EPS Fallback for Voice Services in 5G RAN
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
5G Radio Access Networks (RAN) may lack the necessary functionality to provide voice services, leading to service failures when attempting to establish dedicated bearers or Protocol Data Unit (PDU) sessions, resulting in call setup failures and service disruptions.
Innovation Solution
Implementing an efficient Evolved Packet System (EPS) fallback mechanism where the session management system, including a Session Management Function (SMF) and Packet Data Network (PDN) Gateway (PGW), handles requests for voice services by initially attempting to establish a dedicated bearer through a 4G network, delaying notification of service unavailability to prevent immediate call failure and ensuring service continuity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If 5G RAN attempts to establish dedicated bearers or PDU sessions for voice services, then service coverage is expanded to 5G network, but call setup failures occur due to lack of voice service functionality in 5G RAN
Solution Approach 1:
The patent segments the service delivery function by separating voice service handling from data service handling. When 5G RAN cannot provide voice services, the system segments the call setup process into: (1) initial call request handling by 5G RAN, (2) detection of voice service capability deficiency, and (3) fallback to 4G RAN for dedicated bearer establishment. This segmentation allows 5G to handle data services while 4G handles voice services, resolving the contradiction between expanded coverage and call setup reliability.
Solution Approach 2:
The patent introduces an intermediary mechanism (the session management system) that mediates between the 5G RAN and the core network. When 5G RAN lacks voice service functionality, the intermediary detects this deficiency and facilitates the fallback process to 4G RAN. This intermediary layer prevents direct call setup failure by coordinating the handover between networks, thereby maintaining call setup success rate while preserving 5G network coverage benefits.
2Reliability
If immediate notification of service unavailability is sent to prevent call failure, then call setup reliability is improved, but service continuity may be disrupted due to premature call failure indication
Solution Approach 1:
The patent applies preliminary action by proactively detecting the lack of voice service functionality in 5G RAN before attempting call setup, and pre-establishing the fallback mechanism to 4G RAN. The session management system performs preliminary checks and prepares the alternative path in advance, so when voice service is needed, the system can immediately switch to 4G without causing call failure. This preliminary preparation maintains both call setup reliability and service continuity.
Solution Approach 2:
The patent implements beforehand cushioning by creating a buffer mechanism through the fallback option. When 5G RAN cannot provide voice services, the system has already prepared the 4G RAN as a cushioning alternative. This prevents the harsh impact of immediate call failure by having a pre-prepared safety net, thus maintaining service continuity while ensuring call setup reliability through the alternative path.
3Reliability
If dedicated bearer establishment is attempted through 4G network when 5G RAN is incapable, then call setup success rate is improved, but network complexity increases due to inter-network coordination
Solution Approach 1:
The patent applies universality by designing the session management system to perform multiple functions: it can manage both 5G and 4G networks, detect voice service capability deficiencies, initiate fallback procedures, and coordinate dedicated bearer establishment across different networks. This multi-functional design consolidates the complexity into a single universal manager rather than requiring separate coordination mechanisms for each network, thereby improving call setup success rate while managing network complexity through functional consolidation.
4Stability of the object's composition
If seamless service delivery through 4G network is enabled when 5G RAN cannot provide voice services, then service continuity is maintained, but service delivery time increases due to network switching
Solution Approach 1:
The patent minimizes service delivery time by performing preliminary actions: the session management system pre-detects 5G RAN's voice service capability and pre-preares the fallback mechanism before actual service delivery is needed. When voice service is requested, the system can immediately switch to 4G RAN without undergoing lengthy detection or setup procedures, thus maintaining service continuity while minimizing the time loss associated with network switching.
Data Source
AI summary
Systems, devices, and techniques described herein relate to efficient Evolved Packet System (EPS) fallback. A method may include receiving a rejection message that indicates a rejection to set up a call through a 5th Generation (5G) network by a 5G Radio Access Network (RAN). In response to receiving the rejection message, the method may include transmitting a request to establish a dedicated bearer through a 4th Generation (4G) network. A confirmation that the second dedicated bearer has been established through the 4G network may be received within a predetermined time after transmitting the request.