BE1023429B1 - Long range low power network gateway - Google Patents

Abstract

Gateway suitable for exchanging data with a plurality of connectable objects by means of a first long-range low power wireless radio frequency network (LPWAN), and for exchanging data with a central server by means of a second wireless radio frequency network local WLAN (Wireless Local Area Network. Said gateway may be in the form of a box pluggable into a female socket connected to an electrical distribution network.

Description

TECHNICAL FIELD [0001] The invention relates to a device providing the connection between objects connected to a first radio frequency network and a central server via a second wireless local area radio (WLAN) network. . In a preferred form, the invention relates to a device connectable to an electrical distribution network.

State of the art [0002] Gateways relaying information of connectable objects to a central server or a remote terminal are known. For example, these gateways are gateways between a first low-power wireless network (for example Bluetooth, Zigbee, etc.) and a second local wireless network (WLAN, for example Wi-Fi). These gateways are, for example, Texas Instrument Gateways (http://www.ti.com/tool/tidc-ble-to-wifi-iot-gateway). Other gateways are in pluggable form (http://www.marvell.com/led-lighting/reference-designs/control-reference-designs/ or http://www.alibaba.com/product- detail / new-products-for-2015-high-flying_60206994884.html). Nevertheless, the reach of the Bluetooth-Wi-Fi, ZigBee-Wi-Fi gateways is small. A large number of gangways are needed to serve an extended area.

For example, as regards the ZigBee protocol, it is usable only at short distance (~ 100m maximum in theory), typically a few meters to a few tens of meters. The connectable objects must therefore be close to the gateway, which limits the use of such a network. To increase the range of the network, one can either increase the number of gateways significantly, which is difficult in terms of cost and implementation, or use the ability of Zigbee networks to be deployed in mesh. ). In this type of mesh network, a connected object can, potentially, serve as a relay between another object located out of range of the gateway and the gateway. This kind of networks has various disadvantages: risk of breaking the mesh and communication if an object is faulty, over-consumption of the relay objects limiting their autonomy on battery, latency in the transmissions, scope is limited to a few retransmissions, congestion of communications at the level of relay objects, greater complexity of communication protocols.

However, these bridges suffer from several defects. First, the gateways operate according to a principle of registering objects at a given gateway. Therefore, when the gateway is out of order, the connectable objects are deprived of their connection and are therefore inoperative. This poses a problem of connectivity and indirectly of reliability. Since objects are unable to connect themselves to another gateway, they no longer fulfill their role, which may be important (a fire alarm for example). Then, the footbridges have a limited scope, which limits the number of objects and / or the extent of the area they can serve. Finally, some of its gateways require connected objects with relatively high transmission power (~ 100mW of transmission power for Wi-Fi), which greatly limits the battery life of objects connected to this type of device. network. So you can not have connected objects that consume very little electricity and can therefore be powered from a standard battery (button type, AA, AAA ..., rechargeable or not) with a lifetime up to several years.

[0005] Next to these low-power low-range networks, there are LPWAN networks "Low-Power Wide-Area Network" (LPWAN). A solution for covering a large area with low power consumption therefore resides in the Low-Power Wide-Area Network (LPWAN) networks which are wideband low power, long range, and generally configured radio networks. star. The radiofrequency transmission technologies supporting these networks are mainly developed by LoRa (https://www.lora-alliance.org/, for example the chip described in the patent application EP2763321A1), SigFox (http: //www.sigfox. com / en /, for example patent application WO2014 / 037665A1) and NB-loT (Narrowband Internet of Things) in the context of 3GPP (http://www.3gpp.org/). The range of LPWAN networks is about ten kilometers in open terrain and is significantly greater than the range of GSM or CDMA, 2G, 3G or 4G mobile networks. On the other hand, in networks of LPWAN type, the data transfer rate at the level of the physical layer (the lowest layer of the OSI model) is very greatly reduced, typically of the order of 1 kbit / s or even up to at 100 bits / s, in order to reduce the transmit power while reaching a greater range. The radiofrequency power emitted by the LPWAN gateways as well as the related connected objects are generally of the order of 10 to 25 mW, up to 500 mW in Europe and 1 W in the United States in exceptional cases duly supervised by the standards for emissions in the public frequency bands, called ISM bands.

However, the current LPWAN network technologies suffer from several problems. The gateways are designed as roof-top type GSM relays or at the top of a tower or radio mast and are designed to listen to a large number of connectable objects simultaneously. The gateways of these three systems are therefore not easy to install, require a relatively large and cumbersome signal processing unit to process signals corresponding to many incoming connections simultaneously (up to 64 simultaneous connections currently in the case of LoRaWAN gateways ) and only plays the role of communication gateway. In addition, given the infrastructure installation and maintenance price, the number of these gateways is reduced, which increases the risk of network failure or the presence of gray areas in network coverage. Indeed, if a gateway fails, many connectable objects would be deprived of connection and the presence of shadow areas is highly dependent on the number of gateways installed to cover an extended area.

