cellphones???

[houstondan]

whats the deal with those 100$ gizmos that plug your cellphone into the
headset. does that work???


dan

[Newps]

They work great.

houstondan wrote:
> whats the deal with those 100$ gizmos that plug your cellphone into the
> headset. does that work???
>
>
> dan
>

[Dave S]

I second that... on the ground, and if you can get signal... in the air
too... Make a call right before center hands you over to approach to let
yer ride know you are 20 mins out.

OOOPS.. dont tell the FCC...

Dave

Newps wrote:
> They work great.
>
> houstondan wrote:
>
>> whats the deal with those 100$ gizmos that plug your cellphone into the
>> headset. does that work???
>>
>>
>> dan
>>

[Dan Luke]

"Dave S" wrote:
> I second that... on the ground, and if you can get signal... in the air
> too... Make a call right before center hands you over to approach to let
> yer ride know you are 20 mins out.

My CellSet works great, but I've never been able to use it in the air. My
Nextel phone always says "no service" when airborne. Does Nextel have some
built in software that cuts you off if you connect to too many towers at
once?
--
Dan
C-172RG at BFM

[Dave S]

I have Sprint PCS with automatic cellular roaming. I don't use the
Cellset regularly and the last time I did was on a XC into Dallas.. or
maybe Tyler... cant remember which. I seemed to recall not being able to
get a dependable signal until descending below 5k.

On the ground it worked fine.

Dave

Dan Luke wrote:
> "Dave S" wrote:
>
>>I second that... on the ground, and if you can get signal... in the air
>>too... Make a call right before center hands you over to approach to let
>> yer ride know you are 20 mins out.
>
>
> My CellSet works great, but I've never been able to use it in the air. My
> Nextel phone always says "no service" when airborne. Does Nextel have some
> built in software that cuts you off if you connect to too many towers at
> once?

[Newps]

I have a Cellset also and always get a useable signal. I use Verizon
but the phone will use any other CDMA signal when necessary.





Dan Luke wrote:
> "Dave S" wrote:
>
>>I second that... on the ground, and if you can get signal... in the air
>>too... Make a call right before center hands you over to approach to let
>> yer ride know you are 20 mins out.
>
>
> My CellSet works great, but I've never been able to use it in the air. My
> Nextel phone always says "no service" when airborne. Does Nextel have some
> built in software that cuts you off if you connect to too many towers at
> once?

[John Galban]

Dan Luke wrote:
>
> My CellSet works great, but I've never been able to use it in the
air. My
> Nextel phone always says "no service" when airborne. Does Nextel
have some
> built in software that cuts you off if you connect to too many towers
at
> once?

The old analog 800 Mhz phones (the ones the FCC prohibits in the air)
used to work just fine at cruising altitudes. The downside was that
you lit up every cell within your line of site and ****ed off the phone
company.

The newer digital services (operating on frequencies not prohibited
by the FCC for air use) don't seem to work once you get a few thousand
feet AGL. I was talking to a Sprint engineer about it and he told me
that the antenna patterns on the newer cell services are angled
downward in most places, which degrades the signal received in the
aircraft.

John Galban=====>N4BQ (PA28-180)

[Robert M. Gary]

houstondan wrote:
> whats the deal with those 100$ gizmos that plug your cellphone into
the
> headset. does that work???

What $100 gizmo? My Lightspeed headset came with a cell phone cable.
-Robert

[Doug Carter]

John Galban wrote:
> The old analog 800 Mhz phones (the ones the FCC prohibits in the air)
> used to work just fine at cruising altitudes. The downside was that
> you lit up every cell within your line of site and ****ed off the phone
> company.

....and the dozens of other cell phone users on the ground that had their
call drop because of you.

> The newer digital services (operating on frequencies not prohibited
> by the FCC for air use)

Urban myth. The table of allocation in Part 1 does not authorize the
frequencies allocated to PCS to be used for air to ground service,
period. These tables are controlling regardless of what your
interpretation of Part 22 may be.

don't seem to work once you get a few thousand
> feet AGL. I was talking to a Sprint engineer about it and he told me
> that the antenna patterns on the newer cell services are angled
> downward in most places, which degrades the signal received in the
> aircraft.
>

True; the down tilts are used to mitigate against inter-cell interference.

[abripl]

Others should not have their calls dropped no more than if a person is
calling from top of a hill or in a good position seeing different
towers. A cell phone "dialogs" with every tower in sight and ties up
only ONE channel on each. Which means you use more total channels than
necessary, possibly denying new call service (but not necessarily) to
others in bussy times. If all cell phones in use were doing the same
thing there would be very limited number of chanels open for new phone
calls.

Doug Carter wrote:
>
> ...and the dozens of other cell phone users on the ground that had
their
> call drop because of you.....

[George Patterson]

abripl wrote:
>
> Others should not have their calls dropped no more than if a person is
> calling from top of a hill or in a good position seeing different
> towers. A cell phone "dialogs" with every tower in sight and ties up
> only ONE channel on each.

Not so. The system designer will ensure that every cell within line of sight of
hills or other high spots is using a different set of frequencies. It is only
when the caller is in line of sight of cells relatively far away (usually 40 to
60 miles) that the call will cause conflicts.

George Patterson
I prefer Heaven for climate but Hell for company.

[Doug Carter]

George Patterson wrote:
>
> abripl wrote:
>
>>Others should not have their calls dropped no more than if a person is
>>calling from top of a hill or in a good position seeing different
>>towers. A cell phone "dialogs" with every tower in sight and ties up
>>only ONE channel on each.
>
>
> Not so. The system designer will ensure that every cell within line of sight of
> hills or other high spots is using a different set of frequencies. It is only
> when the caller is in line of sight of cells relatively far away (usually 40 to
> 60 miles) that the call will cause conflicts.

There are algorithms built into the cell selection and re-selection
process that mitigate against interference but if the base station
receiver can't decode the uplink channel from the mobile then you have a
problem.

To achieve a usable BER (Bit Error Rate) and acceptable frame loss to
set up and maintain calls, all cellular and PCS networks, whether they
are CDMA, GSM, TDMA, etc. are designed to a specific C/I+N ratio
(Carrier to Interference plus Noise) rather than S/N (Signal to Noise).

No operator has as much spectrum as they would like and the principal
goal is to lay out the system for maximum frequency "reuse."

Over the years this has led to reduction of base station antenna heights
(few antennas are more than 100' high in an urban system) and down
tilt antennas.

Thus, any given channel may be "reused" 10-100 times in a given city.

The system design presumes the mobile units to be no higher than the
building heights. Any co-channel energy that the unintended base
station receiver hears from aircraft will reduce the C/I+N ratio and may
lead to dropped calls in that cell.

Perhaps more simply,regardless of protocol, if you can't hear your
messages over the interference it does not matter how strong the signal
is, you can't decode it.