Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B3/00—Line transmission systems
  • H04B3/54—Systems for transmission via power distribution lines
  • H04B3/542—Systems for transmission via power distribution lines the information being in digital form
• • G—PHYSICS
  • G08—SIGNALLING
  • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
  • G08B25/00—Alarm systems in which the location of the alarm condition is signalled to a central station, e.g. fire or police telegraphic systems
  • G08B25/01—Alarm systems in which the location of the alarm condition is signalled to a central station, e.g. fire or police telegraphic systems characterised by the transmission medium
  • G08B25/016—Personal emergency signalling and security systems
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B2203/00—Indexing scheme relating to line transmission systems
  • H04B2203/54—Aspects of powerline communications not already covered by H04B3/54 and its subgroups
  • H04B2203/5404—Methods of transmitting or receiving signals via power distribution lines
  • H04B2203/5416—Methods of transmitting or receiving signals via power distribution lines by adding signals to the wave form of the power source
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B2203/00—Indexing scheme relating to line transmission systems
  • H04B2203/54—Aspects of powerline communications not already covered by H04B3/54 and its subgroups
  • H04B2203/5404—Methods of transmitting or receiving signals via power distribution lines
  • H04B2203/5425—Methods of transmitting or receiving signals via power distribution lines improving S/N by matching impedance, noise reduction, gain control
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B2203/00—Indexing scheme relating to line transmission systems
  • H04B2203/54—Aspects of powerline communications not already covered by H04B3/54 and its subgroups
  • H04B2203/5429—Applications for powerline communications
  • H04B2203/5441—Wireless systems or telephone
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B2203/00—Indexing scheme relating to line transmission systems
  • H04B2203/54—Aspects of powerline communications not already covered by H04B3/54 and its subgroups
  • H04B2203/5429—Applications for powerline communications
  • H04B2203/5458—Monitor sensor; Alarm systems