[0007] There is therefore a need to have gateways that connect low-power long-range radiofrequency (LPWAN) networks and local radio frequency (WLAN) networks, to reduce the footprint of the gateways, to facilitate their connection, to ensure the reliability of the connection, to allow the gateways to assume several roles while ensuring a low power transmission of connected objects that can be powered from a standard battery (button type, AA, AAA ... ) with a lifespan of up to several years. SUMMARY OF THE INVENTION [0008] According to a first aspect, the invention relates to a gateway adapted to exchange data with a plurality of low power connectable objects by means of a first radio frequency network, and to exchange corresponding data. with a central server using a second Wireless Local Area Network (WLAN) wireless network. This gateway comprises an LPWAN modem, adapted to the first radio frequency network and configured to exchange data with connectable objects configured to transmit with a radiated power typically less than or equal to 25 mW. The gateway also includes a WLAN modem, adapted to the second radio frequency network. The gateway is in the form of a box having connection means to an electrical distribution network. The connectable objects are configured to emit with a power of less than or equal to 25 mW (typical case of connectable objects powered by a rechargeable battery or not). The gateway is characterized in that the first network is a low-power long-range low-power Wide-Area Network LPWAN.

Preferably, the transmit power of the gateway is less than or equal to 500 mW, even more preferably less than or equal to 100 mW, ideally less than 25 mW, when it transmits at its maximum range.

One of the purposes of this device is to be easily used by reducing the footprint of the gateway and simplifying its installation. Another goal is to reduce the power consumption of connectable objects and to feed them by means of a standard battery (button type, AA, AAA ...) with a life of up to several years. A third goal is to cover an extended geographical area. These goals are achieved by using a gateway between two radio frequency networks, one being low-power long-range (LPWAN), the other being local (eg a Wi-Fi network) and connected to the internet. In addition, the gateway can be plugged directly into a socket, which reduces its size and facilitates installation.

[0009] Preferably, the first LPWAN (Low-Power Wide-Area Network) network has a maximum range in free terrain of at least 1 km, preferably at least 5 km, even more preferably at least 10 km.

Preferably, the WLAN modem, adapted to the first radio frequency network is configured to reduce its transfer rate at the physical layer of the OSI model to less than 2 kbit / s, preferably less than 1 kbit / s, even more preferably less than 500 bits / s.

These networks are low-power networks that make it possible to use plug-in objects that consume little power. Indeed, to increase the range, there are two possibilities: either increase the transmission power, which reduces the lifetime of the batteries of connectable objects, or reduce the data exchange rate. This second solution is implemented in LPWAN networks that are capable of transmitting over distances of the order of one kilometer while keeping a low transmission power (25 mW for example). These networks are therefore able to reduce their data exchange rate and cover a large geographical area. Gateways as described in the invention are inexpensive and easy to install, which allows to multiply the number of gateways covering the same area or neighboring areas overlapping each other. This feature provides a redundant network in terms of coverage of an area by multiple gateways, tolerating the failure of a gateway in overlay areas and thus increase the reliability of the network. Indeed, given the wide range of gateways, it is likely that a connectable object is covered by several gateways which allows it to stay connected if a gateway is missing (following a failure of a gateway for example or fluctuations of the RF transmission channel).

Preferably, the LPWAN modem is configured to adapt its transfer rate at the level of the physical layer of the OSI model for exchanging data with a connectable object as a function of the distance between said gateway and said connectable object, the LPWAN modem being configured to reduce its transfer rate to less than 2 kbit / s, preferably less than 1 kbit / s, even more preferably less than 500 bit / s when transmitting at its maximum range.

Preferably, the connection means of the housing to an electrical distribution network comprise a plug plug in a female power socket. Preferably, the housing may also include a female power socket connectable to said male power socket.

This type of housing is commonly called through plug. The advantage of such a device is not to occupy a power outlet and thus reduce clutter by avoiding installing a power strip.

In an alternative version, the connection means of the housing to an electrical distribution network comprise a base of the electric bulb. In this alternative, the housing may also include a socket for a light bulb connectable to said base of the light bulb. These alternatives reduce the footprint of the gateway by placing it, for example, in a ceiling light.

Preferably, the gateway is configured to organize the data exchanges with the connectable objects on at least one channel, a channel having a central frequency and a bandwidth, said organization of the data exchanges being carried out via the transmission periodic or quasi-periodic beacon messages on a channel, called beacon channel, said beacon messages each comprising: a. an indication that the gateway wants to deliver a message, or that it is able to receive at least one message; b. an indication of at least one channel for exchanging at least one message. This characteristic makes it possible not to have to register the objects before their communication. Indeed, objects that want to communicate must simply listen to the beacon channel and find an available gateway with which to communicate. This feature makes the connection more reliable. Indeed, if a gateway is disconnected, a connectable object can reconnect itself to another gateway.

[0015] Preferably, a connectable object of a communication network, comprising a plurality of gateways, is configured to exchange data with any of the gateways of said communication network. Preferably, the connectable object is configured to receive a plurality of tag messages and to exchange data with a gateway according to the quality of said beacon signal

A connectable object will connect preferably to the gateway with the best signal (highest RSSI, best QoS, ...) in order to reduce its consumption. Alternatively, it will exchange data with the first gateway heard that will have a signal of sufficient quality. This feature makes the connection more reliable. Again, if a gateway is disconnected, a connectable object can reconnect itself to another gateway.

