Communications, Air-interface, Long and Medium range
Encyclopedia
Communications access for land mobiles (CALM) is an initiative by the ISO TC 204/Working Group 16 to define a set of wireless communication protocols and air interfaces for a variety of communication scenarios spanning multiple modes of communications and multiple methods of transmissions in Intelligent Transportation System
Intelligent transportation system
The term intelligent transportation systems refers to information and communication technology that improve transport outcomes such as transport safety, transport productivity, travel reliability, informed travel choices, social equity, environmental performance and network operation...

 (ITS). The CALM architecture is based on a IPv6
IPv6
Internet Protocol version 6 is a version of the Internet Protocol . It is designed to succeed the Internet Protocol version 4...

 convergence layer that decouples applications from the communication infrastructure. A standardized set of air interface protocols
Communications protocol
A communications protocol is a system of digital message formats and rules for exchanging those messages in or between computing systems and in telecommunications...

 is provided for the best use of resources available for short, medium and long-range, safety critical communications, using one or more of several media, with multipoint (mesh) transfer.

Since 2007 CALM stands for Communication Access for Land Mobile, before that year, CALM stood for Communications, Air-interface, Long and Medium range.

Communication Modes

CALM enables the following communication modes:
  • Vehicle-to-Infrastructure (V2I): communication initiated by either roadside or vehicle (e.g. petrol forecourt or toll booth)
  • Vehicle-to-Vehicle (V2V): peer to peer ad-hoc networking amongst fast moving objects following the idea of MANET's/VANET's.
  • Infrastructure-to-Infrastructure (I2I): point-to-point connection where conventional cabling is undesirable (e.g. using lamp posts or street signs to relay signals)


Methods of transmission used by CALM may be based on one or more of the following communication media:
  • Infrared
    Infrared
    Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...

  • GSM (2G, 3G cellular telephone communication technology)
  • DSRC 5.8-5.9 GHz (legacy systems)
  • Various evolutions of the IEEE 802.11
    IEEE 802.11
    IEEE 802.11 is a set of standards for implementing wireless local area network computer communication in the 2.4, 3.6 and 5 GHz frequency bands. They are created and maintained by the IEEE LAN/MAN Standards Committee . The base version of the standard IEEE 802.11-2007 has had subsequent...

     standard including WAVE (IEEE P1609.3/D23), M5
    CALM M5
    CALM M5 is the ISO 21215 standard that incorporates WAVE and adds the following features:* Global 5 GHz spectrum* Regulatory domain management* Directivity and EMC control...

     (ISO 21215)
  • WiMAX
    WiMAX
    WiMAX is a communication technology for wirelessly delivering high-speed Internet service to large geographical areas. The 2005 WiMAX revision provided bit rates up to 40 Mbit/s with the 2011 update up to 1 Gbit/s for fixed stations...

    , IEEE 802.16e
  • MM-wave (63 GHz)
  • Satellite
  • Bluetooth
    Bluetooth
    Bluetooth is a proprietary open wireless technology standard for exchanging data over short distances from fixed and mobile devices, creating personal area networks with high levels of security...

  • RFID


The CALM architecture provides an abstraction layer for vehicle applications, managing communication for multiple concurrent sessions spanning all communications modes, and all methods of transmission.

Applications

Applications for CALM are likely to include in-vehicle internet access, dynamic navigation, safety warnings, collision avoidance, and ad-hoc networks linking multiple vehicles.

Security

The CALM architecture protects critical in-vehicle communication using a firewall controlled by the vehicle.
Parental controls are also being considered as a component of the architecture.

Implementations

The CALM standard is still work in progress. Therefore, large scale implementations of the standard do not yet exist. CVIS is a project funded by the EC in the sixth framework program (FP6). The aim of the project is to develop and implement a communication infrastructure based on the CALM architecture. CVIS will implement CALM M5
CALM M5
CALM M5 is the ISO 21215 standard that incorporates WAVE and adds the following features:* Global 5 GHz spectrum* Regulatory domain management* Directivity and EMC control...

, 2G/3G and IR as communication media. The implementation will be tested at several test locations across Europe with a wide range of ITS applications.

External links

  • http://www.calm.eu ISO TC204 Working Group 16
  • http://www.safespot-eu.org/ SAFESPOT EU Integrated Project on Cooperative Vehicular Systems for Road Safety
  • http://hal.inria.fr/inria-00419466/fr/ Architecture Pour Communication Véhicules-Infrastructure
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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