iPhone 3G driopped calls vs EVDO

I've been reading articles about the iPhone 3G and dropped calls.

Some are saying that it is due to the flip-flop between the EVDO and the 2G
network.
I thought that EVDO was for data - so why would that have any affect
on an increase in "dropped calls" ?

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At 12 Aug 2008 23:43:27 -0500 ps56k wrote:
> I've been reading articles about the iPhone 3G and dropped calls.
>
> Some are saying that it is due to the flip-flop between the EVDO and the
2G
> network.
> I thought that EVDO was for data - so why would that have any affect
> on an increase in "dropped calls" ?


EVDO can be used for either data or voice. Perhaps EVDO voice calls don't
gracefully handoff to non-EVDO towers when one moves out of EVDO coverage?

On 2008-08-13, ps56k <[email protected]> wrote:
> I've been reading articles about the iPhone 3G and dropped calls.
>
> Some are saying that it is due to the flip-flop between the EVDO and the 2G
> network.
> I thought that EVDO was for data - so why would that have any affect
> on an increase in "dropped calls" ?

The iPhone 3G service is not EVDO, EVDO is the high speed data service for
CDMA networks. The iPhone 3G service is UMTS WCDMA, with the high speed
data service on this network being HSDPA.

Unlike CDMA networks, where there is really only one network whether you
call it 2G or 3G, for GSM the 2G GSM service and the 3G UMTS service are
actually provided by full, separate networks which provide both voice and
data services. When you are using the 3G network for data you are also
attached to the 3G network for voice. When you run off the edge of the
3G network AT&T may not have a way to pass in-progress calls over to
the 2G network so those calls may drop.

Dennis Ferguson

Dennis Ferguson wrote:
> On 2008-08-13, ps56k <[email protected]> wrote:
>> I've been reading articles about the iPhone 3G and dropped calls.
>>
>> Some are saying that it is due to the flip-flop between the EVDO and
>> the 2G network.
>> I thought that EVDO was for data - so why would that have any affect
>> on an increase in "dropped calls" ?
>
> The iPhone 3G service is not EVDO, EVDO is the high speed data
> service for CDMA networks. The iPhone 3G service is UMTS WCDMA, with
> the high speed data service on this network being HSDPA.

tnx - I was just reading up on the Amazon Kindle - and had EVDO on the
brain -

Todd Allcock <[email protected]> wrote in
news:[email protected]:

> EVDO can be used for either data or voice. Perhaps EVDO voice calls
> don't gracefully handoff to non-EVDO towers when one moves out of EVDO
> coverage?
>
>

The only time an EVDO data stream doesn't hand off well on Alltel is when
you cross over into an entirely different system. Then, your ppp
connection drops and you get reassigned a new IP, so whatever you were
connected to just loses you.

Works great, even in the boondocks.......well, it will until Verizon hacks
have a chance to screw it up....

Dennis Ferguson <[email protected]> wrote in
news:[email protected]:

> Unlike CDMA networks, where there is really only one network whether you
> call it 2G or 3G, for GSM the 2G GSM service and the 3G UMTS service are
> actually provided by full, separate networks which provide both voice and
> data services. When you are using the 3G network for data you are also
> attached to the 3G network for voice. When you run off the edge of the
> 3G network AT&T may not have a way to pass in-progress calls over to
> the 2G network so those calls may drop.
>
>

In any data radio service, the faster you try to go, the worse the effects
of propagation physics become on that service. The cure is more towers
closer together but that takes money they don't want to spend. Just
switching to higher speed without a more dense infrastructure isn't an
answer, no matter how much you hype it as magic.

It is for this same reason your wifi signal is useless over any distance at
such a blazing speed. The tradeoff in range is to get truly broadband
speeds, not just a "little faster" like the sellphone circuits provide.

One of the reasons the digital sellphone PHONE circuits has such a slow
data rate, 8Kbps or 11Kbps, making music on hold sound like crap, is to get
RANGE that's acceptable without dropping. The other reason, of course, is
the number of users we can cram onto a single sector on one channel.

If, as you say, GSM jacks up the data rates on 3G, range MUST suffer from
the physics of propagation like multipath reflections, intolerance to
fading over a certain level, and our good old buddy just plain noise and
interference.

Radio propagation isn't magic.....no matter what the sales department says.