If you currently operate an aircraft that has one of Gogo Business Aviation’s “legacy” inflight connectivity systems installed (ATG 5000, 4000, 2000 or 1000), you should note that Gogo is migrating its air-to-ground (ATG) network to LTE (long-term evolution) technology and anyone operating an aircraft with a “legacy” Gogo system will be impacted and needs to take action.
Source: aopaGogo updating ATG network to newer technology