tata sky has 40 mhz space on hd tp so they can easily relay 13 hd chs. they give 6 mhz space to each sports ch to relay in top quality and so ledt is 22 mhz which they can easily allocate to rest of 10 chs, they relay star chs in say about 2.5 mhz so it comes to 10 mhz ,2.5 mhz each for nat geo hd and discovery hd and ledt over for rest 5 hd chs