Abstract:
A system for a local network, the system being configured to extend a near field communication (NFC) between an NFC device and an NFC mobile device beyond the range defined by the NFC standards.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 61/775,737, file Mar. 11, 2013, which is incorporated by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    Embodiment disclosed herein relate to systems using near field communication (NFC) technology for digital devices connected to a local network. 
       BACKGROUND 
       [0003]    Near Field Communication Technology, known by the acronym “NFC”, is a wireless, high frequency communication technology having a range of a few centimeters intended to exchange information between several peripherals. This technology results from a combination of a contactless chip card interface and a reader in a single device. An NFC peripheral can communicate with other NFC peripherals as well as with other devices meeting ISO 14443 standards such as e.g., contactless chip cards. 
         [0004]    The NFC standards covering communication protocols and data exchange formats are based on existing radio frequency identification standards (RFID) such as ISO/IEC 14443, FeliCa and ISO/IEC 18092. They include the standards defined by the “NFC Forum” founded in 2004 by Nokia, Philips and Sony comprising today more than 180 members. 
         [0005]    NFC technology is an extension of RFID technology, allowing bidirectional communications between two peripherals, while previous systems, such as contactless chip cards, allowed only unidirectional communication. 
         [0006]    NFC technology is usable only over a short distance of about a few centimeters, which implies a voluntary process from the user by preventing a usage without his knowledge. 
         [0007]    NFC devices may be passive or active. A passive device such as a tag, chip card or a single chip integrated in an object contains information accessible in a read only mode by other NFC compatible devices. The passive device is powered by the electromagnetic field emitted by the reader (active device) so that it does not need its own power supply. On the other hand, an active device generates the electromagnetic field for communicating with a passive device or for establishing a communication channel between two active devices. 
         [0008]    The fact that a device like a smartphone has a power supply does not necessarily mean that it will work in active mode only. A smartphone, or any other portable device like a PDA (Personal Digital Assistant) or a digital tablet, may process its NFC interface in a passive or active mode. In a passive mode, the smartphone emulates a chip card and stores, in a secure memory, the information usually stored in the chip card. Thus, when the smartphone detects the electromagnetic field, it will access the secure memory and answer in a passive NFC mode with the information read from this secure memory. 
         [0009]    The following are examples of known applications that use NFC technology:
       Payment using a contactless bank card or a mobile device (e.g., smartphone, portable computer, digital tablet, PDA, etc.) on a contactless payment terminal;   Parking payment on a terminal accepting contactless payment carried out with a portable phone;   Buying and contactlessly validating a ticket for transportation or a show with the smartphone or other mobile device;   Managing discount vouchers in a shop, couponing by traders, etc;   Accessing and starting a vehicle with a portable phone or other mobile device;   Reading product information (e.g., price, composition, usage, etc.) in a shop;   Controlling physical access to reserved places (e.g., meeting rooms, company, class rooms, etc.)   Exchanging profiles between two users of a social network or game by bringing phones close together (e.g., user peer-to-peer communications);   Reading electronic business cards with a mobile terminal or PDA;   Synchronizing Internet bookmarks and contacts between a PDA and a portable phone;   Retrieving a key or code to a WiFi access point by approaching an NFC mobile terminal to the emitting hotspot; and   Accessing different automation functionalities of a building (e.g., home automation)       
 
         [0022]    NFC systems are designed to enable communication between devices that are positioned close to each other. However, sometimes this may be cumbersome within e.g., a home or a home network in which users wish to access additional functions offered through an NFC link, even if the distance between the devices is greater than the usual NFC communication distance. 
       SUMMARY 
       [0023]    An object of the embodiments disclosed herein is to extend NFC communications between an NFC device and an NFC mobile device beyond the range defined by the NFC standards. 
         [0024]    This object is achieved by a system comprising: 
         [0025]    at least two repeater devices, each repeater device comprising a first communication interface configured to exchange information within a local communication network and a second communication interface locally connected to the first communication interface, the second communication interface comprising an NFC transceiver configured to exchange digital data intended to be transferred to the local communication network via the first communication interface; 
         [0026]    a stand alone device associated with a first repeater device, the stand alone device comprising an NFC communication interface coupled with the NFC transceiver of said first repeater device; and 
         [0027]    a mobile device comprising an NFC communication interface configured to exchange digital data with an NFC transceiver of a second repeater device, said second repeater device being configured to forward, to the local communication network, the digital data received from the mobile device via the NFC communication interface, said digital data being transmitted to the stand alone device via the first repeater device, said first repeater device being at a distance from the second repeater device exceeding a standard range for NFC communications. 
         [0028]    The data read by the second repeater device through the NFC communication interface of the mobile device is thus transferred to the stand alone device due to the local communication network to which the first repeater device is connected to. 
