What is the Difference Between Inter and Intra Handover in LTE?
In LTE (Long-Term Evolution) networks, handover refers to the process of transferring an active connection from one cell or base station to another without interrupting the ongoing communication. Handover ensures seamless mobility for users as they move across different coverage areas while maintaining a stable connection. There are two primary types of handover in LTE: inter-handover and intra-handover. These terms refer to the scope of the handover process, specifically whether the handover occurs within the same cell or network, or across different cells or networks. The distinctions between these two types of handover are essential for understanding the mechanisms that ensure uninterrupted mobile services.
Intra Handover in LTE
Intra handover, also known as intra-cell handover or intra-eNodeB handover, occurs when a mobile device moves from one frequency or channel to another within the same cell or base station (eNodeB). In LTE, the eNodeB (evolved NodeB) is responsible for managing the radio interface, including handling handovers. An intra handover is typically triggered when there are changes in the radio conditions, such as when a user moves within a particular coverage area of the same eNodeB but experiences varying signal strength due to obstacles or interference. These conditions might include factors like radio link failure, signal degradation, or load balancing within the cell.
The process of intra handover involves the mobile device communicating with the serving eNodeB, which analyzes the user’s current conditions and selects an appropriate resource (such as a new frequency or channel) within the same cell. The handover is executed with minimal disruption to the active connection, allowing for the continuation of voice calls, data sessions, and other services. Since the handover happens within the same eNodeB, the core network (EPC – Evolved Packet Core) is not directly involved in this process, and the complexity is lower compared to inter handovers. Additionally, intra handover typically has a faster execution time, leading to fewer interruptions in the service.
Inter Handover in LTE
Inter handover, also known as inter-cell handover or inter-eNodeB handover, occurs when a mobile device moves from the coverage area of one base station (eNodeB) to another, typically due to user mobility across cells or network regions. This type of handover is more complex than intra handover because it involves coordination between two or more eNodeBs and may require interaction with the core network. Inter handovers are essential for supporting user mobility across larger geographical areas, especially in urban or densely populated environments with many cells.
In LTE, an inter handover is triggered when the signal strength from the serving eNodeB deteriorates, and the mobile device detects a stronger signal from a neighboring eNodeB. The new eNodeB will then initiate the handover process, which includes the coordination of resources between the old and new base stations. The core network plays a significant role in inter handovers, as it must manage the transfer of the user’s context (such as IP address, session information, and QoS parameters) from one eNodeB to another. This ensures that the user maintains a seamless connection with minimal service disruption.
Inter handover is typically required when a user moves over long distances, and the coverage area of the serving eNodeB becomes inadequate. It is essential for maintaining continuous service while transitioning between cells, especially in mobile data applications, where users may travel between different areas with varying signal strengths and network resources.
Key Differences Between Inter and Intra Handover
| Aspect | Intra Handover | Inter Handover |
|---|---|---|
| Location | Occurs within the same eNodeB or cell. | Occurs between two different eNodeBs or cells. |
| Complexity | Less complex; does not involve the core network. | More complex; involves coordination between eNodeBs and core network elements. |
| Trigger | Triggered by changes in signal quality, interference, or load balancing within the same cell. | Triggered when the signal quality from the serving eNodeB is weak, and a neighboring eNodeB offers better coverage. |
| Impact on Network | Minimal impact on network; handled within the eNodeB. | Involves the core network for context transfer and resource allocation. |
| Service Continuity | Provides fast and seamless service continuity with minimal disruption. | May cause temporary service interruption as the user switches between eNodeBs and resources are reallocated. |
Conclusion
Both intra and inter handover mechanisms are fundamental for ensuring reliable and continuous connectivity in LTE networks. Intra handover is typically faster and less complex, occurring within a single eNodeB, whereas inter handover involves coordination between multiple eNodeBs and the core network to maintain connectivity as users move across different cells. Understanding the differences between these two types of handovers is critical for network operators in optimizing mobile network performance and ensuring seamless service for users in varying mobility scenarios. Effective management of both intra and inter handovers is vital for delivering a high-quality user experience in LTE networks, especially in environments with high mobility or dense network coverage.