Patent Publication Number: US-2020295819-A1

Title: Wireless video bridge for removing electromagnetic radiation noise, and system comprising same

Description:
TECHNICAL FIELD 
     The present invention relates to a wireless video bridge for removing electromagnetic radiation noise. 
     BACKGROUND ART 
     Recently, installation of security cameras is increasing because of crime prevention, surveillance, information gathering, or the like. Conventionally, although an image captured by a security camera is transmitted through a wired network, there is an attempt to transmit the image through a wireless communication network such as wireless fidelity (Wi-Fi) or long-term evolution (LTE) due to a difficulty in wiring and an increase in installation cost. 
     The conventional Wi-Fi, which is single input single output (SISO)-based wireless communication and in which a disconnection phenomenon of data transmission occurs due to multi pass fading according to delay of a reception signal caused by a surrounding environment such as obstacles, responds with a method of increasing a data compression rate when a data transmission rate decreases due to various wireless communication environment variables, and thus degradation of a high resolution image occurs. 
     In addition, although a patch antenna with a high output is used for remote transmission, there are problems in that an installation cost of the patch antenna increases, and the patch antenna is difficult to install because a position and a direction of the patch antenna have to be considered, and cannot be applied to a remote transmission in an interior because an antenna with a high output such as the patch antenna has to be applied to only an exterior. 
     LTE is a wireless image transmission method which is a big burden to both a provider and a consumer because there is a limitation in that a service has to be provided through a designated network operator, a cost of system building for a related service is expensive, and a user who receives the service has to pay for using LTE data. 
     In addition, an electromagnetic interference (EMI) property needs to be improved to improve transmission performance of an image captured by a security camera. 
     DISCLOSURE 
     Technical Problem 
     The present invention is directed to providing a technology capable of increasing a data transmission rate to guarantee continuity of surveillance when an image captured by a security camera is transmitted. 
     In addition, the present invention is directed to providing a technology capable of remotely transmitting an image captured by a security camera installed at an exterior and an interior. 
     In addition, the present invention is directed to providing a technology configured to remove a harmonic signal which is electromagnetic radiation noise caused by a radiation point. 
     Technical Solution 
     One aspect of the present invention provides a wireless video bridge including an interface, and a shielding part configured to remove a harmonic signal generated in relation to the interface when the wireless video bridge is operating. 
     The shielding part may include at least one from among a bead, a resistor, and a capacitor, the interface may include a local area network (LAN) port configured to communicate with an external device outside the wireless video bridge, and the shielding part may include a first shielding part configured to remove a harmonic signal generated by a data transmission line positioned between the LAN port and a controller of the wireless video bridge for data transmission. 
     The interface may further include a switch port configured to communicate with a switch board of the wireless video bridge, and the shielding part may further include a second shielding part configured to remove a harmonic signal generated by a connecting cable which connects the switch port and the switch board. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1A  is a front view illustrating a wireless video bridge according to one embodiment. 
         FIG. 1B  is a side view illustrating the wireless video bridge according to one embodiment. 
         FIG. 2  is a schematic configuration view illustrating the wireless video bridge according to one embodiment. 
         FIG. 3  is a schematic block diagram illustrating a security camera system according to one embodiment. 
         FIG. 4  is a schematic block diagram illustrating the security camera illustrated in  FIG. 3 . 
         FIG. 5  is a view for describing a beamforming operation between a first wireless video bridge and a second wireless video bridge illustrated in  FIG. 3 . 
     
    
    
     MODES OF THE INVENTION 
     In embodiments according to the concept of the present invention disclosed in the specification, specific structural and functional descriptions are directed only to providing examples for describing the embodiments of the present invention, and the embodiments according to the concept of the present invention may be implemented in various forms, and the present invention is not limited to the embodiments described in the specification. 
