Ten key questions about VoLTE - technology of the future - answered

VoLTE or Voice over LTE services have been launched by 100 operators all over the world, in India Reliance Jio is the first and only telecom operator to launch VoLTE services. Other telecom operators like Airtel, Vodafone too are at various stages of launching their VoLTE services. Simply put, VoLTE means your voice call too is treated like data and a VoLTE enabled phone can handle calling and other data-based activities simultaneously. VoLTE is seen as a promising technology as it helps in optimal use of data along with HD call quality. Ericsson estimates the VoLTE subscriber base in India will reach 370 Million by 2022. Even though the VoLTE device ecosystem has grown rapidly in the last 2-3years, there is still a dearth in availability of entry level VoLTE phones in India. Newest telecom operator in the country, Reliance Jio has also launched its own VoLTE enabled Jio phone priced under an “effectively free” scheme targeting the ‘2G’ or feature phone market of India. It means the technology will now be experienced by not just high end or mid range smartphone users but entry level mobile phone customers too will be using the technology. So I sat down with Rahul Karnik, Engagement Director, Global Performance Partnerships at Ericsson to get a complete lowdown on VoLTE technology around the world and started by asking how mature is the VoLTE technology for deployment in India?

The overall ecosystem for VoLTE has matured over the past five years. This includes the handsets, radio networks, packet core and IMS networks used by operators. Most VoLTE deployments involve equipment components from multiple vendors. Standardization of interfaces, between these components used for VoLTE, has helped in reducing deployment times as well as increasing the reliability of these networks. Learnings from early deployments are allowing vendors to help operators with their VoLTE deployments. In general, VoLTE continues to mature and this can be seen from the improvement in the key performance indicators that are tracked by operators.

Also Read: Is Jio phone flouting the principles of Net Neutrality?

What are the benefits of VoLTE to customers?

The main benefits of VoLTE to customers are: High-definition voice, Faster call setup times, Improved battery consumption compared to OTT voice, Interoperability with voice over Wi-Fi, and the potential to add video as well as messaging, location sharing, whiteboarding, etc. VoLTE calls are more efficient than regular voice over IP calls and help customers by consuming lesser data for voice calls. Finally, VoLTE offers the same “green button” promise that customers have relied upon for a long time. VoLTE is a telecom grade service and provides higher Accessibility, Retainability, and Integrity as compared to over the top voice services.

At the global level, wherever VoLTE has been launched, how has been the uptake?

Overall, the VoLTE uptake has been strong, Network measurements show uneven uptake across regions. In the US, Japan, South Korea and Canada, VoLTE uptake was very strong in 2016, with most networks having more than 60 percent of voice calls on LTE smartphones provisioned using VoLTE. In some networks this figure was close to 80 percent. In Europe, the service is used by relatively fewer people, as many launched networks still require subscribers to configure VoLTE themselves in the device settings, or to buy a special VoLTE subscription. Past launches of the service demonstrate that for VoLTE usage to take off, automatic operator provisioning is necessary. In these circumstances, the VoLTE penetration then quickly rises to the percentage of LTE smartphones that are VoLTE-enabled.

How are operators in other markets charging for VoLTE calls ?

Pricing for telecom services is regulated by the appropriate regulatory bodies for each country. Initial deployments for VoLTE were not allowed to charge separately for VoLTE calls as they were considered to be part of the all-inclusive data plans offered by operators. Since then things have changed and most operators who have launched VoLTE either provide it under “unlimited talk” plan or continue to use a “minutes” based tariff for subscribers who are not part of the plan.

What are the capabilities of a VoLTE call ?

As part of the GSMA IR.92 document, a list of supplementary services which are expected to be supported by VoLTE calls have been defined. These include Ad-Hoc Multi Party Conference, Communication Forwarding (Unconditional, Busy, Not Reachable, Etc.), Barring, Etc.

What are the pre -requisites/factors to be considered ahead of launching VoLTE?

If operators have already launched LTE, the primary factors to be considered are Deployment of the IP Multimedia Subsystem (IMS), Integration of IMS with the other network components, Enabling VoLTE related features in the Radio Access Network (RAN) and other network domains, Implementing Quality of Service (QoS), and performing Device and Application verification. After the network components have been deployed and integrated, operators need to tune and optimize the VoLTE service to ensure a high-quality experience to their customers.

What kind of investment would be needed?

In addition to the Network Readiness activities listed in the previous questions, operators who desire to launch VoLTE services need to consider Operational Readiness and Organizational Readiness. Operational Readiness (People/processes/tools/data to support all operational aspects of VoLTE are in place e.g. Ordering, Fulfilment/Provisioning, Billing, Support, Cancellations, Etc.), and Organizational Readiness (Goes beyond the Network and IT organizations and must identify impact on Marketing/Sales/Customer, Legal, Vendor Partnerships, Etc.) are other considerations that would need investments from the operator.

What is the significance of VoLTE from a 5G perspective? Is it critical for 5G deployment?

Operators have a large amount of spectrum currently allocated for 2G and 3G technologies. As operators move towards 5G and IoT deployments, they will need more spectrum which can be achieved by freeing up what they already have or acquiring more spectrum. One of the reasons that operators still have the 2G/3G networks is that voice is primarily carried over those technologies. VoLTE, due to its spectral efficiency, can help operators in freeing up spectrum currently being used for 2G/3G voice calls. Going to VoLTE can speed up the process of switching off the older technologies, which also helps from an opex/capex perspective.

As far as the spectrum is concerned what will be the requirements VoLTE has? Will VoLTE need more spectrum?

VoLTE has a better spectral efficiency than its predecessors for audio calls. VoLTE can carry, for the same spectrum, between 3 to 6 time more audio calls as compared to 3G or 2G technologies. This is one of the benefits that VoLTE offers to operators. Operators can leverage VoLTE to efficiently use their available spectrum. Over time, we will see the 2G/3G spectrum being re-farmed to LTE.

What is the roadmap beyond VoLTE ?

In order for operators to start offering VoLTE services, they need to deploy IMS (IP Multimedia Subsystem). IMS will then allow for additional services to be offered for both, consumers, and businesses. These services include Video Calling, Voice over Wi-Fi, RCS (Rich Communication Services) which includes Messaging, File/Location Sharing, Presence, Group Conversations, Etc. for consumers. For businesses, the offerings could include Corporate Video Services, Fixed Network Integration, Integrating IP communications within existing business processes, Etc.