Nokia Nokia Neustar Nokia Portions of the radio spectrum that are allocated to a licensed, primary user but are unused or unoccupied at specific locations and times are defined as "white space". The concept of allowing secondary transmissions (licensed or unlicensed) in white space is a technique to "unlock" existing spectrum for new use. An obvious requirement is that these secondary transmissions do not interfere with the primary use of the spectrum. One approach to using the white space spectrum at a given time and location is to verify with a database available channels. This document describes the concept of TV White Spaces. It also describes the problems that need to be addressed for enabling the use of the primary user owned white space spectrum for secondary users, without causing interference, by querying a database which knows the channel availability at any given location and time. A number of possible use cases of this spectrum and derived requirements are also described.