Large scale centralized deployment: Allows hundreds of thousands of remote RRH connect to a centralized BBU pool. The maximum distance can be 20 km in fiber link for 4G (LTE/LTE-A) system, even longer distance (40 km~80 km) for 3G (WCDMA/TD-SCDMA) and 2G (GSM/CDMA) systems. There are reports saying that some Asia operators have deployment C-RAN system which centralized 1200 of RRH to one central office.