     While the embodiments according to the concept of the present invention may be modified in various ways and have various alternative forms, examples of the embodiments are shown in the drawings and described in detail below. There is no intent to limit the present invention to the particular forms disclosed. On the contrary, the present invention covers all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention. 
     It should be understood that, although the terms first, second, and the like may be used herein in reference to elements of the present invention, such elements are not to be construed as limited by the terms. The terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and a second element could be termed a first element without departing from the scope of the present invention. 
     It should be understood that, when an element is referred to as being “connected” or “coupled” to another element, the element may be directly connected or coupled to the other element, or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements. Other words used to describe relationships between elements should be interpreted in a like fashion (i.e., “between” versus “directly between,” “adjacent” versus “directly adjacent,” and the like). 
     The terminology used herein to describe the embodiments of the present invention is not intended to limit the scope of the present invention. The articles “a,” “an,” and “the” are singular in that they have a single referent, however the use of the singular form in the present document does not preclude the presence of more than one referent. In other words, elements of the present invention referred to in the singular may number one or more unless the context clearly indicates otherwise. It should be further understood that the terms “comprise,” “comprising,” “include,” and/or “including,” when used herein, specify the presence of stated features, numbers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, elements, components, and/or groups thereof. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein should be interpreted as is customary in the art to which the present invention belongs. It should be further understood that terms in common usage should also be interpreted as is customary in the relevant art and not in an idealized or overly formal sense unless expressly so defined herein. 
     Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. However, the scope of the present invention is not limited to the embodiments. The same reference numerals in the drawings refer to the same members. 
       FIG. 1A  is a front view illustrating a wireless video bridge according to one embodiment,  FIG. 1B  is a side view illustrating the wireless video bridge according to one embodiment, and  FIG. 2  is a schematic configuration view illustrating the wireless video bridge according to one embodiment. 
     Referring to  FIGS. 1A to 2 , a wireless video bridge  100  may transmit/receive image data. The image data may be image data generated by a security camera (not shown). 
     The wireless video bridge  100  may be a communication device for transmitting/receiving the image data generated by the security camera. For example, the wireless video bridge  100  may transmit/receive the image data using the IEEE 802.11ac standard. 
     In a case in which the wireless video bridge  100  transmits the image data, the wireless video bridge  100  may be connected to the security camera, receive the image data generated by the security camera, and transmit the image data to an external receiving device. In a case in which the wireless video bridge  100  receives the image data, the wireless video bridge  100  may be connected to a storage device and transmit the image data to the storage device. 
     The wireless video bridge  100  may include a plurality of antennas  170 - 1  to  170 - 4  for a multi input multi output (MIMO) function to increase a transmission rate or a transmission amount of image data. In addition, the wireless video bridge  100  may serve a beamforming function for remote image data transmission. 
     Hereinafter, for the sake of convenience in the description, an operation of the wireless video bridge  100  will be described using an example case in which the wireless video bridge  100  is connected to the security camera and transmits the image data generated by the security camera to the external receiving device. 
     The wireless video bridge  100  may include an interface  110 , a controller  130 , a radio frequency (RF) chain part  150 , an antenna part  170 , and a shielding part  190 . 
     The interface  110  may include a local area network (LAN) port  110 - 1  for communicating with the security camera. The LAN port  110 - 1  and the security camera may be connected through a LAN cable. 
     Accordingly, the LAN port  110 - 1  may receive the image data transmitted from the security camera. 
     Here, the image data may be compressed image data. The LAN port  110 - 1  may be an interface for Ethernet communication between the security camera and the wireless video bridge  100 . 
     Image data received through the LAN port  110 - 1  may be transmitted to the controller  130  through one or more data transmission lines DL positioned between the LAN port  110 - 1  and the controller  130  for data transmission. 
     In addition, the interface  110  may further include a switch port  110 - 3  for communicating with a switch board  107 . The switch port  110 - 3  may be connected to the switch board  107  through a connecting cable CL. Therefore, the switch board  107  may be connected to a printed circuit board (PCB). 
