|
The classic deployment
is Geosynchronous Earth Orbiting (GEO), by which a satellite in perfect
balance between centrifugal force and gravity appears to sit quite still
as it revolves around our globe at the same speed at which we rotate.
It can cover a well-defined area, a large one since it is about 23,000
miles high. However, at that distance it takes serious power to get
that much data to earth and carefully aimed parabolic antennas to receive
TV-, voice-, or Web-size portions of that signal. Afloat that means
a sophisticated device that can quickly compensate for changing heading,
pitch, and roll. Getting large quantities of data back up is even more
difficult, leading to asymmetrical data rates.
Another satellite
system architecture is Low Earth Orbiting (LEO), in which the birds
whiz by a few hundred miles up, able to transceive enough signal that
Globalstar and Iridium voice data can work with small omnidirectional
antennas. But it takes a lot of LEOs to cover that much area, and the
technology to keep them all alive and linked to their earth stations
is complicated and expensive. Even GEOs don’t necessarily offer
full ocean coverage, as they concentrate their precious power into spot
beams aimed at the land masses where most customers are. Inmarsat is
the notable exception, formed years ago to serve the marine community.
In short, the satcom
variables—coverage, technology, business plan, etc.—are
awesome, and I haven’t even touched on frequency issues or the
scads of companies with intriguing names like Teledesic, SkyBlaster,
and WildBlue “about” to offer some irresistible new satellite
broadband solution. But let’s look at what’s actually available
for yachtsmen with a high-speed Internet appetite. The discussion thus
far will hopefully help to clarify the products offered by the two major
players, KVH and Sea Tel, as well as related sidebars.
Last year KVH introduced
TracNet, which uses a 400-Kbps Internet downlink available, though down
only, from several DBS (Direct Broadcast Satellite) TV GEOs. On shore,
the uplink portion of the Web dialog—your keystrokes, for instance—is
handled by phone line. KVH did it with cell or Globalstar, putting a
server onboard to manage everything. The new TracNet 2.0 focuses on
the now less-pricey Globalstar for the uplink and is even using it on
the down side when the boat is outside the TV satellite’s continent-centered
coverage (or someone else onboard wants to watch TV). TracNet 2.0 also
boasts compression software that can make Globalstar’s normal
9.6 Kbps act like 56 Kbps. Compression, used in many satellite data
schemes, is a contentious issue. It really does work, but results are
variable according to what sort of data is being squeezed. If regular
“optimal” speed rates are sometimes pie in the sky, compressed
rates are probably worse. At any rate, TracNet 2.0 equipment starts
at about $6,000 but must be accompanied by one of the KVH’s various
satellite TV antennas, which start at $3,500. Service starts at $.99
per minute and can drop to $.33 with a high volume.
Also debuting last
year was Sea Tel’s unique all-LEO broadband product, WaveCall
MCM 3, featuring three Globalstar modems whose multiple streams are
mixed and compressed to feel like speeds to 144 Kbps. The system permits
simultaneous phone calls. The hardware is $10,000, and service plans
range from $2.75 to $1.10 a minute for fast data. Sea Tel just introduced
WaveCall 4003, meant for quite large yachts. It uses high-frequency
GEOs and an antenna engineered to fit a 48-inch dome and offers 512/128
Kbps down/up speeds, both expandable, and voice. Coverage is wide, but
not global. Hardware is $35,000, and a $1,000-a-month contract includes
a gigabyte of data.
KVH’s new F77
is similarly geared to big boats but uses Inmarsat’s latest Fleet
technology, providing global 64-Kbps voice and data like the old B service,
but with lower rates and a choice of billing by the minute or by the
bit. It’s significant that both of these systems allow users to
be constantly online, collecting e-mail as it comes in, or surfing at
leisure, and paying only for the data downloaded.
The accidental $50,000
phone bill may be history, though there is unfriendly software out there
that wants to download stuff when you’re not looking. I’ll
leave it to megayacht skippers and consultants to sort this problem
out as well as all the other variables involved in the difficult business
of broadband at sea. The technology is amazing, but it’s clearly
beyond my means at the moment. If I ever make the Galapagos, I’ll
just have to lay on the beach, Web-less, and watch the GEOs and LEOs
glint in the sky.
KVH Phone:
(401) 847-3327. www.kvh.com.
Sea Tel
Phone: (925) 798-7979. www.seatel.com.
Ben Ellison has been
a delivery captain and navigation instructor for nearly 30 years and was
recently editor of Reed’s Nautical Almanacs.
Next
page > Q&A > Page 1,
2, 3, 4, 5,
6
|