What is the difference between EPC and EPS?

What is the Difference Between EPC and EPS?

When discussing LTE networks, you might have come across the terms EPC and EPS. Today, let’s dive into these two concepts and understand what each one means, how they differ, and their roles in the LTE ecosystem. If you’re familiar with basic network architecture, then you’ll find these terms essential for understanding the 4G LTE network setup.

Let me walk you through the difference between EPC (Evolved Packet Core) and EPS (Evolved Packet System) in LTE. While both are crucial to the network, they refer to different aspects of the LTE architecture.

Evolved Packet Core (EPC)

The EPC, or Evolved Packet Core, is the central part of the LTE network. It’s responsible for handling all the data traffic, from routing and processing packets to ensuring seamless connectivity between users and the network. Essentially, it’s the backbone of the LTE network that supports mobility, security, and service delivery. The EPC handles various functions such as:

• Session Management: Manages user sessions and ensures that the data flow is continuous, even as users move between different cells or access points.
• Data Routing: Routes data between the User Equipment (UE) and the internet, ensuring proper delivery of data to and from the user.
• Mobility Management: Tracks user location as they move across the network to ensure uninterrupted services.
• QoS Management: Ensures that data is delivered with the appropriate quality of service (QoS), based on the user’s subscription and the type of traffic.

The EPC consists of several key elements, such as the MME (Mobility Management Entity), SGW (Serving Gateway), and PGW (Packet Gateway). These elements play a vital role in delivering services to users and maintaining the overall functioning of the LTE network.

Evolved Packet System (EPS)

On the other hand, the EPS, or Evolved Packet System, is the entire system that encompasses both the EPC and the radio access network (RAN) in LTE. It includes not just the core network (EPC), but also the radio access network (RAN) such as the eNodeB (Evolved NodeB) which handles the radio connections to user devices (UE). The EPS ensures that all components of the LTE network can communicate and work together seamlessly to provide high-speed internet and voice services to users.

• Radio Access Network (RAN): Includes all the components that manage the connection between the UE and the EPC, mainly the eNodeB.
• Evolved Core Network (EPC): As mentioned earlier, this is the core network responsible for managing data traffic and mobility.
• Interoperability: EPS ensures the interoperability between the EPC, RAN, and user devices, enabling services like voice over LTE (VoLTE) and data transmission.

In simple terms, the EPS is the complete LTE system, combining both the access network (radio connection) and the core network (EPC). While EPC is just the core part that deals with data routing and management, EPS is the whole setup that integrates the RAN with the core network, ensuring all components work together for seamless service delivery.

Key Differences Between EPC and EPS

To help clarify, let’s summarize the key differences:

As you can see, while EPC is a part of the EPS, the latter is the broader system that encompasses both the core network and the radio access network to ensure full LTE network functionality. Without the EPC, there would be no core network to manage data, but without the EPS, there would be no complete system to deliver services to the user.

So, as we discussed earlier, understanding the roles of both EPC and EPS is crucial for grasping how the LTE system operates efficiently. The two work together to ensure that data is transmitted seamlessly and that you experience smooth connectivity as you use your device on the LTE network.