Preferably, the gateway housing contains at least one object connectable to the first radio frequency network.

Preferably the connectable object contained in the housing is adapted to control the connection of said socket to said male power socket. Alternatively, the connectable object contained in the housing is adapted to control the connection of said electric bulb base to said socket for a light bulb and the connectable object contained in the housing is therefore able to control the socket-socket connection.

Alternatively, the connectable object contained in the housing is configured to perform at least one of the following functions: thermostat, gas detector, smoke detector, presence detector, motion detector, noise detector, light detector, temperature sensor, humidity sensor, video sensor, audio sensor, audio transmitter.

Combining a gateway and a connectable object into a single device reduces congestion, adds flexibility for use, and allows gateways to take on multiple roles.

Preferably, the connectable object contained in the box is configured to detect an interruption of the data exchanges with the gateway and is configured to exchange data with another gateway within range in case of interruption detection of said data exchanges. The advantage of such a gateway is to continue to perform some of its functions even if the WLAN connection is broken. Indeed, the connectable object-gateway can connect to another gateway and continue to send its connectable object information.

[0019] Preferably, a gateway is part of a communication network comprising a plurality of gateways. Preferably, a connectable object that loses its connection with a first gateway is configured to send a message signaling this loss of connection to another gateway.

This feature is intended to ensure the reliability of some systems without requiring additional means of communication. For example, an alarm system in which sensors could no longer reach their gateway could prevent another gateway further away from the connection break.

According to a second aspect, the invention relates to a method of connecting a gateway in a communication network comprising the steps of: a. provision of a gateway according to the invention; b. connecting the gateway to a socket connected to an electrical network; vs. registering and connecting the gateway to a WLAN network; d. issuing beacon messages; e. receiving and / or transmitting data with connectable objects and / or with a central server; f. connecting to another gateway to transmit messages. Step d is performed only when the gateway is configured to issue a tag message. Step f in turn is performed only when the WLAN connection is broken.

The invention also relates to a method of geolocation of an object connectable by at least two gateways whose location is known in a communication network, the method comprising the steps: a. transmission by a gateway of a message; b. reception by the connectable object of the message sent by the gateway; vs. measurement by the connectable apparatus (130) of at least one physical quantity derived from the radio frequency signal enabling the central server (140) to evaluate the distance between the gateway (100, 200, 300) and the connectable object (130) ; d. transmitting the measurement of at least one physical quantity derived from the radiofrequency signal by the gateway (100, 200, 300) to the central server (140);

The steps are repeated for each gateway, the location of the object is obtained by the central server by triangulation after obtaining distances. The roles of gateways and the connectable object can be inverted in steps a, b. and c.

Preferably, the measurement of the distance between the gateway and the connectable object is obtained by measuring the power of the signal received by each of the gateways.

Alternatively, the gateway and the connectable object each comprise an internal clock and the measurement of the distance between the gateway and the connectable object is obtained by performing the following additional steps: a. synchronization of the internal clock of the connectable object based on the received chirps signals; b. retransmission after a time predefined by the connectable object of a message, preferably the message comprises linear chirps; vs. reception by the gateway of the message sent by the connectable object and calculation of the delay since the initial transmission.

These additional steps being performed between step b and c of the geolocation method. Preferably, the exchanged messages comprise linear chirps.

[0024] Preferably, the gateways used in the geolocation method are gateways as described above, said gateways being configured to perform the steps of the method. Alternatively, the distances between the connectable object and the gateways are obtained by measuring the power of the signal received by each of the gateways. Again, the goal here is to maximize the use of the gateway by increasing its flexibility and intrinsic uses.

BRIEF DESCRIPTION OF THE DRAWINGS [0025] These and other aspects of the invention will be clarified in the detailed description of particular embodiments of the invention, reference being made to the drawings of the figures, in which: FIG. 1 shows an example of a gateway according to the invention; FIG. 2 shows a second example of a gateway according to the invention; FIG. 3a shows an exemplary network comprising a plurality of gateways according to the invention; FIG. 3b shows an exemplary network comprising a plurality of gateways comprising a geolocation beacon functionality according to the invention; FIG. 4 shows an exemplary method of connecting a gateway according to the invention; FIG. 5 shows an example of a geolocation method according to the invention;

The drawings of the figures are not to scale. Generally, similar elements are denoted by similar references in the figures. The presence of reference numbers in the drawings can not be considered as limiting, even when these numbers are indicated in the claims.

DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS OF THE INVENTION [0026] FIG. 1 shows an example of a gateway 100 in a communication network 101 according to the invention. In this example, the gateway 100 comprises a first modem (LPWAN modem) 110 adapted to a first low power radio network 111, a second modem (WLAN modem) 120 adapted to a second radio frequency network 121. The gateway 100 can therefore exchange data. with a plurality of connectable objects 130 by means of the first network 111. It can also exchange data with a central server 140 by means of the second radiofrequency network 121. Preferably, the gateway 100 is in the form of a box 150 comprising means for connection to an electrical distribution network. Preferably, the connection means comprise a male plug socket 151 which can be plugged into a female socket connected to an electrical distribution network.

