What is the purpose of the Mobility Management Entity (MME) Pool Area (MPA) in LTE networks?

Last updated on Oct 6, 2023

The Mobility Management Entity (MME) Pool Area (MPA) is a concept in LTE (Long-Term Evolution) networks that plays a crucial role in the mobility management and tracking of user equipment (UE). It is an important part of the LTE core network architecture. Let's dive into the technical details of the purpose and functions of the MME Pool Area:

Mobility Management Entity (MME):

First, let's briefly review the role of the MME in an LTE network. The MME is a critical network element responsible for tracking and managing the mobility of UEs within the LTE network. It is responsible for functions like UE authentication, location tracking, handover management, and paging.

Tracking Area (TA):

In LTE networks, the network coverage is divided into Tracking Areas (TAs), which are groups of cells or sectors. A TA is the geographical area in which a UE can move without having to update its location with the network.
When a UE moves from one TA to another, it must notify the network so that it can be tracked and reached by incoming calls or data sessions. This process involves a TA update.

MME Pool Area (MPA):

The MME Pool Area (MPA) concept is introduced to efficiently manage and distribute the load on the MMEs in the LTE core network.
The MPA is a grouping of multiple TAs. It serves as a higher-level tracking area that can include several individual TAs. This grouping allows for more efficient control and reduces the signaling load on the network.

Load Distribution:

The primary purpose of the MPA is to distribute the UE mobility tracking load among multiple MMEs. This distribution ensures that no single MME becomes overwhelmed with signaling and tracking tasks, which can occur in densely populated or high-mobility areas.
UEs within a specific MPA report their location updates and movements to the MME assigned to that MPA. This way, the tracking load is spread across multiple MMEs.

Reduced Signaling Overhead:

By using the MPA concept, the number of location update and tracking area update messages exchanged between UEs and the core network is reduced. UEs only need to update their location within their assigned MPA, rather than sending updates for every individual TA change.
This reduced signaling overhead is particularly important in LTE networks, as it helps improve network efficiency and conserves radio resources.

Enhanced Scalability:

The MPA concept enhances the scalability of LTE networks. As the number of UEs and the size of the network grow, MMEs can be assigned to specific MPAs, allowing for more efficient distribution of tracking responsibilities.

Support for Localized Service Areas:

MPAs can be customized to support specific localized service areas or zones, such as urban centers, stadiums, airports, or enterprise campuses. This customization allows for efficient management of UEs in areas with unique mobility patterns.

In summary, the Mobility Management Entity (MME) Pool Area (MPA) in LTE networks is a mechanism designed to distribute the load of UE mobility tracking and management among multiple MMEs. It reduces signaling overhead, enhances network scalability, and ensures efficient tracking of UEs as they move between different Tracking Areas (TAs) within the LTE network. The MPA concept is crucial for optimizing the performance and reliability of LTE networks, particularly in densely populated or high-mobility regions.