Wireless MAC Address Remapping During OTA Address Rotation

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Solution Overview

Problem

Wireless networks face challenges in maintaining network services and user privacy due to the rotation of MAC addresses by wireless stations, which can disrupt communications and overload authentication services, and cause IP address depletion and CAM table exhaustion.

Innovation Solution

A method that maintains a mapping between over-the-air (OTA) station addresses and infrastructure station addresses, allowing the wireless LAN controller to translate and remap addresses during MAC address rotation, ensuring continuous service and privacy by associating similar properties and behaviors between old and new addresses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If wireless stations rotate MAC addresses to protect user privacy, then user privacy is improved, but network service continuity deteriorates due to address mapping disruptions

Engineering Contradiction:

Improveuser privacy exposureVSAvoidnetwork service continuity

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent introduces an intermediary mapping mechanism between the rotating MAC address and the infrastructure address. The wireless LAN controller maintains a mapping table that translates between the dynamic MAC address used by the station and a stable infrastructure address used for network services. This intermediary layer allows the station to rotate MAC addresses for privacy while network services continue to function through the stable infrastructure address.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the addressing system into two distinct parts: the over-the-air MAC address that rotates for privacy protection, and the infrastructure address that remains stable for network service identification. This segmentation allows each part to serve its specific function independently - the MAC address can change without affecting the infrastructure address, thus maintaining both privacy and service continuity.

Inventive Principle:

Principle #1Segmentation

2Object-affected harmful factors

If wireless stations rotate MAC addresses frequently, then user privacy is improved, but authentication service load increases

Engineering Contradiction:

Improveuser privacy exposureVSAvoidauthentication service load

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent establishes the MAC address to infrastructure address mapping in advance, before the station rotates its MAC address. The wireless LAN controller pre-configures the mapping relationship and maintains it across multiple MAC address rotations. This preliminary action reduces the need for frequent authentication service interventions, as the mapping infrastructure is already in place to handle address changes.

Inventive Principle:

Principle #10Preliminary action

3Object-affected harmful factors

If wireless stations rotate MAC addresses, then user privacy is improved, but IP address allocation efficiency deteriorates due to address depletion

Engineering Contradiction:

Improveuser privacy exposureVSAvoidIP address allocation efficiency

Core Design Contradiction:

Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent uses the infrastructure address as an intermediary that decouples the MAC address rotation from IP address allocation. The mapping between MAC address and infrastructure address allows the system to maintain a stable reference point for IP address management, even as MAC addresses rotate. This prevents IP address depletion caused by treating each MAC rotation as a new station.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Object-affected harmful factors

If wireless stations rotate MAC addresses, then user privacy is improved, but network infrastructure complexity increases due to CAM table management

Engineering Contradiction:

Improveuser privacy exposureVSAvoidCAM table management complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent segments the address management function into two layers: the data link layer MAC address that rotates, and the network layer infrastructure address that remains stable. This segmentation allows the wireless LAN controller to manage CAM table entries using the stable infrastructure address as the key, rather than the rotating MAC address. As a result, CAM table management becomes simpler and does not require continuous updates with each MAC address rotation.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS11849344B2Dynamic media access control addresses in a wireless network

Publication Date: 2023.12.19 CISCO TECHNOLOGY INC

AI summary

Embodiments identify a station that rotates an over the air station address. As address rotation was not originally designed into wireless networks, the rotation can introduce communication challenges for the station. The embodiments derive that traffic referencing two different over the air station addresses are associated with a single common station. This is accomplished by determining a similarity between properties of two sets of traffic. A first set of traffic references the first over the air station address and a second set of traffic references the second over the air station address. If the properties common across the two sets of traffic indicate sufficient similarity, the embodiments determine that both sets of traffic are associated with a single device. Network configuration of the device is then adjusted based on the determination.