The 21st century has been synonymous with the proliferation of Information and Communication Technology (ICT). The sector has come to play a vital role across multiple areas of human life such as education, health, science, financial markets, security, civil protection, media and entertainment amongst others. As a result, access to efficient and sustainable ICT infrastructure is a key goal worldwide. In order to meet this goal there has been both a sharp increase in demand for bandwidth for communication systems, and a preferential shift from the usage of fixed wire-line technologies to mobile technologies. The drastic increase in demand has put pressure on the supply side of resources; a challenge seen clearly in India where there is a yawning gap in broadband penetration between urban and rural areas.
While the lion share of contribution to broadband subscription in India comes from DSL or A-DSL services (which require the deployment of optical fiber cables), cellular services and unlicensed Wi-Fi based solutions, there are specific limitations. The deployment of optical fibres is an expensive proposition and cellular service providers suffer from diminishing average revenue per user (ARPU), high license fees and infrastructure costs. Unlicensed Wi-Fi solutions meanwhile often have poor physical layer propagation characteristics resulting in low-coverage area. In addition to these limitations, the infrastructure cost for cellular based as well as Wi-Fi based broadband solutions in rural areas is expected to be very high. Furthermore, there remains a key impediment namely the lack of robust cost-effective backhaul. In such a scenario, the solution is utilizing a mesh based last-mile or middle-mile network that is capable of providing coverage within a radius of one to five kilometres. Sub-GHz spectrum not only provides excellent propagation characteristics to reach these distances but additionally does not require investments in infrastructure.
TV White Space (TVWS) is one such band within the Sub-GHz spectrum and is “a part of the spectrum, which is available for a radio communication application (service, system) at a given time in a given geographical area on a non-interfering/non-protected basis with regard to other services with a higher priority on a national basis.” In more layman terms, White Space Spectrum refers to the small gaps or empty spaces that are unused in an otherwise heavily-occupied broadcasting spectrum band. Per a study by the Indian Institute of Technology-Bombay, India has only one terrestrial TV service provider—Doordarshan, and as a result nearly 12 (80%) out of 15 channels of 8Mhz in the “TV-UHF band-IV” are available as TVWS.
The unused band if deployed effectively can assist in the provision of broadband connectivity to rural areas; a key goal of Digital India. It can be used for affordable backhaul to connect Wi-Fi clusters, and can eventually terminate into the urban-sub-urban or village gram panchayat National Optical Fibre Network node. Additionally, this band can be used to provide connectivity in remote locations, difficult terrains and scenarios where it is not possible to deploy fiber. Finally, TVWS can be used to provide backhaul to unlicensed Wi-Fi operations in villages or Panchayats.
An example of the potential of TVWS to provide rural connectivity is Microsoft’s pilot study at Harisal (a small village in Maharashtra). In 2015, the tech giant expressed interest in using White Space to bring low-cost broadband internet access to 500,000 Indian villages , and was allowed to conduct pilot pilots in Harisal, Srikakulam (Telangana) and Varanasi. In March 2016, the Department of Telecommunication (DoT) issued eight licences in the 470-582MHz band to ERNET (an autonomous body under the Telecom Ministry), power equipment maker BHEL, IIT Bombay, IIT Delhi, IIT Hyderabad, IIIT Bangalore, Tata Advanced Systems and Amrawati with the sole purpose of carrying out of experiments in TVWS technology. However in June 2016, DoT decided not to allocate the 470-582 MHz spectrum band for the commercial deployment of TVWS technology; DoT also took the view that this spectrum band would not be de-licensed and the Centre would decide on pricing in the future. In July 2017, after Microsoft was not granted the license to continue operating the pilot project in Harisal, the company drew the curtains on its White-Fi internet connectivity project.
The key factor behind DoT’s decision has been its view that the frequency band can be used for other technologies and should not be limited to TVWS. Furthermore, COAI objected to de-licensing the band on the premise that it “would trigger market distortions and cause considerable losses to the national exchequer” . While there is merit to these arguments, the author of this blog is of the opinion that the decision to not deploy the spectrum band for commercial use has negatively impacted research and development in the field. Projects in addition to that of Microsoft have been put on hold; these include Google’s Project Loon, an IIT-Bombay project wherein students had developed a proof-of-concept network that relied on TV white space for transferring information, and a joint IIT-Madras and Nokia partnership that aimed to use white space spectrum to offer cheap broadband connectivity in remote rural areas.
Moving forward, it is recommended that a stakeholder consultation is organized by the government to discuss its existing stance vis-à-vis the issuance of licenses for the commercial deployment of TVWS technology. By doing so the telecom regulator will not only provide a stimulus to research and development in this field but simultaneously boost rural internet connectivity in India. While the absence of a regulatory framework is a challenge, DoT can draw upon the best practices of countries including South Africa, Singapore, the United States of America and the United Kingdom where white space is currently being deployed.