Definitions

• the present invention relates to a telecommunication network, and in particular it relates to a telecommunication, monitoring and telesignalling network.
• the data transmission takes place in a practically unidirectional manner, if it is excepted the possibility of the confirmation that the transmission from the portable transmitter took place.
• the data transmission on the electrical network by means of peripheral units, located on each light point of the lighting network, to the reception exchanges, located in the substations for distributing the electrical energy to the single street lamps, takes place by using conveyed waves transmission methods, such as, for example, modulated frequencies on carrier frequency.
• a system so conceived presents however some drawbacks. Firstly, there is not a concrete possibility of a communication between the network and the user possesing the remote device, so that the user, apart a simple signal of received message, do not know how and in how many time his demand will be performed; further it is not provided the possibility of furnishing information to the user through the network, beyond the emergency situations. Secondly, the use of a data transmission on the network by conveyed waves presents considerable practical difficulties for its application .
• the emitted signal must have a certain power in order to obtain an appreciable result, there is the risk of noises, as beats with systems of the kind of AM transmission or wire broadcasting, thus with the need of verification, for each cable used, of the pass band and of the possible interference with other signals. Furthermore, the transmission and the data reception speed between the peripheral terminals and the reception exchanges is rather restricted .
• Scope of the present invention is to provide a communication network which is able to overcome the above described drawbacks, by allowing a bidirectional communication between mobile terminal and network, and at the same time providing said network with a data transmission system which is less influenced by possible interferences, and which allows a greater data stream along the network by the use of reduced power.
• Object of the present invention is therefore a telecommunication, monitoring and teles nalling network, characterised by the fact that said network comprises:
• each pick up element being disposed in correspondence of a light point of the public lighting installation connected to said installation, and provided with means for the transmission and the reception through the lines of said public lighting installation;
• each control unit being disposed in a distribution substation of said lighting installation, and being connected to the plurality of pick up elements located on the light points connected to said substation, each control unit being provided with means for the reception and the transmission of data to and from an operative exchange.
• Figure 1 is a schematic perspective view of a telecommunication network according to the present invention ;
• Figure 2 is a schematic diagram showing a network pick up element according to the invention.
• figure 3 is a schematic diagram showing a network control unit according to the invention.
• Figure 4 is a diagram representing an oscillation cycle of the tension of the public lighting network.
• a telecommunication network according the present invention is shown; with 1 the mobile receiving and transmitting terminal is designed.
• Said terminal 1 comprises a processing unit 1 01 , a transmitting group 201 and a receiving group 20] .
• Said terminal is able to communicate with the pick up element 2 disposed on the pole 1 - of the street lamp .0 and connected to the cable 21 which feeds the lamp _2 of the street lamp 10, and which in turn is connected to the urban lighting installation line 20.
• a shunt substation is provided for any given light point number, controlling their power supply.
• the control unit 3 is inserted in parallel with the switch 31 of the said substation, same being connected through the connecting means 41, which in the following will be better described and illustrated, to the operative stati on 40 .
• FIG. 2 a diagram is shown schematically showing a pick up element 2 of the net according to the invention. Same comprises a processing unit 102 provided with a feeder 112 connected through the wire 122 to the cable 21 of the street lamp 10. To the processor 102 a radio interface 202 is connected, to which the transmitting group 213 and the receiving group 222 respectively provided with antennas 232 and 242 are connected. Likewise to the processor 102 the transmitter 312 and the receiver 322 are connected, which in turn are connected through the respective wires 332, 342 to the wire 1 2 coupled to the cable 21 of the street lamp 10.
• FIG. 3 a diagram is shown showing a network control unit 3 of the network according to the invention.
• Said unit comprises a processor 103 connected to the street lighting installation line 20 through a feeder 113.
• the processor 103 To the processor 103 the transmitting group 213 and the receiving group 223 are connected; both said groups are finally connected to the line 20.
• the tension shutter 303 To the processor is further connected the tension shutter 303, the mode of operation of which will be described later.
• the processor is provided with a connection with an interface 403 communicating with the connecting means 41 for the connection with operative station 40.
• Figure 4 is finally shown diagra matically the sinusoid which represents the tension oscillation of the public lighting network.
• the diagram In abscissa the diagram has time values in seconds and in ordinate tension values.
• the diagram is subdivided into 10 subperiods, of which two subperiods 23 are wider in correspondence with the maximum and minimum values of the single obscillation , and 8 subperiods which are equal each other.
• the mobile terminal 1 shown in Figure 1 permits to the user 50 to send a signal 40] through his transmitting unit 201, containing the a d request and other possible data processed or memorized in processor 101 of the terminal 1.
• the signal may be received by the pick up element 2 placed on pole 11 of the street lamp 10. Once received the signal 401, the pick up element 2 will send it to the control unit 3.
• the tranfert of the data from the peripheral unit, similar to the pick up element of the invention, to the communication network takes place by the use of conveyed wave transmission systems, which presents the already mentioned drawbacks.
• said transfert is performed by a system which faces the problem in a quite new and innovative way.
• the starting assumption is based on the fact that every single pick up element is connected to the network and synchronized on the network frequency, that is 50 Hz.
• the wave presents 50 cycles during the space of one second, that is 20 milliseconds (msec) per cycle.
• the signal modulation means 302 of the pick up elements divide furthermore each cycle (see Figure 4) into ten subcycles, of which the two wider cycles 23 in correspondence of the maximum and minimum points of the obscillation are not taken into cons deration. In this manner eight subcycles 24 of 1,5 msec each remain.
• the single pick up element sends in each subcycle a tone, emitted in a range comprised for example within 2 and 4 kHz and characteristic of a single pick up element, where the tone presence shows that a signal bit has been dispatched at a logical level 1, and thus that in a 20 msec space, that is a complete obscillation cycle of the network feeding tension, a signal containing eight data bit, that is a character (byte) may be dispatched. Then in one second only the pick up element may transmit 50 bytes of data.
• the different pick up elements have each a characteristic emission tone, and the emission frequency difference between adjacent pick up elements is tipicaily in the range of 20 Hz, which is an extremely small value, however sufficient because the tone bandwidth is practically of null value. Thanks to this last characteristic it is very difficult that this kind of data transmission be subject to interferences .
• the control unit In order that the control unit be able to distinguish the different messages sent by different pick up elements connected to it (for example 100 pick up elements for a same control unit) it must have a Digital Signal Processing device (DSP). Assuming as frequency distance between pick up element and pick up element a frequency of 20 Hz as above referred, the DSP has to distinguish between the different signals on a total band of 2 kHz.
• DSP Digital Signal Processing device
• the recognizing of each pick up element by the control unit can take place in this manner through their emission tones, with a significative character saving, because no identification data have to be sent.
• a further advantage of the data transmission by tones at the frequencies in the ranges above mentioned, resides in the use of an extremely limited power on all the network.
• the datum aquired from the control unit, and containing the information of the position of the calling terminal, as well as those relating to the kind of requested service, is thereafter conveyed, through suitable connecting means, as for example a transmission made with the aid of a satellite or a connection via optical waveguides, to the operative station, where the datum will be collected and decoded and from where the answer to the user's requirement will be forwarded .
• suitable connecting means as for example a transmission made with the aid of a satellite or a connection via optical waveguides
• the control unit 3 comprises a tension shutter device 303 which has the duty, whenever the switch 31 of the cabin 30 is opened, to deliver a low voltage, in the range of 40-50 V, in alternating current at 50 Hz, on the length of line 20 connected to the different street lamps, so as to guarantee both the feeding and the transmission of the pick up elements placed on street lamps. As soon as the switch 31 is again closed, the shutter 303 will be automatically cut out.
• the thus conceived telecommun cation network permits to the user to receive informations and to trans itt informations by the same network; at the same time, thanks to the transmission system used in the communication between pick up elements and control unit, the data flow is greater then that which may be achievable by known systems, in correspondence with a greater practicality of use and minor signal noise possibilities.

Landscapes

• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Computer Networks & Wireless Communication (AREA)
• Signal Processing (AREA)
• Computer Security & Cryptography (AREA)
• Business, Economics & Management (AREA)
• Emergency Management (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Circuit Arrangement For Electric Light Sources In General (AREA)
• Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
• Alarm Systems (AREA)
• Telephonic Communication Services (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=11354934

Family Applications (1)

Country Status (6)

Cited By (4)

Citations (3)

• 1996
  • 1996-09-04 IT ITGE960074 patent/IT1297151B1/it active IP Right Grant
• 1997
  • 1997-08-20 CA CA002264854A patent/CA2264854A1/en not_active Abandoned
  • 1997-08-20 AU AU42995/97A patent/AU713026B2/en not_active Ceased
  • 1997-08-20 EP EP97918990A patent/EP0923813A1/en not_active Ceased
  • 1997-08-20 BR BR9711989A patent/BR9711989A/pt not_active Application Discontinuation
  • 1997-08-20 WO PCT/EP1997/004528 patent/WO1998010529A1/en not_active Application Discontinuation

Patent Citations (3)

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