In the Memorandum Opinion and Order and Second Report and Order (pdf) released May 23, 2002, the Commission updated the service rules regarding five Industrial/Business Pool VHF frequencies known in the PLMR community as the VHF “color dot” frequencies. These frequencies were moved from Part 90 to Part 95 and became a new Citizens Band Radio Service (CB) named the Multi-Use Radio Service (MURS). The Commission defines MURS as a private, two-way, short-distance voice or data communications service for personal or business activities of the general public.
No licenses are issued for this service. An entity is authorized by rule to operate a MURS transmitter if it:
- is not a foreign government or a representative of a foreign government;
- uses the transmitter in accordance with 47 CFR. 95.1309;
- otherwise operates in accordance with the rules contained in Sections 95.1301-95.1309. ” – http://wireless.fcc.gov/services/index.htm?job=service_home&id=multi_use
What is a MURS Radio, it’s the new version of the old Citizens band (CB Radio) at a higher frequency. However, unlike CB Radios of old, MURS can be used for other things beyond mere voice communications, except for transmissions of “images”. The first that comes to mind is a wireless drive way alarm systems. Although there is a limit on output of only 2 watts, there is no limit on antenna gain. Antenna height is limited to 20 feet above structure or 60 feet above ground, whichever is the greater.
Hand held MURS have a range from anywhere between 2 miles and 8 miles, whereas base station to base station can reach up to 20 miles. (depending on terrain)
These are not HAM radios, which are meant for long range communications, these are the radios you use to scout with. It is important to note that data and voice transmissions are permitted on these frequencies. This give rise to the possibility of using encrypted voice communications using MURS. You can not alter the circuits of the MURS radios themselves which are regulated by the FCC, however, like using echo mics in the 70’s, I see no problem with using altered microphones which contain circuits within them to encrypt voice to data transmissions. Double key encryption would be the preferred method of choice here during TEOTWAWKI, with trusted parties previously sharing keys. Since you can run an entire Linux distro from a USB 4gig pen drive, hard core GPG/PGP data encryption transmissions should be a breeze. Something to be submitted to the open source/patent groups?
I am pretty sure that a lot of the HAM radio programs available for debian/linux distro can be used in some fashion for use with MURS, I’ll poke around with this as soon as I can. Another idea I have has to do with a secure telephone system, now you can not connect your MUR to a telephone network, but as long as the telephone equipment meets the FCC rules there should be no problem with using them exclusively on MURS radios. The FCC has now established an entirely new, Part 95-based certification procedure for manufacturers wishing to enter the MURS market.
Anyway, MURS have made it to my shopping list for this year. I’ll keep you posted on what else I come up with for taking full advantage of the system.