Alternatively, the connection means of the housing 150 to an electrical distribution network comprise a base of the electric bulb.

Preferably, the term connectable object 130 denotes both potentially connectable objects that actually connected objects. Preferably, the term central server 140, can also be understood in the sense "user terminal (final)". The average radiofrequency power radiated by the connectable objects is less than or equal to 25 mW, preferably less than or equal to 10 mW. Therefore, these low power connectable objects that consume very little electricity and can therefore be powered from a standard battery (button type, AA, AAA ...) with a lifetime of up to a few years. Alternatively, the power of these objects can be achieved with a rechargeable battery of a size comparable to standard batteries. These objects are distinguishable from connectable objects requiring high transmission power (object connectable via Wi-Fi, ~ 100mW of transmission power, for example), which greatly limits the battery life of objects connected to this type. network.

Preferably, the male socket 151 is an outlet complying with at least one of the following standards: NEMA1 -15, NEMA 2-15, NEMA 5-15, NEMA 2-20, NEMA 5-20, JIS C 8303 Class II, EEC 7/16, EEC 7/17, EEC 7/5, EEC 7/6, EEC 7/3, EEC 7/4, GOST 7396 C1, BS 4573, BS 546, BS 1363, IS 401, IS 411, MS 589, SS 145, SI 32, TIS 166-2549, AS / NZS 3112, CPCS-CCC, IRAM 2073, Swiss SEV 1011, Danish 107-2-D1, CEI 23-16Λ / ΙΙ, South Africa SABS 164 -1, Brazilian NBR 14136 (2 and 3 pins), BSouth Africa SABS 164-2 (2 and 3 pins). Preferably, the plug 151 is a plug complying with the CEE 7/7 standard.

Preferably, the housing 150 has maximum dimensions (length, width, depth not taken) of between (10, 5, 2) cm and (30, 15, 8) cm. Preferably, the dimensions are between (15, 5, 3) cm and (20, 10, 6) cm. The housing 150 may, for example be in the form of a parallelepiped. Alternatively, any design to integrate the LPWAN 110 modem antenna can be advantageously envisaged. Preferably, the housing 150 is made of a plastic material.

Preferably, the second network 121 is a wireless local area radio network WLAN (Wireless Local Area Network). For example, this network 121 is a Wi-Fi network. Alternatively, this network 121 can be a Bluetooth network, BLE (Bluetooth Low Energy), Zigbee, ZWave, FSK. Preferably, the gateway 100 exchanges data with the central server 140 via a WLAN router 141 connected to the central server 140 via a connection 142. Preferably, the connection is an internet connection.

Preferably, the first network 111 is a low-power Wide-Area Network (LPWAN) low-power long-range wireless radio-frequency network in which the average radiofrequency power emitted by the gateways and the connectable objects is less than or equal to 25 mW, preferably less than or equal to 10 mW. For example, this network 111 is a LPWAN (Low-Power Wide-Area Network): LoRa, SigFox, NWave, OnRamp, Platanus, Telensa, Amber Wireless, M2M spectrum, 3GPP.

Preferably, the first LPWAN network 111 has a range in open terrain of at least 1 km, preferably at least 5 km, even more preferably at least 10 km. For example, the theoretical range of the LPWAN network can reach several tens of kilometers in open terrain. However, the range can be reduced to less than one kilometer in urban areas due to the presence of numerous buildings that prevent the good propagation of radio frequency signals. Scope is defined as the distance at which a communication can be performed at a given transfer rate. In particular, the maximum range is the distance at which one can be performed at a given minimum transfer rate.

Preferably, the LPWAN modem 110, adapted to the first radiofrequency network 111 is configured to reduce its transfer rate at the physical layer of the OSI model to less than 2 kbit / s, preferably less than 1 kbit / s. s, even more preferably less than 500 bits / s. Alternatively, the LPWAN modem 110 is configured to reduce its transfer rate at the level of the physical layer (PHY) corresponding to the maximum range is at most 2 kbits / s, even more preferably at the maximum of 1 kbit / s, ideally a maximum of 500 bits / s. The physical layer is the lowest layer of the Open Systems Interconnection (OSI) model, which is an ISO communication standard describing the functionalities needed to communicate and organize these functions. This model is a layered model and the lowest layer is the physical layer which is responsible for the effective transmission of signals between the interlocutors. The service of the physical layer is limited to sending and receiving a bit or a continuous bit stream. LPWAN networks have the particularity of being able to adapt their transfer rate at the level of the physical layer so that this rate is higher when the object with which the gateway exchange data is close and that this rate is lower when the object is farther away. The purpose of this variable transmission rate is to voluntarily limit the radiated transmission power of the connectable objects 130 to a maximum of the order of 25 mW which ensures a low power consumption while allowing relatively long-distance communications. order of several kilometers in open terrain).

Preferably, the housing 150 of the gateway 100 comprises at least one connectable object 130 to a first radio network 111 wireless low power. For example, the functionality of this connectable object can be one of the following features: thermostat, gas detector, smoke detector, presence detector, motion detector, noise detector, light detector, temperature sensor, humidity sensor , video sensor, audio sensor, audio transmitter. The sensor (s) necessary for the functionality (s) are included in the plug-in box (150).

