Apologies for providing that link. As I explained though, you do require the landlord's permission before you have the work commenced because it involves both internal and external works. Further consideration is whether the landlord only owns the flat and not the building. Further, more than likely, the whole building is under a leasehold and therefore possibly covenanted.
By way of example, an entitled tenant in our block decided upon Sky. A dish exists and there was a spare LNB. He thought that was great and arranged for connection directly with Sky without consulting with anyone. His flat is at the rear of the building. Result, cable hanging from dish to porch, hole drilled in external wall into porch, hole drilled into hall (common area). Cable running all the way down the hall, up to the ceiling, then drilled another hole through into the rear flat.
Some owner residents wanted to snip the cable but I managed to calm everyone down. It turned out the flat owner lived in Germany and the flat was managed. We agreed with the managers, who knew nothing about the cabling, to have the unsightly areas repainted and repaired.
