Backcountry Phones Don Loweburg c.1992 Don Loweburg Photovoltaic technology has extended the limits of comfortable rural living, providing electricity to run our home and business. Last year we made another major shift in our lives when we installed a radiotelephone, the Optaphone+ system. Phone communication now allows us to realize our dream of having our business operate full time from our home in the central Sierras of California. About a month after we purchased our Optaphone+, the local telephone company called and offered us telephone service using a new system they were initiating. There is an element of sardonic humor here. For several years, we and a number of neighbors, all remote, had been lobbying the local telephone company to provide this service. Cynthia and I got tired of waiting and took action; we bought the radiotelephone. It seems that when it rains it pours. Though we already had purchased our telephone system, we ended up benefitting when our company got the contract to install the solar power source required for the telephone systems our neighbors were having installed. Through my work with the local telephone company I learned how their system works, technically and administratively. Three Types of Radiotelephone Systems I encountered three types of systems: single users, 50 line systems for small communities, and systems over 100 lines. All three systems use radio transmission to provide a link between a "base" and a "subscriber". The quality of the connection is adequate for fax and telecommunication.The frequency or band depends on the specific geographic area, but usually is in the VHF (very high frequency 30 to 300 megahertz) or UHF (ultra high frequency 300 to 3000 megahertz) band. Unlike older systems, the mechanics of these radiotelephones are transparent to the sender and receiver. There is no push-to- talk or mobile operator involved. This is largely because these units are "duplex" meaning that the base and subscriber units transmit on different frequencies, allowing you to talk and listen at the same time. In contrast, "simplex" radiotelephones are like CB radios Ä they broadcast and receive on the same frequency. These require you to push a button to talk, and release the button to listen. Optaphone+ for Individuals The Optaphone+ is a single user system. The "base" unit plugs into the telephone jack where the telephone would. The unit then transmits and receives using a yagi, beam-type, antenna. The "subscriber" unit is at the user's remote site. It too is connected to an antenna and the user's telephone plugs into a standard jack on the subscriber unit. Radio waves propagate in straight lines at these high frequencies; a line of sight path is always best. If there are VHF frequencies available in your area, a line of sight path is not as critical, but for UHF, it is. The distance may be in excess of twenty miles, but it is best to check out the radio path's quality before investing in the equipment. When the telephone is not in use, both the base and subscriber are on standby and use very little power. If there is activity at either end, whether a ring-signal at the base or the phone off the hook at the subscriber, then both units activate and a connection is made. During this mode, both units will be transmitting and receiving. When the phone at the subscriber end is hung up, both units return to standby mode. Since the owner is in fact operating a radio transmitter, a station license is required by the FCC (Federal Communications Commission). This is a simple administrative procedure and helps maintain order in frequency allocation. There would be problems if two users were using the same frequency (or channel) at the same time in the same neighborhood. The Optaphone+ system is powered by a 12 Volt DC supply. This may be a photovoltaic source in many cases. The Optaphone was designed to use very little power and can easily be operated from a single 30 Watt photovoltaic module and a 60 Amp-hour battery. This modestly sized battery could provide up to 20 days backup. Low power consumption was a primary factor in our choice of the Optaphone+. Over a thousand lines nation wide are using the Optaphone+. The Community Optaphone Star The Optaphone Star is a multi-user system that shares the low power requirements and basic technology of the single user system. The Star system is designed for modest sized communities (96 subscribers or under) that require phone service. A single base unit can operate on up to several frequencies or channels at the same time, allowing up to six subscriber lines to be in operation. Typically there will be more subscribers than channels, requiring a microprocessor to control the system, i.e., a traffic cop. The advantages of this approach is a cost reduction per line. Optaphone Star systems are currently in service in Montana, Alaska, and Pennsylvania. Optaphone is working on a 96 subscribers system which will be able to carry 24 simultaneous conversations. The Ultraphone for Larger Systems Communities that require more lines would probably use another kind of system. Because of the higher cost and complexity, larger systems are installed by existing local phone companies that wish to extend service into unserved or unfiled territory (an area that no telephone company wishes to serve). The Ultraphone produced by IMM of Pennsylvania is such a system. This is the system installed by the phone company in this area, Ponderosa Telephone Company, O'Neals, California. This is a digital system: conversations are broken up digitally and pieces of each are fed in order on a single channel. The IMM system can carry four lines on each radio channel or frequency, increasing total system capacity to over 100 lines. The subscriber units are often solar powered. Shown is a BetrSolar PV power source and an IMM radiotelephone and antenna all mounted on a pole. Unfortunately, the IMM system is not very energy efficient, requiring 200 Watts of PV array and 200 Amp-hours at 24 VDC battery. The system has 10 days of backup. Though expensive, the customers of the phone company don't pay outright for the system. Instead they pay a modest monthly fee in addition to the normal phone service and long distance charges. The local phone company may often receive a low interest loan from the REA (Rural Electrification Administration) to finance the project. Telephone Service for All Radiotelephone technology has made it possible to extend phone service into previously unserved areas. If an individual has the resources to purchase their own Optaphone or similar system, this might be the best approach, at least the quickest. Others may opt for a community approach. The first step would be for everyone in an unserved area to write to the telephone company to request service. Also, write the PUC (Public Utilities Commission) letting your need and request for service be known. It's important to be polite, but firm. There is no technical reason not to have telephone service. Let them know that you understand the REA has low interest loans available for this kind of project and you are aware of its existence in other areas. Communicate among those in your area participating in the project. Compare notes and make sure the authorities' responses are consistent. Remember, the PUC and the phone company have a mandate to survey our interests. Make sure they do. When you have dealings with these agencies, make sure every promise, action, or response has a time or date attached. Then consistently hold them to their promise. The process may take a while, but telephone service is usually available for citizens wherever they live. Access Don Loweburg, Offline Independent Energy Systems, 231 Main Street, North Fork, CA 93643 ù 209-877-7080 Optaphone: Carlson Electronics, 655 Redwood Dr., Garberville, CA 95440 ù 800-382-6006 ù 707-923-2345