... :where there is cellphone,there need booster,because the weak signal problem is gsm mobile antenna booster so common in everywhere ... 200~300 sq.m.3.You can choose the outputpower and frequency:(1)outputpower can be:10dbm,17dbm,20dbm,23dbm,27dbm,30dbm ... ,33dbm,37dbm,40dbm,43dbm,46dbm.(2)frequency can be:GSM900MHz,DCS1800MHz,WCDMA(3G),CDMA850MHz,CDMA450MHz,CDMA1900MHz,IDEN,EGSM ...