There are a dozen ways to encode a message in that buzz if you don't mind the bandwidth being poor. That is, it will take a long time to send a message of any length. The buzz might also be a cover for the message.
There are other considerations. First, it's essential to have a variety of media for transmitting messages. They need to be set up well in advance, so as to be readily available when an operation is set up. By staking out a multitude of such options, an agency is planning well for the future.
Next, by spreading their operations out over more channels of comm, they also minimize the risk when one is compromised. One never knows when a channel will be compromised, and at some point some of them will be.
By using a variety of channels, including radio, packages (diplomatic and not), tourists, etc., and each channel having sub channels, such as different radio frequencies, different encoding methods, breaking one such method doesn't afford much understanding of the others.
The end result is a plethora of channels with little real traffic on them, mostly "reserved for future use". But to avoid traffic analysis ( http://en.wikipedia.org/wiki/Traffic_analysis ) dummy traffic fills them.
There are other considerations. First, it's essential to have a variety of media for transmitting messages. They need to be set up well in advance, so as to be readily available when an operation is set up. By staking out a multitude of such options, an agency is planning well for the future.
Next, by spreading their operations out over more channels of comm, they also minimize the risk when one is compromised. One never knows when a channel will be compromised, and at some point some of them will be.
By using a variety of channels, including radio, packages (diplomatic and not), tourists, etc., and each channel having sub channels, such as different radio frequencies, different encoding methods, breaking one such method doesn't afford much understanding of the others.