EDGDE Compact is a special adaptation of EDGE GPRS (EGPRS) for the introduction of high speed packet switched data in a D-AMPS (IS-136) network. The problem is that EDGE is based on a 200 kHz radio channel bandwidth whilst D-AMPS uses radio channels with a bandwidth of 30 kHz.
The idea behind EDGE Compact is that part of the 30-kHz carrier spectrum is released. This released spectrum is used to build a stand-alone packet switched data only network for high speed data traffic based on EGPRS. This data network can be deployed in only 600 kHz of spectrum (+ guardband) by using three carriers in a 1/3 reuse pattern.