I think several participants have asked that the "device location" to be 
expressed as lat/lon, with optional height, and the antenna to be specified as 
height above ground.  I think that is the most practical way to obtain the 
data, and is what the current regulations require.  I think it is a mistake to 
try to specify radiation center as the input variable because it conflates what 
you know.  The device itself or an installer can measure the location of the 
device.  GPS is not accurate with respect to height in most cases, but it would 
be forward looking to allow device location to include height.  What we do now 
is use a terrain database to determine height of the device.  The antenna 
height is a measured quantity.  It's often fixed, or the installer knows it.  
It's the height, not the radiation center, that is measured.

Brian


On Oct 28, 2012, at 3:25 PM, Vincent Chen 
<[email protected]<mailto:[email protected]>> wrote:

All,

I'd like to address this at the F2F as an open issue, though I think we are 
mostly in agreement.
The only point of discussion seems to be how to represent the (lat, lon, 
height) in the protocol messages.

1. In the interest of avoiding ambiguity in the "generic" Device-to-Database 
protocol, it still seems
    more precise for the device to report (only) the location of its antenna's 
radiation center:

    (lat, lon, height)

   with associated uncertainties, etc, and where height is optional for some 
types of devices.

  That's the only relevant location when determining available spectrum. It 
seems that that's
  the intent of the FCC rules, even though the text does say "device location".

2. We probably should allow automated GPS-reporting of the location of the 
antenna's radiation
   center. Since GPS cannot report height above ground, the protocol should 
allow the height to be
   entered as:

   - Height relative to ground/surface (manually entered by installer)
   - Height relative to mean sea level (reported by GPS)

   A regulatory domain could restrict to be only one of these.

-vince

On Tue, Oct 23, 2012 at 2:23 PM, 
<[email protected]<mailto:[email protected]>> wrote:
Yes, I also think that separating the device location and antenna parameters is 
a good approach. This is what the requirements document requires too.
So, send the device’s (lon, lat, alt) location with related uncertainties and 
datum; and separately, the antenna parameters. The DB can then combine them, if 
it needs to, to provide the list of available channels.


-          Gabor


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