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CITS-DOC-004

INTERNATIONAL TELECOMMUNICATION UNION / Collaboration On ITS
TELECOMMUNICATION
STANDARDIZATION SECTOR
STUDY PERIOD 2009-2012 / CITS-DOC-004
English only
Original: English
Troy, 3 April 2012
DOCUMENT
Source: / ConsorzioNazionale Interuniversitario per le Telecomunicazioni (CNIT)
Title: / Non-functional ITS requirements: system scalability, service autonomy, service continuity

Proposal:

This document proposes to consider the following non-functional ITS requirements in the gap analysis and quality assessment of current ITS communication standards:

-System scalability: in a distributed architecture, it is defined as the capability of being enlarged by raising the number of active units while standing a larger data traffic and storage demand. Enablers: grid (and cloud) technology, wireless communications, etc.

-Service autonomy: it is defined as the capability of a system to rely on resources it directly controls. Enablers: Service Oriented Architectures (SOA), etc.

-Service continuity: in a large-scale electronic infrastructure, it is defined as the capability of providing the same service (e.g., connectivity) without interruptions. Enablers: system interoperability, federation, and integration.

Description:

The philosophy behind CALM is that of organizing the common architectural framework around which communication entities called “ITS stations” are instantiated [1].

Within the ISO standard the six specific functional blocks in the ITS stations are detailed (Applications, Management, Access, Networking & Transport, Facilities and Security); apart from the OSI communication layers, the two vertical blocks provide secure communication mechanisms and management tools to the ITS stations.

Among the 16 standards published by ISO, a set of access technologies (including M5, MM, 2G, and 3G) are disciplined together with rules and specifications to leverage IPv6 internetworking in the ITS [2].

The main communication strategy is declared as “peer-to-peer” where peers are ITS stations hosted in vehicular equipment, road-side infrastructure, or central ITS systems (i.e. service and control rooms). In the ISO approach, distributed systems are not specifically addressed and the ITS infrastructure is not expected to manage resources like computation, access, and storage.

This approach is very limited when considering large-scale infrastructures where services are provided by heterogeneous, multi-purpose, and federated ITS entities. These infrastructures are warmly requested by the European authorities [3] who specifically require “service continuity” to a new generation of ITS, and envisage an EU-wide transport system as a societal challenge objective of the Horizon 2020 programme [4].

CALM fulfils the requirement of linking vehicles with ITS infrastructure as stated in [3]; nevertheless it would be worth to promote a seamless integration of ITS functionality into popular automotive standards (e.g. AUTOSAR, etc.) to go beyond the realization of a communication link and to enable distributed applications involving vehicles and infrastructure equipment.

As a possible activity within C-ITS, CNIT promotes an abstraction of the CALM standard architecture to virtualize access, connectivity, storage, and computing power in ITS.

Cloud (and grid) computing offers a set of enabling functions permitting: (i) to profile final users by means of Virtual Organizations, and (ii) to infinitely scale the virtual local resources (in terms of storage and computing power) in the ITS stations.

The IPv6 technology on the other hand plays the key role of offering transparent connectivity and interoperability to humans and machines interacting to fulfil ITS applications.

Figure 1: Virtual users and resources in a grid infrastructure, eligible for ITS.

This new approach permits to deploy large-scale ITS and to implement distributed (eventually computational demanding) applications on ITS stations. Virtualization permits to have location transparent, standard and robust ITS services on every (also tiny) platforms.

Traffic modelling and 3D rendering of a road scenario are two examples of ITS computing demanding applications which can be provided through the cloud (or the grid):

Figure 2: 3D rendering of a road scenario (left); traffic modelling in a urban scenario (right).

Of course whenever prompt communications must be delivered (e.g., in safety critical applications), virtualization should be bypassed and the access of local resources should be generally preferred. All safety-critical services and applications will be designed in such a way that the access to virtual resources does not ever cause an overhead in the time response or a deny of service.

References:

[1] ISOIS 21217, “Communications access for land mobiles (CALM) – Architecture”, 2010.

[2] ISODraft IS 21210, “Communications access for land mobiles (CALM) – IPv6 Networking”.

[3] The European Parliament, “Framework for the deployment of Intelligent Transport Systems in the field of road transport and for interfaces with other modes of transport”,Directive 2010/40/EU.

[4] Commission of the European Communities, ”Specific programme implementing Horizon 2020 - the framework programme for research and innovation (2014-2020),” Official Journal of the European Union, vol. 811, 2011.