The VoLTE Re-Evolution - cover

The VoLTE Re-Evolution

February 9, 2017

While 5G testing and PoCs are underway, and IoT is increasingly gaining more and more momentum, many network communication service providers are looking for ways to utilize 4G-LTE to provide quality voice and video, and to introduce new services. LTE technology is keeping an energetic forward pace. AT&T has completely and officially shut down its 2G service as of January 1, freeing up more spectrum for LTE as well as 5G, in spite of millions of customers still remaining on its GSM and other 2G networks. In a July interview with Fierce Wireless, Verizon confirmed that it is on track to shut down its 2G CDMA networks by 2019, with the intention of migrating voice traffic to VoLTE. What’s clear is more than just the signal: it’s the very definite message that if CSPs want to remain relevant and revenue-realizing, they will need to provide VoLTE.

The VoLTE (Voice over Long Term Evolution) over IMS platform covers far more than voice. What does VoLTE present as part of its digital buffet? Among other things, high quality audio, high-definition video, rich communication services, and, most importantly, a real opportunity to reclaim the market taken over by OTT (over the top) services such as Skype, WhatsApp, and Netflix.

With over 90 VoLTE-enabled networks already operation, and with the constant growth of VoLTE-enabled chipsets and phones, VoLTE is a serious contender in that battle for several reasons.

Subscriber and CSP Benefits of VoLTE

VoLTE is a game-changer, and it has racked up resources and dividends for subscribers and CSPs alike.


VoLTE (and Video over LTE) session quality is assured end-to-end. The CSP (Communication Service Provider), who controls traffic settings, can set this type of traffic as high priority, pushing it to the front of the line and accelerating its travel over the network. OTTs, on the other hand, use mobile networks as a pipe, with their services traversing the network at “best effort” quality levels over non-guaranteed bit-rate bearers.

CSPs have an obligation to their paying customers; OTTs are less concerned.

Expecting and receiving better quality service, as well as having access to customer service, is obviously a big step up for subscribers using VoLTE. That also means that, whether as part of a standard plan or a pre-paid package, CSPs can offer paid services that can compete with free OTT, at rates that are likely inexpensive to the subscriber.

Better Battery Life

VoLTE services compare favorably with OTT call apps with regard to network requirements, while simultaneously delivering a consistently higher call quality. Which means a significantly longer smartphone battery charge. That should be popular.


Business users and some general consumers (think any long-distance family members) are prepared to pay for clear, sharp audio and video for conferencing. When a conversation and interaction are important enough, it seems reasonable to upgrade to premium.


VoLTE enables value-added services like chat and specialized apps. There’s more you can do for the subscriber, and especially if they’ve already signed up for a plan, that is a satisfying feeling for them and for the CSP. Bundling small extra services with plans or pre-paid packages can generate both CSP revenue and subscriber loyalty.

Specialized Services

The VoLTE infrastructure extends the opportunity for CSPs to provide specialized client services that really only make sense when provided by the CSP. For example, high-quality live-streaming voice and video could be used to help enhance situational awareness for firefighters and emergency workers handling a disaster recovery scene. This is a new initiative within the public safety ecosystem that began in 2012 and is ramping up around the world, with the plan to use robust LTE networks to help save lives.

Initial Connect Speed

Faster than OTT, faster than placing a traditional call, just about as fast as a speeding bullet: VoLTE call set-up gets you through to your call in nothing flat. Who doesn’t like fast? Nobody, that’s who.

VoLTE Boosts for CSPs

What are some VoLTE benefits that affect CSPs more directly?

Spectral Efficiency

Spectrum is a very costly limited resource: higher spectral efficiency is a huge gain for CSPs. Radio interface between antennae and phones works on a limited spectrum of frequencies, and CSPs pay for the privilege of operating within that spectrum. VoLTE’s big bump up in efficiency means pushing more information over less frequency. That mean providing more service over spectrum that’s already paid for: 20 bits per Hertz instead of 10, for example. It’s just smarter. And it’s a whole lot cheaper.

Single-Tech Simplification

With voice and video services running over LTE, CSPs can incrementally decommission 3G, and 2G if they’re still using it. Running and maintaining multiple generations of networks simultaneously is a heavy spend on services, operations, and spares. It’s frankly a whole lot of headache. How will that work out with 5G coming up fast? 5G actually integrates LTE, so while some things may change, the overall system will be future-compatible.

