> For example, I am curious to learn about wireless Internet 
> connectivity.  Does anyone have some experience to share?

Yes, a lot of them, actually :) I'm actually typing this now on my CDPD 
equipped laptop while I'm waiting for my car to get an oil change. 

I find wireless data via CDPD the only really workable wireless data 
solution -- it gives me a fixed IP number so I am accessible to the 
outside world via telnet, ftp, PING, traceroute, etc, and so I can access 
all those Internet services just as I can from a wired system via 
landline modem connection or Ethernet, etc. (Right now I am using SSH 
[secure telnet] to log in and type this in real time, while on another 
screen I have system logs going by in real time.) 

Since the connection is basically a SLIP connection, as long as no data 
passes OUT from my laptop to the network when there is no signal, (ie, I 
don't type anything), my telnet session stays open , so for example, when 
I am done here at the car shop, I kill the logs, stop typing, and close 
the laptop and either put it in the car (if I want to see logs while 
driving) or put it in the trunk. When I need to use it again, I can check 
to see if there is a signal, and if so, just start work again, and never 
have to re-establish a connection or log in again, etc. This is not 
something you can do with Circuit Switched Cellular Data. 

Both AT&T Wireless and BAMS have unlimited use CDPD programs, although 
unfortunately they cover very limited areas. The most pervasively covered 
area is the east coast from Boston down to DC, where BAMS has the entire 
coastline covered, including the Holland (and now maybe the Lincoln) 
tunnel in NYC, and the Harbor Tunnel in Baltimore. (I can drive from 
Newbury, MA, to Vienna, VA and have almost continuous coverage -- CT used 
to be a dead spot for BAMS (and you have to switch to the A side-- BAMS 
and SNET should just switch their respective sides for CDPD and Cellular 
in CT -- it would make a lot of sense for both companies) but they have 
really been adding more and more sites to their CDPD network there. 
(NOTE: CDPD coverage does NOT correspond to cellular analog or digital 
coverage; special equipment is needed in each tower to allow it to 
support CDPD and cell companies are reticent to spend the money unless 
there is some police force or some compelling reason (read "big 
customer") who needs coverage in the area. So just because Bell Atlantic 
has service in Poughkeepsie, NY (00486 system), doesn't mean there is a 
drop of CDPD coverage, and in fact, despite an alleged tower in 
Middletown NY which supports CDPD (I think its just the NYC  system 
bleeding in due to some unusual topography), there is NOTHING north of 
I-84 anywhere in BAMS large mid-Hudson systems. Perhaps this will change 
with AT&T's acquisition of Vanguard since AT&T usually puts in CDPD in 
the markets it owns (and even pre-AT&T Vanguard had/has some excellent 
CDPD coverage of its own in Maine and eastern PA).

The problem with CDPD is the equipment (ie, the modem) is expensive, and 
initially, there was only really one manufacturer -- a Canadian company 
in Vancouver called Sierra Wireless, which sold the card. Although it 
worked (and works) well, they are a pain service wise, and to just talk 
to a person there you have to call Canada and wait on hold forever to 
ultimately get a very unhelpful answer to your problems. I had to once do 
a cross-ship for one of our Sierra modem cards so we could have 
connectivity and not be done for a week while they fixed one, and they 
refused. We initially paid $800 for the card, had it for less than a 
year, and when we needed it fixed they basically said "You'll just have 
to be without coverage for a few weeks while we fix it." So I called BAMS 
and had them tell Sierra to do a swap, which they did, but all the 
nonsense I had to go through with them soured me to having our company 
purchase anything from Sierra ever again. (And fortunately there are 
alternatives now, including the Novatel Sage modem (external) and the 
single slot Spider card.)


Overall, if you need to be connected to the full spectrum of Internet 
services and protocols, and want to be able to open up your laptop from 
anywhere there is CDPD coverage and work as if you were connected to your 
ISP (actually, better, since CDPD is a FIXED IP as compared to a usually 
dynamically assigned IP via ISP login), then CDPD is a wonderfully 
liberating service.

Most of the big CDPD carriers have flat rate plans with unlimited data 
for around $50 per month (BAMS has $39.95 per month, they are at (800) 
308-DATA; AT&T has unlimited in all their markets for about $70 per 
month, however, some AT&T markets have either too many customers 
(doubtful) or too few channels assigned for CDPD use (AT&T doesn't 
channel hop), so during peak periods it gets VERY VERY slow, especially 
in large markets like NYC. In all fairness, though, BAMS's NY system 
seems to spend as much time registering and re-registering  with the 
network as it does actually sending data -- they really need to get it to 
be smoother than this and not always be "establishing data link" or 
"initializing encryption" -- and it only does this too often in the NY 
market (SPNI 9, ie, ex-NYNEX).

The big problem with CDPD is that there just needs to be more coverage,
and carriers need to work out roaming arrangements with other carriers so
customers don't get stuck with high per-kilobyte bills if they hit some
nearby system. CDPD is extra revenue on top of the cellular network, so
carriers should not object to offering reciprocal unlimited use to other
carriers's customers. (Some sort of flat monthly rate payment system can
be established between larger and smaller carriers as some form of
compensations for disparities in network size.)

Right now, the system works well if you stay in your local area, but if
you travel a lot (and I submit most people who use CDPD are quite mobile
and need to travel extensively), you'll find that either the coverage is 
lacking or if there is coverage that roaming is either outright 
prohibited or quite expensive, which detracts from the overall utility of 
the service. 

(This post and updated SID list are also available at www.wirelessnotes.org)

Regards,

Doug