 His "strict" definition of ECHELON is that it is a satellite interception component of the partners of the UKUSA Agreement.Even among the UKUSA members, according to Campbell, there may be other satellite interception stations not called ECHELON, probably in Australia and possibly in Great Britain.It is generally accepted that ECHELON is a cooperative system, principally among the UKUSA Agreement partners, to intercept satellite, microwave, and other communications around the world, searching for information of interest to its members.