MME Rerouting Control for Signaling Overhead Reduction
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Solution Overview
Problem
The current procedures for MME/SGSN reselection and NAS message rerouting in dedicated core networks are inefficient, leading to unnecessary signaling and potential service disruptions when a dedicated core network node for a specific UE usage type is not supported, resulting in failed rerouting and service continuity issues.
Innovation Solution
Implementing a method where the default MME or MME pool determines whether to reroute NAS messages based on the availability of dedicated MMEs with matching UE usage types, using flags or information elements to prevent unnecessary rerouting attempts and ensuring that the selected MME does not attempt rerouting if the correct dedicated MME is not available, thereby reducing signaling overhead and avoiding 'ping-pong' message exchanges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the default MME attempts to reroute NAS messages to dedicated core network nodes, then service specialization and targeted routing are improved, but signaling overhead increases and service continuity deteriorates when dedicated nodes are unavailable
Solution Approach 1:
The base station performs preliminary checking before forwarding NAS messages to determine whether dedicated core network nodes are available. This preliminary action prevents unnecessary rerouting attempts to unavailable dedicated nodes, thereby reducing signaling overhead while maintaining service specialization capability when dedicated nodes are available
Solution Approach 2:
The system implements feedback mechanisms where the base station receives information about the availability status of dedicated core network nodes. This feedback enables the base station to dynamically adjust its routing decisions, forwarding messages to dedicated nodes when available and to default nodes when unavailable, thus optimizing the balance between service specialization and signaling efficiency
2Loss of energy
If the base station forwards NAS messages to default MME without checking dedicated node availability, then signaling overhead is reduced, but service continuity deteriorates due to unnecessary rerouting attempts and ping-pong message exchanges
Solution Approach 1:
The base station performs preliminary checking of dedicated core network node availability before forwarding NAS messages. This preliminary action identifies when dedicated nodes are available, preventing the system from defaulting to non-dedicated routing and thereby avoiding unnecessary rerouting attempts and ping-pong message exchanges that would degrade service continuity
Solution Approach 2:
The system uses feedback information about dedicated node availability to make informed routing decisions. When feedback indicates dedicated nodes are available, the base station forwards messages accordingly, ensuring service continuity by avoiding the ping-pong effect that occurs when messages are repeatedly rerouted between default and unavailable dedicated nodes
3Productivity
If dedicated core network nodes are deployed for specific UE usage types, then network efficiency and service targeting are improved, but device complexity increases due to multiple MME pools and routing decisions
Solution Approach 1:
The invention extracts the complexity of dedicated core network node management from the MMEs and concentrates it in the base station. The base station assumes the responsibility of checking dedicated node availability and making routing decisions, while default MMEs focus solely on handling messages for UEs without dedicated node support. This extraction simplifies the overall system architecture by centralizing the decision-making logic
Solution Approach 2:
The base station acts as an intermediary between UEs and the core network, mediating the routing decisions based on dedicated core network node availability. This intermediary role allows the system to maintain multiple MME pools with different specializations while simplifying the interaction model, as the base station handles the complexity of determining the appropriate destination MME based on UE usage types and available dedicated nodes
Data Source
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AI summary
A communication system is disclosed in which a base station receives, from a communication device, NAS signalling for establishing a connection via the base station. The base station forwards the NAS signalling to a default MME for setting up the connection to the default MME. The default MME sends, responsive to the base station forwarding the NAS said signalling, a message identifying an MME group to which the NAS signalling should be rerouted. The base station selects an MME based on the message identifying the MME group, and forwards the NAS signalling to the selected MME, and includes information indicating that the NAS signalling shall not be rerouted.