There is no satellite located at 23 degrees east. The closest is Kopernikus3 at 23.5E, but there's no Sky there (not even the free to air Sky News).
All channels on the Sky digital platform are transmitted from Astra2 at 28.2East (and additionally Sky News is FTA on several other satellites).
The non-FTA Sky digital channels are all encrypted in Videoguard, and there is no Videoguard CAM on the market. So you MUST use a Sky digibox to view them (obtainable only by UK residents).
Additionally you will need a card, even for the non-subscription stuff that is encrypted under Videoguard (eg BBC1,2). And additional to that you will need a subscription to most stuff (eg Sky-One, Sky-Sports, UK-Gold,....)
By definition one should never needs any kind of CAM for accessing true free-to-air unencrypted channels. There are a few exceptions to this rule, though... because some particularly monopolistic providers (eg Canal+) have in the past produced receivers in which the firmware of the receiver itself blocks access to ALL channels (including FTA) unless their own smartcard is inserted (into the built-in CAM). But the Humax-5400 is independent of any provider, and so does not behave in that absurd way.
ITN News 24 is one of a couple of dozen FTA channels on Astra2. Others include Sky News, TCM, CNN, The Money Channel, B4U-Music, MBI, QVC, the God channel, Inspiration,.... etc etc. Most, but not all of those, are in Sky's EPG too. For anyone curious to know which subset of the Sky EPG is FTA, try removing your Sky card and then accessing the EPG. You will find that it only now shows you the FTA channels...