Abstract:
A network camera and a network image surveillance system including the network camera are provided. The network camera may include: an image and audio encoding unit configured to convert an optical image incident from a lens, compress an audio signal from a microphone in a predetermined format, and generate compressed streaming data by encoding the converted image and the compressed audio signal; a network controlling unit configured to monitor an input and output status of the compressed streaming data, control a configuration of a packet of the compressed streaming data in accordance with a network quality of system (QoS), control synchronizing the compressed streaming data with a video frame, and transmit the synchronized streaming data; and a network routing unit configured to route input and output of the data via at least one network port and implement redundancy by using a Spanning Tree Protocol (STP).

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority from Korean Patent Application No. 10-2014-0000829, filed on Jan. 3, 2014, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. 
       BACKGROUND 
       [0002]    1. Field 
         [0003]    Apparatuses and methods consistent with exemplary embodiments relate to a network camera and a network image surveillance system including the network cameras. 
         [0004]    2. Description of the Related Art 
         [0005]    A network image surveillance system includes imaging devices such as network cameras installed in an environment of a street, a building, a factory, or the like that a user desires to monitor for a specific purpose or for security, and monitors the environment. 
         [0006]    Since a conventional network image surveillance system has a star-shaped topology or a tree-shaped topology, a network configuration thereof is limited and wiring thereof is complicated. In addition, in Carrier Sense Multiple-Access/Collision Detection (CSMA/CD) asynchronous communication used in the conventional network image surveillance system, images are frequently disconnected. 
       SUMMARY 
       [0007]    Exemplary embodiments address at least the above problems and/or disadvantages and other disadvantages not described above. Also, exemplary embodiments are not required to overcome the disadvantages described above, and an exemplary embodiment may not overcome any of the problems described above. 
         [0008]    One or more exemplary embodiments include a network camera including a router that is mounted therein and is converged therewith. 
         [0009]    In the network camera, physical layers of network ports used for a network communication are implemented as optical cables, and a ring topology structure is used. 
         [0010]    When the network camera is equipped with a routing function and transmits data using the routing function within the network image surveillance system, the network camera transmits the data in units of frames of an image in order to prevent image display from being interrupted. 
         [0011]    Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the exemplary embodiments. 
         [0012]    According to an aspect of an exemplary embodiment, there is provided a network camera including: an image and audio encoding unit configured to convert an optical image incident from a lens, compress an audio signal from a microphone in a predetermined format, and generate compressed streaming data by encoding the converted image and the compressed audio signal; a network controlling unit configured to monitor an input and output status of the compressed streaming data, control a configuration of a packet of the compressed streaming data in accordance with a network quality of system (QoS), and control synchronizing the compressed streaming data with a video frame, and transmit the synchronized streaming data; and a network routing unit configured to route input and output of data via at least one network port and implement redundancy by using a Spanning Tree Protocol (STP). 
         [0013]    The network routing unit may include an internal port configured to communicate with the network controlling unit and two external ports configured to communicate with network communication units including two physical layers, and transmit the compressed streaming data received from the network controlling unit via the internal port to the network communication units via a first external port from among the two external ports. 
         [0014]    The two external ports are further configured to transmit, if an error occurs in the first external port, the compressed streaming data via a second external port from among the two external ports in a routing direction opposite to a direction in which the data is transmitted via the first external port. 
         [0015]    A plurality of network cameras may select a network camera performing a root router function from among the plurality of network cameras by exchanging a Configuration Bridge Protocol Data Unit (BPDU) frame in synchronization with a video frame, and network cameras connected to the network camera performing the root router function from among the plurality of network cameras set a routing port and a routing direction based on a root path cost. 
