The present invention relates to remote reading of domestic or industrial water, gas, heat, and electricity meters each associated with a radio communication module.
At present there exist several types of network enabling remote meter reading by radio:
Attention is given below only to so-called fixed networks, which at present are favored by operators in particular because they do not require any movement of persons to effect remote meter reading.
Attention is more particularly given to laying out these fixed networks in the context of either deploying a new network or extending an existing network, requiring precise definition of the best geographical locations for radio communication modules, repeater intermediate collectors, and the access point or main collector.
The positions of the various meters, and consequently of the associated radio communication modules, are set by the service (water, electricity, or gas) distribution network. Usually, because it must be supplied with power via the electrical mains, the geographical location of the access point or main collector is also imposed.
Consequently, the problem in deploying a fixed network is choosing positions for the repeater intermediate collectors that guarantee a radio link level with sufficient margin as well as minimizing the number of repeater intermediate collectors used to transfer data from the meters to the access point or main collector.
At present there are essentially two known methods of assisting deployment of a fixed remote meter reading network:
In a first known method the number of repeater intermediate collectors to be positioned is estimated using a map. This solution is not satisfactory, however, for the following reasons:
Another known solution consists in effecting radio link surveys in situ using standard radio measurement instrumentation, such as a frequency generator and a spectrum analyzer, to measure transmission power losses. This solution is no more satisfactory, however, because it requires specialist personnel with radio experience, both to operate the measurement instrumentation and more importantly to interpret the results. In particular, in order to comply with the margin tolerated by the equipment that is to be installed, direct deduction cannot be drawn from the results in terms of power loss. Moreover, the measurement instrumentation is physically and structurally very different from the equipment that is to be installed, and so transmission losses measured in this way may not reflect actual transmission losses once the network has been installed.
The object of the present invention is to make a simple system available to installers with no specialist radio skills, providing them with assistance in deploying a fixed remote meter reading network and able to determine optimum future positions for pieces of network equipment, in particular repeater intermediate collectors, and able to optimize the amount of network equipment necessary to cover the network.
The invention achieves this object and firstly provides a system conforming to claim 1 for assisting in the deployment of a fixed remote meter reading network.
The use of such a system preferably consists in implementing the steps of claim 9.
Other features and advantages of the invention become apparent in the light of the following description of a system of the invention and its use in the context of assisting deployment of a fixed remote meter reading network, given with reference to the appended figures, in which:
a to 3j show the steps of using the system of the invention for assisting deployment of one example of a fixed network.
The components of a system for assisting deployment of a fixed remote meter reading network and their interaction are described below with reference to
The system for defining very precisely optimum future geographical locations for the pieces of network equipment, in particular the access point and the intermediate collectors, includes the following components:
The term “mobile unit” refers to a unit that is intended to occupy a fixed position, but that is adapted to be moved to geographically different positions, because of its small overall size.
The term “portable unit” refers to a unit intended to be carried by the installer while it is in use.
The term “to simulate” means to behave like the future network equipment, faithfully reproducing its radio propagation behavior.
Accordingly, the first mobile unit 3 must replace as faithfully as possible the access point or main collector that it is called on to represent. To this end, the radio interface, and in particular the antenna used, must be the same as those equipping a real access point. To reproduce its behavior faithfully, it is also attempted, as far as possible, to design a first mobile unit that has substantially the same overall size as the real main collector, in particular so as to be able to occupy the same positions and to have the same antenna orientations as the real main collector, and thus to reproduce the same radio behavior.
The second mobile unit 4 must also replace as faithfully as possible an intermediate collector that it is called on to represent. Thus its radio operation must be testable, both when receiving information and when relaying information. By way of example, it is possible to use an actual intermediate collector that is used only for assisting deployment, or else equipment that is similar in terms of radio operation and overall size. Here again, the antenna and the radio performance must be identical to those of the intermediate collectors and the shape of the unit must be sufficiently similar to that of a real collector to be able to assume positions and antenna orientations that optimally reflect reality.
The mobile unit 6, the importance of which becomes clear below, must reproduce as faithfully as possible radio reception by an intermediate collector. In respect of this function, this unit is not very different from the second mobile unit 4. Again, and for the reasons stated above, the antenna must be identical to that used in the intermediate collectors and the shape of the unit must be sufficiently similar to that of a real collector to reproduce faithfully its radio propagation behavior.
Moreover, according to the invention, the portable unit 7 is able to control the operation of the measurement mobile unit 6 by radio in three distinct operating modes:
The first mode is an access point/collector mode M1 in which the measurement mobile unit 6 initiates radio communication with the first mobile unit 3 simulating the operation of the access point, after which it effects a measurement indicative of the intensity of the signal that it receives from the first mobile unit 3 during this exchange.
The second mode is a collector/collector mode M2 in which the measurement mobile unit 6 initiates radio communication with the second mobile unit 4 simulating the operation of the intermediate collector and effects a measurement indicative of the intensity of the signal that it receives from the second mobile unit 4 during this exchange.
