Hey, VoLTE integration in 4G LTE has been an integral part in integrating voice and data transmission. Can you educate me on how VoLTE is different from traditional voice services?
Speaking of traditional voice calls, it used circuit switching technology to make calls. Whereas, VoLTE or Voice over LTE used packet-switched technology (voice data as IP packets). As mentioned, VoLTE integrates voice and data services on the same LTE network, allowing simultaneous use of voice and high-speed data services, which is unavailable on traditional voice calls.
What enhanced features does VoLTE offer in 4G LTE networks and how is it possible?
VoLTE uses IP packets to send voice calls and use resources dynamically. With 4G LTE, VoLTE provides superior voice quality with natural-sounding conversations. The time taken to establish a call on is significantly less when compared to 2G/3G networks. With incorporation of communication protocols like RCS (Rich Communication Protocol) it replaces traditional messaging with a richer, more versatile messaging experience for the users.
Speaking of the VoLTE integration, what are the shortcomings faced in harnessing these features in practical deployments?
The main disadvantages are inconsistent LTE coverage resulting in call drops, and maintaining QoS (quality of service) especially in congested network environments. With SRVCC (Single Radio Voice Call Continuity) technology or the fallback system, and Inter-RAT mechanisms integrated in VoLTE, call dropping is reduced by transferring ongoing voice calls to a 2G or 3G network.
Say Hello to VoLTE: The Feature You Didn’t Know You Needed
As James and Adam are discussing their queries on VoLTE, you also must have numerous questions circling around VoLTE. From the era where mobile phones proudly showcased VoLTE features to the current generation, often unaware of the in-built VoLTE capabilities in their phones, there is much to discover about VoLTE and technology advancements awaiting in its path.
Exploring Voice Communication Techniques in Legacy Networks
What transformed your call experience to the crystal clear conversations of the modern age?
Earlier traditional voice services employed 2G/3G networks for voice services. The 2G voice calls used the circuit-switched technology, where a dedicated circuit was established for the duration of the call. 2G networks provided basic voice and SMS services.
In 3G UMTS ( Universal Mobile Telecommunications System) networks introduced higher data speeds and supported advanced multimedia messaging (MMS). Similar to 2G, voice calls were still handled using circuit-switched technology. However, 3G networks also introduced packet-switched data services, enabling better use of network resources.
What is VoLTE? Getting vocal with 4G LTE Communication Networks
LTE (Long Term Evolution) introduced an all-IP (Internet Protocol) network, designed primarily for high-speed data services. An All-IP network is a type of telecommunications network that uses Internet Protocol (IP) for all types of communication, including voice, data, and multimedia services. This approach leverages the flexibility and efficiency of IP to deliver a wide range of services over a single, unified infrastructure.
The IP Multimedia Subsystem (IMS) is a standardized architectural framework built according to 3GPP Standards, for delivering IP-based multimedia services over LTE networks. IMS leverages IP (Internet Protocol) for all communications, providing a unified platform for delivering diverse multimedia services.
Voice over Long Term Evolution
VoLTE (Voice over LTE) was first introduced in 2012. The technology was initially developed and standardized by the 3rd Generation Partnership Project (3GPP) as part of the LTE (Long Term Evolution) specification. The first commercial deployment of VoLTE was launched by MetroPCS (now Metro by T-Mobile) in the United States in August 2012, in collaboration with Ericsson and LG.
Voice over LTE (VoLTE) is a technology that allows voice calls to be made over an LTE network. VoLTE works by packet switching technique. It converts voice calls as data packets and transmits it over the LTE network, providing high-speed data transmission.
The Science Behind Clear Calls: How VoLTE Works in LTE Networks?
When you make a call to your workplace or home, do you know what goes behind it to connect the call to the other side?
Call connection in a VoLTE call and a GSM call
Step 1: Initiating a VoLTE Call
When you make a call using VoLTE, your phone starts by converting your voice into digital data packets. This process is handled by advanced audio codecs, such as AMR-WB (Adaptive Multi-Rate Wideband), which compress and encode your voice to ensure the best possible quality while keeping data usage to a minimum.
Step 2: Transmitting Voice Data Packets
Once your voice has been converted into data packets, they are sent over the 4G LTE network using a dedicated bearer (a data path or channel). This bearer acts as a virtual tunnel specifically designed to carry VoLTE traffic, ensuring that your voice packets receive priority treatment and minimize any latency or interruptions.
Step 3: Receiving and Decoding Voice Data Packets
On the receiving end of the VoLTE call, the process is reversed. The voice data packets are received by the other person's phone and are then decoded back into audible voice signals. This allows the person you're calling to hear your voice clearly and without any quality loss.
Step 4: Enabling Simultaneous Voice and Data
One of the significant advantages of VoLTE is its ability to support simultaneous voice and data usage. While you're on a VoLTE call, you can continue to browse the internet, check emails, or use applications without experiencing any interruption or degradation in voice quality.
