X2 Mesh Address Discovery for Direct Base Station IPSec Connections
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Solution Overview
Problem
Current Long Term Evolution (LTE) wireless network technologies do not support the X2 Mesh architecture for transport network layer address discovery, as the existing procedures are configured to discover central security gateway-assigned tunnel inner addresses, which are not sufficient for IPSec Transport Mode communications between base stations.
Innovation Solution
A method and system for base stations to request and determine suitable transport layer addresses for establishing base-station-to-base-station connections, where the response includes both tunnel inner and outer addresses, allowing direct IPSec connections without relying on the security gateway, thereby supporting the X2 Mesh architecture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the existing TNL address discovery procedure is used, then the tunnel inner address assigned by the central security gateway can be discovered, but the X2 Mesh architecture cannot be supported because the procedure is configured to discover only central SeGW-assigned TIA addresses
Solution Approach 1:
The address discovery procedure is made dynamic by allowing the replying base station to adaptively include different address types (tunnel inner address only, or both tunnel inner and outer addresses) based on the communication architecture requirements. This enables the same procedure to support both X2 Star and X2 Mesh architectures without requiring separate discovery mechanisms.
Solution Approach 2:
The procedure changes the parameter being discovered from solely the tunnel inner address to potentially including both tunnel inner address and outer address. This parameter expansion allows the discovery procedure to provide sufficient information for IPSec Transport Mode communications while maintaining backward compatibility with existing procedures.
2Ease of operation
If the tunnel inner address alone is used for X2-interface communications, then the central security gateway can be used for S1 and X2 traffic, but direct base-station-to-base-station communication without the security gateway cannot be established
Solution Approach 1:
Base stations are enabled to self-configure direct connections by discovering both the tunnel inner address and the outer address. The replying base station provides both addresses in the response, allowing the requesting base station to establish direct IPSec Transport Mode connections without requiring centralized security gateway mediation, thus improving communication efficiency while maintaining security through direct peer-to-peer encryption.
Data Source
AI summary
A request is sent from a first base station to a second base station for a transport layer address assigned to the second base station that is suitable for establishing a connection between the first base station and the second base station. The second base station determines whether to include an outer address assigned to the second base station in a response to the request. If that is the case, the second base station sends the response to the first base station that includes a tunnel inner address assigned by a security gateway to the second base station and the outer address. The first base station determines whether the outer address is included in the response. If that is case, the outer address is used to establish the connection between the first base station and the second base station without using the security gateway.