         [0029]    The stand alone device may thus be located a long distance away from the NFC featured mobile device and still receive data in a manner similar to the manner offered by direct NFC communications (i.e., as if the mobile device was located only a very small distance away from the stand alone device). 
         [0030]    This solution uses bi-directional NFC repeater devices connected to the local communication network, each being provided with NFC communication capabilities. For example, a home or a household is equipped with several repeater devices; each repeater device comprises a mechanism for communicating with at least one other repeater device, such that all of the repeater devices of the home network are connected together. The communication can be made through several means such as e.g., WiFi, Internet, radio frequency, power lines (PLC Power Line Carrier) or any other technology with a longer communication range than the NFC standard range. 
         [0031]    Each repeater device comprises NFC capabilities such that the digital data comprising commands or instructions from an NFC mobile device can be read by at least one repeater device if the NFC mobile device is placed close to the repeater device. The repeater device receiving command data from an NFC mobile device forwards said command data to any other repeater device of the home network through the home network. Thus, a single NFC mobile device can be used to communicate with other devices (e.g., stand alone devices) of the home network even if the NFC mobile device is located a distance away from the stand alone devices. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0032]    The embodiments disclosed herein and their advantages will be better understood with reference to the enclosed drawings and the following detailed description, in which: 
           [0033]      FIG. 1  shows a block diagram of a repeater device comprising a LAN and NFC communication interfaces 
           [0034]      FIG. 2  shows a block diagram of a system according to a disclosed embodiment comprising a plurality of repeater devices connected to a local network allowing the transfer of data from an NFC mobile device to a distant device via repeater devices placed respectively close to the mobile device and to the distant device. 
           [0035]      FIG. 3  shows a block diagram of an embodiment of the system disclosed herein comprising a gateway configured to forward information from one repeater device to another. 
       
    
    
     DETAILED DESCRIPTION 
       [0036]    A repeater device R is schematically illustrated in  FIG. 1  as comprising a first communication interface CI 1  able to exchange data with a local network LAN and a second communication interface CI 2  able to communicate with an NFC device via an NFC transceiver. The first and the second communication interfaces are locally connected together so that data received from the second communication interface CI 2  or NFC interface are transferred to the first communication interface CI 1  or LAN interface and vice-versa. In addition, the LAN interface may transmit data coming from the local network back to the NFC interface. 
         [0037]    According to a desired configuration, repeater devices R 1 , R 2 , R 3 , R 4  are connected to each other in a bidirectional local network LAN via their first communication interface CI 1  as illustrated by  FIG. 2 . The system of the invention comprises a set of repeater devices each associated with a stand alone device and a set of repeater devices configured to communicate with a mobile NFC device. In the example of  FIG. 2 , the system comprises repeater devices R 1 , R 2 , R 3 , R 4 , . . . whose second communication interface CI 2  or NFC interface may be linked either to at least one NFC mobile device P or at least one stand alone device D 1 , D 2  having NFC capabilities. 
         [0038]    The local network LAN is preferably wireless using a standardized radio frequency connection such as defined in Wi-Fi standard, but it may also be wired using a standard cable connection such as e.g., Ethernet links, or hybrid using a combination of wireless and wired connections. 
         [0039]    The mobile NFC device P may comprise a smart card of a passive or active type, smartphone, PDA, tablet, remote control or any other potable or hand held device adapted to transmit data to a repeater device R 1 , R 2 , R 3 , R 4 , . . . of the LAN network. 
         [0040]    An active smartcard as described in e.g., U.S. Pat. No. 7,128,274 is provided with an internal power source that generates an electromagnetic field for communicating with the repeater device R 1 , R 2 , R 3 , R 4 , . . . . 
         [0041]    A passive smart card acts as an RFID device powered by an electromagnetic field generated by the repeater device. The other mobile NFC devices (e.g., smartphone, tablet, PDA, etc.) may be set to either the passive or active mode. 
         [0042]    The stand alone devices D 1 , D 2  may comprise a fixed appliance provided with an NFC communication interface placed near a repeater device R 1 , R 2 , R 3 , R 4 , . . . at a distance within the NFC range (e.g., up to 10 cm). A connection between the stand alone device D 1 , D 2  and the LAN network communication interface is thus facilitated since communication is possible via the repeater device. For example, in a home network, devices such as a television set, decoder or set top box, DVD and/or HD (hard disc) reader/writer, media player, personal computer, security alarm, heat controller, air conditioner, etc. may be activated/deactivated or controlled with via an NFC connection with a repeater device R 1 , R 2 , R 3 , R 4 , . . . . 
         [0043]    In the system represented by  FIG. 2 , a portable NFC device P sends, via the NFC link of repeater device R 2 , digital data in form of a command addressed to stand alone device D 1  associated with repeater device R 1  and/or to stand alone device D 2  associated with the repeater device R 4 . 
