Other DTH ops like Videocon and Tata Sky add new channels in all packages (according to the package the channel/s has been allotted to ) plus from the date of activation of that package till the 6th month Tata Sky charges old rates if there is an increase in package prices. Infact in Videocon they provide at same rate for 6 months from date of increase as they credit differential amount of increase in ur account
In Airtel they have various versions of the packages like July 2014, Sept 2014 etc. etc. which they create as and when changes happen in package rates or new channels are added. So if i am on Sept 2014 XYZ19 HD Package, i will not receive any new HD Channels they add after Sept 2014 as that are included in later versions of the packages but SD channels will be added in older versions of the packages (according to whichever package it has been allotted). This is the most irritating thing in airtel, they also give 6 months price protection as old rates are charged for that period but again without new channels. Earlier they used to not add even SD chs in older versions of the package