363-206-305
Applications
2-62
Issue 3 June 2000
Intelligent Vehicle Highway System
(IVHS)
2
The IVHS is beginning and will grow to play a major role in the roadway systems
of the future. The primary use in the near-term is to reduce congestion. This is
done in several ways:
■
The IVHS provides more efficient and optimal traffic management, which
attempts to avoid congestion in the first place.
■
The IVHS provides better management of congestion caused by random
occurrences, such as accidents or breakdowns.
■
The IVHS eliminates many of the foreseeable causes of congestion, such
as toll-taking, by automating these functions.
In the future, the IVHS system will also help travelers plan their routes by providing
up-to-the-minute traffic and highway information. The DDM-2000 FiberReach,
OC-3, and OC-12 Multiplexers are a perfect match for the networking needs of
these systems.
Figure 2-47 shows a typical IVHS application. An IVHS network carries data
between roadside equipment, such as traffic counters, speed sensors, variable
messaging signs, video cameras, toll-gathering equipment, pay phones and call
boxes, and a traffic operations center, where incoming data is processed and
responses are generated. The DDM-2000 FiberReach, OC-3, and OC-12
Multiplexers provide a perfect backbone for carrying this information. The DDM-
2000 SONET ring capability, when coupled with diverse fiber routing on opposite
sides of the roadway, makes the backbone completely self-healing in the face of
failures. Such reliability is absolutely essential, especially as travelers come to
depend more and more on IVHS networks.
DDM-2000 FiberReach supplies a single system solution for the small access
cabinets, each of which requires a few voice-frequency (VF) and DS0 data
channels, as well as DS1-based services. The bandwidth management
capabilities of the DDM-2000 FiberReach, OC-3, and OC-12 Multiplexers allow
flexible allocation of bandwidth to match the dynamics of a roadway system which
is undergoing unpredictable changes in traffic patterns, breakdowns, accidents,
and repairs. Such bandwidth management provides a system which meets the
IVHS network needs in a cost-effective manner.