Preferably, the gateway 100 becomes a connectable object 130 connected to the first radiofrequency network 111 if the connection to the network 121 WLAN is not established. In this case, the connectable object 130 contained in the box 151 is configured to detect an interruption of data exchanges with the gateway 100 and is configured to exchange data with another gateway 100 in range in case of interruption detection of said data exchange. In this situation, the gateway 100 can not act as a gateway relaying communications between two networks (111 and 121). It can nevertheless continue to act as a connectable object by connecting to another gateway of the first network 111.

Preferably, the data exchanges between the gateway 100 and the connected objects 130 are on at least one channel. A channel is defined by a center frequency and a bandwidth. Preferably, the data exchanges are organized via the periodic or quasi-periodic transmission of beaconed messages on a channel, called beacon channel, said tag messages each comprising: a. an indication that the gateway wants to deliver a message, or that it is able to receive at least one message; b. an indication of at least one channel, preferably different from the beacon channel, for exchanging at least one message.

Preferably, the beacon message allows the connectable objects 130 to communicate at any time with a gateway 100 and without prior registration. Preferably, a connectable object 130 connects preferentially to the gateway 100 having the strongest signal beacon (high RSSI, received signal strength indication) or having the best quality of service (QoS). Alternatively, a connectable object 130 selects a gateway 100 to convey in good condition a given type of traffic, or that is available, which has a good rate, good transmission delays or a low rate of packet loss. Alternatively, the gateway 100 selected is one with a high signal-to-noise ratio.

Figure 2 shows a second example of gateway 200 according to the invention. In this example, the gateway 200 comprises, in addition to the elements described in the first example of the gateway 100, a socket 210 of the electrical distribution network. This socket is connectable to the male socket 151 of the housing 150. The gateway 200 therefore includes a plug "through" and therefore does not occupy a socket. A through plug is a socket comprising a plug plugged into a socket connected to an electrical distribution network, an apparatus operating with electricity and taking off a portion of the power and a female socket in which another device operating at the same time. electricity can be connected.

Alternatively, the connection means of the housing to an electrical distribution network comprise a base of the electric bulb. In this alternative, the housing may also include a socket for a light bulb connectable to said base of the light bulb.

Preferably, the housing 150 of the gateway 200 comprises at least one connectable object 130 to a first radio network 111 wireless low power. For example, the functionality of this connectable object can be one of the following features: thermostat, gas detector, smoke detector, presence detector, motion detector, noise detector, light detector, temperature sensor, humidity sensor , video sensor, audio sensor, audio transmitter.

Preferably, the functionality of the connectable object 130 of the gateway 200 is a controlled socket function 210, that is, a user can connect or disconnect the male and female receptacles 151. 210. In other words, a user can turn on or off the female outlet 210 remotely. The plug 210 then functioning as a remotely controllable switch.

Preferably, the connectable object 130 contained in the casing 151 of the gateway 200 is configured to detect an interruption of the data exchanges with the gateway 200. In the event of interruption of the data exchanges with said gateway 200, the The connectable object 130 in the boxes 151 is configured to exchange data with another gateway 200 within range.

FIG. 3a shows an exemplary network 301 comprising a plurality of gateways 300 according to the invention. Preferably, the gateways 300 comprise the elements and functionalities of the gateways described in the previous examples of gateways 100 and 200.

Preferably, the data exchanges between the gateways 300 and the connected objects 130 are on at least one channel. A channel is defined by a center frequency and a bandwidth. Preferably, the data exchanges are organized via the periodic or quasi-periodic transmission of beaconed messages on a channel, called beacon channel, said tag messages each comprising: a. an indication that the gateway wants to deliver a message, or that it is able to receive at least one message; b. an indication of at least one channel, preferably different from the beacon channel, for exchanging at least one message.

Preferably, the beacon message allows the connectable objects 130 to communicate at any time with a gateway 300 and without prior registration. Preferably, a connectable object 130 connects preferentially to the gateway 300 having the most powerful beacon signal (high RSSI, received signal strength indication) or having the best quality of service (QoS).

Preferably, a connectable object 130 which loses its connection with a first gateway 300 is configured to send a message signaling this loss of connection to another gateway 300. For example, an alarm system in which the sensors could not no longer joining their gateway can prevent another gateway further away from the connection break thus ensuring the services for which they are configured.

Preferably, the connectable object 130 contained in the casing 151 of the gateway 300 is configured to detect an interruption of the data exchanges with the gateway 300. In the event of interruption of the data exchanges with said gateway 300, the The connectable object 130 contained in the boxes 151 is configured to exchange data with another gateway 300 within range.

Preferably, the connectable objects 130 are configured to receive tag messages and to automatically connect to a gateway 300 according to the quality of the beacon signal. For example, when a connectable object 130 wants to send a message to a gateway 300, it starts by listening to the beacon channel in search of at least one gateway 300. Based on the beacon message or messages received during a transmission period (Remember that the transmission of tag messages is periodic), the object 130 evaluates the quality of the signal via the RSSI or via an indicator such as QoS and it selects the gateway 300 having the best quality. Then, the connectable object 130 sends its message to the selected gateway 300.

