Dynamic VPNv4 Route Generation for LTE X2 Backhaul

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Solution Overview

Problem

Current LTE networks face administrative complexity and high overhead in manually configuring and maintaining static routes for X2 traffic between eNodeBs, leading to inefficient routing and increased latency, especially with the introduction of bandwidth-intensive applications like CoMP and eICIC that require lower latency and higher bandwidth.

Innovation Solution

Implementing a method in cell site routers to automatically discover X2 IP addresses and generate dynamic, optimal routes for inter-base station traffic, eliminating the need for manual route configuration and reducing reliance on the mobile core network for routing, by using address discovery modules and automatic routing modules to create and manage Virtual Private Network (VPN) routes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If static routes are manually configured between eNodeBs for X2 traffic, then routing control is achieved, but administrative complexity and configuration overhead increase significantly

Engineering Contradiction:

Improvemanual route configurationVSAvoidrouting management complexity

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The system enables eNodeBs to automatically discover X2 peer IP addresses and generate corresponding VPNv4 routes without manual intervention. The eNodeB autonomously populates the X2 peer IP address in an X2 peer address field and triggers automatic route generation, eliminating the need for operators to manually configure routes for each eNodeB pair.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system pre-configures template routes with placeholder IP addresses (e.g., 0.0.0.0/0 or 255.255.255.255/32) that automatically resolve to actual X2 peer IP addresses when needed. This preliminary route template configuration reduces the complexity of dynamic route management by providing a predefined structure that automatically populates with actual addresses.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If static routes are configured for all neighboring eNodeBs, then complete routing coverage is achieved, but routing state memory requirements increase

Engineering Contradiction:

Improverouting coverageVSAvoidrouting state memory

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The system dynamically generates and removes VPNv4 routes based on real-time X2 neighbor relationships. Routes are automatically created when X2 peers are discovered and removed when peers are no longer needed, allowing the routing state to adapt to changing network topology rather than maintaining static routes for all possible neighbors.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system automatically discards VPNv4 routes when X2 peer relationships are terminated and recovers routing resources. When an eNodeB is removed from the network or X2 peer relationships end, the corresponding routes are automatically removed from the routing table, freeing up routing state memory for active neighbors.

Inventive Principle:

Principle #34Discarding and recovering

3Device complexity

If X2 traffic is routed through the mobile core network, then routing simplicity is maintained, but latency increases for bandwidth-intensive applications

Engineering Contradiction:

Improverouting infrastructureVSAvoidX2 traffic latency

Core Design Contradiction:

Device complexityVSLoss of time

Solution Approach 1:

The system segments X2 traffic from general mobile core traffic by creating dedicated VPNv4 routes for X2 communications. This segmentation allows X2 traffic to be routed directly between eNodeBs through optimized paths in the mobile backhaul network, separating it from traffic that requires mobile core network processing and reducing latency for time-sensitive applications.

Inventive Principle:

Principle #1Segmentation

4Measurement precision

If manual route configuration is performed for network extensions, then routing accuracy is maintained, but administrative overhead increases

Engineering Contradiction:

Improveroute configuration accuracyVSAvoidnetwork maintenance efficiency

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The system uses feedback from X2 peer discovery processes to automatically update routing configurations. When eNodeBs discover X2 peers through standard X2 interface procedures, this information is fed back to the routing system, which automatically generates corresponding VPNv4 routes, ensuring routing accuracy matches the actual network topology without manual intervention.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS9264971B2VPNv4 route control for LTE X2 son using unique route targets

Publication Date: 2016.02.16 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

According to an embodiment, a network device automatically creates a more optimal route entry for inter-base station traffic to be transmitted between a local and a remote base station through a backhaul network. The network device automatically discovers an IP address of the remote base station used for inter-base station traffic based upon traffic transmitted by the local base station to the network device or transmitted between the local and the remote base stations. The network device generates a unique route target (RT) value based upon the remote IP address and inserts it into an import route target list. Upon receiving a route update message including routes transmitted by a route reflector in the backhaul network, the network device installs a route entry into a routing table based upon determining that an RT value of one of the routes matches the unique RT value in the import route target list.