Step 5: Enhancing Voice Quality with HD Voice
VoLTE also supports advanced calling features, such as HD Voice, which takes audio quality to the next level. When both parties on a call have HD Voice-compatible devices and are connected to a network that supports the feature, they can experience even richer, more natural-sounding voice quality, making it feel like they're having a face-to-face conversation.
VoLTE Architecture: The Framework for Crafting Clear Calls in 4G LTE Networks
Architecture of Voice over LTE
There are various components that get involved in the process from call initiation to completion.
UE (User Equipment)
UE stands for User Equipment. It refers to the device used by a user to access the VoLTE network, such as a smartphone, tablet, or laptop, or even a machine-to-machine (M2M) device.
eNodeB (evolved Node B)
eNodeB, also known as evolved Node B, serves as the base station for the LTE wireless communication standard. It comprises elements like Radio Link Control (RLC) and Radio Resource Control (RRC) for functions such as radio bearer allocation, radio admission control, and connection mobility control.
MME (Mobility Management Entity)
The eNodeB connects directly to the MME (Mobility Management Entity). MME provides essential control plane functions that support mobility, session management, and security. It is critical in ensuring that voice calls are set up efficiently, maintained with high quality, and handed over seamlessly as users move. It manages the complex interactions between the mobile device, eNodeB, S-GW, P-GW, and the IMS core, ensuring a robust and reliable voice service over the LTE network.
S-GW (Serving Gateway)
The SGW is necessary to route and forward user data packets. It acts as the mobility anchor for the user plane during inter-eNodeB handovers and also for mobility between LTE and other 3GPP cellular networks (2G/3G systems).
P-GW (Packet Data Network Gateway)
The PGW establishes connectivity between the UE and external packet data networks. It is considered the entry and exit point of traffic for the UE. The PGW helps in functions like policy enforcement, packet filtering, and packet screening for users.
PCRF (Policy and Charging Rules Function)
The PCRF, or Policy and Charging Rules Function, provides policy control decisions and manages QoS for the data flows.
IMS (IP Multimedia Subsystem)
The IP Multimedia Subsystem is the core network for managing multimedia services. The IMS core provides the service layer for multimedia telephony, including the Proxy Call Session Control Function (P-CSCF), Interrogating CSCF (I-CSCF), Serving CSCF (S-CSCF), and Media Resource Function (MRF).
P-CSCF (Proxy Call Session Control Function)
The P-CSCF is the first contact point for the UE within the IMS network. It receives the SIP INVITE, a message used to establish a session, which can be a voice call, video call, or any multimedia session over an IP network, and forwards it to the I-CSCF.
I-CSCF (Interrogating Call Session Control Function)
The I-CSCF handles all incoming connection requests to users within the operator's network. When a user attempts to register on the IMS network, the I-CSCF queries the HSS (Home Subscriber Server) for the user's subscription data and preferences. Based on this data, the I-CSCF determines the most suitable S-CSCF (Serving Call Session Control Function) to handle the user's registration request.
S-CSCF (Serving Call Session Control Function)
The S-CSCF is the central node in the IMS core that handles session control. It manages the initiation and termination of communication sessions, handles the control aspects of active sessions, and routes SIP (Session Initiation Protocol) messages within the IMS network to ensure proper communication paths. For every session it controls, the S-CSCF generates billing records.
HSS (Home Subscriber Server)
The HSS is a comprehensive database that stores information about subscribers. During the UE (User Equipment) attach process, the HSS provides the MME with necessary subscriber information to authenticate and authorize the UE on the network.
MRF (Media Resource Function)
The MRF is responsible for providing various media-related services and functionalities. It plays pre-recorded announcements and generates tones required for various services, such as voicemail, interactive voice response (IVR) systems, and call progress tones.
Use Cases of VoLTE Capability in Real-World IoT Applications
As we discuss VoLTE, it's important to understand where VoLTE is found in IoT and the role it plays in the connected environment.
Voice-Enabled IoT Devices
VoLTE can be used in IoT devices that require voice communication capabilities, such as wearables and connected vehicles. It provides high-definition voice quality, ensuring clear and reliable communication.
Emergency Health Services
IoT devices used in health monitoring and emergency services can leverage VoLTE to provide immediate voice communication with emergency responders. This improves response times and outcomes.
Continuous Connectivity Applications
VoLTE provides seamless handover between cells in the LTE network, maintaining continuous and reliable connectivity. This is essential for real-time monitoring and control applications.
Remote Monitoring Services
Industrial IoT devices can use VoLTE for voice communication between field workers and central control rooms. This enhances coordination and response times.
Learn More: 7 IoT Applications in 2024
The Perks You Can't Ignore: Benefits of VoLTE
VoLTE offers several significant advantages that enhance the mobile communication experience. Here are the key benefits:
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Improved Call Quality
VoLTE incorporates audio codecs like AMR-WB (Adaptive Multi-Rate Wideband), AMR-NB (Adaptive Multi-Rate Narrowband), and EVS (Enhanced Voice Services) to support High Definition (HD) voice. This offers better clarity and captures more nuances of the human voice.
