Monday, March 12, 2007

GPS, timezones, and patents

I've had a lot of experience using my cool gadget-of-the-week Nuvi 670 on trips over the past 3 weeks (east coast US, west coast US, Bristol UK, and Ipswich UK -- yes, all of that in the past 3 weeks!) and techie though I am, I am still quite impressed by how well it works, especially with all the roundabouts in England.

However, one thing that bothers me with this unit is that the time continuously is reported as my originally configured EST/EDT. So, upon arriving in the UK yesterday, the anticipated arrival time in Ipswich showed as 5AM rather than 10AM.

Why doesn't the unit automatically adjust the clock for the local timezone (or at least have an option to do so)? It's not like the unit doesn't know where I am at any given moment. It's not like the timezone maps are all that complicated -- hey it has *road* maps and speed camera POIs which I'm sure are much more variable and complex.

Looking at Garmin's web site I found the following timezone FAQ:

Q. How do I get local time displayed? What about daylight-saving time?

A. GPS units operate on UTC time. UTC is the Universal Coordinated Time or Greenwich Mean Time (GMT). You can input a local offset (or difference) from UTC so that the unit will display your local time. This option is located under the unit's operational setup. A chart is provided in products' owner's manuals to help you select the appropriate offset for your area. If needed, the chart will also show the UTC offset during daylight-saving periods. New Garmin GPS units allow you to select the time zone you are currently in or select a time zone for a projected location by selecting from one of eight U.S. time zones or 24 international time zones. You may also turn an adjustment for daylight saving to auto, on, or off.

So, no mention of automatic adjustment.

Given that this is such an obviously useful feature, I wondered if the reason for the lack of the feature was because of our oft-maligned patent system. A quick search in the US published patents turned up a patent #5,089,814 assigned to Motorola:

A portable receiver has a time of day clock and receives a signal indicative of the location of the portable receiver. The portable receiver has a memory which has a plurality of locations with corresponding time zones. Upon reception of the location signal, the receiver determines the time zone of the location and the time zone of the time of day clock. The time of day clock is then adjusted to correspond to the time zone of the location. The location signal may also be used to adjust the operating frequency of the receiver.

This feels like another one of those patents that don't rise above what one would consider the non-obviousness bar, but which made it through the patenting system anyway. No offense meant for Motorola or for the inventors as this is how the patent system works and if you don't play the game according to the rules set by the US PTO, you loose.

Note that I have no clue if this particular patent is the reason or even if that patent would really read on GPS systems (the patent was developed for paging systems, not GPS systems), but given the obvious match of GPS and automatic timezone adjustment, I have to assume that there's something holding back that feature and the most likely culprit is our patent system.

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