This week BBC News ran a story on how taxi drivers in Japan are hearing the unexpected sounds of cooing babies on their CB radios. The cause: U.S.-purchased baby monitors from nearby U.S. military bases that are interfering with communication frequencies. Why would this happen? It’s likely that the baby monitors were manufactured to work on region two communication frequencies, and while being used in Japan, they’re interfering with communication frequencies allocated to region one.
The International Telecommunication Union (ITU) divides the world into three regions. Each region has its own frequency-band allocations; that is, in each region, each frequency band is allocated to a specific use. Sometimes a local authority like the Federal Communications Commission (FCC) in the United States regulates the use of frequency bands.
Say you want to find out how a specific frequency like 2GHz is allocated. Type “frequency allocation 2GHz” into Wolfram|Alpha.
Here you see FCC allocations for the United States (ITU region two). In the pod at the bottom, you see the allocations for all three ITU regions. You could of course have asked the same question in terms of a wavelength by typing “frequency allocations 15cm“.
You can also find the allocations by location, for example, “frequency allocation 2GHz Japan“.
Or you may give a more local location such as “frequency allocation 5GHz Lake Titicaca“.
Wolfram|Alpha understands latitude and longitude values. So you can do “frequency allocation 15GHz 75W 40N“.
The next time you are setting up your own transmission device, you can be aware of what frequencies are available without encroaching on frequency bands.