Radio Service Control for CS Calls to PS-Only Users
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Solution Overview
Problem
Existing wireless communication systems face challenges in providing circuit switched voice services to users subscribed only to packet switched data services without increasing network load, handling emergency calls during normal calls, and managing network congestion effectively.
Innovation Solution
Implement methods and apparatuses in user equipment to manage service requests and bearer setups, including sending specific service requests, rejecting inappropriate calls, and adjusting services to reduce network load during congestion, such as through signal exchanges with core network entities like GMSC, MME, and base stations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If circuit switched voice services are provided to packet switched only users, then service versatility is improved, but network load increases
Solution Approach 1:
The patent introduces a service restriction notification mechanism as an intermediary that mediates between CS service requests and PS-only users. The notification is sent to the user equipment to indicate that CS services are not available, preventing unnecessary network signaling and load while maintaining service versatility for users who actually need CS services.
Solution Approach 2:
Instead of allowing CS service requests to proceed through the full network signaling path and then rejecting them, the patent inverts the approach by proactively sending service restriction notifications to PS-only users. This prevents the generation of unnecessary CS service request signaling in the first place, reducing network load while maintaining the capability to provide CS services to users who need them.
2Reliability
If emergency calls are supported during normal calls, then reliability is improved, but device complexity increases
Solution Approach 1:
The patent extracts the emergency call handling logic as a separate, prioritized function within the user equipment. When an emergency call is detected, the system extracts and processes this call type differently from normal calls, allowing emergency calls to be established even when the device is in a normal call state. This separation of concerns manages device complexity while improving reliability.
Solution Approach 2:
The patent implements preliminary detection and handling of emergency call indicators before full call establishment proceeds. By detecting emergency call requests early in the signaling process and taking preliminary actions to prioritize them, the system ensures emergency calls can be supported during normal calls without requiring complete redesign of the call handling architecture.
3Quantity of substance
If services are adjusted during network congestion, then network load is reduced, but service quality deteriorates
Solution Approach 1:
The patent applies local quality by sending service restriction notifications specifically to PS-only users during network congestion, rather than uniformly degrading service for all users. This targeted approach reduces network load from CS service requests while maintaining service quality for users who have proper CS service subscriptions and for emergency services.
Solution Approach 2:
The patent implements partial action by selectively applying service restrictions only to PS-only users who request CS services, rather than restricting services for all users during congestion. This partial restriction is sufficient to reduce network load from unnecessary CS service attempts while maintaining adequate service quality for legitimate CS service users.
Data Source
AI summary
In a user equipment of a wireless communication system, a method for signal transmission and reception may include: sending a request for a Circuit Switched voice network (CS) service to a Gateway Mobile Switching Center (GMSC) to send and receive data to and from a second user equipment; and receiving a call reject response corresponding to the service request from the GMSC, wherein the call reject response is sent by an entity in a core network of the second user equipment. According to an embodiment, it is possible to provide a suitable service to a sender terminal making a CS service request to a receiver terminal having subscribed only to a PS service without increasing network load.