Preferably, the gateways 300 emit their beacon signal at different times. For example, a newly connected gateway 300 begins by listening to the beacon messages of the surrounding gateways that are transmitted during a period T. The beacon messages are transmitted in fixed time intervals of the period T. Once it has listened to a complete cycle gateway 300 chooses a free slot and starts transmitting its beacon message.

FIG. 3b shows an exemplary network 301 comprising a plurality (in this example 3) of gateways 300 according to the invention. Preferably, the gateways 300 comprise a geolocation beacon functionality of a connectable object 130. Preferably, the geographical position of each of the gateways 300 is known.

Preferably, the geolocation of a connectable object 130 is obtained by triangulation via the measurement of the distances (d1, d2, d3) between said object and each of the gateways 300. For example, these distances are obtained by direct measurement. arrival times of the signals exchanged or by measuring the round-trip time of the signals exchanged between the connectable object 130 and each of the gateways 300.

For example, the determination of the distance can be done on the basis of the power of the received signal (RSSI). The connectable object 130 transmits a signal to each of the gateways 300. Each of the gateways 300 determines the RSSI of the received signal. The RSSI decreasing as the distance increases, the gateways 300 can evaluate their distance from the connectable object 130. The higher the RSSI, the closer the object 130 is and the lower the RSSI, the more the object 130 is distant. At least two distances (one per gateway) are thus obtained and the position of the connectable object 130 is given by the intersection of two circles respectively centered on each of the gateways 300 and of radii respectively equal to each of the measured distances (d1, d2, d3). When two gateways 300 are used, an uncertainty between two possible positions can remain as to the position of the object 130. This uncertainty disappears if at least three gateways 300 are used.

Alternatively, the determination of the distance can then be done by measuring the round-trip time of the signals transmitted from the gateways 300. The advantage of this technique is that it avoids having to synchronize perfectly. the gateways 300 and the connectable object clocks 130. The gateways 300 thus each transmit a signal to the connectable object 130. The object 130 processes each received signal and sends them back to each of the gateways 300. The distance between each of the gateways and the object is therefore equal to c / 2 * (t-t1-tp) where c is the speed of light, t the time of reception of the signal by the gateway, t1 the time of emission of the signal by the gateway and tp the processing time by the known connectable object. This provides at least three distances (one per gateway) and the position of the connectable object 130 is given by the intersection of three circles respectively centered on each of the gateways 300 and radii respectively equal to each of the measured distances. Alternatively, it is the connectable object 130 that transmits the signals and gateways 300 that respond.

Preferably, it is the server 140 which is configured to calculate the distance between the connectable object 130 and the gateways 300 from a physical measurement (signal power, flight time) and to calculate the position. of the connectable object 130 by triangulation.

[0054] Preferably, the signals exchanged are linear chirps. A linear chirp is a periodic signal of constant amplitude modulated linearly between a start frequency and an end frequency defining a bandwidth around a carrier frequency. Its equation, for a period T, ranging from -T / 2 to + T / 2 is:

where C (t) is the expression of chirp in complex exponential form, i the imaginary unit (i2 = -1), B the frequency band of chirp, T the period of chirp and A the amplitude of the envelope constant.

The chirps have the following property: when they are multiplied by a "conjugated chirp":

and that the Fourier transform of the product is calculated, a peak is obtained in the frequency domain. The chirps signals have two uses: they allow the connectable objects 130 to synchronize its internal clock and return the signal exactly after the time tp, and they allow the gateways to calculate very precisely the time interval t-t1 -tp . In both cases, the temporal measurements consist of the search for frequency peaks in the Fourier transform of the product of the chirps by their conjugated chirps. Alternatively, it is the connectable object 130 that transmits the signals and gateways 300 that respond.

Alternatively, one can use a geolocation method described in patent application EP2767847 included by reference.

According to a second aspect, the invention relates to a connection method 400 (FIG. 4) and a geolocation method 500 (FIG. 5).

Figure 4 shows an example of connection method 400 of a gateway 100, 200, 300 comprises the following steps: a. S410: provision of a gateway 100 adapted to exchange data with a plurality of connectable objects by means of a first low power radiofrequency network, and to exchange data with a central server by means of a second radio frequency network wireless local area network (WLAN) wireless, said gateway comprising: a modem adapted to the first radio frequency network and configured to transmit with a power of less than or equal to 25 mW, and a WLAN modem; the gateway is in the form of a plug-in box in a female socket connected to an electrical distribution network; b. S420: connection of the male plug 151 of the gateway 100, 200, 300 in a socket connected to an electrical network; vs. S430: registration and connection of the gateway 100, 200, 300 to the second WLAN network 121; d. S440: [Optionally] issue periodic beacon messages by gateway 100, 200, 300; e. S450: reception and / or transmission of data with connectable objects and / or with a central server; f. S460: [optional] connection to another gateway to transmit messages. Step d is performed only when the gateway 100, 200, 300 is configured to organize the time via the transmission of a beacon signal. Preferably, this option is used when the communication network 101 comprises a plurality of gateways 100, 200, 300. The step f is performed only when the gateway 100, 200, 300 comprises a connectable object functionality and that the connection to the 121 WLAN network is not established. In this case, the gateway 100, 200, 300 behaves as a connectable object 130 and stops transmitting its beacon message. Preferably, it retains the geolocation tag functionality.