         [0044]    The following transmission modes may be used to forward the command: 
         [0045]    a) Broadcast mode: all repeater devices R 2 , R 3 , R 4  receive the same command without a specific identifier of a repeater device or of a stand alone device D 1 , D 2 . In this case, the NFC transceiver of the repeater device sends an interrogation signal to test a presence of a stand alone device within the NFC range. If such a device is present, its NFC communication interface replies to the interrogation signal with a response signal informing the repeater device that the stand alone device is ready to receive the command. The broadcasting mode thus allows activating several stand alone devices D 1 , D 2  at a same time, with a portable NFC device P, if they are placed near a repeater device R 1 , R 4  of the LAN network and their NFC interface is powered on. 
         [0046]    The broadcast mode allows using an NFC featured smart card in a passive mode, which may be read by any repeater device in the network to automatically send a command to one or more other repeater devices R 1 , R 4 , and to their associated stand alone devices D 1 , D 2 . 
         [0047]    b) Push mode: a command is addressed to a specific stand alone device while the other stand alone devices ignore the command even if they are placed within the NFC range and have an NFC interface powered on. In this case, the command comprises a device identifier and/or an identifier of the repeater device to which a stand alone device is associated with. After checking the identifier of the command, the NFC transceiver of the repeater device forwards the command to the stand alone device only when a match is found with the identifier of the repeater device or the identifier of the stand alone device. 
         [0048]    The push mode requires a user interface on the mobile NFC device allowing the selection of a specific stand alone device to be controlled with a command. For example, in a system setup phase all repeater devices and associated stand alone devices may be registered with their particular parameters in an application. A user can thus create and address specific commands to a specific stand alone device. The NFC interface of the mobile device is preferably used in active mode. 
         [0049]    According to an embodiment, the application on the mobile device may also be allowed to create predefined groups of stand alone devices to which a same command can be addressed. 
         [0050]    c) Pull mode: the mobile NFC device P interrogates a repeater device to detect active stand alone devices associated with the other repeater devices of the network. Once one or more active devices are detected, commands may be sent to these devices either in broadcast mode or, individually, in push mode. In this case, a first repeater device of the network is requested by the mobile device to explore the network and discover each active repeater device, which are requested in their respective turn to send an interrogation signal to an associated stand alone device, if any. The responses of the stand alone devices received by the repeater devices are forwarded to the network and read by the mobile NFC device in contact with the first repeater device. An application of the mobile device identifies each discovered stand alone device and creates a list allowing the selecting and activating, deactivating or controlling of a stand alone device by a specific command addressed to one device or a common command addressed to all or a group of devices. 
         [0051]    According to a further embodiment, the mobile NFC device P may be provided with an application allowing it to send commands to the stand alone devices either in broadcast, push, or pull mode, or a combination of these modes, depending on a mode selection made on the user interface. 
         [0052]    According to a further embodiment illustrated in  FIG. 3 , each repeater device R 1 , R 2 , R 3 , R 4  may be connected to a gateway G server in charge of managing the bidirectional communications between the repeater devices of e.g., a local network LAN. The connection between the repeater devices and the gateway G may be wireless, wired or mixed as in the network configuration of  FIG. 2 . The above discussed transmission modes are also operable in this embodiment since they do not depend on the configuration of the local network. 
         [0053]    According to a further embodiment, an acknowledgement message may be returned to the mobile NFC device when the command has been received and/or executed successfully by one or more stand alone devices associated with their respective repeater device. 
         [0054]    As the NFC communication technology has a short range of up to 10 cm, the repeater device and the mobile NFC device or the stand alone device must be close to one another so that encryption of the transmission is in general not necessary. However, for high security purposes, the transmission may be encrypted using a pairing mechanism between the concerned devices. The pairing may be applied as described for example in the European document EP1078524B1. The command transmitted from the repeater device to the stand alone device is encrypted by a unique pairing key known by the repeater device and the stand alone device. The latter verifies the pairing with the repeater device preferably at each reception of a command. If the pairing verification is successful, the command is executed by the stand alone device. An advantage of this pairing feature is that it prevents associating an unauthorized stand alone device to a repeater device. 
         [0055]    A similar pairing mechanism may also be applied between the mobile NFC device and each repeater device of the network. In this case, the mobile NFC device stores all of the necessary pairing keys in order to be able to communicate with any repeater device of the local LAN network. An advantage of this pairing feature is that it prevents communications between a repeater device and an unauthorized mobile device. 
         [0056]    In order to save power, an NFC communication between a repeater device R 1 , R 4  and an associated stand alone device D 1 , D 2 , as well as the communication between the mobile NFC device and a repeater device, is deactivated after successful transmission of the command. In the case of an unsuccessful transmission, the NFC communication is deactivated after a predetermined time. 
         [0057]    It should be appreciated that a stand alone device can also receive a command directly from the NFC mobile device when it is placed close to the NFC interface.