Move to keep Analog Cell Phones

"Donald Newcomb" <[email protected]> wrote in
news:[email protected]:

> All that is lacking is higher power
> car phones with good external antennas.

You boys are describing the old IMTS "Carphones".....
Rotary-dialled narrow-band FM radio with the simplest of interfaces in the
trunk running 10, 25, 50 watts on 152 Mhz, which is MUCH farther ranged in
the trees of the countryside than 800 or 1900 could ever offer. Search
Google for IMTS Carphones and check it out.

To alert us when we had a call, the phone in the car blew the car horn
about the same "ringing" sequence as a regular telephone. (Don't forget to
turn it off at night..(c;...it'll suck a car battery dead in a couple of
hours, anyway, even if you don't transmit. It's tubes!)

These powerful Carphones and the tall-towered VHF terminal equipment they
connected to had ranges in the countryside of 20-50 miles...or to the side
of the next mountain, if they weren't mountaintop located. You could drive
for hours and never have to change towers...er, ah....if you could afford
the $4.50/minute..(c; The price kept the very few channels the FCC made
available to them from being cluttered with idle chitchat...

I can't believe there are actually websites CAPTURING what we say on
cellular newsgroups and posting them all for years! I found a lot of my
own postings looking for IMTS phones for sale!...(c;

--
Larry

---

› See More: Move to keep Analog Cell Phones

In <[email protected]> "Donald Newcomb" <[email protected]> writes:
[ ... ]
>> Mostly, but not completely correct... While a better antenna [a] and
>> a bit mor epower are the key issues, there's also a physical
>> distance limit due to timing slot concerns.
>>
>> I don't recall the exact numbers, but 20 km as a maximum range
>> comes to mind.

>35 km for regular vanilla GSM. Extended range is available (at a cost). No
>limit I know of for CDMA or TDMA.

I've got one spot in the (extended) NYC area where this an isse,
and I'd guess there are similar ones (see below).

There are ferries that travel from Long Island (east of NYC)
across Long Island Sound up to Connecticut. I made it a point
of walking around on the upper level - which gave me line
of sight to structures on the shore, and probably towers,
alomst the entire length.

For roughly the middle third of the trip the phone's display,
for whatever that's worth... showed numerous bars of
signal strength. But if I tried making a call it either
didn't succeed or I got that famous "underwater" audio
clipping and mangling.

I'd guess there are similar issues on te Great Lakes,
where coverage would be pretty useful.
--
_____________________________________________________
Knowledge may be power, but communications is the key
[email protected]
[to foil spammers, my address has been double rot-13 encoded]

"Larry" <[email protected]> wrote in message
news:[email protected]...
> "Donald Newcomb" <[email protected]> wrote in
> news:[email protected]:
>
> > All that is lacking is higher power
> > car phones with good external antennas.
>
> You boys are describing the old IMTS "Carphones".....
> Rotary-dialled narrow-band FM radio with the simplest of interfaces in the
> trunk running 10, 25, 50 watts on 152 Mhz, which is MUCH farther ranged in
> the trees of the countryside than 800 or 1900 could ever offer. Search
> Google for IMTS Carphones and check it out.

I don't think anyone is asking to bring back IMTS (which I do remember quite
well). That was a completely different service from AMPS cellular. Folks
just want a cellular system that will duplicate the coverage of the AMPS
system they already had.

Another possible solution would be a good satellite roaming system, similar
to ACeS in East Asia. This is how Globalstar was supposed to work but it
never really worked that way. Anyone dumb enough to try to activate the
cellular side of a North American Globalstar phone will find himself trying
to set up an 800 MHz only account on an old analog rate plan. You end up
with two accounts, as though it were dual NAM. One account is the satellite
side and the other is is the cellular side; they have different phone
numbers and you have to switch manually between them. It end up being much
easier to have two phones: one cellular, the other satellite. ACeS and
Thuraya phones will switch automatically between cellular (GSM 900) and
their respective satellite systems.

--
Donald Newcomb
DRNewcomb (at) attglobal (dot) net

"danny burstein" <[email protected]> wrote in message
news:[email protected]...
> I'd guess there are similar issues on te Great Lakes,
> where coverage would be pretty useful.

Once upon a time I was in the Mediterranean, working on and off the coast of
Italy. I had a little 4-element, 900 MHz Yagi to help and had all sorts of
"bars" but as soon as we hit 18 nm off the coast it was like a brick wall.
All the bars in the world didn't help. Needless to say, they didn't have ER
GSM.

