On 9/27/21 13:34, Mark Lindsey via VoiceOps wrote:
In the top 25 cellular market areas, nationwide cell phone providers are
already required to provide Z-axis (elevation) data within 3 meters for
80% of calls [for compatible devices]. The requirements increase each
year; by 2026, /all/ cellular providers are required to provide z-axis
precision for dispatchable location of +/- 3 meters everywhere in the US.
This is all in addition to providing +/- 50 meter horizontal (x, y axis,
also known as latitude and longitude) precision for 911 calls.
Interesting as elevation accuracy for GPS is worse than lat/long.
So when first responders get dispatched to 34.2270545 degrees north,
117.6422397 degrees west, 538 meters AMSL, where do they go? (I just
randomly typed those numbers so if it's under a mountain don't blame me.)
Considering just the x/y axis, determining the right room or suite in a
large single-story office building, factory or warehouse is going to be
a challenge. In a huge multi-story high-rise with poor to no internal
GPS reception it's going to be nearly impossible. Especially if it's in
the middle of a bunch of other high-rise buildings with corresponding
multipath and reflections.
--
Jay Hennigan - [email protected]
Network Engineering - CCIE #7880
503 897-8550 - WB6RDV
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