The project is a collaborative effort to trial the TVWS approach by building and deploying a sizeable cellular network testbed in the city of Cambridge UK, running on TV white space frequencies.
The trial extends across five Cambridge sites where residents, in all age brackets, typically didn’t have access to home broadband. To support them Microsoft built an open-source TVWS database client, selecting ip.access’ E40 small cell to enable the TVWS spectrum to operate. The connectivity provided by the trial enabled some residents to find employment, reconnect with friends and begin using online services for the first time.
The trial network serves about 30 users with 20-40GB of traffic each day across five cells, achieving a maximum link throughput of 60Mbps (with 2x2 MIMO on a 5MHz duplex link) and all the users experienced speeds of at least 4Mbps.
In a summary of the project, Microsoft states that “Since some of the LTE devices can operate on TVWS frequencies with no modifications, they can be sourced for less than $100. We have also found that small cell price is similar to the price of today’s TVWS hardware.”
To operate in TVWS spectrum, devices require a spectrum grant from a certified TVWS database. As a part of the project, Microsoft built an open-source TVWS database client for an LTE small cell and this was tested on ip.access’ E40 small cell. Microsoft certified most of its client’s functionality with a test house in accordance to ETSI TVWS database rules.
Nick Johnson, ip.access’ CTO, said: “The internet touches almost every aspect of modern lives. Yet, even in developed markets there are still significant numbers of people who are not connected to it, either due to limited coverage and connectivity in the area or limited funds to pay for such connectivity. Our project proves that cellular technology in TVWS is a cost-effective and high quality solution to these issues.”