UWB outdoor in EU

Hi all

Given the recent interesting topic concerning UWB outdoor and FCC regulation (FCC regulation on UWB) I would like to understand better what is the situation in Europe.

Does anybody has a clear view concerning UWB outdoor applications in EU, in particular for fixed transmitters?

For what I understood:

1) Harmonized standard ETSI EN 302 065-2 enables the application under the LT2 rules, with -41.3 dBm/MHz PSD and LDC/DAA mitigation techniques in the 3.1-4.8 band, providing the registration/authorization of the installation.

2) EU Decision 2019/785 of 14 May 2019, in its Art. 3, does not allow any kind of fixed outdoor device. Here, only LT1 type is mentioned.

Any other idea or experience concerning the effective possibility of using infrastructure-based UWB systems outdoor in Europe?

Compared to the FCC, the ETSI rules are more clear, less permissive, but are self certified as is generally the case under ETSI domain.

Short answer: only legal way to operate an ETSI compliant UWB location system outdoors with fixed anchors is EN 302-065-2 LT2, which requires operating in the 3.4 to 4.8 GHz band, and “may” require local registration/authorization for each site.

UWB systems can be operated under two regulations (and links to what I think are current versions):

EN 302-065-1 Generic UWB Applications

EN 302 065-2 UWB Location Tracking

Note that just because a system may do location tracking with UWB signals doesn’t mean it can’t fall under the EN 302 065-1 directive.

The EN 302 065-1 restrictions state:

the UWB transmitter equipment conforming to the present document is not to be installed at a fixed outdoor location, for use in flying models, aircraft and other forms of aviation.

Allowed operation is 6.0 to 8.5 GHz without any mitigation, or 3.1 to 4.8 and 8.5 to 9.0 GHz with mitigation. Only LDC (low duty cycle) mitigation is available on the DW1000 since it cannot do DAA (detect and avoid). LDC limits duty cycle to 0.5% which works for TDoA/multitime style systems in some cases, but often doesn’t work for TWR/multirange style systems unless the capacity is very low.

The EN 302-065-2 restrictions state:

LT1 (6.0 to 8.5 GHz without DAA): Fixed outdoor LT1 transmitters are not permitted.

LT2 (3.4 to 4.8 GHz without DAA): The transmitting terminals in these systems may be located indoors or outdoors, and may be fixed or mobile.

LAES: Not generally useful, special case.

LT1 systems can’t have fixed outdoor transmitters. Exactly what constitutes “fixed” and “outdoor” are subject to some debate, but something like an athletic field or an outdoor stock yard seem clearly excluded.

LT2 seems like the opening for fixed outdoor location systems, but LT2 systems are subject to registration/authorization and local coordination for a specific site which makes them encumbered for general deployment. A further issue is that the lower band is not as generally useful world wide, and support for the lower bands is not indicated yet for future chips.

Under LT1, the directive suggests outdoor systems can be built with receive only fixed anchors. Realistically, a good location system can’t be built this way. Without transmitting anchors, you can’t use TWR/multirange. So that leaves TDoA/multitime algorithms. But for those to work, you have to synchronize the anchors somehow. The best way is to have anchors transmit packets to each other, or to have fixed reference tags, but that isn’t allowed outdoors for LT1.

If you build a wired synchronization system, as suggested in Decawave APS007, or as used in the Zebra Dart system, you run into problems in practice. For one such issue, the time delay in network cables vary with temperature sufficiently to shift accuracy quite a bit. The insulation expands with temperature, changing the capacitance, which changes the delay, among other factors. So the only way to make a truly accurate UWB system is to have transmitters at fixed known locations to reference against, be they other anchors (such as we do) or fixed reference tags (which is what the Dart system does despite having wired sync).

Our Ciholas products are CE marked under EN 302-065-1, the generic UWB directive, and we operate them at 6.5 GHz, channel 5. The manual limits use to indoor operation. Whether customers follow that rule is up to them.

The use case limitations of UWB (outdoor, flying, toys, etc) are really a weird set of rules that are not typical for radio systems, cause a lot of trouble, are not globally harmonized, and don’t have clear enforcement requirements. If I could change anything about UWB, it would be this.

Mike Ciholas, President, Ciholas, Inc
3700 Bell Road, Newburgh, IN 47630 USA
+1 812 962 9408

Thank you Mike.

What I was trying to arise with my previous post is that we have, on one side, the ETSI standard (eg the EN 302-065-2) that opens under certain conditions to fixed outdoor transmitters with LT2 mode, but on the other side we have the European law (2019/785 of 14 May 2019) closing to it.

I’m also not completely sure regarding relationship among EN 302-065-2 and EN 302-065-1. Basically, I could be compliant to the RED adopting the harmonized standard EN 302-065-2 if my system is for location and tracking. Is it mandatory to comply with the EN 302-065-1 too? Some differences concerns the restrictions, as mentioned below, and the LDC criteria.

The new decision language is basically unchanged from when it was first adopted in 2007 by my reading.

Here’s the language from 2007:

The Member States shall, as early as possible and no later than six months following the entry into force of this Decision, allow the use of the radio spectrum on a non-interference and non-protected basis by equipment using ultra-wideband technology provided that such equipment meets the conditions set out in the Annex to this Decision and it is either used indoors or, if it is used outdoors, it is not attached to a fixed installation, a fixed infrastructure, a fixed outdoor antenna, or an automotive or railway vehicle.

Here’s the language from the recent decision you referenced:

Within six months after this Decision takes effect, Member States shall designate and make available the radio spectrum, on a non-interference and non-protected basis, for equipment using ultra-wideband technology provided that such equipment meets the conditions set out in the Annex and it is used indoors or, if it is used outdoors, it is not attached to a fixed installation, a fixed infrastructure or a fixed outdoor antenna. Equipment using ultra-wideband technology which meets the conditions set out in the Annex shall also be allowed in motor and railway vehicles.

The change seems to be allowing use in motor and railway vehicles which was from a decision in 2014 as best I can tell.

I’m no expert in EU law, but whatever mechanism allowed LT2 seems to be unchanged by this new decision. I’m not sure how LT2 is allowed, but it must be by some mechanism separately from these documents.

Here is some background on LT2 systems from 2011:

Somehow that report’s objective to enable LT2 systems became codified in EN 302 065-2. I don’t know how that came to be, but EN 302 065-2 clearly allows fixed outdoor operation of LT2 systems (as well as the also mentioned LAES systems).

My understanding is that you can be compliant under EITHER EN 302-065-1 or EN 302-065-2. It is up to you to select which rule you operate under.

In my opinion, if you fall under EN 302 065-1, generic UWB applications, you should do so. This means indoor, no aviation, 6.0 to 8.5 GHz band. The mere fact your packets create timing that you could use to locate doesn’t negate using EN 302 065-1 which gives no limitation on what the packets are used for.

Indeed, the more unclear question is whether a system under EN 302 065-2 can be allowed to carry non location information such as serial number, sensor data, etc. That use is not specifically allowed under EN 302 065-2, nor specifically disallowed, but it seems logical such use is allowed and I would interpret it that way as well.

Use on road and rail is governed by EN 302 065-3:

My brief reading of it suggests the only real change from LT1 is limiting to -51.3 dBm/MHz strength without LDC, or -41.3 dBm/MHz with LDC. Basically this means road and rail systems have to be low duty cycle to use “full” power.

Mike Ciholas, President, Ciholas, Inc
3700 Bell Road, Newburgh, IN 47630 USA
+1 812 962 9408