NEW DELHI: Free Space Optical Communication or FSOC technology may see an uptick in its adoption in India by telecom operators given that commercial 5G services roll outs are underway, and by internet service providers (ISPs) to extend the reach of broadband services in hard-to-reach rural areas, according to companies working in this space.
In industry parlance, FSOC refers to outdoor optical wireless communication (OWC) whereas indoor or short-distance OWC is called light Fidelity (LiFi). LiFi promises to offer a secure network, with up to 100 times faster speeds than Wireless Fidelity (WiFi) and is likely to find uses in smart cities, smart homes, Industry 4.0, to connect robots and machinery, and the Internet of Things (IoT) among others.
While WiFi is a mainstay for connectivity inside homes, offices and enterprises, LiFi has seen limited implementations in India, including in an institute in the union territory of Ladakh, in Nadabet along the India-Pakistan border in Gujarat by Ahmedabad-based Nav Wireless Technologies, and an indoor LiFi set up in the Department of Telecommunications (DoT) by Delhi-based Velmenni.
Notably, LiFi uses the visible light spectrum in indoor and outdoor conditions to transmit data but WiFi relies on radio waves to provide internet connectivity.
According to an International Telecommunication Union (ITU) article, financial services and healthcare sectors may adopt LiFi due to its high security as the light does not travel beyond the walls of a room. On the consumer side, it could support advanced gaming and Virtual Reality (VR) applications.
In the telecom space, OWC backhaul links for 5G network infrastructure will underpin faster roll out of the fifth-generation services as deploying fiber to all mobile towers quickly will not be possible, said Hardik Soni, Co-founder & CTO, Nav Wireless Technologies, claiming that Radio Frequency (RF)/Microwave-based backhaul would not be able to provide desired bandwidth for 5G Services.
“Similarly, 5G private networks can also make use of OWC backhaul links for quick turnaround time,” he said.
Further, once a high-speed 5G signal is available outside premises, getting it reached inside with the same capacity would prove to be a challenge as the network will be riding on a high-frequency spectrum which would impede indoor reception, the executive said. “LiFi transceivers can be used to bridge the outdoor and indoor environment wirelessly while maintaining the high network throughput.”
To be sure, the low band for 5G provides greater propagation, making it ideal for urban deployments, by contrast, the high band (26GHz) offers greater bandwidth but suffers from low propagation capabilities.
Reliance Jio, Bharti Airtel, Vodafone Idea, and Adani Data Networks have acquired spectrum in the 26GHz band for captive private wireless/private network deployments.
The Centre had put 72,098MHz spectrum to auction across the low, mid and high frequency bands, of which 51,236MHz (71% of the total), was sold with bids amounting to Rs 1.5 lakh crore in the country’s first 5G airwaves sale.
Jio and Airtel aim to extend the coverage of their 5G network, based on the standalone (SA) and non-standalone (NSA) modes, across India in a 12-15 months timeline.
Nav Wireless says it has indigenously developed indoor and outdoor, both types of OWC solutions and claims that its outdoor point-to-point OWC can deliver over 1Gbps bandwidth throughput for more than 10 kilometers, which complements fiber.
Project Taara, a brainchild of Google-parent Alphabet’s moonshot lab ‘X’, said that its WOC links use beams of light in the near-infrared band (193THz), which has abundant bandwidth and no interference, to transmit data at speeds of up to 20Gbps.
Mahesh Krishnaswamy, Director & Project Lead, Project Taara, said that the company’s WOC links are ideal for deployments in areas where it is not economically feasible, or is too difficult to lay fiber, such as over rivers and sea straits, across rugged terrains and national parks, or in areas where it is unsafe to dig trenches for cables.
“Taara’s links are light and portable, each terminal weighing around 13 kg and consuming just 60W of power, like an incandescent light bulb. Setting up two links takes only a few hours, meaning we can deploy fast and deliver high-speed internet to more people,” Krishnaswamy added.
US-based Taara has been working in India since 2017 and has a working partnership with Airtel, and ISP Bluetown in India to connect governments and rural parts of the country to this technology.
Satya N. Gupta, Chairman – India & BIMSTEC, Asia at Bluetown told ETTelecom that the ISP currently has 10 FSOC sites deployed between Delhi and Uttarakhand.
“FSOC can bridge the middle-mile communication gap in the areas where the optical fiber cable is difficult to deploy, like river crossing, railway track crossing, and difficult terrains. There we can use FSOC to get the bandwidth and distances which are at par with the optical fiber cable and much more than what the radio can give where there is a limit of up to one gigabit only,” Gupta said.
In the context of 5G, he added that FSOC will be extensively deployed albeit on a need-basis for connecting mobile towers as it will not be possible to lay fiber in certain terrains. Industry statistics show that fiberisation of towers needs to increase from 30% currently to about 70% to carry the high bandwidth of 5G.
Nav Wireless’ customers include telecom operators and ISPs in India, as well as, Bharatnet, the state governments for Wide Area Network projects, defense establishments, and tourism boards, among others, on a need-based model.
The technology, the executives said, can offer various advantages to telcos and ISPs alike in terms of cost savings and increasing the reach of broadband internet vis-a-vis fiber.
“By Using OWC, telecom operators and ISPs can save 40%-50% costs vis a vis fiber and at the same time can deploy network quickly resulting in better network coverage,” said Soni.
While LiFi technology has been in existence for several years, its large-scale adoption has been hampered by a lack of formal industry standards. “In this context, efforts have started recently in IEEE 820.15.7, IEEE 802.11 as well as ITU-R to standardise the LiFi technology,” said Soni.
The nascent technology faces challenges from high costs as it is yet to attain the scale of economies. The performance of the WOC links, on the other hand, can be hampered by weather conditions and natural elements like fog, smog, dust, and heavy rain, and line of sight (LOS) in dense urban areas.
Going ahead, LiFi and FSOC will be used in 5G, 6G, private and wireless networks, as laying and maintaining fiber may not be feasible. OWC links will also be in demand for high bandwidth Ground to Space backhauls for satellite internet services in LEO, MEO and GEO orbits, according to Nav Wireless.
