[Scan-DC] Re: Coverage better w/ analog cell?

[Steve Uhrig]

On 5 Jun 2002 at 6:55, Carl, Eco14@aol.com asked:
 
> I have an analog cell phone and the coverage stinks in certain areas
> where the towers are less frequent.  Will upgrading to a digital phone
> give me more coverage or better reception?

The analog system is still significantly more mature than the digital 
ones. Especially in rural and low population/low traffic areas, 
analog remains superior.

I was an analog holdout until about a year ago, because my analog 
phone worked where my associates' digital phones did not. I got tired 
of them borrowing my phone to get calls out. I finally switched, and 
am sorry I waited so long.

There's not much analog left, so competition for the few frequencies 
allocated for analog is greater. Your chances of getting bumped are 
higher than with digital. Remember, CDPD is analog, and that is used 
in many MDT systems as well as for commercial data to PDAs etc., so 
analog is not going to become obsolete anytime imminently.

My personal experience, with top quality analog and digital phones 
both, is analog is better speech quality. The system operators are 
not trying (cannot actually) to compress heavily on analog to 
increase channel capacity and loading (more $$$), so the increasingly 
lower sampling rate on digital does affect speech quality. You get 
used to it though, and there are many more features on digital, and 
calls are cheaper.

Remember, too, the max power allowed for analog handsets is 600 
milliwatts, and 3 watts RF out for mobiles. The max power allowed for 
digital, period, is 200 milliwatts. Analog handset to digital 
handset, that's about a 5dB advantage, which is significant. 6dB 
advantage doubles your range. If you compare to a mobile at 3 watts, 
that's nearly 12dB advantage of analog over digital. 6dB doubles 
range, so 12dB would nearly quadruple it, with a 3 watt analog over a 
200 milliwatt digital handset. That's another reason analog may work 
where digital does not.

I used a Convertacom for my analog cell phone, and for my digital 
now. The analog Convertacom or car kit or whatever they call it 
(mobile console which connected the handset to an external antenna, 
full size handset, speaker and mic for hands free, charged the 
battery, etc.) had an amp to bump up the analog handset power to 3 
watts.

My new digital car kit is all of the same, except no RF amplifier or 
separate handset. 200 milliwatts max.

AND, the most important consideration, is most digital phones will 
revert back to analog in areas where analog is stronger and digital 
is either weaker or not there at all. My digital phone, a Batwing 
Startac 7868, beeps and shows a large letter A or D for analog or 
digital. I live 5 minutes from the PA line here in Harford County, 
and as soon as I start to wander north, I go into an analog-only 
signal area for about ten minutes until I pick up the York, PA or 
Wilmington DE system on digital. I'm with Verizon, which is CDMA.

So, you could go with a digital phone and all the advantages, and not 
lose the ability to communicate in areas where analog works and 
digital is not built out yet.

I'm not certain if all phones will revert to analog, but I expect the 
majority do.

On certain types of law enforcement cellular intercepts, BTW, where 
the target is using digital, it is possible for law enforcement to 
schmooze the service 
provider to force the target handset over to analog where standard 
off-air monitoring (very unusual any more) and periodic signal 
sniffing RDF can occur. Most 
users will never notice.

CDMA with Verizon in the Baltimore/DC area has worked much better 
than TDMA with Cell One or Cingular or whomever they are now. CDMA is 
a spread 
spectrum format, more secure, and far fewer dropouts. Some of the 
others I work with have TDMA, and if they are driving down Route 95, 
switching sites every 60 seconds, it's nearly impossible to keep a 
conversation with them. They keep getting dumped. Doesn't happen, 
ever, with Verizon/CDMA, in the Baltimore system at least.

You also can fit 3x as many CDMA signals into the same space as one 
TDMA. That will mean something in the future as systems are loaded 
more heavily. Lots more capacity on CDMA; less chance of getting 
bumped.

Systems are filling up here and starting to load heavily. We'll be 
seeing more and more instances of getting bumped off a busy system as 
the months pass. CDMA seems to have the least problems.

We don't sell cell phones so I won't go into the many advantages of 
digital, but you will see better rates, far more features, and 
ultimately better coverage as well as fewer lost calls. If you get a 
phone which is dual mode digital with analog revert, you'll still 
have coverage in the rural areas where digital has not been built out 
yet.

Hope this helps.

Regards ... Steve
 
*******************************************************************
Steve Uhrig, SWS Security, Maryland (USA)
Mfrs of electronic surveillance equip
mailto:Steve@swssec.com  website http://www.swssec.com
tel +1+410-879-4035, fax +1+410-836-1190
"In God we trust, all others we monitor"
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