     The controller  130  may control the overall operation of the wireless video bridge  100 . 
     The controller  130  may modulate the image data. For example, the controller  130  may modulate the image data through a 256-quadrature amplitude modulation (QAM) method. That is, the controller  130  may control an amplitude and a phase of the image data using an in-phase carrier wave and a quadrature carrier wave to generate a plurality of subcarriers. The number of subcarriers may correspond to the number of plurality of RF chains  150 - 1  to  150 - 4  included in the RF chain part  150  and the number of plurality of antennas  170 - 1  to  170 - 4  included in the antenna part  170 . A modulation method of the controller  130  is not limited to the 256-QAM method. 
     The controller  130  may assign the plurality of subcarriers to the RF chain part  150  and transmit the plurality of subcarriers through the antenna part  170 . Here, the controller  130  may control the RF chain part  150  to perform beamforming through the antenna part  170 . 
     The RF chain part  150  may include the plurality of RF chains  150 - 1  to  150 - 4 . The plurality of RF chains  150 - 1  to  150 - 4  may receive the assigned subcarriers, and amplify the subcarriers. 
     The antenna part  170  may include the plurality of antennas  170 - 1  to  170 - 4 . The plurality of antennas  170 - 1  to  170 - 4  may transmit the subcarriers transmitted from the corresponding plurality of RF chains  150 - 1  to  150 - 4  to the external receiving device. 
     The plurality of antennas  170 - 1  to  170 - 4  may be connected to the corresponding plurality of RF chains  150 - 1  to  150 - 4  through corresponding antenna ports P 1  to P 4  and antenna cables C 1  to C 4 . That is, the plurality of RF chains  150 - 1  to  150 - 4  and the plurality of antennas  170 - 1  to  170 - 4  may form one transmission path for subcarrier transmission. 
     For example, the first antenna  170 - 1  may be electrically connected to the first RF chain  150 - 1  through the first antenna port P 1  and the first antenna cable C 1 . The second antenna  170 - 2  may be electrically connected to the second RF chain  150 - 2  through the second antenna port P 2  and the second antenna cable C 2 . The third antenna  170 - 3  may be electrically connected to the third RF chain  150 - 3  through the third antenna port P 3  and the third antenna cable C 3 . The fourth antenna  170 - 4  may be electrically connected to the fourth RF chain  150 - 4  through the fourth antenna port P 4  and the fourth antenna cable C 4 . 
     Here, in  FIGS. 1A to 2 , each of the numbers of plurality of RF chains  150 - 1  to  150 - 4  and plurality of antennas  170 - 1  to  170 - 4  is four, but is not limited thereto, and may be various numbers. 
     The shielding part  190  may remove (or block) noise, that is, a harmonic signal, generated by the wireless video bridge  100  when the wireless video bridge  100  is operating. For example, the harmonic signal may be a harmonic signal generated in relation to (or caused by) the interface  110  positioned on the PCB. 
     The shielding part  190  may include a first shielding part  190 - 1  configured to remove harmonic signals generated by one or more data transmission lines DL positioned between the LAN port  110 - 1  and the controller  130  for data transmission. 
     For example, the first shielding part  190 - 1  may include at least one from among a bead, a resistor, and a capacitor. That is, the first shielding part  190 - 1  may be formed using at least one from among the bead, the resistor, and the capacitor. Here, the first shielding part  190 - 1  may be formed for each of the data transmission lines DL. 
     In addition, the shielding part  190  may further include a second shielding part  190 - 3  configured to shield harmonic signals generated by one or more connecting cables CL for connecting the switch port  110 - 3  and the switch board  107 . 
     For example, the second shielding part  190 - 3  may include at least one from among a bead, a resistor, and a capacitor. That is, second shielding part  190 - 3  may be formed using at least one from among the bead, the resistor, and the capacitor. Here, the second shielding part  190 - 3  may be formed for each of the data transmission lines DL. 
