Each band has a dedicated transmit or receive frequency. The amazing part of these little radios are the data rates they can accommodate. The tricky part can be the limited power available by the radios. The need to supply services to over 100-computer systems demanded some performance The system has a small microwave antenna and equipment box located on the roof of the buildings. Cisco systems is the manufacturer of the equipment.
Radio is a never-ending evolution of technology.
I enjoy playing around with packet radio on the ham bands. The experience of packet made it easier for me to plan the system. I believe somewhere a person with ham experience powered this generation of technology. I look for hams to use PC sound cards to break the 9600 baud barrier for packet radio and make it an affordable hobby for more hams. Ham Radio is there to provide communications in times of emergency.