Cellular Update --------------- by The Glitch There is rising interest in the cellular scene, the retail and the free aspects of it. Here's some insight into what's going on! Expanded Spectrum -- yes, the cellular system, designed not to be overcrowded like the earlier mobile systems, is now getting packed in some urban areas. The FCC allocated 156 more channels to the system, bringing the total number of channels from 666 to 832. All manufacturers in the current marketplace are coming out with new phones (or upgrades to ol der phones) to cover the new channels. Uniden has upgraded their primary line, the CP-1000, to the CP-1100. Motorola has a new line, the Mini-Tac, which is feature-packed and much smaller than their previous Oyna-Tac series. This also has 832 channels. The NEC P-9000 portable (about the size of a cordless) also has 832 channels with an available upgrade to the earlier portables. Mitsubishi had designed the radio circuits of their older model line to be able to cover extra frequencies, so all it needs is a change of software EPROMS for its upgrade. Audiovox has a new model called the BC-20 with not only 832 channel capability, but also a very useful "self-test" mode (available to service technicians) which allows full manual control of the phone, including receiving any of the 832 channels individually (for testing purposes only, o f course). I do expect to see other manufacturers, such as Novatel, Oki, Hitachi (a.k.a. AT&T), Fujitsu, Panasonic, and many others. The new channels are non-linear with the rest, with some appearing "above" the old cellular band and the rest "below" the band. Likewise, some cellular test gear manufacturers, such as IFR, are coming out with new software upgrades to facilitate testing of the newer phones. For the cellular system to have the ability to know if a subscriber's phone is capable of being told to move to a higher channel, the phone must some how be able to tell the cellular switch that it can accept such a command. Fortunately, when cellular came out, there were some extra bytes in the programming to allow for this. This is called the "Station Class Mark" or SCM. It is a 4-bit binary number. Bit #1 is a "1" for 832 channels or "0" for the old 666. Bit #2 is "1" for voice-activated transmit (used as a battery saver in portables) or "0" for a mobile unit. Bits #3 and #4 dentify the power class of the phone: 00 = 3 watts, 01 = 1.2 watts, 10 = 0.6 watts, and 11 is currently undefined. So when the phone sends out a call, it will send something to this effect: 703-591-1635 (sample phone number) 8E0F1234 (sample serial number) 1000 (sample SCM) 00 (this is the "group ID") 05 (this is the "access overload class") Most cellular systems will not be upgrading their equipment for quite some time, or at least until they begin to get overcrowded. But come the time that they do, the cellular system will try to keep these newer phones on the upper channels when space permits so that the older cellular equipment won't have to deal with overcrowded conditions. If you are in the market for a cellular phone, don't worry about getting an older or even a newer phone with 666 channels, as I seriously doubt they will fall into obsolescence for many years to come.