LISP: A novel approach towards a future communication infrastructure multilink service

Abstract

Future Communication Infrastructure (FCI) air ground data link services can use various technologies (radio links) to achieve the end to end data exchange objectives. Such functionality has been developed and standardized by ICAO under the Aeronautical Telecommunication Network (ATN) activities and is also available in the Internet Protocol Suite (IPS) world, but is currently not yet operationally deployed for ATM purposes. Work comprised in SESAR P15.2.4 project provides an initial perspective of the “Multi Link Operational Concept”, i.e. the notion of using multiple data links to support the communication exchanges in the context of the future SESAR concept of operations. In the context of this task the perimeter of the FCI is limited to just the three future technologies (LDACS, AeroMACS, and SATCOM) and the ATN/IPS-based network layer. This contribution introduces LISP (Locator/Identifier Separation Protocol) as novel approach in order to enhance the ATN/IPS-based network layer. LISP is an open IETF RFC [5] describing a solution for the scalability problem of the Internet routing caused mainly by provider independent addresses and multi-homing of customer networks to different Internet service providers. The concept is based on the separation of the device identity from the physical device location in an IP network. The current approach in the IP world is overloading of IP semantics. Who and where are both represented by the same IP address. Change of location leads to a different IP address and hence changes identity causing existing sessions to be interrupted. LISP is a network-based solution supporting seamless communication while allowing roaming between different locations. LISP is an incrementally deployable architectural upgrade to anexisting infrastructure. An interesting application is the seamless migration from IPv4 to IPv6 due to its address family agnostic behavior. Early adopters will be able to use their existing infrastructure and applications and immediately benefit from LISP. This paper focuses on usage of LISP technology in aeronautical networks in order to achieve mobility, high availability and security for safety critical communication between aircraft and ground infrastructures. Fast convergence, make-before break in multilink environments, easy deployment and operation, manageable security, avoidance of scalability limits and independence of service provider infrastructure are the main topics of interest. Typical use cases demonstrate the network power of LISP support both, future aeronautical data, and voice applications. This makes LISP an interesting candidate technology to handle the mobility of the aircraft while maintaining communications when moving between different ground stations. We show how the LISP mobility system can be enhanced to include application type or QoS specific information into the data link selection. This allows path preference selection for individual data transactions transparent to the application and implementation of outgoing traffic engineering whilst utilizing the basic LISP mechanisms. Finally we discuss make-before break handover in order to improve required communication performance (RCP) figures such as availability of use or continuity.