What on earth is a northern arc?
If you are referring to pointing the dish north rather than south to get signal, that is scientifically impossible. Geostationary orbits have to be over the equator.
If you are referring to the Eastern Arc, it is for new customers only for now.
Didn't you know that DISH has plans to pole mount a satellite on a 22,000 mile long pole situated exactly at the North Pole? They'll be installing guy wires in Russia, Finland, Greenland, and BC Canada.