Abstract:
An apparatus for transmitting signals between UWB networks is disclosed, which comprises: a signal converter for converting received optical signals from another UWB network into UWB signals, transmitting the converted optical signals within a UWB network, and converting UWB signals generated from within the UWB network into optical signals; and an optical signal transmission means for directing the received optical signals the signal converter and a further UWB network.

Description:
CLAIM OF PRIORITY  
         [0001]    This application claims priority to an application entitled “Apparatus for transmitting signals between ultra wideband networks,” filed in the Korean Intellectual Property Office on Jun. 9, 2003 and assigned Serial No. 2003-36729, the contents of which are hereby incorporated by reference.  
         BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to an apparatus for transmitting signals between ultra wideband networks, and more particularly to an apparatus for converting ultra wideband (hereinafter, referred to as ‘UWB’) signals into optical signals and transmitting the converted signals between UWB networks.  
           [0004]    2. Description of the Related Art  
           [0005]    An UWB transmission is radio transmission technology that has an occupied bandwidth of at least 500 MHz or taking at least 20% of a central frequency. The UWB transmission and Millimeter Wave (MMW) transmission are the only known technologies capable of supporting radio transmissions at speeds more than 100 Mbps. However, the transmission distance of UWB signals, at transmission speeds more than 100 Mbps, decreases relatively to less than 10 m. As shown in FIG. 1, UWB have been applied to a picocell (within 10 m), but expanding the transmission distance using the UWB has not been pursued.  
           [0006]    Referring to FIG. 1, both a picocell 1   10  and a picocell 1   20  are within 10 m. Communication between terminals STA 1   11 , STA 2   12 , STA 3   13  and STA 4   14 , or STA 5   21 , STA 6   22 , STA 7   23  and STA 8   24  in each cell is possible, but not outside of each cell. For example, UWB signals can be transmitted/received between the STA 1   11  and the STA 2   12  existing in the picocell 1   10 . However, UWB signals can&#39;t be transmitted/received between the STA 1   11  existing in the picocell 1   10  and the STA 7   23  existing in the picocell 2   20 .  
           [0007]    In such UWB signals, since the transmission distance limited, the application range is also limited.  
         SUMMARY OF THE INVENTION  
         [0008]    Accordingly, the present invention has been made to reduce overcome the above-mentioned problems occurring in the prior art. One object of the present invention is to provide an apparatus capable of expanding the transmission distance of UWB signals. An other object of the present invention is to provide an apparatus for transmitting UWB signals between UWB networks. Still another object of the present invention is to provide an apparatus for expanding an application range of UWB signals.  
           [0009]    In accordance with the principles of the present invention, an apparatus for transmitting signals between UWB networks is provided and includes a signal converter for converting received optical signals from another UWB network into UWB signals, transmitting the converted optical signals within a UWB network, a nd converting UWB signals generated from within the UWB network into optical signals; and an optical signal transmission means for directing the received optical signals the signal converter and a further UWB network. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    The present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:  
         [0011]    [0011]FIG. 1 is a diagram of a communication area in a conventional ultra wideband network;  
         [0012]    [0012]FIG. 2 is a block diagram of an apparatus for transmitting signals between UWB networks according to an embodiment of the present invention;  
         [0013]    [0013]FIG. 3 is a diagram of a data format of signals transmitted between UWB networks according to an embodiment of the present invention; and  
         [0014]    [0014]FIG. 4 is a diagram of a system for transmitting signals between UWB networks according to an embodiment of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0015]    A preferred embodiment according to the present invention will be described with reference to the accompanying drawings. For the purposes of clarity and simplicity, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.  
         [0016]    [0016]FIG. 2 is a diagram of an apparatus  100  for transmitting signals between UWB networks according to an embodiment of the present invention. Referring to FIG. 2, the apparatus  100  according to an embodiment of the present invention includes a first port  110 , a second port  120 , an optical signal transmission means  130  and a signal converter  140 .  
         [0017]    The first port  110  receives optical signals from other UWB networks. The second port  120  transmits optical signals to other UWB networks.  
         [0018]    The signal converter  140  converts optical signals into UWB signals and transmits the converted signals within a UWB network. Further, the signal converter  140  converts UWB signals generated within the UWB network into optical signals. As those skilled in the art will recognize, the conversion between the optical signal and the UWB signal may be performed by various methods and the conversion methods are not limited in the present invention.  
