Satcom selections

Unlike many voyaging sailboats, power voyaging boats have both the electrical power and antenna mounting space to accommodate bigger and more power hungry satellite communications systems. Below is a look at the latest communications choices for power voyagers.

U.K.-based Inmarsat sets the gold standard for mobile satellite communications. Founded in 1979 to improve the communications abilities of ships at sea, Inmarsat now boasts some 287,000 subscribers worldwide, including maritime, aviation and land-mobile users.

Right now Inmarsat is midway through the process of launching their fourth generation of communications satellites. Besides being the largest payload ever blasted into space with an Atlas booster rocket, these new I-4 satellites have 20 times the data capacity of their predecessors – a feature Inmarsat plans to exploit fully with a data service they’re calling Broadband Global Area Network (BGAN). BGAN offers connectivity at speeds of up to 492 kbps on the downlink side, and up to 382 kbps on the uplink – speeds that make applications like Web browsing or videoconferencing in remote locations more feasible than ever.

With two of the new I-4 satellites now in place, BGAN is already available to land-mobile users in Inmarsat’s Atlantic and Indian Ocean regions. TV journalists were among the earliest adopters of this new technology – if you’ve viewed a live report from the Middle East on CNN, chances are it was transmitted via BGAN. Inmarsat gear that supports BGAN for marine use is under development and expected to become available in 2007.

In the interim, Inmarsat’s present generation of “Fleet” terminals was introduced a few years ago as a bridge to the BGAN future. Fleet terminals are available in three size ranges, with coverage area and data throughput rates increasing according to the size of the antenna. Fleet F33 terminals are the smallest of the lot, with an antenna dome measuring about one foot (33 centimeters) in diameter and a dialup data rate of 9,600 bps. For larger vessels that can accommodate the antenna, Fleet F55 (22-inch dome) and F77 (31-inch dome) terminals can move data at speeds of up to 64 kbps and 128 kbps, respectively. It’s anticipated that there will be some migration to the new BGAN service for F77 and F55 users, with F33 remaining a standalone solution for smaller vessels with less intense data requirements.

All Fleet terminals support voice and fax calls, as well as a data mode called Mobile Packet Data Service, or MPDS. MPDS lets users share a common 64-kbps data channel with other concurrent Inmarsat users, with the actual data rate varying depending on the number of terminals signed on at any given moment. MPDS is intended for interactive applications like e-mail, Web browsing or instant messaging, and the user is charged by the amount of data transferred over the network, not connect time.

Fleet terminals are available from a variety of companies such as KVH, EMS Satcom, or Thrane & Thrane. KVH, for example, offers a complete line of Fleet products under its TracPhone brand, TracPhone F77, F55 and F33.

In the past, Inmarsat gear has always been fixed-mount with an external antenna on deck and a terminal unit and handset down below. However, the company recently announced a collaborative agreement with Asian Cellular Satellite (ACeS) to offer more portable personal communications solutions as well.

ACeS has been a regional provider of satellite communications in the Pacific Rim area since 2000. The company has its own Garuda-1 satellite and offers a low-cost ($750) handheld telephone developed by Emerson, which functions as both a satphone and a GSM cellular phone where service is available.

Under the deal with Inmarsat the ACeS network will be expanded to cover the globe using the I-4 satellite constellation in addition to its own bird. This extended coverage is expected to roll out in early 2007, following the launch of Inmarsat’s third new satellite.

In the meantime, the existing providers of handheld satellite services like Iridium and Globalstar are busy with their own plans for the future.

With some 169,000 users onboard, Iridium expects their present network of satellites will remain in orbit and operational well beyond 2010. Still, the company announced this year it has started on plans for its next generation of satellites, promising increased bandwidth while remaining backward-compatible with existing equipment. The company added a new land-based gateway station in Alaska in 2006 and plans an additional five gateways by the end of 2007.