         [0016]    According to an aspect of another exemplary embodiment, there is provided a network image surveillance system including: a server, a monitoring terminal, a switch, and at least one network camera, wherein the at least one network camera may include an image and audio encoding unit configured to generate compressed streaming data by converting an optical image incident from a lens, compressing an audio signal received from a microphone in a predetermined format, and encoding the converted optical image and compressed audio signal; a network controlling unit configured to monitor and receive an input and output status of the compressed streaming data, control a configuration of a packet of the received compressed streaming data in accordance with a network quality of system (QoS), and transmit the compressed streaming data in synchronization with a video frame of the image; and a network routing unit configured to route an input and output of the data via at least one network port and implement redundancy by using a Spanning Tree Protocol (STP), and wherein the server, the monitoring terminal, the switch, and the plurality of network cameras form a ring topology structure. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    These and/or other aspects will become apparent and more readily appreciated from the following description of the exemplary embodiments, taken in conjunction with the accompanying drawings, in which: 
           [0018]      FIG. 1  is a block diagram of a conventional network image surveillance system; 
           [0019]      FIG. 2  is a block diagram of a network image surveillance system having a ring topology structure according to an exemplary embodiment; 
           [0020]      FIG. 3  illustrates an internal configuration of a Bridge Protocol Data Unit (BPDU) frame; 
           [0021]      FIG. 4  illustrates an internal configuration of a Bridge identifier (ID); 
           [0022]      FIG. 5  illustrates an example of a cost table; 
           [0023]      FIG. 6  is a block diagram of a network camera equipped with a network routing function according to an exemplary embodiment; 
           [0024]      FIG. 7  illustrates an example in which a network image surveillance system transmits data in a sequential transmission mode according to an exemplary embodiment; and 
           [0025]      FIG. 8  illustrates an example in which a network image surveillance system distributes and transmits data via Virtual Local Area Network (VLAN) setting according to an exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0026]    Reference will now be made in detail to exemplary embodiments which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. In this regard, the exemplary embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the exemplary embodiments are merely described below, by referring to the figures, to explain aspects of the present description. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. Also, well-known functions or constructions are not described in detail since they would obscure the exemplary embodiments with unnecessary detail. 
         [0027]      FIG. 1  is a block diagram of a conventional network image surveillance system. As illustrated in  FIG. 1 , the conventional network image surveillance system may include a server  100 , a monitoring terminal  200 , a first switch/router  110 , second and third switches  120  and  130 , a repeater  140 , and a plurality of network cameras  121 ,  122 ,  123 ,  131 ,  132 ,  133 ,  134 , and  141 . 
         [0028]    In the conventional network image surveillance system, when an interval between the first switch  110  and the second switch  120  and an interval between the first switch  110  and the third switch  130  exceed a certain distance, for example,  100  meters, signals from the first, second, and third switches  110 ,  120  and  130  to the network cameras  121 ,  122 ,  123 ,  131 ,  132 ,  133 ,  134 , and  141  are damaged during transmission, and therefore the damaged signals need to be compensated for by the repeater  140  or other switches. 
         [0029]    For example, when the second switch  120  desires to receive a signal from the network camera  141  located  100  meters away therefrom, the second switch  120  may receive the signal via the repeater  140 . 
         [0030]    Due to these constraints, to install the plurality of network cameras  121 ,  122 ,  123 ,  131 ,  134  and  141 , the conventional network image surveillance system has a tree-shaped network via a hub or the first, second, and third switch/routers  110 ,  120  and  130 , and the repeater  140 . 
         [0031]    Since the conventional network image surveillance system has a star- or a tree-shaped topology, its network configuration is limited, and its wiring is complicated. 
         [0032]      FIG. 2  is a block diagram of a network image surveillance system having a ring topology structure according to an exemplary embodiment. Referring to  FIG. 2 , the network image surveillance system may include a server  100 , a monitoring terminal  200 , a switch and/or router  110 , and a plurality of network cameras  121 ,  122 ,  123 ,  124 ,  125 ,  126 ,  127 , and  128 . 
         [0033]    The plurality of network cameras  121 ,  122 ,  123 ,  124 ,  125 ,  126 ,  127 , and  128 , and the monitoring terminal  200  perform data communication via any of various communication networks, such as an internet or an intranet. 
