MPE Status Exchange Over Xn for Reliable 5G Handover
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In 5G wireless communication systems operating at high frequencies, the need to comply with maximum permissible exposure (MPE) regulations can lead to unpredictable power back-off, causing radio link failures and sub-optimal handover decisions due to lack of MPE-related information exchange between source and target gNBs.
Innovation Solution
Exchange MPE status and required power back-off information during handover through the Xn interface, enabling the target gNB to make informed admission control decisions and optimize UL scheduling to avoid failures and resource wastage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If MPE compliance is enforced with power back-off in high frequency 5G systems, then MPE regulation compliance is achieved, but radio link reliability deteriorates due to unpredictable power reduction causing handover failures
Solution Approach 1:
The source gNB performs preliminary actions by determining MPE-related information (power back-off values, MPE restriction indicators) before handover and includes this information in the handover request message sent to the target gNB. This allows the target gNB to prepare appropriate configurations in advance, preventing radio link failures during handover execution.
Solution Approach 2:
The system implements feedback mechanisms where the source gNB provides MPE status information to the target gNB through the handover signaling interface. This feedback enables the target gNB to adjust its admission control and scheduling decisions based on the actual MPE constraints that will affect the UE's uplink transmission power after handover.
2Object-affected harmful factors
If power back-off is applied to comply with MPE regulations, then MPE exposure limits are met, but handover decision quality deteriorates due to lack of MPE information exchange between gNBs
Solution Approach 1:
The handover request message serves as an intermediary carrier that transports MPE-related information (power back-off values, restriction indicators, cumulative MPE reduction values) from the source gNB to the target gNB. This intermediary mechanism ensures that critical MPE information is preserved and transmitted across the network interface, enabling informed handover decisions.
Solution Approach 2:
The source gNB performs preliminary determination of MPE impact on uplink transmissions and prepares this information before initiating handover. By calculating and including power back-off values and MPE status indicators in advance, the system prevents information loss that would otherwise occur without such preliminary information gathering and transmission.
3Reliability
If MPE-related information is exchanged during handover, then handover success rate improves through informed target gNB decisions, but signaling complexity increases due to additional information elements in handover messages
Solution Approach 1:
The handover request message is enhanced to serve multiple functions: it simultaneously carries traditional handover parameters (target cell identity, resource allocation) and new MPE-related information elements (power back-off values, MPE restriction indicators). This multi-functionality approach consolidates information exchange in existing signaling structures rather than requiring separate dedicated signaling procedures, thereby limiting the increase in overall signaling complexity.
Solution Approach 2:
The invention introduces new parameter fields (e.g., powerBackOffValue, mpeRestrictionIndicator, cumulativeMPEReductionValue) within the existing handover signaling framework. By parameterizing MPE information in a structured manner compatible with existing protocols, the system enables reliable handover execution without fundamentally redesigning the signaling architecture, thus balancing improved handover success rates with controlled signaling complexity.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Systems, methods, apparatuses, and computer program products for exchanging maximum permissible exposure related information over xn during handover (HO. A method may include receiving, at a source network node, a measurement report including an event indication on a target network node. The method may also include sending a handover request message to the target network node for handover of a user equipment. The handover request message may include information comprising the event indication, or a user equipment operation restriction or a power adjustment indication related to the user equipment. The method may further include receiving, in response to the handover request, a handover request acknowledgment message or a handover failure message that takes into account the event indication and the information.