Petrocom has set up a GSM-850 network in the northen Gulf of Mexico. I don't
know if they are using ER or not.

--
Donald Newcomb
DRNewcomb (at) attglobal (dot) net

>In <[email protected]> "Donald Newcomb" <[email protected]> writes:
> [ ... ]
>>> Mostly, but not completely correct... While a better antenna [a] and
>>> a bit mor epower are the key issues, there's also a physical
>>> distance limit due to timing slot concerns.
>>>
>>> I don't recall the exact numbers, but 20 km as a maximum range
>>> comes to mind.
>
>>35 km for regular vanilla GSM. Extended range is available (at a cost). No
>>limit I know of for CDMA or TDMA.

I believe the maximum range for CDMA is about 35 miles.

--
Bob Scheurle | "There's nobody getting
[email protected] | rich writing software."
Remove X's and dashes | -- Bill Gates, March 1980

In message <[email protected]> "Donald Newcomb"
<[email protected]> wrote:

>
>"danny burstein" <[email protected]> wrote in message
>news:[email protected]...
>> In <[email protected]> "Donald Newcomb"
><[email protected]> writes:
>> Mostly, but not completely correct... While a better antenna [a] and
>> a bit mor epower are the key issues, there's also a physical
>> distance limit due to timing slot concerns.
>>
>> I don't recall the exact numbers, but 20 km as a maximum range
>> comes to mind.
>
>35 km for regular vanilla GSM. Extended range is available (at a cost). No
>limit I know of for CDMA or TDMA.

The ~35KM limit applies to all TDMA-based technologies, including what
is commonly known as "TDMA" in Canada and the US, as well as GSM and
iDEN.

--
I don't approve of political jokes...
I've seen too many of them get elected.

"DevilsPGD" <[email protected]> wrote in message
news:[email protected]...
> The ~35KM limit applies to all TDMA-based technologies, including what
> is commonly known as "TDMA" in Canada and the US, as well as GSM and
> iDEN.

Why?

--
Donald Newcomb
DRNewcomb (at) attglobal (dot) net

"jfitz" <[email protected]> wrote in message
news[email protected]...
> "Donald Newcomb" <[email protected]> wrote in message
> news:[email protected]...
>>
>> The problem is really not one of analog vs. digital but rather very low
>> power & no antenna vs. high power & good antenna. The only reason that
>> this
>> problem exists is that the wireless carriers only care about the 99% who
>> live and work in cities & towns (where the wireless executives live and
>> work) and could care less about folks who live and work in the boonies.
>
> So the "99%" should subsidize the tremendous cost of building cell towers
> for those who have CHOSEN to live in the boonies?
>

AND for those who frequently travel into the boonies.

Donald Newcomb wrote:
> "DevilsPGD" <[email protected]> wrote in message
> news:[email protected]...
>> The ~35KM limit applies to all TDMA-based technologies,
>> including what is commonly known as "TDMA" in Canada and
>> the US, as well as GSM and iDEN.
>
> Why?

Timing. Propagation delay over that distance gets too large.

-Quick

"Donald Newcomb" <[email protected]> wrote in
news:[email protected]:

> Another possible solution would be a good satellite roaming system,

I have boater friends on Iridium, the failed satcom company the military
saved. $1.50/min from any point on the planet with polar LEOs, I think.
Seems to work fine. When Iridium went bankrupt, but before the govt save,
I bought one for $25, just as a souvenir. I have all the toys with it, but
won't be putting it online. It works fine outside, but, of course, is
pretty useless inside as the satellite signal is just too weak from 200
miles away at Zenith.



--
Larry

"Donald Newcomb" <[email protected]> wrote in
news:[email protected]:

> Once upon a time I was in the Mediterranean, working on and off the
> coast of Italy. I had a little 4-element, 900 MHz Yagi to help and had
> all sorts of "bars" but as soon as we hit 18 nm off the coast it was
> like a brick wall. All the bars in the world didn't help. Needless to
> say, they didn't have ER GSM.
>
>

I sail on a French-made Amel Sharki 41' ketch along the southeast coast of
USA. I have a Decibel Products 800 Mhz, 11 element yagi that's end-
mounted, made for 800 Mhz paging relay service from a paging friend. It's
very broadbanded at this band. SWR is 1.15:1 across cellular after a
little tuning of the gamma match on it.

