Bharti Airtel is still testing its 4G voice or Voice over LTE service and a pan-India launch will take place only by January-March of 2018.\r\n\r\n\r\n\r\n"VoLTE is a very complex technology," CEO Gopal Vittal said. "There is a lot of optimization. It has to be tested device by device," he said, adding that it will take 6 to 9 months for a pan-India launch.\r\n\r\n"Once that\u2019s done, we will be able to pick up a lot of traffic," he said, adding that tests have already been carried out in a few places. He also said that the launch of VoLTE will help the company shift traffic away from the 3G network and decongest it for data.\r\n\r\nVoLTE offers higher definition, or clearer, voice calls than 2G and 3G calls. It also reduces the amount and complexity of the telecom network as it treats voice as just another type of data.\r\n\r\nIn traditional 2G and 3G networks, voice is treated, and carried, separately from data traffic and this increases the complexity of the network, making them more costly to maintain and operate.\r\n\r\nPart of the reason that Reliance Jio is able to offer unlimited calls for Rs 150 per month, while rivals charge Rs 350 per month for the same facility, has to do with the cost efficient design of VoLTE.\r\n\r\nMany Airtel users are waiting eagerly for the launch of VoLTE to experience higher quality voice calling, and are likely to be disappointed by the indicated timeline of last quarter of the current financial year (January-March 2018).