See https://www.a516digital.com/2018/02/end-of-over-air-freeview-tv-software.html
End of over-the-air Freeview TV software updates
February 28, 2018The DTG is closing its over-the-air software download service, dubbed "The Engineering Channel".
Since the launch of Freeview, TV and set-top-box manufacturers have been able to use a dedicated data stream that was broadcast in the background alongside the BBC's digital TV signals to send software updates to their receivers.
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Internet connectivity was part of the specification for receivers that wanted to display the "Freeview HD" logo, and is now an integral part of the newer Freeview Play service. Most manufacturers don't issue updates for older non-connected TVs or boxes.