Introduction
With the advent of 4G, tariff plans offering “unlimited voice” has become a norm in India. It was initially triggered by RJIO but, now all operators are offering it. The cheapest plan of this kind requires a subscriber to pay a fixed monthly fee of Rs 149 only for all calls that are made within the operator’s own network. However, RJIO’s subscribers face no such restrictions. For them, “unlimited voice” packs also include calls made to a subscriber of a competing operator’s network, as long as these calls are restricted within India. The other operators are also offering similar plans but at a much higher monthly fee. But, why did a 4G operator took the lead in offering “unlimited voice” plans and not others? Is he not scared of “network congestion” driven by excessive usage? To evaluate the risks one needs to understand the characteristics of a 4G voice call and compare it with one that is carried over 2G.
VoLTE is Efficient
4G networks are optimized for carrying data. It is significantly more efficient in offering huge data capacities. Voice is carried over 4G network as data. Technically it is called VoLTE (Voice over LTE). Voice in the LTE form is packetized, unlike 2G voice which is “circuit switched”. In layman’s term, “circuit switched” voice calls are inefficient as it blocks network resources even when the line is held unused (parties have paused for thinking). On the other hand, in a similar situation, packet switch calls frees up resources dynamically for other users, thereby significantly increasing network efficiency. Also, 4G technology uses more advanced techniques for increasing efficiency, which is not supported by 2G. Typically, data rates for circuit switched voice calls vary between 6 to 24 Kbps (KiloBits/Sec) depending upon the type of vocoder used (higher vocoder rates result in better quality). Calls with higher bitrate will need more network resources to carry it. To map the impact on 4G network, the bitrate of voice calls needs to be converted to MB (MegaBytes). That’s what I plan to do next.
