India’s top two telecom operators are preparing to deploy Voice over LTE ( VoLTE ) technology on their networks in association with Finnish gear maker Nokia to take on Reliance Jio Infocomm, which is expected to start operations soon and base its services on this technology.Bharti Airtel and Vodafone have awarded IP multimedia system solution deal for VoLTE deployment to Nokia, people familiar with the matter said, while the No. 3 carrier Idea Cellular is in “active talks” with the Finnish company to stitch a similar deal.The existing operators have been cagey about the technology so far, but with the handset ecosystem maturing rapidly they seem to have decided to take on Jio on its own turf, the people said on condition of anonymity.“They (Bharti and Vodafone) are in the process of deploying the solution and are in a testing phase,” one of the persons said. “However, the scale might be different from telco to telco, and will depend on the number of subscribers that they are planning to target,” he said.Although the contract values couldn’t be ascertained, the deals will initially be for urban areas which are likely to see most demand for 4G services and could be scaled up as adoption expands.Jio had last year given a contract worth $100 million (about Rs 670 crore) to Nokia for pan-India VoLTE deployment. After signing the deal, an operator can launch VoLTE services within a month.India’s leading telecom operator Airtel currently has 4G airwaves in 15 circles, while its closest competition Vodafone has 4G spectrum in five circles and Idea offers 4G data on one spectrum band and voice on another in 10 circles.VoLTE allows an operator to offer both voice and data without switching between bands, with voice being just another application that rides on an LTE data network, a technology that Jio has adopted.Airtel, which offers 4G services across more than 350 towns in India, will use VoLTE as a complimentary service to its existing voice offering. “Wherever Airtel has LTE network, subscribers will be able to do VoLTE call, once it launches VoLTE. In case VoLTE is not available, Airtel will fall back the call within the network to lower technologies, which are 2G and 3G,” another person said.Without commenting on the deal with Nokia, an Airtel spokesperson said, “We currently have no plans to launch VoLTE services as the device ecosystem supporting it is too nascent.”Vodafone India and Nokia declined to comment on the development, while Idea Cellular didn’t revert to ET’s queries.For Jio, VoLTE will be the base engine for delivering voice service since it has limited 2G and no 3G fallback network of its own. It is banking on tie-ups with Reliance Communications if it needs backup voice airwaves.Airtel’s chief technology officer Abhay Savargaonkar had recently told ET that the company was conducting lab trials of VoLTE, but said that it will wait for the technology to mature first. Idea had also said that it would introduce VoLTE once the ecosystem, mainly handsets, is matured to support it in India.With these deals, Nokia has become the only vendor to have provided IP multimedia system solution for VoLTE services to all the big 4G LTE telecom service providers in India. Nokia’s NFV-based IMS solution will not only allow these telcos to launch VoLTE, but would also enable them to launch RCS and other multimedia communications services going forward.An analyst said that VoLTE as a technology and service is extremely important for telecom operators and that they need to aggressively look at investing in it to counter the VoIP (voice over internet protocol) and OTT (over-the-top, or apps) threat.“As a technology both VoLTE and VoIP are IP. VoLTE has a huge number of advantages over VoIP and by embracing VoLTE, telcos can significantly armour themselves against the VoIP threat,” said the analyst, who did not wish to be named. He said VoLTE is a better voice engine than the circuit switch.