When we look at the advancement of technology, we tend to think of the razzle-dazzle gadgets at the leading edge of technological development. Yet, a fascinating aspect of technological progress that doesn’t get as much attention is the application of added capability to improve systems considered “mature.”
A good example of this is the steady improvement in high-frequency single sideband (HF SSB) as it has been adapted to modern needs via the use of digital processing and computers. A communications tool that was predicted by many to be eclipsed by the use of satellites broadcasting on UHF and SHF frequencies, HF SSB has become a thoroughly modern and effective way to send not only voice communications, but worldwide email as well.
It seems that in this case, technology has acted as a rising tide that lifts all boats. So while advanced satellite phones may be newer and sexier than HF SSB radios, both areas of marine communications are experiencing impressive gains in capability as technology moves forward.
Let’s look first at the leading-edge satellite systems. Putting communications equipment on satellites, of course, allows communications companies to provide coverage over large sections of the earth without having to rely on skipping signals off the ionosphere. Not relying upon the ionosphere to relay radio signals also means higher frequencies can be used. Higher frequencies mean (generally speaking) a high data rate and more channels, thus more users per satellite.
One of the downsides to satellites is the cost of building, launching and operating them. Plus, for the user, satellites often require more complicated/expensive antennas. Another downside is in an emergency situation. A satellite phone works like any other phone in that you are talking to one person at a time. An HF SSB radio, on the other hand, allows you to broadcast your distress message to both the Coast Guard and others, who can all be listening on that channel. However, for ease of use, it’s hard to beat a satphone. You use it as you do a cell phone, dial the number and talk.
Iridium, the original satellite phone system, has had a short, exciting life. The original incarnation of Iridium failed to attract sufficient customers to pay its bills, and in 1999, the satellites seemed on the precipice of fiery destruction. Motorola, the lead player in the consortium that built Iridium for a reported $5 billion, released a plan to “de-orbit” the satellites by burning them up in the atmosphere. The system was eventually purchased for $25 million by a technology-savvy group of investors.
Starting with a clean slate and a multi-year, $72 million contract from the Department of Defense, the new Iridium is providing service worldwide using its sophisticated satellite constellation.
Even after a few years of operation, the Iridium system concept is still impressive in its call-handling abilities. Not only can the Iridium spacecraft relay calls from a user on the surface to a land station, but they can relay calls from a user on the surface to another satellite and then another before the final satellite in the chain sends the signals down to an earth station thousands of miles away. This ability to “skip” calls across its constellation of satellites allows Iridium to offer coverage at the North and South poles, even though it doesn’t have an earth station at those locations.
Last fall, Iridium introduced the EuroCom unit with an omnidirectional antenna for users who want to install Iridium in a fixed mode inside a vessel’s bridge or nav station.
Opting for a tried-and-true “bent-pipe” approach, the other satphone system, called Globalstar, rolled out after Iridium. Globalstar satphone users send their signals up to the nearest satellite, which acts like a transponder and relays the signals back down to earth. There must be an earth station in view to pick up these signals. Thus, in those areas without earth stations in view, there is no coverage. However, the coverage area for Globalstar is extensive — covering the vast majority of the North Atlantic, for example.
Like its competitor, Globalstar had some financial problems when it was unable to sign up as many users as projected. Even though it is currently undergoing financial restructuring, Globalstar officially remains in operation.
The pioneer of marine satellite communications, Inmarsat, has developed a series of products to provide satcom capability to mariners. Many of the products were initially developed for merchant ships, and that market describes the bulk of Inmarsat’s customers. However, the company also offers products for voyaging boats. These include their Mini-M voice and data service, Standard C, which is a text-based service, and two new services: Fleet 77 and Mini-C.
Fleet 77 is a service for larger yachts and commercial vessels that offers 64-kilobit-per-second connectivity and uses a packet switched approach, whereby users pay for the megabits they use, not the time they are connected. Mini-C is similar to the long-time text-based service, Standard C; however, it has a tight integration to a built-in GPS receiver for position reporting.
In the past decade, the trend in communications satellites and sport utility vehicles (SUVs) has been pretty similar. Just as SUVs have become ever-bigger and more powerful, steadily larger and brawnier spacecraft have been lofted into orbit to handle communications chores. The Inmarsat spacecraft currently in orbit, the Inmarsat 3 series, are an order of magnitude more powerful and capable than the Inmarsat 2 they replaced. The I-3s can handle data at 64 kbps. Contrast this with the next generation Inmarsat 4 spacecraft, now being built by Astrium in the U.K. Inmarsat claims the Gen 4s will be 100 times more powerful than the Gen 3s and will deliver 432 kbps.
What about HF SSB, however? How has advancing technology helped land-based HF radio compete with all this satellite development? The key to the current success of HF SSB communications as a medium for sending email and digital files was the application of digital technology a decade or two ago to well-developed and seemingly mature technology of analog HF radio. By converting the radio signal into a digital stream, it’s possible to use a computer to closely examine the bits and make a decision, based on certain rules, whether the bits represent noise or information. The noise is then discarded and the information assembled into a message or a digital file.
This capability, which has been steadily refined by a series of digital radio wizards, especially in the last 10 years, has given HF SSB radio a new lease on life as a tool for the voyaging sailor. While many voyagers may not install satellite communications systems due to expense, many find HF email the perfect solution. It’s not as fast as many satellite systems, but it works worldwide. For ocean voyagers who want to exchange email messages, get weather forecasts and weather charts and still have the ability to talk and listen in on marine nets, plus call land stations and other vessels, HF SSB fits the bill.
For those voyagers who have amateur radio licenses, the Winlink 2000 system (www.winlink.org) allows you to send email messages from a network of stations around the world maintained by fellow ham-radio operators. Since this service uses ham-radio frequencies, users are not allowed to use the WinLink system for business purposes.
Basic HF email systems include MarineNet in Jupiter, Fla. (www.marine net.net) and SailMail in Palo Alto, Calif. (www.sailmail.com). These services provide voyagers with HF email connectivity, software, radio hardware in the case of MarineNet, and basic customer support.
The high-end systems that straddle the recreational- and professional-mariner markets are CruiseEmail in Hollywood, Fla. (www.cruiseemail.com), Telaurus Communications in Cedar Knolls, N.J. (www.telaurus.com), Globe Wireless in Foster City, Calif. (www.globe wireless.com) and SeaWave LLC in Middletown, R.I. (www.seawave.com). All of these companies have sizeable staffs providing customer service and technical support. They also have multiple broadcast/receive sites networked together by layered telecom links, like very-small-aperture satellite terminals (VSATs), T1s or DSL lines.
As good as HF SSB has gotten at sending email and small digital files, many in the HF SSB camp are working to make it even better. CruiseEmail’s founder, Dr. John Gregory, reports that his system is expanding to nine stations, including stations in Greece and Grenada. CruiseEmail is also working on software that will analyze a user’s radio signal and let them know if their radio is not broadcasting on the proper frequency. “If your signal is too low or too high, our software will detect it and alert the user,” Gregory said.
And Mike Cunningham, director of marketing at SeaWave, claims that further development of digital HF is inevitable, given the investment companies like his are making. “We’re investing millions of dollars into digital HF. We’re really making HF a viable alternative to satellites.”
Steadily improving technology paves the way for Buck Rogers-like satellite phones, but it also enables older technologies like HF SSB to become more agile and effective. That’s all to the good for ocean voyagers.