         [0034]    According to an exemplary embodiment, a network camera may be a data transmission apparatus that transmits data via a network and may be applied to not only a digital image processor but also to image processing apparatuses such as smartphones, hand-held apparatuses, notebooks, personal digital assistants (PDAs), and personal multimedia players 
         [0035]    (PMPs). This is equally applied to exemplary embodiments and modifications thereof which will be described later. 
         [0036]    The monitoring terminal  200  receives data from the plurality of network cameras  121 ,  122 ,  123 ,  124 ,  125 ,  126 ,  127 , and  128 . The monitoring terminal  200  may include a personal computer (PC), a network video recorder (NVR), a digital video recorder (DVR), a notebook, and various other devices. 
         [0037]    As illustrated in  FIG. 2 , in the network image surveillance system having the ring topology structure, when a power is initially turned on, each of the plurality of network cameras  121 ,  122 ,  123 ,  124 ,  125 ,  126 ,  127 , and  128  selects a root router camera. The root router camera refers to a camera located at a final data transmission stage. 
         [0038]    According to an exemplary embodiment, each of the plurality of network cameras  121 ,  122 ,  123 ,  124 ,  125 ,  126 ,  126 ,  127 , and  128  transmits data in synchronization with a video frame in order to select a root router camera, and exchanges a configuration Bridge Protocol Data Unit (BPDU) frame illustrated in  FIG. 3  with each other in order to ascertain a network situation. 
         [0039]    In particular, the root router camera is identified via a process of exchanging a root path cost by using a Bridge identifier (ID)  311  within the configuration BPDU frame and a cost table as an exemplary embodiment illustrated in  FIG. 5 . 
         [0040]    The identified root router camera generates and sends out BDPU frames in units of video frames. 
         [0041]    When the identified root router camera sends out the BPDU frames, other network cameras connecting to the root router camera set a routing port and a routing direction, based on the root path cost. 
         [0042]    When a routing setting is completed via the above-described process, data may be transmitted in a sequential transmission mode as in an exemplary embodiment illustrated in  FIG. 7 . 
         [0043]      FIG. 6  is a block diagram of a network camera  600  according to an exemplary embodiment. Referring to  FIG. 6 , the network camera  600  may include a network controlling unit  610 , a network routing unit  620 , network communication units  631  and  632 , and an image and audio encoding unit  640 . 
         [0044]    The image and audio encoding unit  640  performs encoding by converting an optical image incident from a lens, performing an audio processing on an audio received from a microphone, and compressing the image and audio in various formats. 
         [0045]    Streaming data obtained by the compression in the image and audio encoding unit  640  is transmitted to a monitoring terminal (e.g., the monitoring terminal  200  of  FIG. 2 ) via any of various networks such as the internet, the intranet, or a local area network (LAN). 
         [0046]    The network controlling unit  610  receives the streaming data from the image and audio encoding unit  640  and controls a data packet configuration or the network routing unit  620  to efficiently transmit the streaming data according to quality of service (QoS) states of the network. 
         [0047]    The network controlling unit  610  may be implemented so as to control a priority of the streaming data according to whether the streaming data is an I frame, a B frame or a P frame. 
         [0048]    The network controlling unit  610  may be also implemented so as to synchronize and transmit the streaming data by a video frame period. 
         [0049]    The network controlling unit  610  may include a memory that stores the compressed streaming data received from the image and audio encoding unit  640 . The memory may include a read only memory (ROM) and a random access memory (RAM). The network controlling unit  610  may further include an input/output (I/O) unit for inputting and outputting data. 
         [0050]    The network controlling unit  610  may further include a direct memory access (DMA), a timer, or the like in order to effectively process the received or stored data, and control the network camera via a data bus and an I/O bus. 
         [0051]    The network routing unit  620  is implemented so as to serve as a communication node such as an access point, a router, a switch, or a gateway, complies with a network standard and a protocol defined by Institute of Electrical and Electronics Engineer (IEEE) for network compatibility, and uses a Spanning Tree Protocol (STP). 
