What is the QCI range in LTE?
Today, we’re going to dive into an important concept in LTE networks called QCI, which stands for Quality of Service Class Identifier. If you’ve been following along with our previous discussions, you’ll already know that in LTE, Quality of Service (QoS) plays a significant role in delivering a superior mobile experience. QCI is one of the key parameters used to define how different types of traffic are treated in the network.
To understand the QCI range, let’s first break down what QCI is and why it matters in LTE. QCI is essentially a numerical value that is assigned to different types of traffic or services in an LTE network. It helps prioritize the traffic based on its type and required quality of service. For instance, voice calls, video streaming, and web browsing all have different QoS requirements. The QCI value helps the network decide how to treat each type of traffic—whether it should be prioritized or treated with lower priority.
Each QCI value corresponds to specific network parameters like latency, packet loss, and throughput. In LTE, the range of QCI values is defined from 1 to 9, and each value indicates a specific level of service for a particular type of application or service. Let me explain how these values relate to the real-world services you use.
- QCI 1: This QCI is used for voice calls (Voice over LTE or VoLTE). It requires the highest priority with low latency and low packet loss to maintain a clear and uninterrupted voice call.
- QCI 2: This QCI is typically used for video calls or other real-time communication services. It ensures good video quality with low latency.
- QCI 5: Used for web browsing or similar applications, where low latency is not as critical, but good throughput is necessary.
- QCI 9: This is typically used for background traffic or non-critical data such as email synchronization or app updates. It allows for higher delays and less priority in the network.
Now that we’ve seen the basic mapping of QCI values to services, it’s important to note that the QCI values affect the entire data flow from your device to the network. When a device sends a request (e.g., to make a call or start a video stream), the network uses the QCI value to prioritize how it treats that request, ensuring that critical services like voice calls receive high priority over non-essential services.
The QCI range (from 1 to 9) is specifically designed to meet the different requirements of various services, ensuring that each service is delivered in the most optimal way possible. For example, a low QCI value is used for services that require minimal delay and high reliability, while higher QCI values are assigned to less sensitive services that can tolerate delays or packet loss.
As we’ve learned in earlier articles, LTE networks are built with a focus on providing high-speed data and low-latency services. The QCI range helps ensure that this goal is met by differentiating traffic types based on their importance and requirements. It’s a key element of the network’s ability to deliver a seamless experience for users, whether they are making a VoLTE call or streaming a video.