     Since the first shielding part  190 - 1  and the second shielding part  190 - 3  are disposed at radiation points for removing the harmonic signals generated by the LAN port  110 - 1  and the switch port  110 - 3  which are the radiation points when the wireless video bridge  100  is operating, the harmonic signals, which are electromagnetic radiation noise, are removed so that an electromagnetic interference (EMI) property of the wireless video bridge  100  can be improved. 
     Operations of the components of the wireless video bridge  100  have been described using the example case in which the wireless video bridge  100  is connected to the security camera and transmits the image data generated by the security camera to the external receiving device for the sake of convenience in the description, but are not limited thereto. For example, the wireless video bridge  100  may receive a signal transmitted from the external receiving device through the RF chains  150 - 1  to  150 - 4  and the antennas  170 - 1  to  170 - 4 . 
     Here, the RF chains  150 - 1  to  150 - 4  may filter a signal of a using frequency band out of received signal radio waves, amplify the filtered signal, and transmit the amplified and filtered signal to the controller  130 . 
       FIG. 3  is a schematic block diagram illustrating a security camera system according to one embodiment. 
     Referring to  FIG. 3 , a security camera system  200  may include a transmission device  300  and a receiving device  400 . 
     The transmission device  300  and the receiving device  400  may communicate through a plurality of channels. Here, wireless LAN, Wi-Fi, mobile communication networks, ZigBee, Bluetooth, and the like may be used. Wi-Fi may be the IEEE 802.11ac standard. 
     The transmission device  300  may include a security camera  310  and a first wireless video bridge  330 . The receiving device  400  may include a second wireless video bridge  410  and a storage device  430 . Components and operations of each of the wireless video bridges  330  and  410  illustrated in  FIG. 3  may be the same as those of the wireless video bridge  100  described with reference to  FIGS. 1A to 2 . 
     The security camera  310  may be installed at a predetermined position (exterior or interior), and may surveil a region from the position at which the security camera  310  is installed. The security camera  310  may control pan/tilt and the like to secure a shooting angle and a shooting view. The security camera  310  may be an internet protocol (IP) camera or closed circuit television (CCTV) camera. 
     The security camera  310  may capture an image of the region at which the security camera  310  is installed and generate image data. The security camera  310  may transmit the captured image to the first wireless video bridge  330 . For example, the security camera  310  may compress the image data, and transmit the compressed image data to the first wireless video bridge  330 . 
     The security camera  310  and the first wireless video bridge  330  may be communicably connected through LAN such as Ethernet. As an example, the first wireless video bridge  330  may be separated from the security camera  310 , and installed (or positioned) outside the security camera  310 . As another example, the first wireless video bridge  330  may be integrally formed with the security camera  310 . The first wireless video bridge  330  may be built in the security camera  310 . That is, the first wireless video bridge  330  may be embedded in the security camera  310 . 
     The first wireless video bridge  330  may transmit image data transmitted from the security camera  310  to the receiving device  400  through beamforming. Specifically, the first wireless video bridge  330  may perform pairing with the second wireless video bridge  410  and may be communicably connected to the second wireless video bridge  410  through a plurality of RF chains and a plurality of antennas included in the first wireless video bridge  330 . In this process, the first wireless video bridge  330  may determine a direction of the second wireless video bridge  410  with respect to the first wireless video bridge  330 . Next, the first wireless video bridge  330  may shift phases of subcarriers assigned to the plurality of RF chains such that a direction in which points at which beam patterns transmitted from the plurality of antennas commonly intersect are connected is toward the second wireless video bridge  410 . In addition, the first wireless video bridge  330  may amplify amplitudes of the beam patterns transmitted from the plurality of antennas. 
     The second wireless video bridge  410  may receive the image data transmitted from the first wireless video bridge  330 . For example, the second wireless video bridge  410  may receive the image data using the IEEE 802.11ac standard. 
