Its time to upgrade to HD.
During this free STB replacement offer by TS, you can also opt for HD STB by paying additional charge, instead of SD STB.
I believe it costs more if you go for voluntary upgrade from SD to HD.
I have 2 TS connections, one is Bangalore & another in Coimbatore, both are old SD STB's.
I upgraded both STB's to HD by paying Rs.990 extra. The existing Dish will work with HD.
In Coimbatore, they have replaced both STB & Remote, but in Bangalore only STB was replaced. I checked with CC & they confirmed that only STB will be replaced for Bangalore region.