation ranging silicon into a sub-$100 accessory, it is telling the supply chain that UWB has hit the cost point where every tag, remote, key fob, and wearable is a candidate. And a buyer who has used Precision Finding once expects it from the next tracker they buy, whoever makes it. Direction finding is now table stakes.

Can third-party accessories use Precision Finding today?

There are two routes into Apple's ecosystem, and they have different owners.

• Nearby Interaction API. Since iOS 15, your own app can open a UWB session between an iPhone and your accessory and read distance plus direction in real time. iOS 16 added background sessions bootstrapped over a Bluetooth LE pairing, which is what makes hands-free gate detection and point-to-find features work. Your hardware must implement Apple's Nearby Interaction accessory protocol; Qorvo's DW3000 family and NXP's Trimension SR150 ship with that interoperability already validated.
• Find My network accessory program. Your tracker appears in Apple's Find My app and rides Apple's crowdsourced finding network, and the accessory specification includes UWB support for the native Precision Finding screen. The cost: Apple's certification queue, anti-stalking requirements, and a user experience you do not control, with location data staying inside Apple's app rather than yours.

Pick route one when ranging is a feature of your product. Pick route two when your product is finding itself. Apple opened the door, on Apple's terms.

What does FiRa 3.0 certification mean for your roadmap?

The FiRa Consortium, founded in 2019 by NXP, Samsung, Bosch, and others, runs the certification program that tests UWB devices for PHY and MAC interoperability across vendors. Certification is how a tag maker proves one SKU will range against a Samsung Galaxy, a Pixel, and a third-party anchor without a vendor-specific firmware fork. The 3.0 specification generation extends that program and tracks the next IEEE UWB amendment, 802.15.4ab, so hardware you qualify now should face a re-certification, not a redesign.

Two practical notes:

• Android matters here. Google exposes UWB through the androidx.core.uwb Jetpack library, and FiRa-certified hardware is the clean path to ranging against Android handsets.
• Apple does not use FiRa certification for its own ecosystem. It publishes its own accessory interoperability requirements, so a cross-platform product carries two test matrices, not one.

Enterprise buyers have started writing FiRa certification into RFPs the way they once wrote in Bluetooth qualification, so budget for it even if your launch target is iPhone only. Certify once, then test against Apple anyway.

Where the UWB patent thicket actually bites

UWB patents stack in three layers, and the risk profile differs at each.

• Radio layer. The 802.15.4z HRP PHY, secure ranging with scrambled timestamp sequences, and the coming 802.15.4ab work. Holders include NXP, Qualcomm, Samsung, and Apple. Buy certified silicon and the module vendor has largely dealt with this layer for you.
• Implementation layer. Angle-of-arrival antenna arrays, clock synchronization, multipath and non-line-of-sight mitigation. Partly covered by your chip vendor, partly not.
• System layer. Using ranging to track an object, guide a user to it, fuse UWB with camera or inertial data, hand off between anchors. These claims read on what your product does, not on what your chip does, and a silicon purchase transfers zero rights here.

The system layer is where accessory makers get surprised, because foundational filings from the 2010s remain in force into the 2030s, long after the radio itself became a commodity. Standards compliance and freedom to operate are different documents. The chip is licensed, your product is not.

How to ship a precision finding product without rebuilding the IP

You have three options: design around, build your own portfolio, or license. Designing around system-level claims is hard when the claim covers the user-facing behavior, the arrow on the screen, rather than one radio technique you can swap. Building your own portfolio typically takes 2 to 4 years per family from filing to grant, which is longer than most accessory product cycles.

Licensing is the third path, and it is the one Position Imaging exists for. The portfolio holds hundreds of granted US patents across RF ranging, real-time positioning, computer vision, and machine learning, and it is cited in filings from Apple and Bosch in the same art. Recent grants, including US 11,774,249, US 12,079,006, US 12,066,561, and US 12,000,947, sit squarely in the system layer described above: tracking and locating objects with RF ranging and sensor fusion.

The practical difference shows up in the schedule. A license negotiation runs in weeks against a known, granted claim set. Prosecution runs in years against an unknown one, with your launch date as the hostage. Weeks of diligence beats years of dispute.