What is the Difference Between PGW and SGW in LTE?
Let me explain the difference between PGW (Packet Gateway) and SGW (Serving Gateway) in LTE networks. These two components are crucial for the proper functioning of data transmission and network connectivity in LTE. To understand their differences, let’s first break down what each one does.
SGW (Serving Gateway) is responsible for handling the data plane in an LTE network. It is an intermediate entity that forwards user data packets between the eNodeB (evolved NodeB) and the PGW. The SGW acts as the gateway between the Radio Access Network (RAN) and the core network. It also plays a vital role in routing and forwarding the user’s IP packets. Additionally, the SGW manages mobility by ensuring seamless handovers when a user moves across different eNodeBs within the same network. When the user moves from one cell to another, the SGW ensures that the data session continues without interruption, facilitating smooth service.
On the other hand, PGW (Packet Gateway) is responsible for providing the interface between the LTE network and external packet-switched networks such as the internet or private networks. The PGW handles the user’s data traffic from the SGW and routes it to external networks. It also manages IP address allocation for the UE (User Equipment) and supports functions like packet filtering, Quality of Service (QoS) enforcement, and policy control. The PGW ensures that the user’s data is appropriately delivered to the correct destination while maintaining service quality according to the defined QoS parameters.
Here’s a summary of the key differences:
- Function: SGW handles data transfer between the RAN and the core network, while PGW connects the LTE network to external networks like the internet.
- Data Flow: The SGW forwards user data from the eNodeB to the PGW. PGW routes the data to external networks and handles IP address allocation.
- Mobility Management: SGW handles mobility within the LTE network, ensuring that sessions are maintained even when the user moves between cells. The PGW, however, does not handle mobility but manages the user’s session with external networks.
- Location: SGW is located closer to the RAN, whereas the PGW is located in the core network.
In short, the SGW and PGW have complementary roles within an LTE network. The SGW acts as an intermediary, forwarding data and handling mobility within the LTE network, while the PGW is responsible for connecting the LTE network to the outside world, managing IP addresses, and enforcing QoS policies.
In a previous article, we discussed the importance of the core network in managing data sessions. The SGW and PGW are integral components of this core network, ensuring seamless communication and service continuity for users as they move between different network areas.