MME Tracking for Group Mobility in Wireless Relay Networks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication networks, mobile devices connected to mobile relay nodes supporting group mobility face challenges in tracking changes in the serving Mobility Management Entity (MME) as the mobile relay node moves, leading to difficulties in updating MME identification information when handovers occur, resulting in inefficient network transitions and lack of context information transfer.
Innovation Solution
A method is introduced where the mobile device receives and updates MME identification information directly from the MME or indirectly through the mobile relay node, using registration messages and stratum signaling, ensuring continuous context management and efficient handovers by bounding the mobile device context with the relay node context, even when the mobile relay node changes its serving base station.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the mobile device remains connected to the mobile relay node during group mobility, then the mobile device maintains continuous connectivity without cell reselection, but the mobile device cannot track changes in the serving MME and loses context information during handovers
Solution Approach 1:
The mobile relay node acts as an intermediary that carries and transmits the mobile device's context information between different serving MMEs. When the mobile RN moves to a new MME's coverage area, it forwards the stored context information to the new MME, enabling seamless handover and preventing information loss while maintaining continuous connectivity.
Solution Approach 2:
The mobile device performs preliminary actions by sending a TAU request to the new MME upon detecting MME change (through system information or handover commands), including its identity and current serving cell information. This preliminary action triggers the context transfer process before actual data transmission resumes, ensuring no information is lost during the transition.
2Loss of information
If the mobile device sends TAU requests frequently to track MME changes, then the mobile device maintains up-to-date MME information, but network signaling overhead and processing load increase
Solution Approach 1:
The mobile relay node performs self-service by automatically tracking and updating its own serving MME information, then forwarding this information to the mobile device when needed. This eliminates the need for the mobile device to continuously query or send TAU requests to track MME changes, reducing signaling overhead while maintaining accurate MME information.
Solution Approach 2:
Instead of continuous TAU requests, the system uses periodic updates triggered by specific events such as handover commands or system information broadcasts indicating MME changes. This periodic action approach maintains up-to-date MME information only when necessary, optimizing network signaling efficiency.
3Speed
If the mobile relay node performs handovers to change serving base stations, then the mobile RN maintains optimal connectivity, but the serving MME changes and the mobile device loses track of the previous MME identity
Solution Approach 1:
The mobile relay node serves as an intermediary that stores and forwards the mobile device's context information including the previous MME identity. During handover, the mobile RN maintains this information in its buffer and transmits it to the new MME, ensuring that the previous MME identity is preserved and transferred even as the serving base station changes.
Solution Approach 2:
The mobile device's context information is nested within the mobile relay node's context container. The mobile RN holds the mobile device's TAU request and context information in its buffer, embedding it within its own signaling messages to the MME. This nesting ensures that the previous MME identity is carried along during handover without requiring separate transmission.
Data Source
AI summary
A method and apparatus for updating a wireless mobile device with mobility management entity (MME) identification information when the mobile device camps on a mobile relay node (RN), that supports group mobility, connected to a first base station (BS) supported by a first MME. In one embodiment, the mobile device receives an identity associated with a second MME when the mobile RN connects to a second BS served by a second MME without first sending a registration message. In another embodiment, the mobile device receives mobile RN specific MME identification information. Upon decamping from the mobile RN and camping on a new BS, the mobile device transmits the identity associated with the second MME or the mobile RN specific MME identification information for establishing a connection with the network.