What is VOLTE and What You Need To Know

August 31, 2021
What is VoLTE and how does it work - featured image

What if I told you that Voice over LTE (VoLTE) has contributed to the phone experience of telecom subscribers throughout the lockdown –although it receives less recognition than emerging technologies like 5G and cloud?

Comcast Statistics revealed that the Covid-19 situation last year created a huge demand for calls and data services — making voice and video traffic increase by 212% over its network in 2020. Users rely on voice calls to keep in contact with their families and friends.  Businesses, on the other hand, turn to voice and video conferencing to improve remote operations. 

The technology that supports this growing demand is known as VoLTE. Although less popular than the others making headlines in the technology space, VoLTE played a vital role during lockdowns by supporting high-definition calls, faster connection, and simultaneous data and phone services. 

But what is VoLTE and how exactly does it work? 

In this article, we will discuss: 

  •  What is VoLTE?
  •  How does VoLTE work?
  •  VoLTE Requirements
  •  Challenges when implementing VoLTE in the US
  •  Will VoLTE go mainstream in the US any time soon?

What is VoLTE?

Voice over Long Term Evolution offers an uninterrupted wireless communications service supplied over IP by-way-of LTE Network. Compared with the 3G network, it requires less bandwidth and has up to three times the data and voice capacity– creating a high-definition calling experience. 

Who uses VoLTE? 

VoLTE is vital in the lives of operators  (ATT, T-Mobile, Verizon); Original Equipment Manufacturers (Samsung, Huawei); network vendors, and the consumers as it continues to enrich the phone call experience of many. 

Benefits of VoLTE

In terms of cost and operation, VoLTE offers a number of key benefits. VoLTE:

  • Removes the necessity to hold data on one network and voice on the other
  • Simultaneously operates video calls over LTE multimedia services including video sharing, messaging, and file transfer.
  • Extends mobile phone battery life by up to 40%
  • Provides a remarkably smooth calling experience
  • Delivers improved use of spectrum relative to traditional voice 

How does VoLTE work

How does VoLTE work?

VoLTE is built on the IP Multimedia Subsystem (IMS) architectural framework, utilized in both mobile and fixed-line networks. The IMS framework serves as a common tool for providing an enhanced calling experience.

Most network operators use GSM/CDMA or the traditional circuit-switched to transmit voice calls. Internet and data services.  Other calls are delivered over IP-based networks such as 3G, 4G, and LTE.  Because these channels do not work synchronically, it’s off-center to be able to browse the web and talk on the phone at the same time.

With VoLTE, voice calls are transmitted as packet data the same way as emails, Skype messages, and other internet-based messaging apps. 

It also employs a number of technologies that are all integrated to make and receive calls. This includes the device model, the device firmware version, mobile network provider, and last but not the least, VoLTE signal coverage in an area. 

In sum, VoLTE operates like this:

  1. The device establishes a connection with the nearest cellular tower. Take note that the cellular tower must support VoLTE.
  2. The user then makes a call on his VoLTE-enabled device, which is transmitted to this cell tower just like a regular voice call.
  3. Before the call is sent to the recipient, the cellular tower transmits voice calls into data packets using VoLTE technology. 
  4. The line is connected after the recipient accepts the call using their VoLTE enabled device.

As of August 2019, 262 operators had invested in VoLTE in 120 countries, with 194 operators having launched VoLTE-HD voice services in 91 countries. These figures are projected to rise in the near future. Because of VoLTE’s great performance, worldwide operators agree that creating a universal VoLTE network will be a “lifeline” initiative to ensure voice service.

How does VoLTE works and it's requirements

VOLTE Requirements

To be able to make and receive VoLTE calls, mobile devices must have 4G LTE radios and software that supports the functions of VoLTE. In addition, VoLTE calls must be supported by a wireless provider because certain cellular networks employ dedicated LTE channels for VoLTE, so smartphones must have the antennas to sustain such signals.

The requirements for voice-over LTE (VoLTE) solutions belong to the cellular subscribers’ and cellular carriers’ requirements. Below are the most fundamental of these specifications:

Subscriber Requirements

  • Telephony
  • Quality
  • Ubiquity
  • Battery

Carrier Requirements

  • Cost
  • Efficiency
  • Complexity
  • Reusability

According to Business Standard, in 2020, it was estimated that VoLTE had 2.1 billion users across the globe, with 272 carriers investing in the technology in 119 countries. Deloitte research predicted a rise in these figures, reaching 5 billion VoLTE users by the end of 2023, and 6.4 billion by the end of 2025. 

What is VoLTE and the challenges with implementation

Challenges with implementing VoLTE in the US

An operator’s primary service is voice calls. Despite the abundance of web applications available to us now, this remains the case. Many customers still prefer to make and receive phone calls. Failure to provide this service leads to poor satisfaction ratings and churn.

With any technology, VoLTE comes with its own set of challenges. Below are potential issues of voice-over LTE:

  • Signaling Considerations

The signaling load doubles when non-voice application services such as video streaming and online gaming are added. According to a study by Oracle, global LTE Diameter signaling traffic increased at a 78 percent compound annual growth rate (CAGR) from 2013 to 2018. With this, the operator will have to identify the faulty component and resolve the issue.

  • Abusing the VoLTE Bearer

By modifying the software or operating systems on two devices, a person could easily create a specialized “VoLTE bearer” to transport non-VoLTE traffic. The devices would potentially be able to send and receive any type of data. Because VoLTE carriers are normally zero-rated, this user would receive free data, resulting in a financial loss for the CSP.

How does VoLTE works and will it go mainstream in the US?

Will VoLTE go mainstream in the US any time soon?

VoLTE is interoperable with the main US carriers, including AT&T, T-Mobile, US Cellular, and Verizon.

VoLTe is now the only call option to certain carriers, notably Verizon, which already has transitioned to an all-digital network.

For marketing purposes, a few carriers address VoLTE as HD Voice, indicating a clearer call quality than a standard mobile connection. Anyone using a smartphone has used HD calls at some point. This is because most MVNO (mobile virtual network operators) and prepaid carriers are also using HD Voice. 

According to Juniper Research’s latest study, the outbreak of Covid-19 heightened the demand for remote communication services. The study noted that mobile voice and video calling solutions will be widely adopted in North America and Europe during the next four years.

VoLTE connections will expand to 5.5 billion by 2025, a significant rise from 3.3 billion in 2021. According to the research organization, VoLTE services, which were originally established for 4G, are now included in 5G specifications.  The growing use of 5G subscriptions by mobile users will accelerate this 60% rise within the next four years.

In order to accommodate growing VoLTE traffic, the research suggests that improving the quality of digitalization within core networks should be the highest concern for operators. 

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