What is LTE handover procedure?

What is LTE Handover Procedure?

Today, let’s dive into the LTE handover procedure, which is an essential aspect of maintaining seamless connectivity when you’re on the move. You might have already come across terms like “handover” or “handoff” when talking about mobile networks, but what exactly happens during the LTE handover procedure?

In simple terms, a handover in LTE refers to the process of transferring an ongoing call, data session, or service from one base station (eNodeB) to another without interrupting the user’s experience. Whether you’re making a phone call or streaming a video while moving, LTE handovers ensure that your service continues smoothly as you move between different cell towers or network cells.

To understand this better, let’s break down the LTE handover procedure and the different types of handovers in LTE:

• Intra-eNB Handover: This occurs when the handover happens within the same eNodeB, meaning that the mobile device moves to a different cell but stays within the same base station’s control. This type of handover is typically faster as it involves fewer network resources.
• Inter-eNB Handover: This handover occurs when the mobile device moves from one eNodeB to another. The key difference is that it involves two different base stations and is slightly more complex because it requires coordination between the two eNodeBs.
• Inter-RAT Handover: This type of handover happens when a device moves from one Radio Access Technology (RAT) to another, for example from LTE to 3G (UMTS) or 2G (GSM). It ensures that the user remains connected across different technologies and network generations.

Here’s how the LTE handover process typically works:

1. Measurement: First, the User Equipment (UE) constantly measures the signal strength of neighboring cells and reports these measurements back to the eNodeB (or base station). The eNodeB analyzes these reports and decides whether a handover is necessary based on the signal strength and quality.
2. Preparation: Once the decision is made, the target eNodeB (the one the UE will handover to) is informed, and it prepares resources for the handover, like establishing the new connection parameters and updating the routing of the data flow.
3. Execution: During the execution phase, the source eNodeB releases the resources that were allocated for the connection, while the target eNodeB establishes a new connection with the UE. The handover is performed, and the UE starts communicating with the new eNodeB.
4. Completion: Once the handover is complete, the UE continues its communication with the new cell without any interruption in service. The network ensures that the session remains intact, and the user can continue their activity (call, data session, etc.) as if nothing changed.

Why is handover so crucial in LTE networks? The handover process ensures that mobile users can stay connected even when they are moving between different cells or network regions. Whether you’re driving through a city or walking between buildings, the LTE network ensures that your device transitions smoothly between cells to maintain the quality of your service. This is key for applications like voice calls, video streaming, and other real-time services, where even a small interruption can negatively impact the user experience.

In previous articles, we’ve explored other aspects of LTE, such as its architecture and network elements. Understanding handovers adds another layer to your knowledge of how LTE manages mobility and ensures high-quality service delivery, especially when you are constantly on the move.