Generally speaking, there are two frequency ranges, otherwise known as "bands", in which satellite transmissions are broadcast.
This is a lower powered wide beam (approx. 1/3 of the earth). Due to the energy being dissipated over such a wide area a larger dish is required to capture enough signal to be usable, typically 1.8M solid or 2.3M Mesh dish is the minimum required. As this beam-type has such a wide coverage area, many of the free services
can be found here, however such large dishes are not generally practical for travellers.
This is a higher frequency, higher powered beam and with its ability to be formed into very high powered spot
beams, the Pay/subscription networks can mainly be found here. The reasons for this because for one, they are able to use much smaller dishes (typically 65cm-1M) these of course being easier and cheaper to purchase and install, but also because they can target their subscriber base using finely tuned spot
beams allowing maximum power in their key regions.
Because of this, there is not too much on Ku band that is free. One or two channels on some of the satellites. However, there is a service called 'Aurora' also known as RABS - Remote Area Broadcast Services
, transmitted from Optus B1. This is a free service but is on a weak beam and requires a minimum dish size of 1.2M (solid) or 2M mesh.