The third mode is a listening mode M3 in which the measurement mobile unit 6 intercepts a response signal transmitted by a radio communication module 2 in response to an interrogation signal sent by the portable remote meter reading unit 5 and effects a measurement indicative of the intensity of the intercepted signal.
Consequently, all tests carried out by the measurement mobile unit 6 are radio controlled (commands C) by the portable unit 7. In the above-mentioned three modes M1 to M3, measurements carried out by the measurement mobile unit are of the RSSI (received signal strength indication) type, for example.
Whichever operating mode M1 to M3 is used, the measurement effected by the measurement mobile unit 6 is transmitted in the form of a radio signal R to the portable unit 7, which is adapted to receive this measurement.
The portable unit 7 contains programs for responding to the measurement received in this way to produce information relating to the quality of the radio link determined from said measurement. This information, which takes into account the imposed safety margins in terms of radio link quality, is directly usable by the installer to decide whether or not a tested location offers sufficient quality for a future network layout. To this end, the portable unit 7 includes means 72 for displaying this information.
To enable the installer to select and launch tests in any of the above-mentioned three modes M1 to M3, it advantageously includes three manual control buttons 70a-70c. This addresses concerns about optimized cost and simplicity, but the control interface could of course be more complex, and for example it could use selection via a pull-down menu appearing on a display screen.
The unit 7 further includes a radio antenna 71 for sending radio control commands C and for receiving signals R including measurements made by the measurement mobile unit 6 in one of the three modes M1 to M3.
In this example, the display means of the portable unit 7 include light-emitting diodes 72. In the preferred embodiment shown in
To enable direct interpretation by the installer, the number of diodes lit in each set is a function of the quality of the link. For example, the portable unit may be calibrated so that if at least the two left-most diodes of each set are lit, then the installer may directly conclude that the radio link under test is satisfactory and may therefore validate a potential future geographical location.
Conversely, if no diode or only one diode is lit, the installer may conclude that the location is not satisfactory.
The diodes may furthermore be controlled so as to indicate other types of information to the installer. For example:
It should be noted that other display interfaces could be used without departing from the scope of the invention: for example, direct display of a validation or non-validation message on a liquid crystal display screen could be envisaged. What is important here is to enable the installer directly to validate or invalidate a geographical location tested in situ.
It is preferable for no radio control commands C to be sent to the measurement unit 6 by the portable control unit 7 unless it has been verified that the frequency occupancy level would enable the test to be carried out correctly. If the frequency band is already occupied by another application, there is a risk of erroneous measurements. Also, the portable radio control and display unit 7 is advantageously adapted to measure automatically the frequency occupancy level used to communicate before any radio exchange between the portable unit 7 and the measurement mobile unit 6.
To enable the installer to decide how to proceed, the portable control and display unit 7 advantageously includes an additional light-emitting diode 73 that is lit if the frequency occupancy level is greater than a predetermined threshold. The installer then knows that measurement will need to be restarted.
By means of the invention, an installer with no particular radio skills may very simply carry out the tests and validate or invalidate geographical locations using the equipment available to them. The mobile and portable elements are preferably combined in a common carrying case to form an easily transportable kit.
The radio and software means used in each of the mobile and portable units constituting the system are not described in more detail, being standard and having no features specific to the invention. The various means of the same kit should nevertheless be matched, to prevent any interference with other kits or other radio systems. To this end, it is sufficient in particular:
The radio frequencies used for communication between the system components depend of course on the fixed network to be deployed. All radio communication are effected in the UHF band, for example, notably at 868 megahertz (MHz).
An example of use of the system of the present invention for assisting deployment of a network is described below with reference to
The starting point is the non-limiting assumption that the fixed network to be deployed is intended to cover the geographical configuration shown in
It is seen in
Modeling on a map using prior art techniques could determine only the number of intermediate collectors necessary to deploy the network (as it happens four for the example shown here), but the system of the invention provides a very precise knowledge of the future geographical locations of the intermediate collectors.
Use of the system of the invention consists in determining successive preferred future locations for intermediate collectors, starting with first level collectors situated as close as possible to the access point and progressively determining the positions of higher level intermediate collectors on moving away from the access point.
The installer with a carrying case containing the network deployment assistance system preferably proceeds as follows:
a1) Initially, the installer goes to the access point location AP and places the first mobile unit 3 simulating the radio operation of said access point or main collector at the geographical location AP corresponding to the required or imposed future location of the access point or main collector of the network.
a2) The installer then proceeds to determine possible locations for first level intermediate collectors, i.e. those nearest the access point. To this end, it is necessary to determine the future geographical location of a first level intermediate collector for each group of radio communication modules associated with meters situated at least partially in a first coverage area of the access point (in this example the area Z1 and the groups G1 and G2). This is done by using the access point/collector operating mode M1 and the listening mode M3 successively for one or more positions of the measurement mobile unit 6 and by recording position information corresponding to the first position of the measurement mobile unit 6 for which the information obtained on the display means of the portable unit 7 corresponds to a radio link of sufficient quality in the access point/collector operating mode M1 and in the listening mode M3.
