What is QCI Value in VoLTE?
Today, let’s dive into an important concept in VoLTE (Voice over LTE) – the Quality of Service Class Identifier, or QCI value. As we discussed earlier in some related topics about VoLTE and LTE networks, QCI plays a key role in ensuring that your voice calls and other services are delivered with the best possible quality. So, let me explain it clearly for you.
Understanding QCI
The QCI value is a numerical identifier used in LTE and VoLTE networks to define the level of service quality for different types of traffic. It specifies the priority, packet delay budget, and packet error loss rate that a particular traffic flow can tolerate. In simple terms, it helps the network understand how important a type of traffic is and what kind of resources should be allocated for it. For example, voice calls need a lower delay and high reliability, so they are given a different QCI value compared to video streaming or general web browsing.
QCI Values and Their Purpose
Each QCI value is associated with specific parameters that define the quality requirements for a service. The higher the priority of the service, the lower the allowed packet delay and packet loss. VoLTE (Voice over LTE) traffic, which is voice calls, typically has a specific QCI value that ensures low delay and high reliability. Let’s break down the QCI values for you:
| QCI Value | Service Type | Priority | Packet Delay Budget | Packet Error Loss Rate |
|---|---|---|---|---|
| 1 | Voice (VoLTE) | Highest | 100 ms | 10^-2 |
| 2 | Interactive Video | High | 150 ms | 10^-3 |
| 3 | Video Streaming | Medium | 200 ms | 10^-4 |
| 4 | Background Traffic | Low | 1000 ms | 10^-6 |
How QCI Affects VoLTE Calls
In the context of VoLTE, the QCI value is particularly crucial because voice calls require low latency and minimal packet loss. When you make a call over LTE, the network assigns a specific QCI value, usually QCI 1, to prioritize your voice traffic. This ensures that your voice call is given the highest priority in the network, providing you with a smooth and clear call experience. For example, if you’re on a call, the network will minimize the time it takes to transmit data and reduce the chances of data loss, which could otherwise affect the call quality.
As we learned in previous articles, the performance of different services on the network is determined by how the network handles various traffic types. The QCI value is a key part of this decision-making process, making sure that critical services like VoLTE are prioritized over less critical data transmissions like email downloads or social media updates.
Why is QCI Important in VoLTE?
QCI is essential for delivering a high-quality user experience on LTE networks, especially when it comes to real-time services such as voice calls and video conferencing. By assigning different QCI values to various types of traffic, the network can allocate resources more effectively, ensuring that services like VoLTE get the best possible conditions for uninterrupted communication. Without QCI, the network wouldn’t be able to distinguish between the needs of voice calls and data traffic, potentially leading to poor call quality.
In summary, QCI is a vital component that helps the LTE network prioritize different types of traffic based on their quality requirements. By understanding how QCI values work in VoLTE, you can see how the network ensures that your calls are clear, with minimal delay and no interruptions. As we continue to explore topics like VoLTE performance and network optimization, you’ll find that these details are key to making sure your service is always up to par.