Answer:
GSM
Step-by-step explanation:
Personal Communications Services (PCS) are 2nd generation cell phone technology that uses digital techniques to transmit voice and data. Since 1995, there has been an emergence of three PCS technologies with the third PCS technology being the one that uses Global System for Mobile (GSM) communication. The use of TDMA in the 1st and 3rd PCS technology is slightly the same but different in a few ways. They both use this technology to allow cell phones to transmit signal independently and in turns. 3RD PCS, however, uses both FDMA/TDMA for transmission. The 2nd, on the other hand uses CDMA.