Preferably, the gateway 100 provided is a gateway 100, 200, 300 comprising the elements and functionalities described above.

FIG. 5 shows an example of a geolocation method 500 of a connectable object 130 by a plurality of gateways 300 whose position in a communication network is known, the object 130 and the gateways 300 each comprising, in addition , an internal clock. The method comprises the following steps: a. S510: transmission by gateways 300 of a message, preferably the message comprises linear chirps; b. S520: reception by the connectable object 130 of the message sent by the gateway 300; vs. S530: synchronization of the internal clock of the connectable object 130 based on the received chirps signals; d. S540: retransmission after a time predefined by the connectable object 130 of a message, preferably the message comprises linear chirps; e. S550: reception by the gateway 300 of the message sent by the connectable object 130 and calculation of the delay since the initial transmission; f. S560: calculation of the distance between the gateway 300 and the connectable object 130.

The steps are repeated for each gateway 300 and the location of the object 130 is obtained by triangulation.

Alternatively, it is the connectable object 130 that transmits the signals and gateways 300 that respond. In other words, the roles of the gateways 300 and the connectable object 130 are inverted.

In another alternative, knowing the position of the different gateways 300, exchanges with the connectable object 130 take place only with a single gateway 300, the other 300 gateways or listen to these exchanges and, from of these exchanges, calculate their own distance from the connectable object 130 (via the time offsets measured in the chirps). Preferably, it is the connectable object 130 which transmits the signals and a gateway 300 which responds.

The present invention has been described in relation to specific embodiments, which have a purely illustrative value and should not be considered as limiting. In general, the present invention is not limited to the examples illustrated and / or described above. In particular, the invention also relates to combinations of the technical characteristics of the embodiments described above. The use of the verbs "to understand", "to include", "to include", or any other variant, as well as their conjugations, can in no way exclude the presence of elements other than those mentioned. The use of the indefinite article "a", "an", or the definite article "the", "the" or "I", to introduce an element does not exclude the presence of a plurality of these elements. The reference numerals in the claims do not limit their scope.

In summary, the invention can also be described as follows. A gateway adapted to exchange data with a plurality of connectable objects using a first long-range low power wireless radio frequency (LPWAN) network, and to exchange data with a central server using a second wireless radio frequency network local WLAN (Wireless Local Area Network). Said gateway can be in the form of a plug-in housing in a female socket connected to an electrical distribution network.

Claims (20)

