Method and apparatus reporting a vehicular sensor waveform in a wireless vehicular sensor network
This document discloses using multiple wireless vehicular sensor nodes to wirelessly receive multiple, time-interleaved vehicular waveform reports from the nodes. Each vehicular waveform report approximates a raw vehicular sensor waveform observed by a magnetic sensor at the node based upon the presence of a vehicle. The vehicular waveform reports are products of this wirelessly receiving process. The document also discloses apparatus supporting the above outlined process. The vehicular waveform reports may be time synchronized.
1. A method, comprising the step of:
operating a wireless vehicular sensor node communicatively coupled to a magnetic sensor, comprising the steps of:
using a vehicle sensor state from said magnetic sensor to create a waveform characteristic and a vehicular waveform;
turning-on a vehicle presence based upon a rising edge in a latest of said waveform characteristics;
turning-off said vehicle presence based upon a falling edge in said latest of said waveform characteristics; and
generating a long report approximating said vehicular waveform for wireless transmission when said vehicle presence is turned on.
2. The method of claim 1 , wherein the step operating said wireless vehicular sensor node further comprises the steps of:
wirelessly receiving a time synchronization message; and
transmitting said long report based upon said time synchronization message across at least one wireless physical transport.
3. A wireless vehicular sensor node, comprising:
means for using a vehicular sensor state from a magnetic sensor to create a vehicular sensor waveform and a waveform characteristic based upon said magnetic sensor observing the presence of a vehicle; and
means for operating a wireless transmitter based upon said waveform characteristic to send a long report across at least one wireless physical transport to approximate said vehicle sensor waveform.
4. The wireless vehicular sensor node of claim 3 , wherein at least one member of the group consisting of said means for using and said means for operating further comprises at least one instance of at least one member of the group consisting of:
at least one computer accessibly coupled to a memory including at least one program step included in a program system directing said computer;
a finite state machine; and
a field programmable logic device.
5. The wireless vehicular sensor node of claim 4 , wherein said program system comprises the program steps of:
using said vehicle sensor state to create said waveform characteristic;
turning-on a vehicle presence based upon a rising edge in a latest of said waveform characteristics;
turning-off said vehicle presence based upon a falling edge in said latest of said waveform characteristics; and
generating a long report approximating said vehicular waveform for transmission across a wireless physical transport based upon said vehicle presence.
6. The wireless vehicular sensor node of claim 3 , wherein said transmitter supports at least one wireless communications standard.
7. The wireless vehicular sensor node of claim 6 , wherein said transmitter supports at least one member of the group consisting of:
a version of the IEEE 802.15 communications standard;
a version of the Global System for Mobile (GSM) communications standard;
a version of the General Packet Radio Service (GPRS) communications standard;
a version of the IS-95 communications standard; and
a version of the IEEE 802.11 communications standard.
8. The wireless vehicular sensor node of claim 3 , wherein said transmitter supports a wireless communications protocol incorporating elements of a Code Division Multiple Access communications scheme.