Article by Pat Schrawder
SORTING OUT THE LATEST ON SATELLITE PHONES
Communication is your most vital necessity when you are on your boat. No matter what your emergency is, you need to be able to talk to someone. Today’s boater have lots of choices from the CB radio, to VHF, SSB, cellular phone and the latest- satellite phone. VHF is the most common and best all around communication tool, but it has its disadvantages. The increasing use of cellular phones has been a big advance, but what about the satellite phone? We get a lot of questions about them and there seems to be a fair amount of confusion about what to buy and whether or not to buy. For example, how does a satellite phone differ from a cellular phone? How does it work? What does it cost and how do you choose the right one? Let’s try to answer some of those questions.
Without becoming overly complicated, let’s compare the satellite phone to its closest cousin, the cellular phone. Both of them use radio waves to send their signals. The cell phone sends its signal to the closest land based tower that “forwards” the call to other towers closest to the cell phone you are calling or, in the case of a call to a landline, to the telephone office and on to the receiver just like any other landline-to-landline call. Satellite phones send the signal to the satellite(s) of that particular company which, in turn, processes the call and relays it back to earth via a gateway. The gateway routes the call to its destination using regular landlines and/or cellular networks. If an individual satellite phone calls another satellite phone, the call (depending on the service) is direct to satellite and back from that satellite to the receiving phone using no landline or other infrastructure. This is a huge advantage during a major catastrophe like a hurricane when landlines are down.
The primary advantages of cell phones are that they are smaller, cheaper, have better availability, better quality sound, convenient features and they can work, in most cases, inside a building. The main disadvantage of cellular phones is that they do not work everywhere. You have to be within range of a cell tower and much of the world does not have cell tower coverage. Additionally, you can lose your signal if you get behind a line of trees or dip down into a valley, etc.
Satellite phones, on the other hand, can provide coverage worldwide, depending on the company. But no system is perfect. Satellite phones must have direct line of sight to a satellite so the portable units cannot be used inside a building or under other cover. They can be bulkier than cell phones, although some newer models are being made that are smaller. Still, they are more expensive to purchase and to use and have fewer choices of models and places to purchase them.
Within the satellite community of phones and service, there are some distinct differences and each company will tell you that theirs is the best. The main difference is in their satellite system and which type of satellites they use. One type is geostationary, meaning they are at a fixed height and rotate freely around the earth at the same speed as the earth’s rotation. It is common for them to have directional antennas and that limits their service area. The other type is LEO or Low Earth Orbit and they are moving relative to the earth’s surface at varying heights. Geostationary systems can produce an annoying echo due to their higher height and the time delay it takes for the signal to get from your phone to the satellite and back. Signals sent to the lower LEO system satellites are faster and have an unnoticeable echo and require less power. This makes the number of satellites in the system more critical, however, so that you can be assured of having a reachable satellite overhead, wherever you are.
For boaters, there is the choice of a portable or permanently mounted unit. You have seen the fixed units on boats. They look like a large dome. The dome units require ship’s power to operate but can only be used when you are on the boat. The portable units require recharging but you can use them in other situations than on your boat.
There are three primary providers of satellite phones and service: Globalstar, Iridium and Inmarsat. Another entry is Thuraya but their coverage is only available in a large region of northern, central and western Africa, the Middle East, Central Asia and the Indian Subcontinent. Next week, we’ll take a look at the three major manufacturers of phones and providers of service. I’ll do my best to compare the three in terms of equipment, rates and coverage area. We’ll also discuss the pros and cons of buying versus renting.
Pat and her husband, Larry are owners of L&L Marine Electronics on Golf Course Road in West Ocean City, MD.
