London Zoo is trialling the latest development in remote internet facilities. The aim of the Zoological Society of London (ZSL) is to see if using TV White Space (TVWS) connections can improve connections to it various projects in Africa and elsewhere to monitor and protect endangered species. One fortunate side effect is that it is providing some extremely cute webcam feeds.
The current two month trial uses webcams in three enclosures which could otherwise only be connected to the internet with difficulty. Despite being in central London, the site has extremely poor 4G cellphone connections. This is due to the number of both trees and buildings in the area that shield the signals. Wifi, in its various guises, needs direct line of sight between the transmitter and receiver, again problematical given the location.
TVWS uses the same UHF spectrum as digital TV. Those frequencies have the advantage that a) line of sight is not needed; b) the signals can penetrate leaves and go into buildings in ways 4G and wifi signals cannot - the reason the frequencies for chosen for TV transmission in the first place and c) the signals carry significantly further than other technologies, apart from expensive satellite based internet systems which are often not available over the areas they wish to monitor the wildlife in.
TVWS uses the bits of the UHF spectrum that are not used for TV transmission in the immediate area. In most cases national telecoms authorities arrange for a separation of one TV channel between the various frequencies available at any one location. This is a result of possible interference in analog systems. Digital TV is not so prone to this so that intermediate frequency can be used for TVWS data - the London test is to confirm that this is the case in an area covered by 11, due to be 12, different TV frequencies. Six of these are 200Kw transmitter power, the most powerful used in the EU, from Crystal Palace. Three are relatively low power 70w from a relay used to "fill in" problem areas where analog signals from Crystal Palace had multiple "ghost" images, known in TV engineering as "multipath signals".
The ZSL trial is in association with Google as they maintain a database of the white space available. The equipment has GPS locators to tell it where it is and therefore what frequencies are available for use. Two webcams are located to show the enclosures for the meerkats and Galapagos tortoises so are dark at night but the third is located within the holt of the oriental small clawed otters. Unusually for otters, these are not solitary animals but remain in family groups. This makes for some charming scenes as they groom each other each evening before settling down to sleep or wake up, groom and change position in the huddle. (See below the orange)
The meerkats and tortoises feeds can be accessed from the main link above. The ultimate aim is to see if the technology can be used in the ZSL's work with various conservation bodies. It already has remote cameras in places like Kenya through its Instant Wild program. Part of this involves giving live feeds to stop poaching while there is a crowd sourcing scheme to identify the creatures captured by still camera traps in order to provide a survey of the biodiversity in the area.
TVWS has considerable potential to provide data links in places where it would otherwise be impossible to reach. One suggestion is that it could provide ship to shore links, especially for lifeboats and rescuers.
"It could give them (the crew) voice, it could give them video, and in the future it could also send information from medical machines back to base, so if there's an emergency at sea you can send that information back, so they know what to expect," he says
The main commercial aim is to provide broadband access for remote rural areas like parts of the USA where terrain and distance from an exchange make connecting expensive and complex.