claims A gateway (100) adapted to exchange data with a plurality of low power connectable objects (130), said connectable objects (130) being configured to transmit with a maximum radiated power of less than or equal to 25 mW by means of a first radio frequency network (111), and for exchanging data with a central server (140) by means of a second radio frequency network (121), said second radio frequency network being a wireless local area network (WLAN), said gateway (100) comprising: an LPWAN modem (110), adapted to the first radio frequency network, and a WLAN modem (120) adapted to the second radio frequency network; said gateway (100) being in the form of a housing (150) having connection means to an electrical distribution network and being characterized in that the first radio frequency network (111) is a long-range low power network, in star type LPWAN (Low-Power Wide-Area Network). 2. Gateway (100) according to claim 1, wherein the maximum range of the first radiofrequency network (111) is, in open terrain, at least 1 km, preferably at least 5 km, even more preferably at least from 10 km. The gateway (100) according to any one of the preceding claims, wherein the LPWAN modem (110) is configured to receive data from a connectable object (130) with a transfer rate at the physical layer of the OSI model, less than 2 kbit / s, preferably less than 1 kbit / s, even more preferably less than 500 bit / s. Gateway (100) according to any one of claims 1 to 2, wherein the LPWAN modem (110) is configured to adapt its transfer rate at the physical layer of the OSI model for the exchange of data with a connectable object (130) as a function of the distance between said gateway (100) and said connectable object (130), the LPWAN modem (110) being configured to reduce its transfer rate to less than 2 kbit / s, preferably less than 1 kbit / s, even more preferably less than 500 bits / s when transmitting at its maximum range. The gateway (200) according to any one of the preceding claims, wherein the housing connection means (150) to an electrical distribution network comprise at least one of the following: a plug (151) plug into a power outlet female connected to said power distribution network, a base of light bulb connectable to a socket connected to said power distribution network. The gateway (200) of any preceding claim wherein the housing (150) further comprises a current receptacle (210) connectable to said male receptacle (151). 7. Gateway (100, 200) according to any one of the preceding claims, wherein the gateway (100, 200) is configured to organize the data exchanges with the connectable objects (130) on at least one channel, a channel having a frequency central and a bandwidth, said organization of data exchanges being carried out via the periodic or quasi-periodic transmission of beacon messages on a channel, called beacon channel, said tag messages each comprising: a. an indication that the gateway (100, 200) wants to deliver a message, or that it is able to receive at least one message; b. an indication of at least one channel for exchanging at least one message. 8. Gateway (100, 200) according to any one of the preceding claims, wherein the housing (150) contains at least one connectable object (130) to the first radio frequency network (111). 9. Gateway (200) according to claims 6 and 8, wherein said connectable object (130) contained in the housing (150) is adapted to control the connection of said socket (210) to said male power socket ( 151). 10. Gateway (100, 200) according to any one of claims 8 to 9, wherein the connectable object (130) contained in the housing (151) is configured to perform at least one of the following functions: thermostat, gas detector, smoke detector, presence detector, motion detector, noise detector, light detector, temperature sensor, humidity sensor, video sensor, audio sensor, audio transmitter. The gateway (100, 200) according to any one of claims 8 to 10, wherein the connectable object (130) contained in the housing (150) is configured to detect an interruption of data exchange with the gateway (100, 200). ) and is configured to exchange data with another gateway (100, 200) within range. A communication network (301) comprising a plurality of gateways (300) according to any one of the preceding claims and a plurality of connectable objects (130), wherein each of the connectable objects (130) is configured to exchange data with a any of the gateways (300) of said communication network (301). The communication network (301) of claim 12, wherein the gateways (300) are gateways (300) according to any one of claims 5 to 8 and wherein a connectable object (130) is configured to receive a plurality of tag messages and for exchanging data with a gateway (300) according to the quality of said beacon signal. A communication network (301) comprising a plurality of gateways (300) according to any one of claims 1 to 11, wherein a connectable object (130) which loses its connection with a first gateway (300) is configured to send a message signaling this loss of connection to another gateway (300). A method of connecting a gateway (100, 200, 300) in a communication network (301) comprising the steps of: a. providing a gateway (100, 200, 300) adapted to exchange data with a plurality of low power connectable objects (130), said objects being configured to transmit with a maximum radiated power of less than or equal to 25 mW at means of a first low-power Wide-Area Network (LPWAN) low power long-range radiofrequency network (111), and for exchanging data with a central server (140) via a second radio frequency network (121) wireless local area network (WLAN) wireless, said gateway comprising: an LPWAN modem (110), adapted to the first radio frequency network (111), and a WLAN modem (120) adapted to the second radio frequency network (121) said gateway (100, 200, 300) being in the form of a housing (150) having a plug (151) plugable into a female receptacle (210) connected to an electrical distribution network; b. connecting the gateway (100, 200, 300) to a female electrical outlet connected to an electrical network; vs. recording and connecting the gateway (100, 200, 300) to the second radio frequency network (121); d. receiving and / or transmitting data with connectable objects (130) and / or with a central server (140). A method of connecting a gateway (100, 200, 300) in a communication network (301) according to claim 15, wherein the gateway (100, 200, 300) provided in step a. is a gateway (100, 200, 300) according to any one of claims 1 to 11 and further comprising the following additional optional steps: a. issuing beacon messages, this step being performed after step c. of claim 15 and when the gateway (100, 200, 300) is configured to transmit a beacon message; b. connection to another gateway (100, 200, 300) for transmitting messages, this step being performed only when the connection to the second radio frequency network (121) is broken and when the gateway (100, 200, 300) comprises a connectable object ( 130). 17. Method of geolocation of a connectable object (130) by at least two gateways (100, 200, 300) according to any one of claims 1 to 11, whose location is known in a communication network (301), the method including the steps: a. transmitting by a gateway (100, 200, 300) a message; b. receiving by the connectable object (130) the message transmitted by the gateway (100, 200, 300); vs. measurement by the connectable apparatus (130) of at least one physical quantity derived from the radio frequency signal enabling the central server (140) to evaluate the distance between the gateway (100, 200, 300) and the connectable object (130) ; d. transmitting the measurement of at least one physical quantity derived from the radiofrequency signal by the gateway (100, 200, 300) to the central server (140); the steps being repeated for each of the gateways (100, 200, 300), the location of the object is obtained by the central server (140) by triangulation after obtaining the distances, the gateway roles (100, 200, 300) and connectable object (130) that can be inverted in steps a., b. and c. 18. A geolocation method according to claim 17, wherein the measurement of the distance between the gateway (100, 200, 300) and the connectable object (130) is obtained by measuring the power of the signal received by each of the gateways ( 100, 200, 300). The geolocation method according to claim 17, wherein the gateway (100, 200, 300) and the connectable object (130) furthermore each comprise an internal clock and wherein the distance measurement between the gateway ( 100, 200, 300) and the connectable object (130) is obtained by performing the following additional steps: a. synchronizing the internal clock of the connectable object (130) based on the received chirps signals; b. retransmitting after a time predefined by the connectable object (130) of a message, preferably the message comprises linear chirps; vs. receiving by the gateway (100, 200, 300) the message sent by the connectable object (130) and calculating the delay since the initial transmission; the exchanged messages including linear chirps, the further steps being performed between step b and c of claim 16, the roles of gateways (100, 200, 300) and the connectable object (130) being interchangeable in the additional steps. A communication network (301) comprising a plurality of gateways (100, 200, 300) according to any one of claims 1 to 11, wherein the gateways (100, 200, 300) are configured to perform the steps of any one of Claims 15 to 19.