Communications, Air-interface, Long and Medium range
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CALM (Communications Access for Land Mobiles) 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 (ITS). The scope of CALM is to provide a standardized set of air interface protocols 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.
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[edit] 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:
- Infra Red
- GSM (2G, 3G cellular telephone communication technology)
- DSRC 5.8-5.9 GHz (legacy systems)
- W-LAN, Various evolutions of the IEEE 802.11x standard including WAVE (IEEE P1609.3/D23), M5 (ISO 21215)
- Wi-Fi (WiMAX, IEEE 802.16e)
- MM-wave (62 GHz)
- Satellite
- Bluetooth
- 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.
[edit] 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.
[edit] 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.