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Faster Call Setup Times
VoLTE dramatically reduces call setup time. Traditional voice calls on 2G or 3G networks often experience delays, but with VoLTE, the call setup is almost instantaneous, leading to a more efficient and pleasant calling experience.
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Simultaneous Voice and Data
VoLTE allows the use of voice and data services simultaneously. Users can continue using data services while on a call without any interruptions. This capability is particularly useful for multitasking, such as using navigation apps while on the call.
What is VoNR? Introducing Voice over NR with 5G Networks
5G networks introduce substantial network improvements like employing millimeter wave (mmWave) spectrum, massive MIMO (Multiple-Input, Multiple-Output), and beamforming to handle more connected devices, achieve high data speeds, and near-instantaneous connectivity.
With the introduction of 5G standalone (5G SA), 5G networks can now work independently, without leveraging the existing 4G LTE infrastructure. This paved the way for a more advanced voice service technology - VoNR or Voice over NR.
Voice over NR or Voice over 5G
VoNR was developed alongside the 5G specifications by the 3rd Generation Partnership Project (3GPP) as part of the 3GPP Release 15. The first commercial deployments of 5G Standalone (SA) networks, supporting VoNR, began around 2020.
Voice over NR (VoNR), also known as Voice over 5G (Vo5G), is the new standard for voice calls on 5G networks. It works on 5G standalone architecture (5G SA), by leveraging the 5G core network (5GC) and a 5G New Radio (NR) access network to enable both voice and data services to be delivered over 5G.
In 2021, M1 Limited (M1), a Singaporean telecommunications company, partnered with Samsung to achieve a significant milestone by making available Voice over 5G New Radio (VoNR) on M1’s 5G Standalone (SA) network.
VoNR (or Vo5G) provides an end-to-end voice service entirely over the 5G network, from the user device to the core network and back to the recipient's device, eliminating the need for fallback to LTE (as in VoLTE) and allowing seamless high-quality voice calls.
Today, VoNR is gaining more traction as more and more telecom operators are enabling VoNR capabilities for their users to have a seamless 5G experience.
Closing Notes:
Looking ahead, the future potential of VoLTE is promising. As Vo5G is still in the early stages, VoLTE remains the best option for users to enjoy clear, high-quality voice calls. Additionally, emerging features like VoLTE roaming, voice over Wi-Fi and richer communication services will offer users more flexibility and improved connectivity options. VoLTE will be pivotal in mobile communication, and ongoing technology advancements will expand its capabilities in voice communication.
Amusing Tech Chronicles
Facts and Anecdotes Related to this Edition of Wireless By Design
Modern Electronic Mail of Voice Networks
Traditional voice calls are like postal mail, slower and less efficient. But VoLTE acts like modern-day electronic mail, providing almost immediate voice communication with higher clarity and less delay.
The HD Streaming in Voice Communication
While watching a video on standard definition, you might have experienced lower quality with buffering issues, whereas streaming in HD provides clear and crisp visuals with minimal interruptions. VoLTE is the HD streaming for voice calls, offering higher sound quality and more reliable connections compared to traditional 2G or 3G voice calls.
The Optic Speed Calling
The earlier dial-up internet was slow and often interrupted, but its successor fiber optic internet turned out faster and more reliable. Similarly, traditional voice calls over 2G/3G networks are like dial-up, with more latency and lower quality, while VoLTE provides fast, high-quality, and uninterrupted voice communication.
Cavli IoT Connectivity Modules with VoLTE Integration
Cavli's advanced cellular connectivity modules, spanning across diverse technology stacks such as Cat 1, Cat 4, automotive-grade, and 5G, offer robust VoLTE support to ensure seamless, high-quality connectivity for your IoT deployments. By integrating these modules, you can empower your IoT devices with uninterrupted voice and data communication capabilities, even in the most challenging network environments.
Go Beyond and Explore
IoT devices must be equipped with specific hardware components to support VoLTE. These include a VoLTE-compatible LTE modem, IMS support, QoS capabilities, efficient power management, optimized antennas, high-quality audio hardware, compliance with network requirements, and robust security features. For instance, the Qualcomm Snapdragon X60 is a Modem-RF system that supports VoLTE and VoNR for advanced voice call features.
VoLTE relies on IP-based communication, which can be vulnerable to interception if encryption and security protocols are not properly implemented. Potential security challenges include man-in-the-middle (MITM) attacks, signaling-based attacks like denial of service (DoS), eavesdropping, and spoofing. Ensuring robust security measures and encryption is essential to protect VoLTE communications.
VoLTE and Vo5G (VoNR) offer different benefits. VoNR (Voice over 5G) generally provides superior voice quality, lower latency, and a unified 5G network experience compared to VoLTE (Voice over LTE). However, VoLTE is more widely available at present as it utilizes existing 4G infrastructure. VoNR is becoming more prevalent as 5G Standalone (5G SA) networks expand.
Authors
Shariq Jalaluddin
Manager - Corporate Marketing
Cavli Wireless
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