LTE Satellite Paging via STA-PCH State and Priority Signaling
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Solution Overview
Problem
In mobile satellite systems (MSS), existing paging techniques struggle to effectively reach users in disadvantaged areas, such as inside buildings, due to limited satellite communication resources and the inability of satellite base station subsystems (SBSS) to inspect compressed and encrypted SIP messages for determining suitable multimedia sessions for enhanced paging.
Innovation Solution
The implementation of a new RRC Satellite Tracking Area-PCH (STA-PCH) state and the use of dedicated bearer activation features in 3GPP LTE release 9 and beyond, allowing the SBSS to selectively invoke enhanced paging for users in ECM-Idle or RRC STA-PCH states without inspecting compressed SIP messages, by utilizing interactions between P-CSCF, PCRF, PGW, SGW, and MME to identify suitable multimedia sessions for high penetration alerting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If enhanced paging is used to reach users in disadvantaged areas, then the probability of reaching users is improved, but satellite communication resources (power and bandwidth) are consumed
Solution Approach 1:
The patent applies local quality by differentiating paging strategies based on user location and service type. Enhanced paging is selectively applied only to users in disadvantaged areas (inside buildings) for specific services (voice calls), rather than applying it universally. This localized approach improves reliability for affected users while conserving satellite resources for other scenarios.
Solution Approach 2:
The patent changes the parameter of paging signal transmission by introducing a new RRC state (STA-PCH) and modifying the paging procedure parameters. When a user is in the STA-PCH state and an incoming voice call is detected, the system transitions to enhanced paging mode with adjusted transmission parameters (higher power, different waveform) to ensure delivery to users in disadvantaged areas.
2Adaptability or versatility
If SBSS inspects compressed and encrypted SIP messages to identify suitable multimedia sessions, then selective enhanced paging can be implemented, but SBSS complexity increases
Solution Approach 1:
The patent introduces an intermediary approach by using the MME (Mobility Management Entity) as a mediator between the SIP signaling path and the SBSS. The MME receives compressed and encrypted SIP messages, extracts relevant information (such as service type indication), and forwards this processed information to the SBSS. This allows selective enhanced paging capability without requiring the SBSS to directly inspect complex compressed SIP messages, thereby reducing SBSS complexity.
3Reliability
If enhanced paging is applied to all incoming multimedia sessions, then user coverage is improved, but satellite bandwidth and power consumption increase
Solution Approach 1:
The patent applies local quality by differentiating paging strategies based on user location and service type. Enhanced paging is selectively applied only to users in disadvantaged areas (inside buildings) for specific services (voice calls), rather than applying it universally. This localized approach improves reliability for affected users while conserving satellite resources for other scenarios.
Solution Approach 2:
The patent applies partial action by implementing enhanced paging only for specific subsets of incoming sessions rather than all sessions. The system identifies suitable sessions based on service type (e.g., voice calls) and user state (ECM-Idle or RRC STA-PCH), then applies enhanced paging only to these partial cases. This reduces unnecessary bandwidth and power consumption while maintaining effective coverage for targeted users.
Data Source
AI summary
Enhanced paging for an LTE mobile satellite system (MSS-LTE) network, including determining that a user terminal (UT) is in a second state in which the UT has established a Non-Access Stratum (NAS) protocol signaling connection with the network and an active Radio Resource Control protocol (RRC) connection with the network; determining, as a result of the UT being inactive while the UT is in the second state, that the UT is in a third state in which the UT maintains the NAS connection and releases or suspends the RRC connection; receiving a request to establish a multimedia session with the UT; transmitting, in response to receiving the request and the UT being in the third state, an E-RAB SETUP REQUEST including a priority value indicating the session is suitable for a high penetration alerting procedure; receiving the E-RAB SETUP REQUEST; and in response to receiving the E-RAB SETUP REQUEST, transmitting a high penetration alert signal to the UT.