What is Uplink?

The term uplink indicates transmissions from user devices to the network infrastructure in RF wireless communications like cellular or satellite networks. 

Wireless networks are composed of 2 main parts - the network side (operator) and the mobile/fixed subscriber side (users). The users access the network through various devices like smartphones, mobile phones, tablets etc. Uplink is used to indicate the transmission of information from the mobile or fixed terminal (subscriber) side to the network side. The frequency used for all uplink transmissions is known as uplink frequency.

In GSM cellular networks the 890-915 MHz band is used as uplink frequency. In satellite C-Band communications 5925 MHz to 6425 MHz is the uplink band. Satellite networks also use 14.0-14.5 GHz (Ku-Band) and 27.5-31.0 GHz (Ka-band) for uplink. An RF device called an upconverter is used to convert the baseband frequency to an RF frequency for transmissions of signals that enable the uplink.

Some companies sell uplink and downlink services to television stations, corporations and to other telecommunication carriers. A company may specialize in providing uplink services, downlink services or both.

In wireless networks, ‘uplink’ is also used to indicate other terms related to uplink transmissions like uplink channels, uplink frame structures, uplink packets etc. The transmission of signals from the network to the user's device is called downlink. Click here to learn more about downlink.