WLAN IMSI Extraction During Association
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Solution Overview
Problem
Current WLANs face challenges in determining the International Mobile Subscriber Identity (IMSI) of devices attempting to associate, which hinders early load and performance evaluation between Wi-Fi RAN/WLAN and 3GPP RAN, leading to suboptimal network steering and potential performance reduction.
Innovation Solution
A method and apparatus for a WLAN to receive a MAC address and determine if an IMSI is stored, obtaining and storing the IMSI during authentication, allowing early evaluation of load and performance information from 3GPP RAN for informed steering decisions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the WLAN waits to obtain IMSI during authentication (Layer 3 process), then the authentication process is completed properly, but the load steering decision is delayed until after Layer 2 connection is established
Solution Approach 1:
The patent applies preliminary action by obtaining the IMSI identifier during the Layer 2 association phase, before the Layer 3 authentication process begins. This allows the WLAN to perform load evaluation and make steering decisions early in the connection process, rather than waiting until authentication completes. The IMSI is extracted from authentication request messages that are transmitted during Layer 2 setup, enabling proactive load management.
2Loss of time
If the WLAN obtains IMSI early during Layer 2 association, then load steering decisions can be made timely, but the device may already have established Layer 2 connection and IP address before deferral
Solution Approach 1:
The patent implements feedback by continuously monitoring load conditions on both WLAN and 3GPP RAN, and using this information to dynamically control the association process. When unfavorable WLAN conditions are detected, the system provides feedback to prevent association, thereby avoiding the problem of devices establishing connections that will later need to be deferred. This feedback mechanism ensures steering decisions are both timely and effective.
3Device complexity
If the WLAN implements simple defer mechanism without early IMSI determination, then the system complexity is reduced, but the load sharing capability between WLAN and 3GPP RAN is insufficient
Solution Approach 1:
The patent applies preliminary action by obtaining the IMSI identifier during the Layer 2 association phase, before the Layer 3 authentication process begins. This allows the WLAN to perform load evaluation and make steering decisions early in the connection process, rather than waiting until authentication completes. The IMSI is extracted from authentication request messages that are transmitted during Layer 2 setup, enabling proactive load management.
Solution Approach 2:
The patent uses an intermediary approach by introducing a new message type (Association Request message) that carries the IMSI identifier. This intermediary message structure allows the WLAN to obtain the IMSI without requiring changes to the core authentication protocols, thereby maintaining system simplicity while enabling advanced load sharing capabilities.
4Loss of information
If the WLAN uses EAP-SIM or EAP-AKA authentication to obtain IMSI, then the IMSI can be obtained, but the process occurs at Layer 3 after Layer 2 connection is already established
Solution Approach 1:
The patent uses an intermediary approach by introducing a new message type (Association Request message) that carries the IMSI identifier. This intermediary message structure allows the WLAN to obtain the IMSI without requiring changes to the core authentication protocols, thereby maintaining system simplicity while enabling advanced load sharing capabilities.
Data Source
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AI summary
According to a first aspect there is provided a method of operating an entity of a Wireless Local Area Network (WLAN). The method comprises receiving a Media Access Control (MAC) address for a device that is attempting to associate with the WLAN (S101 ), and determining if an International Mobile Subscriber Identity (IMSI) associated with the MAC address is stored in the WLAN (S102). The method further comprises, if an IMSI associated with the MAC address is not stored in the WLAN, obtaining an IMSI for the device during authentication of the device to the WLAN (S103), and causing storage within the WLAN of the obtained IMSI in association with the MAC address (S104).