Guest Contributor | Mar 12, 2019 | 0
Technology for long-range wireless connectivity revealed
Singapore – The Ammbr Foundation released details on the long-range wireless technology that will make the Ammbr mesh router capable of picking up signals from up to eight kilometres.
The Ammbr foundation intends to help connect the 4.1 billion people who don’t have Internet connections, through the implementation of innovative technology that allows improved connections in rural areas and over longer distances. The key, according to Derick Smith from Ammbr, is tapping into unused frequencies known as television white space (TVWS).
TVWS technology can operate in conditions where line-of-site is not possible due to obstructions such as vegetation and walls, and theoretical calculations show that a 600-megahertz TV white space signal can cover 16 times as much area as a 2.4-gigahertz Wi-Fi signal. The technology will allow Ammbr routers to extend their range up to 8 km, provide a much wider coverage footprint and allow the devices to reach neighbouring routers in areas not possible before TVWS.
TVWS exists due to a lack of use of the full set of terrestrial TV channels available and to protect television broadcasters from interference caused by adjacent analogue TV transmitters using the same channels. As stations transition to more spectrally efficient digital television, many of these broadcast bands will remain vacant and will be available for broadband use. In Africa, many rural areas have close to 100% TVWS spectrum available which makes these areas an ideal candidate for TVWS.
TVWS is part of a wider movement of Dynamic Spectrum Access technologies that seeks to more efficiently make use of spectrum that is only licensed nationally to primary users by allowing secondary users to access the primary spectrum where it is not used in specific regions or at a specific time. Access to TVWS spectrum is made possible by using a geolocational spectrum database that checks what channels a TVWS base station can use at its specific GPS position without causing any interference to neighbouring television receivers.
The UHF band used by TVWS is the sweet spot of the radio frequency spectrum that terrestrial broadcast television has been sitting on for over 60 years – TVWS has finally provided the solution to access this critical high value spectrum for broadband access. Although TVWS trials have been running since 2008 in 20 countries, currently only the USA, the UK, Singapore and South Africa have finalized TVWS regulation. It is hoped that the recent approval of TVWS in South Africa in 2018 will create the catalyst for regional approval of TVWS across Southern Africa – possibly even creating a regional TVWS geolocation spectrum database.
The TVWS spectrum lets Ammbr owners install the routers to connect to the Ammbr network in varied terrain, from dense vegetation to mountainous regions, and up to 8 km away from other Ammbr routers. This is critical in rural communities with low population densities – a key demographic where the last mile is often too costly for operators using cellular technology.
Last week, Ammbr released the demo version of the fully integrated Wi-Fi, television white space (TVWS) and blockchain capable routers – a first of its kind. These routers will be used in a series of trials around the world in places such as Cape Town, South Africa (where a TVWS regulatory framework was published in April) and parts of the United States as well as Europe
Ammbr Research Labs’ (ARL) David Johnson, who has been involved in the efforts to draft these regulations and carried out R&D and trials for the past six years together with the dedicated CSIR TVWS team, described TVWS as “the elusive promise to bridge the global connectivity gap”.