Two Way Radios

This is a license-free radio service in the 27MHz band. It may be used for personal and business purposes. The problem with CB radios is that they require a relatively large antenna to operate properly, due to the large wavelength. CB was once the only practical two-way radio system for individuals, and as such served several distinct types of users such as truck drivers, radio hobbyists, and those who needed a short-range radio for particular tasks. While some of these users have moved on to other raadio services, CB is still a popular hobby in many countries. In the United States it is strongly associated with semi truck drivers and rural life. It is not particularly suitable for indoor operation due to the reduced penetration ability of the 27MHz radio waves. So, it can’t really be considered as a serious alternative to GMRS/FRS.

Citizen’s Band
Multi-Use Radio Service (MURS)

The FCC defines MURS as “a private, two-way, short-distance voice or data communications service for personal or business activities of the general public”. It consists of 5 frequencies in the VHF band, more precisely in the 151 – 154MHz range. It has a power limit of 2 watts, which is 4 times that of FRS, without a limit on antenna gain. No license is needed for MURS operation, but you have to respect the operation rules. There isn’t a big variety of MURS radios on the market yet, but it is definitely an interesting alternative.

Frequency-hopping spread spectrum at 900MHz

Very recently, two way radios using the 900 MHz band have emerged. This band, much like the MURS above, does not require a license, and is much less congested. With the usage of frequency-hopping spread spectrum, up to 10 billion virtual channels can be created, ensuring privacy and minimizing cross chatter. One example of this type of radio is the TriSquare TSX300-VP.