Globalstar™ Telephone Data Test
25 November 2000
Don Rickerson
Unit tested: Qualcomm GSP-1600
Software: R4.7.1.0.3, WDC: wEA00, 254-378-8113
Associated equipment: Laptop computer using Windows 98
Special equipment: Special serial interface cable for Qualcomm phone
Location: Manassas, VA
Dial-Up Networking (DUN) on Windows was installed using the CD that comes
with the Qualcomm serial cable. The software was installed with no problem using
the installation "wizard." The CD also contains instructions for
creating DUN interfaces on Mac, Palm, Linux, and Unix systems.
I used the phone on my covered deck, so about half the sky was blocked by my
aluminum-sided house. The roof on the porch consists of plywood and shingles. I
expected the satellite signal would pass though the roof, but just in case I sat
by the edge of the deck and had the computer and phone on a plastic deck table.
The Qualcomm serial cable was connected between the phone and the serial port on
the computer (COM1). The temperature during the test was below freezing.
I turned the phone on and allowed it to acquire the satellite; that took
about 15 seconds. I then clicked on the Globalstar™ DUN icon on my laptop. The
phone displayed the "PPP" interface starting, and I was on the network
within 5 seconds. The Globalstar™ data connection is rated at 9600 bits per
second (bps) with at throughput of 7700 bps. The connection was as fast as being
on a LAN.
Then I checked my e-mail, and the two short messages I had sent to myself
earlier downloaded quickly. Next, I created a message to my webmaster and
attached an 85-kilobyte file. The transfer was completed in just over 70
seconds. (An 85-kilobyte file is 680 kilobits. 680 kilobits ÷ 7700bps = 88
seconds.) This speed was possible because of the compression used in the data
transfer and the fact that the network was not loaded.
Next I clicked on the web browser and entered my web site, www.skyhelp.net
. It took over two minutes to fully bring up the main page of our bloated site.
Although this is the fastest and most inexpensive satellite data service
available to date, there are a few tips that will help you save time on the
network:
-- On e-mail, restrict the size of messages being sent to you. Most e-mail
clients will allow you to adjust this. You can expand the size if you have a
special message, but restricting the size of incoming traffic will save you from
accidentally downloading megabytes of your friend's vacation photos until you
get to cheaper bandwidth.
-- "Push" data arrangements can be used to have information you
need periodically sent to you as an attachment to e-mail. For example, weather
charts can be e-mailed to sailors each day at times they specify.
-- Web sites can be made satellite friendly by reducing or eliminating
graphics, using only HTML text, and getting directly to the information you
want. Make sure the web site supports the no-graphics mode for browsers.
-- Users can turn off graphics on their browsers.
Don
