[aprssig] Balloon Tracking Question
noskosteve at yahoo.com
Sat Feb 26 13:50:58 EST 2011
--- Andrew Rich wrote:
> In some cases it might be ok to use
> You could SMS it once it has landed to see where it is
Thanks Andrew, but ...On board is not a good idea. Not even SMS, please!
FCC/agency aside, there *is* a technical reason. For the same reason Andrew states below. When a cell phone is on, it is communicating with sites. Cellular *means* that one frequency, used in one cell, is *re-used* many times over in other cells of the same system because you only (normally) get into one cell site using that RF (or code) channel.
The cellular system design depends on you being stronger in one or two cell sites and virtually non-existent in all the other sites. Each time you get stronger in one site (of the same system)the system wants to hand you to that site.
Your frequency/code is used in other sites all over the *same* systen (and near-by systems) and you will lock them out at altitude and possibly confuse the system.
I wasn't in the system software end of thing, so I can't comment whether they consider the effects of high altitute phones when writing system software. In some areas, like Denver, where you can be in the foot hills and cover a larger area, they must have hooks for this.
It will interfere in many cities away and different carriers. You may not notice a thing, but systems will choke in places.
Also, at altitude the unit will most likely be transmitting at its highest power level, not that you'll notice or care... CDMA works that way, without going into detail, and makes matters their worst..
Bad carma. Kinda like APRS beaconing every 6 seconds on .39 at altitude...
Cheers, Steve, K9DCI
> The reason they dont want you to use them up high is it
> confuses the network
> Most mobile networks are cellular. They rely on the device
> being down and low
> If you start seeing more of the network than you should,
> you start to get lots of handovers etc
> Helicopters are a classic example.
> They give them a UHF to phone patch in some cases.
> ----- Original Message ----- From: "Keith VE7GDH" <ve7gdh at rac.ca>
> To: "TAPR APRS Mailing List" <aprssig at tapr.org>
> Sent: Sunday, February 27, 2011 3:59 AM
> Subject: Re: [aprssig] Balloon Tracking Question
> > Jason KG4WSV wrote...
> >>> I strongly recommend a backup; cellular
> >> Operating a cell phone at high altitudes is a
> violation of FCC regulations.
> > I don't think Dave was suggesting that the cell phone
> go along for the ride
> > on the balloon. I believe he meant it as a backup for
> the ground teams - hi!
> > 73 es cul - Keith VE7GDH
> > --
> > "I may be lost, but I know exactly where I am!"
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