The White Space Database stores TV broadcasting information about the Philippines, calculates radio propagation of TV broadcastings based on terrestrial data, and draws TV broadcasting areas.
Figure 1 shows a screen shot of the White Space Database. The area marked in red indicates the calculated TV broadcasting areas on channel 31 in Cebu Island. This channel is used for TV broadcasting in the red area, however, it is available for wireless systems in the other area as TV White Space. When wireless systems operate in TV White Space, it is necessary to check whether a wireless system is in the red area or not. As there are multiple TV channels, it is required to check it throughout the all TV channels. Practically, the criteria of the TV channel availability in the database are not so simple as mentioned above, since interferences from wireless systems to TV broadcastings also need to be taken into consideration.
In deciding TV White Space availability, it takes too much time and workload when this analysis is conducted manually for all the TV channels. Consequently, NICT implements a feature to create a list of availability on each TV channel in the White Space Database. By dropping a pin on the map, setting some parameters and clicking a button, the White Space Database shows a list of channel availability at the top of the screen as shown in Figure 1. The green mark means available and the red mark means unavailable for wireless systems to use the channel.
In actual operation of the White Space Database, processes can be automated, so that an operator has no need to manually operate every time manually by operators. Location information acquired by GPS of a wireless system is sent to the White Space Database and the list of TV White Space is automatically calculated. The list is sent back to the wireless system and the channel(s) is(are) selected by the wireless system for its operation.