5 benefits of VoLTE over traditional CS voice calls
VoLTE is a telecommunications specification (by GSMA, IR.92) defining how to enable mobile voice services over packet switched networks, such as LTE (4G), Wi-Fi and 5G. It creates a foundation for globally interoperable consumer, business and enterprise voice and communication services across LTE, Wi-Fi and 5G. It enables operators to offer high-quality, simultaneous voice and communication services and 4G/5G mobile broadband on smartphones and other voice capable devices. VoLTE is delivered via the IP Multimedia Subsystem (IMS). volte benefits
VoLTE subscriptions are estimated to reach 3 billion at the end of 2020 and 6.4 billion by the end of 2025. This will account for almost 90 percent of all combined LTE and 5G subscriptions. The shutdown of 2G and 3G networks will accelerate VoLTE adoption and VoLTE roaming agreements. VoLTE will support subscribers and roamers with voice services, as the current most used 4G voice solution, Circuit-Switched Fallback (CSFB), will not work without 2G or 3G.
Five benefits of VoLTE
VoLTE provides five benefits over traditional CS voice calls.
Migration to IP
VoLTE enables operators to migrate their circuit switched infrastructure (e.g. 3G) to a fully IP centric network. Without VoLTE, 4G networks cannot support voice service, therefore operators wishing to offer this communication capability will need to still support legacy technologies and use CSFB (CS Fallback) techniques to redirect the user towards them when a call is made or received.
Voice Quality
VoLTE offers higher voice quality than legacy circuit switched voice. As shown in Figure 1, VoLTE provides voice in wider range of frequency and enhances the voice quality significantly. With implementation of EVS (Enhanced Voice Services) codec, the range is even extended, and customers can enjoy very high-quality voice.
Fast Call setup
Another prominent advantage of VoLTE is the shorter call setup time compared to legacy circuit switched voice services. Call setup time is the time it takes from initiating the call to hearing from or speaking to the called party, and VoLTE reduces the call setup time to about a third of that of legacy circuit switched voices.
Multimedia communications
VoLTE also enables video calls to be provided in conjunction with HD voice (ViLTE: Video over LTE). This means that not only video calls are possible between VoLTE subscribers, but also switching between Video and Voice is supported.
Efficiency
As VoLTE calls are natively supported by LTE networks, the scarce radio resources are used much more efficiently than with legacy technologies.
IPLOOK’s IMS products and VoLTE services
IPLOOK has developed IP multimedia subsystem (IMS) products that incorporate IMS applications which are installed on hardware devices built to the Advanced Telecom Computing Architecture (ATCA) standard (the leading hardware standard for telecom carriers), and which form the core networks of mobile phone services. IPLOOK also provides telecom carriers with solutions that help them deliver a wide range of optimized voice services.
IPLOOK’s IMS products consist of a Proxy-Call Session Control Function (P-CSCF) and a Serving/Interrogating Call Session Control Function (S/I-CSCF). These are part of a control system that performs call control, a Telephony Application Server (TAS) incorporated in a service delivery system that controls additional mobile phone services, and an IMS Access Gateway (IMS-AGW) that controls packet and relays voice data.
An IMS application sample is shown in Figure 2. As this makes clear, introduction of IMS products to a telecom carrier’s core network makes it possible to offer Voice over LTE (VoLTE) service in which voice calls using the LTE communication system are possible. This supports voice calls and video calls with high sound quality, minimal delay, and high stability. Moreover, high-speed data communication can be used even during a call.