There are 66 active satellites in the Iridium constellation, orbiting the planet in low earth orbits about 500 miles up. Presently Iridium is the only satellite service providing total global coverage, including all oceans and the Polar regions as well. The native data rate for Iridium gear is 2,400 bps, but throughput can be effectively doubled using compression techniques like those offered by the latest version of Iridium’s Direct Internet Data Service.

In addition to handheld units, fixed-mount Iridium phones offer reliable coverage and additional features. For instance, the Thrane & Thrane Sailor SC4000 is a fixed terminal unit, which can accommodate a vessel’s PBX via a standard RJ-11 jack, or up to four dedicated handsets mounted in convenient locations around the boat.

Another option is the SeaWave Integrator, which houses an Iridium phone, a GSM cellular telephone and a GPS in one “black box.” E-mail is built-in, as is simple access to a variety of weather products. The Integrator’s least-cost routing feature votes between the Iridium and GSM cellular services to establish voice calls or data connections via the most economical means available. SeaWave also offers an optional Ship Tracking and Reporting (STAR) feature that lets an owner or friends keep tabs on the whereabouts of a particular vessel.

The Globalstar constellation consists of 48 satellites arranged in low earth orbits concentrated over major landmasses. As a result, full ocean coverage is not available, although Bermuda, the Bahamas and Caribbean are well within the satellite footprint. There is nominal coverage over the North Atlantic between the U.S. and Europe.

Globalstar’s 200,000 registered users can also look forward to network improvements. Globalstar went public with a stock offering on November 2, 2006 (NASDAQ: GSAT), and plans to use the funds from this IPO to procure and launch their next generation of satellites and improve their land-based gateway stations. Like Iridium, Globalstar activated a new gateway station in Alaska in 2006.

More recently, Globalstar announced availability of a new handheld phone. Manufactured by Qualcomm, The GSP-1700 is 45 percent smaller and almost half the weight of the previous GSP-1600 handheld, with improved battery life as well.

Globalstar’s GCK-1410 Vehicle Kit can be used to cradle a GSP-1600 phone, with connections for an external antenna, charging power and data. As this is written, there is no word on whether a similar accessory will be available for the new GSP-1700 handheld.

Globalstar’s GSP-2900-MST is a fixed-mount phone with a 7-inch stick antenna that can be mounted up to 30 feet from the base unit. For a cleaner look and slightly better performance, Globalstar’s GSP-2900-LP uses a “teacup” antenna mounted inside a protected enclosure. The 2900 family of phones supports both voice and data, and connects to a standard telephone instrument for voice calls.

Globalstar’s native data rate is 9,600 bps, but Sea Tel’s WaveCall MCM3 gangs together three Globalstar modems in parallel for increased data throughput. The MCM3 lets a user conduct a voice call and remain online with a data connection simultaneously. When no voice call is in progress, the triple-modem configuration effectively boosts the data rate to 19.2 kbps, dropping back in speed if the device needs to grab one of the lines for voice communications. This fixed-mount solution couples a 20-inch, radome-style antenna with a separate indoor unit that supports an ethernet connection to a computer or onboard network.

Yet another option remains for vessels with a real need for high-speed data and simultaneous voice connections. Very small aperture terminals (VSAT) are commonly used on land by a diverse body of users, including gas stations, car dealers and even WalMart. VSATs typically use antennas less than three feet in diameter fixed in position to point at a specific satellite. This technology can be adapted for seafaring duty using a microprocessor-controlled antenna that analyzes the boat’s position and gyro information to remain pointing at a fixed spot in the sky, regardless of the boat’s orientation.

Several factors come into play when weighing satellite options. Examine satellite footprints closely to choose an option with coverage for the vessel’s planned cruising area. Cost is obviously a factor, along with antenna size, weight and placement. Power consumption also merits at least some deliberation, especially if the gear will be left in an “always on” state. Also consider the availability of service and support, in case this help is needed.

By Ocean Navigator