     In addition, the second wireless video bridge  410  may perform bidirectional communication with the first wireless video bridge  330 . The second wireless video bridge  410  may transmit a signal associated with the transmission device  300  to the transmission device  300 . The signal associated with the transmission device  300  may include a signal (or data) for the transmission device  300 , for example, at least one of the security camera  310  and the first wireless video bridge  330 , or a control signal for controlling the at least one of the security camera  310  and the first wireless video bridge  330 . 
     The second wireless video bridge  410  may transmit the image data transmitted from the transmission device  300  to the storage device  430 . Here, the storage device  430  and the second wireless video bridge  410  may be communicably connected through LAN such as Ethernet. As an example, the second wireless video bridge  410  may be separated from the storage device  430  and formed (positioned) outside the storage device  430 . As another example, the second wireless video bridge  410  may be integrally formed with the storage device  430 . The second wireless video bridge  410  may be built in the storage device  430 . 
     That is, the second wireless video bridge  410  may be embedded in the storage device  430 . 
     The storage device  430  may store the image data transmitted from the transmission device  300 . The storage device  430  may include a local storage such as a direct attached storage (DAS), a network storage such as a network attached storage (NAS) or storage area network (SAN), a cloud storage, and other various storages. For example, the storage device  430  may be a network video recorder (NVR), a digital video recorder (DVR), or the like. 
     The storage device  430  may be connected to a display device (not shown) formed outside the receiving device  400 . The image data stored in the storage device  430  may be displayed through the display device. 
     The display device may be formed as a personal computer (PC), a data server, or a portable device. The portable device may be formed as a laptop, a mobile phone, a smart phone, a tablet PC, a mobile internet device (MID), a personal digital assistant (PDA), an enterprise digital assistant (EDA), a digital still camera, a digital video camera, a portable multimedia player (PMP), a personal navigation device or portable navigation device (PND), a handheld game console, an e-book, or a smart device. For example, the smart device may be formed as a smart watch or smart band. 
       FIG. 4  is a schematic block diagram illustrating the security camera illustrated in  FIG. 3 . 
     Referring to  FIG. 4 , the security camera  310  may include a lens part  311 , an image sensor  313 , a signal processing part  315 , a compressing part  317 , and an interface  319 . 
     The lens part  311  may collect light and project an image in front of the lens part  311  onto the image sensor  313  installed behind the lens part  311 . 
     The image sensor  313  may generate an analog signal corresponding to the image projected from the lens part  311  and convert the analog signal to a digital signal. For example, the image sensor  313  may convert the analog signal to the digital signal through a low voltage complementary metal oxide semiconductor (LVCMOS), a low voltage differential signaling (LVDS), and a mobile industry processor interface (MIPI). 
     The signal processing part  315  may perform image signal processing on the digital signal. For example, the signal processing part  315  may perform the image signal processing such as auto exposure (AE), auto focus (AF), and auto white balance (AWB) on the digital signal. 
     In addition, the signal processing part  315  may convert the digital signal, on which the image signal processing is performed, to image data, for example, video format data. For example, the signal processing part  315  may convert the digital signal, on which the image signal processing is performed, to YUV video format data, wherein YUV is a color encoding system typically used as part of a color image pipeline. 
     The compressing part  317  may compress the image data using a standard such as moving picture experts group  4  (MPEG-4), high efficiency video coding (HEVC), and H.264, and transmit the compressed image data to the interface  319 . 
     The interface  319  may be connected to the first wireless video bridge  330 . The interface  319  may transmit the compressed image data to the first wireless video bridge  330 . 
     The interface  319  may be an interface for Ethernet communication between the security camera  310  and the first wireless video bridge  330 . The interface  319  may be electrically connected to the first wireless video bridge  330  through a network cable. 
     Here, the security camera  310  compresses the captured image and transmits the compressed image to the first wireless video bridge  330 , but is not limited thereto, and the first wireless video bridge  330  may also compress the image data according to an embodiment. 
