P-CSCF Selection in UE-to-Network Relay SIP Signaling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is ambiguity regarding which Proxy Call Session Control Function (P-CSCF) an SIP message should be transmitted to when a UE establishes a connection to a UE-to-Network relay in wireless communication systems.
Innovation Solution
A method and device for transmitting SIP messages in wireless communication systems, where the UE establishes a connection with a UE-to-network relay and transmits the SIP message to a P-CSCF through the relay, using either a P-CSCF address acquired from the relay or a pre-stored address, which may be received through a discovery message or DHCP message, depending on the PLMN and connection mode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the UE uses a pre-stored P-CSCF address when connecting to a UE-to-Network relay, then signaling overhead is reduced, but the solution becomes invalid when the PLMN changes requiring a new P-CSCF address
Solution Approach 1:
The patent implements dynamic P-CSCF address selection based on PLMN status. The UE checks whether the current PLMN matches the PLMN associated with the pre-stored P-CSCF address and dynamically adjusts the address source: using the pre-stored address when PLMN matches (reducing signaling overhead) and acquiring a new address from the relay when PLMN changes (ensuring correctness). This dynamic adaptation resolves the contradiction between minimizing signaling overhead and maintaining adaptability to PLMN changes.
Solution Approach 2:
The patent changes the parameter of P-CSCF address selection based on the PLMN parameter. When the PLMN parameter changes (indicating a network change), the system transitions from using a static pre-stored address to acquiring a new address from the relay. This parameter-based control mechanism allows the system to optimize signaling overhead under stable conditions while adapting to network changes when necessary.
2Reliability
If the UE acquires a new P-CSCF address from the relay every time, then the correct P-CSCF is always selected, but signaling overhead increases
Solution Approach 1:
The system dynamically determines the P-CSCF address source based on PLMN comparison. When the current PLMN matches the stored PLMN, the system uses the pre-stored address (avoiding unnecessary signaling). When they differ, the system acquires a new address from the relay (ensuring correctness). This dynamic approach maintains reliability while minimizing signaling overhead by avoiding redundant address acquisitions.
Solution Approach 2:
The patent uses pre-configured P-CSCF addresses and their associated PLMN information as preliminary data stored in the UE. This preliminary action allows the system to quickly determine whether address re-acquisition is necessary by comparing current PLMN with stored PLMN, thereby avoiding unnecessary signaling overhead while ensuring correct P-CSCF selection when network conditions change.
3Loss of time
If the UE stores P-CSCF address information in advance, then connection establishment is faster, but the stored address may become invalid after PLMN changes
Solution Approach 1:
The patent implements dynamic validation of pre-stored P-CSCF addresses by comparing the current PLMN with the stored PLMN. When they match, the pre-stored address is used (fast connection establishment). When they differ, the system acquires a new address (ensuring validity). This dynamic check mechanism maintains both fast connection establishment and address validity.
Solution Approach 2:
The system performs preliminary storage of P-CSCF addresses along with their associated PLMN information during initial network configuration or previous connections. This preliminary action enables faster connection establishment by avoiding repeated address acquisition, while the accompanying PLMN information provides the basis for validity verification when network conditions change.
Data Source
AI summary
A method for transmitting a session initiation protocol (SIP) message by a user equipment (UE) in a wireless communication system, according to an embodiment of the present invention, comprises the steps of: establishing connection with a UE-to-network relay; and transmitting an SIP message to a proxy call session control function (P-CSCF) by means of the relay, wherein the P-CSCF corresponds to a P-CSCF address obtained by means of the UE-to-network relay or a P-CSCF address stored in the UE.