L2 Tunneling for Single-Radio Handoff Latency Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current mobility solutions in heterogeneous access technologies, such as Mobile IP, suffer from high handoff delays and rely on dual-radio operation, which is not always feasible due to interference and co-existence issues, leading to suboptimal service continuity in mixed-network environments.
Innovation Solution
The implementation of a Single-Radio Handover solution using Data Link Layer (L2) tunneling between wireless networks, enabling tighter handover control, synchronization, and lower latency by establishing L2 tunnels for control signaling and data packet forwarding between source and target networks, allowing network-initiated handoffs and radio resource management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If L3 mobility solutions (Mobile IP) are used, then inter-access mobility is supported, but handoff delay becomes extremely high
Solution Approach 1:
The patent establishes L2 tunnels between source and target access networks in advance before handoff occurs. This preliminary setup of data paths and control signaling mechanisms enables the target network to be ready to immediately accept traffic when handoff is triggered, eliminating the need for post-handoff path establishment and significantly reducing handoff delay while maintaining inter-access mobility
2Reliability
If dual-radio operation is used, then handoff control and synchronization are improved, but device complexity and interference issues increase
Solution Approach 1:
The patent introduces network-side L2 tunneling as an intermediary mechanism that enables coordinated handoff control without requiring the mobile device to operate multiple radios simultaneously. The network establishes separate L2 tunnels for data forwarding between source and target networks, allowing single-radio devices to handoff seamlessly while the network manages the complexity of multi-path coordination
Data Source
AI summary
An example of this invention provides low latency handovers between Mobile WiMAX and 2G/3G/LTE networks with only a single radio transmitting at any given point in time, by establishing L2 tunnel between 3GPP MME and WiMAX ASN for control plane signaling to perform pre-registration, pre-authentication and context transfer to the target network, while UE maintains its connection to the source network, and by setting up bearer path for packet forwarding between Servicing Gateway and WiMAX ASN. An example of this invention uses a virtual eNB to facilitate low latency L2 handoffs to legacy 2G/3G networks with minimum impact to SGSN and MME.