a3) Potential locations for second level intermediate collectors are then determined; for this it is necessary, for each group of radio communication modules associated with meters situated at least partially in a coverage area of the access point larger than the first area, to determine the future geographical location of a second level intermediate collector by placing the second mobile equipment 4 in the position designated by the position information recorded at the first level (in this example this means the area Z2 and the group G3). This is done by successively using the collector/collector operating mode M2 and the listening mode M3 for one or more positions of the measurement mobile unit 6 and recording the geographical coordinates of the first position for which the information obtained on the display means of the portable unit 7 corresponds to a radio link of sufficient quality in the collector/collector operating mode M2 and in the listening mode (M3).
a4) Optimum future locations for collectors of even higher levels are determined in exactly the same manner, by repeating the preceding step a3) and testing the connections between the second mobile device 4 placed at one of the locations determined for a lower level and one or more potential locations of the measurement mobile unit 6 for the immediately higher level (in the example, this means the area Z3 and the group G4).
b and 3c illustrate application of the steps a1) and a2) described above to deployment of the network in the context of
a21) Placing the measurement mobile unit 6 at a first location (see
a22) Pushing the button 70a on the portable control and display unit 7, to cause the measurement unit 6 to operate in the access point/collector mode M1; using the display means of the portable control and display unit 7 to verify whether the information received does or does not correspond to a radio link of sufficient quality between the first mobile unit 3 and the measurement unit 6; it is considered here that only one light-emitting diode 72 of the set of four diodes corresponding to this test lights; the installer then concludes directly, without having to interpret the results any further, that the location is not satisfactory.
a23) Moving the measurement mobile unit 6 to a second location, as shown in
a24) Verifying whether the radio link between the measurement unit 6 and the radio communication modules 2 of the group G1 is also satisfactory (
e illustrates application of the step a2) described above to deploying the network in the
f to 3h illustrate application of the step a3) described above to determine a second level location (coverage area Z2) associated with the group G3 of meters.
In practice, the installer does not know the extent of the first area Z1 but the deployment assistance system assists in identifying when level changes. More precisely,
Consequently, the installer knows that it is now necessary to seek to determine the second level location.
g and 3h correspond to the tests effected on successive links to seek a second level location. The installer must proceed as follows to implement the step a3) described above:
a31) first placing the second mobile unit 4 (which simulates the radio receiver and repeater operation of an intermediate collector) at a first level location tested as satisfactory (see
a32) placing the measurement mobile unit 6 at a first location in an area close to the group G2 of radio communication modules 2 associated with the meters 1 (see
a33) pressing the button 70b on the portable control and display unit 7, to cause the measurement unit 6 to operate in the collector/collector mode M2; using the display means of the control and display unit 7 to verify whether or not the received information corresponds to a radio link of sufficient quality between the second mobile unit 4 and the measurement unit 6; it is assumed here that four light-emitting diodes 72 light; the installer then concludes, again directly, that this time the location is satisfactory for the radio link between the first mobile unit 3 and the measurement unit 6; otherwise, the installer would have had to repeat the test for another geographical location of the measurement unit 6;
a34) then checking whether the radio link between the measurement unit 6 and the radio communication modules 2 of the group G3 is also satisfactory (
i illustrates application of the step a4) described above to deployment of the network in the
As in the previous situation (passage from area Z1 to area Z2) the installer does not know the extent of the first area Z2 but, once again, the deployment assistance system gives assistance in determining when the level changes. Here, the installer realizes that he/she is no longer in the second level area Z2 but in a higher level area Z3 on realizing that it is impossible, after repeating the step a33) described above, to find a location for which sufficient link quality is obtained between the measurement mobile unit 6 and the second mobile equipment 4, the test again being effected by controlling the unit 6 from the control and display unit 7 so that it operates in the collector/collector mode M2.
Consequently, the installer now seeks to determine the third level location. To this end, the procedure is exactly as described for the preceding steps a31) to a34), comprising placing the measurement mobile unit 6 at the third level location to be tested and the second mobile equipment 4 at a second level location previously judged satisfactory and testing, again in the same manner, both the quality of the link between the measurement unit 6 and the second equipment 4 (operating mode M2) and also the quality of the link between the measurement unit 6 and each of the modules 2 of the group G4 (operating mode M3 combined with use of the portable remote meter reading unit 5). For simplicity,
Thus after performing all of the above tests using the deployment assistance system of the invention, the installer has recorded all the geographical positions (location and orientation) to be used for intermediate collectors when actually installing the network. The complete topology of the fixed network (positions of the access point, of the modules 2, and of the intermediate collectors) is thus determined completely, as shown in
Although not described in the context of network deployment (
Although the system is described in the context of designing a new fixed network, it should be noted that it is equally simple to extend or to add to the coverage of an existing fixed network by using the deployment assistance system of the invention. For this it suffices, starting from the intermediate collectors already installed, to define progressively the additional intermediate collectors that it is necessary to add.
Number | Date | Country | Kind |
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EP 09305234.8 | Mar 2009 | EP | regional |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP10/52890 | 3/8/2010 | WO | 00 | 11/16/2011 |