When I had Verizon's AMPS online, hooked to a 3W Motorola bagphone running
off ship's 12VDC house batteries, service was near perfect with the beam
hauled up the mast and pointed towards shore at 55' for about 45-50 miles
offshore. Every offshore sailor should be carrying a 99 cent thrift store
bagphone, even if they won't let you put it on the air! With the little
beam, it works farther than VHF marine usually does and can dial 911 by
law. Our boat has one that's not provisioned for emergency comms...another
backup.



--
Larry

"Quick" <[email protected]> wrote in
news:[email protected]:

> Timing. Propagation delay over that distance gets too large.
>
> -Quick
>
>

The other problem, on land, is the multipath delays, the same physics that
causes terrible "ghosts" on UHF TV at any distance without a very
directional antenna, i.e. your little cellphone antennas. Data
transmissions, even these really slow ones, is torn apart when the direct
signal and another signal that has bounced off a building or mountain or
AIRPLANE OVERHEAD comes in later than the main signal.

When multipath occurs on FM, whether it's FM radio or FM 2-way or AMPS,
you'll hear the multipath cause the analog FM signal to fade in and out in
the fringe areas as the long path signal reinforces, then a little later
opposes the main signal. Your FM broadcast radio, VHF or UHF analog TV has
that fading in and out rapidly from a passing aluminum cloud (airplane)
going overhead. As the plane moves, the multipath signals drive it crazy.
Computers, including digital phone magic, don't like confusing signals
fading in and out rapidly or any other way. YOU moving in a car with
multipath is why the signal comes and goes and drops your call.

It's the same physics we always had....it's the same RF radio system, no
matter what the modulation schemes put on it are....



--
Larry

"JohnF" <[email protected]> wrote in news:MlTGe.50077$5N3.36389@bgtnsc05-
news.ops.worldnet.att.net:

> AND for those who frequently travel into the boonies.
>
>
>

And ESPECIALLY for those city dwellers with the broken fanbelt 42 miles
from the city on Route 59, 8 miles from the nearest farmhouse with a
landline.....it benefits them, too!

--
Larry

Larry wrote:
> "Quick" <[email protected]> wrote in
> news:[email protected]:
>
>> Timing. Propagation delay over that distance gets too
>> large.
>>
>> -Quick
>>
>>
>
> The other problem, on land, is the multipath delays, the
> same physics that causes terrible "ghosts" on UHF TV at
> any distance without a very directional antenna, i.e.
> your little cellphone antennas. Data transmissions, even
> these really slow ones, is torn apart when the direct
> signal and another signal that has bounced off a building
> or mountain or AIRPLANE OVERHEAD comes in later than the
> main signal.
>
> When multipath occurs on FM, whether it's FM radio or FM
> 2-way or AMPS, you'll hear the multipath cause the analog
> FM signal to fade in and out in the fringe areas as the
> long path signal reinforces, then a little later opposes
> the main signal. Your FM broadcast radio, VHF or UHF
> analog TV has that fading in and out rapidly from a
> passing aluminum cloud (airplane) going overhead. As the
> plane moves, the multipath signals drive it crazy.
> Computers, including digital phone magic, don't like
> confusing signals fading in and out rapidly or any other
> way. YOU moving in a car with multipath is why the
> signal comes and goes and drops your call.
>
> It's the same physics we always had....it's the same RF
> radio system, no matter what the modulation schemes put
> on it are....

I'm not sure, but doesn't CDMA deal really well with multipath?

-Quick

"Quick" <[email protected]> wrote in message
news:[email protected]...
> Donald Newcomb wrote:
> > "DevilsPGD" <[email protected]> wrote in message
> > news:[email protected]...
> >> The ~35KM limit applies to all TDMA-based technologies,
> >> including what is commonly known as "TDMA" in Canada and
> >> the US, as well as GSM and iDEN.
> >
> > Why?
>
> Timing. Propagation delay over that distance gets too large.

Well, I've seen an exact expalnation of how this works with GSM's TDMA air
interface; number of slots, number of timing advance steps available, length
of each step in nS and meters, etc. I have not seen any such explanation for
TDMA or iDEN. It would very much surprise me if the math worked out the same
for all three.

--
Donald Newcomb
DRNewcomb (at) attglobal (dot) net