From ‘Surfing at sea’ (Page 41) – ‘Web surfing from the parking lot’

 
Nov/Dec 2003
 

When reviewing and reporting on new technology, I prefer to make a temporary installation of the equipment on my boat and go sailing. In the case of the KVH tracNet system, however, time and the amount of work required to make a temporary installation that would be usable at sea precluded following the usual course. Accordingly, I arranged to visit KVH�s facility in Newport, R.I.

The visit was on a Friday in early April. Living in Florida, I had forgotten that the arrival of the vernal equinox is primarily a celestial event and might not be connected even remotely to local climate conditions. It was cold in Newport. Accordingly, we did our �sea trials� of the tracNet system in a vehicle, specifically a KVH van with antennas, including satellite antennas sprouting from the roof. In some ways, this test mode was more severe than what we would have encountered on the water. Speed of movement was as high as � and in some cases, much higher than � what we might have had on a boat, turn rates were at least comparable, and the interference from nearby structures was far greater than it would have been at sea.

Initially, the system was configured to route received signals to a TV set that predictably delivered clear, sharp pictures. Turning on the tracNet mode disabled the TV reception and substituted the DirecPC feed. Using a laptop computer, I requested access to my yacht club�s website (http://www.pagyc.com), the Pass-a-Grille Yacht Club near St. Petersburg Beach, Fla.). The system response was virtually instantaneous. The club�s site includes a number of aerial photos used to illustrate access to the club from the Gulf of Mexico and various other local waterways. The images emerged with virtually no delay. Although I did not attempt to measure the downlink data rate, it was obviously very high. The same level of performance was evident on all other sites called for. Contact with the DirecPC feed from the satellite was solid and was not interrupted, even in areas where nearby buildings might interfere with the signal path. A digital cellular modem was used for the uplink, since this operating mode is likely to be chosen by many boats operating in close proximity to the shore in areas where on-water cellular service is available. The satellite downlink system operates at Ku band (12.2 to 12.5 GHz).

My view of the capability of the tracNet system is necessarily based on an initial impression of the system balanced against previous experience, which was primarily with Globalstar and Iridium hand-held satellite phones, Inmarsat Mini-M, and a cellular modem supported by a Compac iPaq. Recently we voyaged from our home port in St. Petersburg to Maine and back using a Globalstar satphone when offshore and a Compac iPaq with a cellular modem for email communication when near shore and in harbor. The Globalstar was quite satisfactory; however, at 9.6 Kbps and a typical cost of $1.29 per minute, Web surfing was clearly out of the question. The iPaq and wireless modem was marginally satisfactory for email, with very large along-shore areas totally devoid of service and with far less than fully satisfactory performance from the iPaq computer. TracNet�s ability to reach the DirecPC server via the Globalstar link will be a major advantage until the availability and quality of coastwise cellular service improves.


 

By Ocean Navigator