PROMOT Computer Menus

PROMOT (PRObe vehicle concept for MOnitoring road Traffic) studies the efficiency of the probe vehicle concept in general and the compares the performance protocols for uplink probe vehicle transmission, viz. ALOHA and polling. To a limited extent, it can be used a network planning tool.

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PROMOT runs under DOS.

Main Menu

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Select the San Francisco Bay Area or Eindhoven road network
Compute the traffic flows in this network
Compute how many probes messages are available per road segment and per unit of time
For the ALOHA random access scheme, compute the throughput of probe messages
For a polling scheme, compute the throughput of probe messages
Leave this program

Radio Propagation Parameters

Screen Dump 1

Egli's Model assumes that in macro-cellular links over smooth, plane terrain, the received signal power (expressed in dB) decreases with "40 log d". Also a "6 dB/octave" height gain is experienced: doubling the height increases the received power by a factor 4.

Path loss is computed from the semi-empirical model

Moreover Rayleigh fading is considered in the signal capture model. Shadowing is not taken into account.

Digital Modulation Parameters

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The default parameters are taken similar to the U.S. IS54 digital cellular phone system.

Generation of Traffic Messages

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The fleet of probe vehicles is taken as a certain percentage of all vehicles. Probes are assumed to be equipped with positioning and radio communication equipment.

The probe vehicles are assumed to generate traffic messages according to the supply or the demand transmission scheme. The transmitted probe messages contain the position of the probe vehicle and the link travel time experienced.

The analysis used to compute the above figure focuses on one particular road link a of the freeway with a traffic flow of q_a vehicles per hour and average travel time of Z_a minutes. Using Little's Law, the expected number of vehicles present on road link a is q_a Z_a. We call this the link traffic density. For a penetration grade p, the expected number of probe vehicles that are present in segment a is




        p q_a Z_a

Presentation and Criteria

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Little is known about how many probe messages are needed to reliably estimate the real-time traffic situation. presumably Automatic Incident Detection requires the largest throughput, ATMS also requires quite detailed information, while ATIS information system are less demanding. This menu allows the user to set his own criteria.

DOS Executable.

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Chapter: Wireless Data Networks Chapter: Computer Software Chapter: Network Concepts and Standards Section: Intelligent Transportation System, Probe Vehicles, PROMOT Software