Saving Bandwidth with WiFi

VoWiFi uses the same technology as VoLTE: when an LTE antenna is in range, phones can connect to it for VoLTE service and a regular call. But in addition, when WiFi is available, phones can be set to prefer the WiFi antenna for the call. The call is passed back once again as the subscriber leaves the WiFi antenna area and returns to LTE service. The subscriber will not notice the handover in either case: it is designed to be seamless. This provides the subscriber with identical service while saving bandwidth and spectrum for the CSP. Essentially, it’s a more intelligent use of resources.

Optimized Bandwidth

VoLTE uses advanced codecs. A codec refers to an algorithm that compresses and encodes voice and video data as it enters the system, and then decompresses it on the other side, so it can be properly heard. While there are dozens of codecs, VoLTE uses those that provide hi-def voice: AMR-WB (wideband) and NB (narrowband), for example. The advantage of these specific codecs is that they can change according to fluctuating bandwidth mid-call, which the average codec can’t do. AMR is flexible, and compensates for less bandwidth when there is less available. Importantly, it adapts to give the subscriber an optimal experience when the bandwidth changes mid-call. There’s also another generation of codecs moving into the spotlight these days: EVS (enhanced voice service), which promises to drive audio quality and bandwidth efficiency to even greater heights.

VoLTE Challenges

VoLTE-specific dilemmas must also be acknowledged and responsibly addressed.

First of all, with VoLTE presenting one platform for all services, we’re reminded of the Andrew Carnegie (or Mark Twain) quote: “Put all your eggs in one basket, but WATCH that basket!” We suggest you do, and we can help with that.

Bandwidth Tending

VoLTE advanced codecs such as AMR-WB and NB present not just optimization, but a concern as well.

Mobile network resource usage is incredibly dynamic and constantly changing. You’ll need to keep an eye on call quality while the call bandwidth fluctuates and switches mid-call. The RADCOM MaveriQ solution (including the QTrace and QExpert tools) provide CSPs with a real MOS (mean opinion score) regardless of bandwidth fluctuation or switching. MaveriQ can also record and play back VoLTE calls, so you don’t have to rely on our scoring: you can actually listen and see how the call went. RADCOM’s MaveriQ can record and play back compressed calls, using a matching algorithm for playback. This is very useful for QoS (quality of service). It goes without saying that CSPs must make it their priority to be aware of and comply with any local legal regulations regarding call recording and playback.

Handover Monitoring

LTE-based handovers need to work smoothly. If the handover fails for any reason, subscribers will have their calls and data disconnected. Each call handover, or data transfer handover, whether it’s LTE to WiFi, WiFi to LTE, or LTE to 3G and vice versa as subscribers pass through different antenna sectors, must be carefully monitored. CSPs could wind up with some very unhappy customers, or ex-customers, otherwise, and they won’t even know what happened until it’s too late.

This crucial and complex handover monitoring is well and smoothly handled by RADCOM’s MaveriQ solution. We are experts at making sure you know if a call disconnects, when it drops, and why. That’s integral to assuring customer satisfaction with your service, as well as to preventing customer churn.

Yes, You Most Likely Will Need to Offer VoLTE

According to a Global Mobile Suppliers Association report, as of this past October, more than 150 CSPs in 72 countries had invested in VoLTE, including more than 90 CSPs who had already launched VoLTE commercially, in 52 countries. A recent Ericsson Mobility Report predicts that VoLTE consumer subscriptions should climb over 200 million by the end of 2017. VoLTE subscriptions are set to reach a cool 3.3 billion by 2022, with about a 60% share of global LTE subscriptions.

A recent market research study indicated that VoLTE revenue will have a compound annual growth rate of approximately 34% from 2016 to 2020, with VoLTE subscribers accounting for upwards of $200 billion in revenue by the end of 2020. VoLTE installation and integration may be an expense for CSPs now, but it is an inevitable investment that must be made in order to battle OTT dominance as well as keep a competitive edge within the CSP market. And, judging by the financial estimates, it will apparently also bring significant rewards.

Happy, loyal customers who are satisfied with their quality of experience and quality of service are likely to not only be thrilled with the benefits and abilities of VoLTE as it matures, they are also an excellent potential market for other CSP service offers. There are a lot of new verticals opening up: it’s up to you to decide how your company can best take advantage of the opportunities. Read more here to see how RADCOM can help with your VoLTE service.

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