Why downlink frequency is greater than uplink frequency in mobile communication

Uplink and downlink, also called upload and download, refers to the two-way communication between a cell tower and your phone . Downlink definition – signal coming from a cell tower to your cellular device. Uplink definition – signal leaving your cellular device and going back to a cell tower.

Since a mobile station (cellphone) cannot afford to transmit at high power to compensate for this loss, it must transmit on a lower frequency as a lower frequency presents lesser free space path loss. Therefore, mobile-to-base station (uplink) frequencies are lower than base station-to-mobile(downlink) frequencies.

The uplink frequency range specified for GSM is 933 – 960 MHz (basic 900 MHz band only). The downlink frequency band 890 – 915 MHz (basic 900 MHz band only).