voip

The TRAI, after consulting on the possibilities of ‘migrating to an IP-based network’ for interconnecting voice-data over IP network (VOIP) in 2014, has now issued recommendations to the DoT stating that IP-based networks are increasingly gaining traction, therefore facilitating interconnection between IP-based networks is imminent.

“Today in many cases, the voice traffic is also being carried over IP. As IP based networks continue to proliferate and traditional circuit switch networks are gradually being phased out, there exists need to facilitate interconnection at IP level”

Conventionally, in the current telecom scenario, circuit switch networks carries voice data, facilitated through a PBX (Private Branch Exchange) system that uses analog signals to enable voice-calls. For Eg: In a 2G or 3G network, the user is able to make calls as analog signals pass through multiple switches before a connection is established. Moreover, during the call, no other network traffic can use those switches.

While, IP-based networks (VoIP or VoLTE) facilitates exchange of mobile-data through computer servers, as well as voice-data through 4G LTE networks. In a scenario where an IP-based network is used to make voice-calls, the transfer of voice between two users takes place through small data packets. The packets identify the most shortest or efficient route from one end of the user, to the user at the other end, without the need of multiple switches.

After the previous consultation in 2014 regarding migration to IP based network, stakeholders said that an imminent transition towards IP based network was widely anticipated, and that it was essential to amend the license conditions to ‘explicitly’ provide for IP based interconnection.

With the rise of LTE networks, VoLTE (Voice over LTE) is picking up a grip in the Indian market as more LTE-enabled smartphones hit the shelves. In addition, Reliance’s Jio, which is expected to launch commercially by April, explicitly uses LTE connectivity to make Jio-to-Jio calls only, due to current regulations in the industry. With the newly proposed TRAI regulations,  more telcos could adopt and proivde VoLTE services to customers.

According to Clause 27.3 of Unified License, which deals with interconnection between the networks of two different licensees, ‘a circuit-switched network can interconnect with an IP-based network through a Media Gateway Switch’. However, there is no ‘explicit’ mention of an interconnection at IP level between two different licensees.

The TRAI, after reviewing comments from stakeholders proposes the following addition to the Clause 27.3 of Unified License:

“Interconnection between two networks of different Licensees for carrying circuit switched traffic shall be as per national standard of CCS NO.7 and for carrying IP based traffic as per Telecom Engineering Centre (TEC) standards as amended from time to time and also subject to technical feasibility and technical integrity of the Networks and shall be within the overall framework of interconnection…..”

If the government accepts the above regulation, Reliance’s Jio users who depend on VoLTE standard will be able to call subscribers of non-VoLTE networks, and vice-versa, by using a Media Gateway Switch, under existing regulations. Note that a VoLTE call uses a 4G LTE connection, instead of the traditional circuit-switched 2G or 3G network.

Image Credit: King Huang under CC BY 2.0