         [0052]    The STP is an Open System Interconnection (OSI) 2-layer protocol which prevents generation of loops in a duplex network. The STP is a standard defined in IEEE 802. 1D/1w/1s and is commonly used as an industrial standard. 
         [0053]      FIG. 6  illustrates an example in which the network routing unit  620  is a routing switch. The network routing unit  620  may include an internal port Port 0  performing an internal communication with the network controlling unit  610 , and two external ports Port 1  and Port 2  communicating with the network communication units  631  and  632 . 
         [0054]    Referring to  FIG. 6 , the network communication unit may include a first physical layer  631  and a second physical layer  632 . It should be noted that the first physical layer  631  and the second physical layer  632  may be replaced by a first optic physical layer and a second optic physical layer. An Ethernet Label may be used as a physical layer, and an optical cable may be used as an optic physical layer. 
         [0055]    When an optical link (Optic PHY) is used as the optic physical layer, a network image surveillance system may be established in which a distance between network cameras that enables data transmission is extended to about 100 Km. 
         [0056]    According to another exemplary embodiment, the network routing unit  620  may perform a network distribution by supporting a virtual local area network (VLAN) function. 
         [0057]    According to an exemplary embodiment, the network cameras may perform a routing function and be able to communicate with each other and to route data without separate routers or switches as in  FIG. 1 . 
         [0058]    Referring back to  FIG. 2 , when an error occurs in the fourth network camera  124  while data is being transmitted from the first network camera  121  to the second network camera  122 , data is being transmitted from the second network camera  122  to the third network camera  123 , and data is being transmitted from the third network camera  123  to the fourth network camera  124 , the network image surveillance system changes this routing direction to a routing direction in which data is transmitted from the third network camera  123  to the second network camera  122  and from the second network camera  122  to the first network camera  121 . 
         [0059]      FIG. 7  illustrates an example in which a network image surveillance system transmits data in a sequential transmission mode, according to an exemplary embodiment. When a setting of the routing between network cameras is completed in the above-described manner, since each of the two external ports of each network camera is connected to each other in a daisy chain form, each network camera receives a BPDU frame and sequentially transmits a data packet from a network camera that is the farthest from a network camera performing a root router function, to an adjacent camera during a predetermined period of time. In other words, the data packet finally reaches the network camera performing the root router function. 
         [0060]      FIG. 8  illustrates an example in which a network image surveillance system distributes and transmits data via Visual Local Area Network (VLAN) setting, according to an exemplary embodiment. 
         [0061]    When the network is disconnected during typical data transmission in  FIG. 7  or  8 , by using a BPUD frame transmitted from the network camera performing the root router function, a network camera functioning as a new root router is selected by an STP, and a root path cost calculation is performed to calculate a new routing path. 
         [0062]    As described above, according to the one or more of the above exemplary embodiments, as an image surveillance system is configured to include network camera performing a routing function, wiring of the image surveillance system is simplified, and the number of necessary network equipment such as a switch, a router, and a repeater is decreased. As a result, the cost of implementing the system is reduced. 
         [0063]    According to the one or more of the above exemplary embodiments, as buffering and routing are performed in units of frames of an image generated by each network camera, the interruption of image display may be reduced, and the efficiency of video transmission may be improved. 
         [0064]    The exemplary embodiments can be implemented through computer readable code on a computer readable recording medium to control at least one processing element to implement any above-described embodiment. The computer readable recording medium may be any type of recording device that stores data which can be read by a computer system. 
         [0065]    The computer readable recording medium may include read-only memory (ROM), random-access memory (RAM), CD-ROMs, magnetic tapes, floppy disks, optical data storage devices, etc. The computer readable recording medium can also be distributed over a network coupled to computer systems so that the computer readable code is stored and executed in a distributive manner. Furthermore, the processing element may include a processor or a computer processor, and processing elements may be distributed and/or included in a single device. 
         [0066]    It should be understood that the exemplary embodiments described therein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each exemplary embodiment should typically be considered as available for other similar features or aspects in other exemplary embodiments. 
         [0067]    While one or more exemplary embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the inventive concept as defined by the appended claims.