Random Access Signaling for High-Priority User Privacy

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Solution Overview

Problem

The plaintext RRC establishment cause in contention-based random access procedures can be easily intercepted by attackers, revealing the identity information of high-priority users, compromising user privacy.

Innovation Solution

A random access method where high-priority terminals determine the RRC establishment cause based on network congestion status or access identity, and encrypt uplink scheduling information using temporary keys, ensuring privacy protection and preferential access.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the terminal sends the RRC establishment cause in plain text to indicate high-priority user identity, then the network can identify and prioritize high-priority users, but the user identity information is disclosed and user privacy is compromised

Engineering Contradiction:
Improvepriority service reliabilityVSAvoididentity information disclosure
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an intermediary mechanism by using different RRC establishment cause values as indirect indicators of user priority. Instead of directly transmitting user identity or priority status, the terminal selects specific establishment cause values (e.g., emergency, high priority access) that implicitly convey priority information to the network device without exposing actual user identity, thus protecting privacy while enabling priority recognition

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the parameter representation method by encoding priority information into the RRC establishment cause parameter itself. The terminal dynamically selects different establishment cause values based on user priority level and network congestion status, transforming the static parameter into a dynamic indicator that conveys priority information without directly exposing user identity

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the terminal always reports high-priority RRC establishment cause to ensure preferential access, then access priority is maintained, but user privacy is continuously exposed and security is compromised

Engineering Contradiction:
Improveaccess efficiencyVSAvoiduser privacy
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The patent implements a dynamic strategy where the terminal adjusts its RRC establishment cause reporting behavior based on network conditions. When the network is not congested, the terminal uses generic establishment causes to protect privacy; when congested, it switches to high-priority establishment causes to ensure access. This dynamic adaptation balances privacy protection with access priority needs

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies different quality levels of information disclosure in different network conditions. In normal conditions, minimal information is disclosed (generic establishment causes); in congested conditions, more specific priority information is disclosed (high-priority establishment causes). This local differentiation optimizes the balance between privacy and access efficiency based on specific network contexts

Inventive Principle:
Principle #3Local quality

3Object-affected harmful factors

If the terminal encrypts uplink scheduling information using temporary keys, then security and privacy are enhanced, but device complexity and computational overhead increase

Engineering Contradiction:
Improvesecurity vulnerabilityVSAvoidencryption complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-generating temporary encryption keys before the random access procedure and pre-agreening key derivation methods with the network device. This preparation eliminates the need for complex real-time key generation and management during the access process, reducing computational overhead while maintaining strong security

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses disposable temporary encryption keys that are generated for each random access procedure and then discarded. These short-lived keys provide strong security without requiring long-term key management infrastructure, reducing system complexity while ensuring that compromised keys cannot be reused to decrypt future communications

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Data Source

PatentEP4654521A1Random access method, terminal, network device, and communication system
Publication Date: 2025.11.26 HUAWEI TECH CO LTD
  • EP4654521A1 patent drawingFigure 1~2
  • EP4654521A1 patent drawingFigure 3
  • EP4654521A1 patent drawingFigure 4

AI summary

This application relates to the field of wireless communication technologies, and discloses a random access method, a terminal, a network device, and a communication system. In this application, if the terminal is a first-type terminal, an RRC establishment cause may be determined in a random access procedure based on a network congestion status, and an uplink scheduling message including the RRC establishment cause is sent to the network device. If the terminal is a second-type terminal, in a random access procedure, an RRC establishment cause may be determined based on an access category of the terminal. The first-type terminal is a terminal allowed to initiate a priority service, and the second-type terminal is a terminal that is of a user and that is configured to be of a high-priority access class. According to the random access method provided in embodiments of this application, identity information of a high-priority user may not be disclosed, and user privacy can be protected.