       FIG. 5  is a view for describing a beamforming operation between the first wireless video bridge and the second wireless video bridge illustrated in  FIG. 3 . 
     Referring to  FIG. 5 , the first wireless video bridge  330  and the second wireless video bridge  410  may perform pairing and may be communicably connected. Here, the plurality of antennas of the first wireless video bridge  330  and the plurality of antennas of the second wireless video bridge  410  may form beam patterns. 
     The first wireless video bridge  330  may determine a direction in which the second wireless video bridge  410  is positioned with respect to the first wireless video bridge  330 . Next, the first wireless video bridge  330  may amplify the beam patterns while changing directions of the beam patterns (for example, shifting phases of subcarriers) such that a direction in which points at which the beam patterns of the first wireless video bridge  330  commonly overlap are connected is toward the second wireless video bridge  410 . 
     The second wireless video bridge  410  may also operate like the first wireless video bridge  330 . 
     Accordingly, the beam patterns output from the first wireless video bridge  330  toward the second wireless video bridge  410  may increase, and the beam patterns output from the second wireless video bridge  410  toward the first wireless video bridge  330  may increase. Accordingly, the image data transmitted from the security camera  310  can be remotely transmitted. 
     The above-described device may be formed as hardware components, software components, and/or combinations of hardware and software components. For example, the device and components described in the embodiments may be formed using one or more general purpose computers such as processors, controllers, arithmetic logic units (ALU), digital signal processors, microcomputers, field programmable gate arrays (FPGA), programmable logic units (PLU), microprocessors, other devices capable of executing and responding to instructions, and special purpose computers. A processing device may perform an operating system and one or more software applications performed on the operating system. In addition, the processing device may also respond to the execution of the software to access, store, manipulate, process, and generate data. It is described that one processing device is used for the sake of convenience of the understanding, but the skilled in the art may know that the processing device may include a plurality of processing elements and/or a plurality kinds of processing elements. For example, the processing device may include a plurality of processors, or one processor and one controller. In addition, the processing device may be another processing configuration such as a parallel processor. 
     The software may include computer programs, codes, instructions, or combinations of one or more thereof, the processing device may be configured to operate according to wishes, and the software may also individually or collectively instruct the processing device. The software and/or data may be permanently or temporarily embodied in certain apparatuses, components, physical devices, virtual equipment, computer storage media or devices, or transmitted signal waves to be interpreted by the processing device or to provide the instructions or data to the processing device. The software may also be dispersed to, stored in, and executed by computer systems connected through a network. The software and data may be stored in one or more computer readable recording media. 
     The method according to the embodiment may be realized as a program instruction type method which can be performed by various computers and stored in computer readable media. The computer readable media may store program instructions, data files, data structures, and the like individually or combinations thereof. The program instructions written in the media may be instructions which are specifically designed and formed for the embodiment or may also be instructions commonly known to and used by the skilled in the computer software. Examples of the computer readable recording media include hardware devices such as magnetic media such as hard discs, floppy discs, and magnetic tapes, optical media such as compact disk read only memories (CD-ROM) and digital versatile discs (DVD), magneto-optical media such as floptical disks, ROM, random access memories (RAM), and flash memories which are specifically configured to store and execute program instructions. Examples of the program instructions include machine codes interpreted by compilers and also include high-level codes which can be executed by computers using interpreters and the like. The above-described hardware device may be configured to operate with one or more software modules for performing the operation of the embodiment and vice versa. 
     As described above, while the embodiments have been described with reference to specific embodiments and drawings, various modifications and alterations may be made by those skilled in the art from the above description. For example, when the described technologies are performed in orders different from the described methods, and/or the described components such as a system, a structure, a device and a circuit are coupled or combined in the form different from the described method, or replaced or substituted with other components or equivalents, the appropriate result may be achieved. 
     Therefore, other implementations, other embodiments and equivalents within the scope of the appended claims are included in the range of the claims to be described.