With its 4G LTE services already available in several Indian cities—such as Chandigargh, Mohali, Kolkata, Panchkula and Pune—Bharti Airtel now plans to launch 4G LTE voice services in Bangalore. In a formal announcement on its Twitter account, the company says the Bangalore service will be available within 3 weeks reports The Times of India.

The company has adopted Circuit Switched Fall Back (CSFB) technology to provide voice calls over its 4G network across India. What this means is that even using a 3G or 2G network, Bharti Airtel can still offer voice to its LTE subscribers using the CSFB technology. Successful trials of CSFB technology were conducted earlier this year in Bangalore, Kolkata, and Pune.

Furthermore, Bharti Airtel has teamed up with Chinese manufacturer Huawei for 4G devices in India, with Huawei's Ascend P1 LTE being exclusively announced for their 4G LTE network. Bharti Airtel has also been testing other devices from Samsung, ZTE, and Indian manufacturers such as Micromax.

The telco will roll out 4G services soon in metros such as New Delhi and Mumbai, and states such as Haryana and Kerala. A few months ago, the company acquired a 100 percent stake in Wireless Business Services, a company founded by U.S. chipmaker Qualcomm.

While Bharti Airtel currently has a monopoly in the 4G LTE Indian market with other telcos yet to roll out their services, the big question is will subscribers quickly switch to 4G? It might be a hard sell following the recent reduction in data rates for 2G and 3G services by most of the Indian telecom operators.

Perhaps the biggest setback subscribers will face is having to upgrade their devices to ones that can support 4G LTE services, in order to make full use of what's available. Generally speaking, there are not too many options available in India for 4G LTE supported devices, but that will eventually change as 4G LTE services are rolled out and readily available across India.

One continuing puzzle is why neither Bharti Airtel, or any other Indian telecom operators, are offering 4G LTE in New Delhi or Mumbai at the moment. Both metros are vibrant cities, are key parts of India's growing and emerging economy, and also the entry point to India for most business travelers and foreigners. It's safe to assume many of them already have 4G LTE devices and would like to use their devices within India, but again, options are quite limited at the moment.