Technology

High-Performance Ranging (HPR)

HPR is Noccela’s proprietary UWB positioning protocol. It measures distances by ranging, which gives the accuracy and coverage of two-way ranging, while keeping each tag’s airtime and energy use low and keeping a two-way radio link to every tag.

Talk to an engineer TWR vs TDoA explained

Positioning accuracy, up to: 10 cm
Coverage per base station, up to: 500 m²
Active tags at 1 Hz within radio range: 1,000
Configurable update rate: 0.1–50 Hz

Figures for Noccela systems using HPR. Capacity counts moving tags within radio range of a base station.

The trade-off HPR addresses

UWB positioning systems mostly use one of two methods. Each is good at something the other is not.

Two-way ranging (TWR)

The tag and a base station (UWB anchor) exchange messages, and the round-trip time gives the distance. With distances to three or more base stations, the position follows.

Strengths: accurate, wide coverage, no clock synchronisation between base stations, and the tag can receive.

Cost: several messages per base station for every position. With four base stations that is roughly an order of magnitude more transmissions than one blink, which limits tags per area and battery life.

Time difference of arrival (TDoA)

The tag sends one short blink. Base stations timestamp its arrival, and the differences between the timestamps give the position.

Strengths: one message per position, so tags last long and many fit in one area.

Cost: base stations must share a common clock to within a fraction of a nanosecond, because light travels about 30 cm per nanosecond. Accuracy drops outside the area the base stations enclose, and tags that only transmit need a side channel for configuration.

HPR

HPR was designed to keep what ranging does well while cutting its airtime cost.

Ranging-based: positions come from measured distances, so there is no timing network, and coverage is up to 500 m² per base station.
Compact exchange: the message exchange is kept short, so that a tag’s airtime per position stays close to that of a blink.
Two-way link: every tag can receive configuration, alerts and firmware.
Thin base stations: the positioning logic runs in the engine, in the cloud or on-premise.

TWR, TDoA and HPR side by side

General characteristics of each method. Real systems vary with vendor, configuration and site.

Comparison of two-way ranging, time difference of arrival and High-Performance Ranging
Property	Two-way ranging (TWR)	TDoA	Noccela HPR
How a position is made	The tag exchanges messages with each base station; distance comes from the round-trip time	The tag sends one short message (a blink); base stations compare its arrival times	Distances from a compact two-way exchange; positions from the distances
Tag airtime per position	High: several messages per base station	Low: one blink	Low: designed to stay close to a single-blink budget
Base station clocks	No synchronisation needed	Must share a common time base to within a fraction of a nanosecond (cables or wireless)	No timing cables; one PoE cable per base station for data and power
Accuracy and coverage	High, also towards the edges of coverage	High inside the area enclosed by base stations; weaker outside it	Accuracy up to 10 cm; coverage up to 500 m² per base station
Tags per radio area	Limited by the airtime each tag uses	High	1,000 active tags at 1 Hz within radio range; tags at rest do not use capacity
Tag battery life	Shorter: the tag transmits and listens more	Long	Typically several years, depending on utilisation and update rate
Link back to the tag	Yes	Usually not over UWB; configuration needs a side channel	Yes: configuration, alerts and over-the-air updates
Defined by	IEEE 802.15.4; FiRa Consortium; omlox	FiRa Consortium (downlink and uplink TDoA); omlox	Noccela (proprietary)

TWR vs TDoA vs AoA: the vendor-neutral guide

Why the two-way link matters

Configuration

Change a tag’s update rate, sleep timeout or mode from the platform. A forklift tag can report often, a pallet tag rarely, and both can be changed later without touching the tag.

Alerts on the device

Make a tag buzz and flash when its wearer enters a zone, help someone find a tagged asset, or confirm on an Andon Button that a call was received.

Over-the-air updates

New tag firmware is delivered over UWB through the base stations, so improvements reach tags in the field without collecting them.

What HPR means for your use case

Tracking people? Define the purpose first, prefer safety-only modes and pseudonymised badges, keep retention short and consult employees before go-live. Privacy by design for people tracking

HPR and the standards

HPR is proprietary. It is Noccela’s own protocol, not a published standard, and it is not certified by a standards body. The radio it runs on follows the IEEE 802.15.4 UWB physical layer on channel 5.

The standards have moved on. The current base standard, IEEE 802.15.4-2024, includes the secure-ranging features first published as 802.15.4z. The FiRa Consortium added downlink TDoA to its core specification in 2023 and uplink TDoA, where infrastructure tracks tags, in 2025. omlox standardises two-way ranging, uplink and downlink TDoA, and an energy-saving two-way mode in which several anchors overhear a single tag exchange.

Hybrids are not unique. Combining ranging accuracy with low airtime is an idea that several vendors and omlox now pursue in different ways. HPR is Noccela’s implementation, developed in our own products since 2017. What we publish about it is what it delivers in our products: the numbers on this page.

How to choose. If interoperability with third-party tags or smartphones is your first requirement, look for systems certified to an open standard. If you want accuracy, long tag life, a two-way link and a system that calibrates itself from one supplier, HPR is built for that.

Frequently asked questions

What is High-Performance Ranging (HPR)?

HPR is Noccela’s proprietary UWB ranging protocol. Positions are computed from measured distances, as in two-way ranging, while each tag’s airtime per position is kept low and every tag keeps a two-way link for configuration, alerts and over-the-air updates.

Is HPR two-way ranging (TWR) or TDoA?

Neither exactly. It is ranging-based like TWR, so base stations need no timing network, but it keeps the message exchange compact, so that a tag’s airtime per position stays close to that of a TDoA blink. The TWR vs TDoA guide explains both methods.

Is HPR a standard?

No. HPR is Noccela’s proprietary protocol. The radio underneath follows the IEEE 802.15.4 UWB physical layer on channel 5. Standards-based positioning modes are defined by the FiRa Consortium and omlox; Noccela devices are not certified by either.

Can third-party UWB tags or smartphones be used in an HPR network?

Not as HPR tags. An HPR network locates Noccela tags. Positions from other systems can be added to a site as external tags through the HTTP API. Noccela demonstrated smartphone positioning in 2023; it is not a product today.

How many tags can an HPR system handle?

Up to 1,000 active tags at 1 Hz within radio range. Tags that are not moving sleep, thanks to the accelerometer, and do not use capacity. Capacity depends on the update rate: tags reporting less often leave airtime for more tags.

Does HPR need line of sight?

Like all UWB positioning, HPR is most accurate with a clear line of sight between tag and base stations. Walls, racks and machines reflect and weaken the signal; more base stations and good placement compensate. See UWB accuracy and range.

Test HPR on your own site

A pilot shows accuracy, coverage and battery life in your environment, with your assets and people, before you commit.

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