Because traditional serial devices such as RTUs, flow meters and legacy PLCs use proprietary protocols, an unauthorized individual would need to replace the host with the exact same radio model, have knowledge of the protocol, and copy the host as configured for the application.

In a GE MDS licenses-free frequency hopping spread spectrum (FHSS) radio, this person would also have to know the network address. One of the advantages of FHSS is it provides better performance with heavy interference, however it also provides an added layer of security to a network. Originally designed to provide transmission security for military applications during World War II, the carrier frequency changes several times per second and requires another radio-to be set to the exact same pattern-to listen to any data being transmitted.

In a FHSS radio, each pseudo-random sequence of hops is generated based upon a user-selected key that can result in tens of thousands of different combinations making it virtually impossible to reproduce. And because the signal is spread over a range of frequencies, the communications link is more resilient to interference or jamming. Also, the spreading technique makes it more difficult for unwanted listeners to intercept network traffic.

An unauthorized person gaining access to a central network control center, and therefore control of the network, is a much bigger risk than a person accessing individual sites or a single purpose serial network.