It’s easier (and cheaper) than ever for boaters
to stay in touch with the rest of the world by phone.
Cell phones can be grouped into two basic categories—analog and digital. All early cell phones were analog, which means they transmitted a continuous fluctuating “wave,” similar to a radio signal. While analog offers broad coverage and is still used in some areas, it can carry only one call per wavelength (as compared to around 15 with digital), which makes it expensive and time-consuming to operate. Although analog is nearing the end of its life cycle (many carriers no longer even offer it), it remains the only game in town in some places. If you’re in one of those places, you’ll want a “dual” or “multimode” phone, which works on both analog and digital networks.
Most cell phones sold today use digital technology, encoding and translating
data into a series of ones and zeros similar to computer code. Digital phones
offer improved voice quality, longer battery life, encryption (which helps
prevent eavesdropping) and more efficient use of bandwidth—not to mention the
extra bells and whistles like text messaging, caller ID, voice mail, e-mail and
web access. But digital phones are generally less powerful than the old analog
models. Maximum outputs are typically rated at 0.6 watts (but are always within
a .02- to 0.6-watt range), as opposed to 3 watts of power from older units.
Essentially, the newer phones carry sound better, but not as far.
Can You Hear Me Now?
Fortunately, there are ways to boost both range and transmission quality. Some may be as simple as stepping outside or calling from as high up as possible (to provide a better, unobstructed line of sight to the nearest cell tower); other options include the addition of external antennas or power boosters. Today’s handheld cell phones typically have a range of 3 to 10 miles offshore, depending on how close the nearest tower is. Adding an amplifier and external antenna can boost coverage five- to tenfold.
External antennas range in simplicity from those used on cars to more robust models designed specifically for boats. Models include Shakespeare’s deck-level 5412-P antenna for powerboats and the masthead-mounted 5412-S for sailboats. Both are 2-foot, 3-decibel gain antennas and both cost around $200. Masthead antennas in general will outperform deck-level installations, but the use of properly sized coaxial cable from the phone to the antenna is critical—particularly in longer runs, where power loss can effectively cancel any gains brought about by higher antenna placement.
Power boosters such as Digital Antenna’s DA 4000 cell-phone amplifier ($270
online) provide signal amplification when used with an external antenna.
According to the manufacturer, the DA 4000 boosts transmit signals for
low-powered digital cell phones up to 3 watts, which would also presumably help
signal loss in those higher antenna installations.
Satellite phones (usually referred to as “Sat phones”) provide expanded or even global coverage, depending on the service provider chosen. Although prohibitively expensive when first introduced, Sat phone rates have dropped dramatically (from over $10 to less than 17 cents per minute). Regular users can find Sat phones and rate plans similar in price to cell phone plans, while the infrequent user may be better off renting a Sat phone for a day, week or month.
Sat phones receive and relay signals either to a terrestrial station (called a gateway), which in turn passes them off to a standard telephone network, or from satellite to satellite until it reaches one that can communicate directly with the unit dialed. The satellites themselves have either a geosynchronous orbit (GEO) or a low earth orbit (LEO) depending on the system. GEO satellites take 24 hours to orbit the earth at an altitude of 22,300 miles (meaning they would appear motionless to someone watching them from the ground). This altitude means each GEO satellite is able to provide coverage for up to one third of the earth’s surface at all times. The downside here is that phones utilizing GEO satellites require more power to reach them, meaning bulkier units with larger batteries.
LEO satellites are lower (between 90 and 600 miles) and circle the earth much
faster—once every 100 minutes or so. These lower altitudes need smaller, less
powerful phones to reach them—but the faster orbit also means any particular LEO
satellite will only be in range and able to provide service to a user for around
8 minutes. A complex switching arrangement allows satellites to “hand off”
customers from one satellite to the next one coming into range.
Virginia-based Iridium developed the world’s first LEO satellite phone service in 1998. Its 66 satellites (with a price tag of $5 billion) make Iridium the only system that can provide two-way voice communications via Sat phone from virtually any location on earth. Globalstar, headquartered in California, followed a year later with a $3.8 billion system of 48 LEO satellites, but coverage only ranges from 70 degrees north latitude to 70 degrees south and offshore 200 to 300 miles. And instead of using inter-satellite relays, the Globalstar system relies on ground support stations. Both Iridium and Globalstar anticipated robust business when they launched, but the proliferation of cheaper cellular phone networks drove both companies into bankruptcy.
Iridium filed for Chapter 11 in 1999, Globalstar in early 2002. A group of investors purchased Iridium’s assets for only $25 million in 2000 and soon after won a $72 million Defense Department contract. Globalstar is likely to emerge from bankruptcy as well. The good news for consumers is that not only are both services fully operational, but also prices and rates have been reduced significantly. Iridium phones, such as the original Motorola 9500 series (which are slightly larger than a cell phone) and the newer, smaller 9505, start out at around $800 and $1,200 respectively (refurbished units can be found for as little as $395). Iridium rate plans run between 99 cents and $1.49 per minute, with monthly subscriptions starting at $32.
Qualcomm manufactures many of Globalstar’s phones. Their GSP-1600 phones run around $500 and have the added cost-saving ability to use cellular networks where available, switching between analog, digital and, if cell service is lost, back to satellite. Globalstar’s monthly access starts at around $34, with rates as low as 17 cents per minute.
As wireless phone choices continue to expand and the technology continues to
improve, boaters can look forward to even more over-water communication options.
Just be sure to say “Ahoy” when you answer the phone. Alexander would have
wanted it that way.
Frank Lanier is an FCC licensed Coast Guard electronics technician in Chesapeake, Va.