Wireless Access Point Tunneling for Seamless Mobile Handover
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The handover process between access points in wireless networks is computationally intensive due to security and quality of service messaging, leading to unacceptable delays, especially for mobile units that need to frequently switch between access points, particularly in scenarios like VoIP and video streaming.
Innovation Solution
Establishing a tunnel between the old and new access points to extend the mobile unit's data path, allowing communication to continue uninterrupted while transitioning, by leveraging the existing association parameters and security context, thus decoupling authentication from the handover process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If security and quality of service messaging is performed during handover between access points, then security and QoS are maintained, but handover delay increases significantly
Solution Approach 1:
The patent performs security association setup and QoS parameter configuration in advance during the initial association between mobile unit and access point. These security contexts and QoS parameters are then cached and reused during handover operations, eliminating the need to re-negotiate them during handover. This preliminary action resolves the contradiction by maintaining security and QoS reliability while dramatically reducing handover delay.
Solution Approach 2:
The patent extracts security authentication and QoS negotiation from the handover process itself, separating these functions into distinct phases. Security associations are established once during initial connection and extracted as reusable contexts. During handover, only lightweight data path redirection is performed, while the extracted security and QoS parameters are reused. This extraction resolves the contradiction by maintaining security/QoS without including their heavy messaging in the handover timeline.
2Speed
If multiple access points store mobile unit information to accelerate handover, then handover speed improves, but processor resources and memory space are consumed
Solution Approach 1:
The patent introduces a controller as an intermediary component that centralizes the caching of mobile unit security contexts and QoS parameters. Rather than having every access point store information about every mobile unit, the controller acts as an intermediary that holds these data structures and provides them to relevant access points during handover. This resolves the contradiction by enabling fast handover through centralized information management without the distributed resource consumption of universal caching at all access points.
Data Source
AI summary
Fast transitions between access points (APs) in a wireless network may be accomplished when a mobile unit (MU) moves between the APs, by causing a first tunnel to be established between the APs, and causing a second tunnel to be established between the new AP and the MU. A data path having established security and quality of service parameters between the MU and the old AP may be extended through the tunnels, so that communication with the MU is not disrupted while transitioning between APs. Transition processing thus may be decoupled from movement of the MU, so that the MU may continue to receive access to data over the data path. Optionally, once the data path has been so extended, the MU and new AP may engage in authentication and other messaging to formally affect a handover of the data path to the new AP. The APs and MU may be configured to communicate according to the 802.11 protocol.