There are two types of satellite systems in Australia currently and to help you understand I think the easiest way to explain it is that they are like AM and FM. FM receiver cannot pick up the AM and vice versa.
The easiest way to distinguish between the two systems are that generally KU band systems are 1.5 meter dishes and smaller and C band is 1.8 meter dishes and bigger.
The majority of KU band systems are 85cm and smaller and as a result are a lot more accessible for both convenience, price and regulations.
Currently many councils are requiring people to obtain council permission to erect a satellite dish bigger than one metre and some councils are charging up to $400 for this service. As a result of these issues KU band is far more popular and is growing exponentially. The process of installing a 85cm dish and satellite decoder into your house is a very simple process.
The amount of Free to Air channels in Australia is growing extremely quickly.
There are currently 2 transponders on Optus B3 and these transponders are being filled up very quickly. All around the world, KU band systems are growing very quickly and will continue to strenghten its position as the premier delivery method for satellite channels.