• Daisy chain connection between all units and Chain Control Unit.
• Use of open band transmission channels.
• Up to 100 meters between two adjacent transmitters.
• Built-in redundancy option – if one repeater failed, another will automatically take it place.
• Up to 127 ballasts per chain  – provides total range of ~3.8 Km with typical installation where the distance between light posts is 300m
• Cell phone control option from the street cabinet to a Control Center with optional SMS message warning to any type of cell phone.
• Supports either electronic ballasts directly or magnetic ballast with additional sensor unit Field proof applications are street lightning control, traffic lighting monitoring,

Detailed System Description

A system overview is described in the figure below. Transceiver units create a communication chain. The first transceiver is connected to a Chain Controller. The Chain Controller communicates with a Control Center using an existing cellular network infrastructure. The cellular communication might implement SMS messaging or internet connection using GPRS communication.
The system might alternatively use any other means of communications between the Chain Controls to the control center, e.g. land line phone communication via a modem, direct Internet connection via ADSL etc.
Each transceiver unit based on a programmable device and includes digital (discrete lines or serial communication) and optionally analog interfaces.
A Chain Controller can support up to 127 ballasts (larger number of ballasts will be supported in future versions);
In order to enhance the communication reliability each transceiver is capable of communicating with up to 4 Neighbor transceivers. In case of a failure with one of the transceivers the system skips it and communicates with one of its neighbor transceivers.
The RF communication utilizes free, unlicensed frequency range of 433 MHz, 868 MHz or 915 MHz (the frequency in use depends on the regulatory at the instillation area). The unit can use one of 40 available channels within each range.

System Schematic Diagram

A system schematic diagram is detailed in the figure below. A series of transceivers are communicating with a chain controller, where each transceiver might control several ballasts (B1 – B3 in the diagram).
Each Chain Controller has a built in cellular communication module for sending the chain information to the control center and for getting commands for the chain’s ballasts from the control center. The Chain Controller might be also programmed to turn the lights on/off or the perform dimming at specific times. The Central Controller is used for communicating with all Chain Controllers, transfer the data collected from the chain controllers to the Central Computer and forward central Computer Commands to the appropriate Chain Controller. There is no limit to the number of chains supported by a single Central Controller.
The Central Controller is communicating with a Central Computer (typically a PC) that runs a control application. The way of communication between the Central Controller and the Central Computer is USB or RS232 serial link.
If desired the Chain Controller might be connected directly to a computer using RS232 or USB communication link (instead of the cellular communication).

TECHNICAL SPECIFICATIONS
Transceiver Unit
Operating Voltage    4 – 6Vdc
Typical current consumption   Max 40mA (Ave 15mA)
RF Operating Frequency 433 / 868 or 915 MHz. Up to 40 channels per frequency band.
Output Transmission Power   10 dBm (~150 meter range, open air)
Max number of ballasts per transceiver  3
Operational ambient temperature  -40˚C / +85˚C
Physical Dimension (without antenna)  60 x 100 x 25 mm

Chain Controller
Operating Voltage    110 or 220 VAC
Typical Power Consumption   10 Watt
Operation ambient temperature   -40˚C / +85˚C
Cell Phone     GSM 900 /1800 or GSM 850/1900
Local Computer Interface   RS232 or USB
Max Number of ballasts per chain  127
Physical Dimension    TBD

Central Controller
Operating Voltage    110 or 220 VAC
Typical Power Consumption   10 Watt
Operation ambient temperature   -40˚C / +85˚C
Cell Phone     GSM 900 /1800 or GSM 850/1900
PC Interface     USB Full Speed
Physical Dimension    TBD
Number of Chain Controllers Supported  Unlimited

Main Control Functions
Lamp State Monitoring    On/Off/Fail/Old
Lamp Power Consumption
Set Lamp Power     Full, Dim level, off
Note: the actual supported functions depends on the propertied of the ballast in use
Commands might be sent to single ballast, group of ballasts or all ballasts

Installation Examples