White Space Devices
White Spaced Devices (WSDs)
|Master White Space Device||This is a device which consults a white-space database in order to obtain a list of available TV channels at the devices location, and the corresponding maximum permitted WSD EIRP in each available channel.|
|Slave White Space Device||This is a device which does not directly communicate with a white-space database but is under the control of a master WSD.|
|Dynamic Spectrum Access (DSA)||technique enabling radio communications devices to work on available radio spectrum.|
|White Space Database||This communicates to a master WSD a location-specific list of available TV channels and the corresponding maximum permitted WSD EIRP in each available channel.|
TV White Space (TVWS) refers to the unused frequencies in the TV Broadcast spectrum by primary (DTT and PMSE) users.
TVWS users transmit at power levels that will not cause interference to primary users.
Traditional analog TV channels had "guard channels" between services for protecting against interference between the channels, this no longer required due to the move to DTT as it consumes less bandwidth.
The TVWS devices are given different frequency availability based on their location and antenna height.
The use of Whitespace frequencies within the DTT band is strictly monitored and using dynamic spectrum access ensures that the current DTT and PMSE signals are not effected by WS devices.
A typical use of Whitespace is Internet connectivity for remote users in a footprint of the DTT transmission, using the backbone of an ISP and the DTT infrastructure.
One of the benefits of using UHF frequencies is it's ability to provide a signals even when in NLOS (None line of site) much like DTT does.
Whitespace development is now expanding into other countries, the USA and UK are at the forefront of development in this Technology.
Whitespace with investment from Google and Microsoft, can help underdeveloped countries such as South Africa and and Tanzania where only a very small percentage are online.
Blake have designed several aerials suitable for this type of use, please contact us directly for more details.