         [0019]    The optical signal transmission means  130  transmits the optical signals received through the first port  110  to the signal converter  140  and the second port  120 . The optical signal transmission means  130  may include (may be constructed by) either photocouplers or optical switches. The photocouplers distribute inputted signals and transmit the distributed signals. The optical switches transmit inputted signals to the signal converter  140  or the second port  120   
         [0020]    The optical signal transmission means  130  stores (in for example a controller, not shown) a predetermined identification numbers in advance in order to control the switches, when optical switches are used. The optical signal transmission means  130  transmits a corresponding optical signal to the signal converter  140  only when a destination ID of the inputted optical signal corresponds to or is equal to the its own identification number. Otherwise, when the destination ID of the inputted optical signal is not equal to the its own identification number, the optical signal transmission means  130  transmits a corresponding optical signal to the second port  120 .  
         [0021]    [0021]FIG. 3 is a diagram of a data format  300  of signals transmitted between UWB networks according to an embodiment of the present invention. Referring to FIG. 3, signals transmitted between UWB networks include a destination ID area  310  and a data area  320 . Accordingly, when the present invention receives such signals, the optical signal transmission means  130  (having optical switches) compares destination IDs included in the received signals with its own identification numbers. When the destination IDs are equal to its own identification numbers, the optical signal transmission means  130  transmits the received signals to a signal converter in a corresponding UWB network.  
         [0022]    [0022]FIG. 4 is a diagram of a system for transmitting signals between UWB networks according to an embodiment of the present invention. An UWB network is expressed as a picocell in FIG. 4.  
         [0023]    Referring to FIG. 4, picocells picocell 3   30 , picocell 4   40  and picocell 5   50  are connected through signal transmission apparatuses  100   a ,  100   b  and  100   c  between UWB networks as shown in FIG. 4. For example, the picocell 3   30  is connected to the picocell 4   40  through a second port  120   a  of the signal transmission apparatus  100   a  between UWB network and a first port  110   b  of the signal transmission apparatus  100   b  between UWB network. Further, the picocell 4   40  is connected to the picocell 5   50  through a second port  120   b  of the signal transmission apparatus  100   b  between UWB network and a first port  110   c  of the signal transmission apparatus  100   c  between UWB network.  
         [0024]    In addition, signal transmission between UWB networks includes a downstream transmission and an upstream transmission In the downstream transmission a central station  200  transmits signals to each of picocells  30 ,  40  and  50 . In the upstream transmission each of the picocells  30 ,  40  and  50  transmits signals to the central station  200   
         [0025]    Regarding the downstream transmission, when photocouplers are used (in the optical signal transmission means  130   a ,  130   b  and  130   c  in the signal transmission apparatuses  100   a ,  100   b  and  100   c  between UWB networks) data that is output from the central station  200  is first divided by the optical signal transmission means  130   a  in the signal transmission apparatus  100   a . A portion of the divided data is converted into an UWB signal and is transmitted to the picocell 3   30 . Another portion of the other divided data is transmitted to the signal transmission apparatus  100   b  between UWB networks through the second port  120   a  of the signal transmission apparatus  100   a  between UWB networks. Further, optical signals received through the first port  110   b  of the signal transmission apparatus  100   b  between UWB networks is further divided by the optical signal transmission means  130   b  in the signal transmission apparatus  100   a . A portion of the divided signals are converted into UWB signals and are transmitted to the picocell 4   40 . Another portion of the other divided signals are transmitted to the signal transmission apparatus  100   c  between UWB networks through the second port  120   b  of the signal transmission apparatus  100   b  between UWB networks. Advantageously, the transmission distance of the UWB signals is expanded, since data is transmitted from the central station  200  to the plurality of picocells by passing through the plurality of signal transmission apparatuses between UWB network.  
         [0026]    Furthermore, in downstream transmission, when optical switches are used (in the optical signal transmission means  130   a ,  130   b  and  130   c  in the signal transmission apparatuses  100   a ,  100   b  and  100   c  between UWB networks) the optical signal transmission means  130   a ,  130   b  and  130   c  determine whether data with destination information output from the central station  200  will be received by a corresponding picocell or will be transmitted to a next picocell. As a result of the determination, (1) the optical signal transmission means  130   a  transmit the data to one of signal converters  140   a  and the second ports  120   a , (2) the optical signal transmission means  130   b  transmit the data to one of signal converters  140   b  and the second ports  120   b , and (3) the optical signal transmission means  130   c  transmit the data to one of signal converters  140   c  and the second ports  120   c . Advantageously, when data security is required, this method is preferred, since data output from the central station  200  is transmitted to one picocell at a time.  
         [0027]    Regarding upstream transmission, when a random UWB terminal outputs UWB signals, a signal transmission apparatus between UWB networks in a corresponding cell sends the data upward to the central station side.  
         [0028]    For example, when a UWB terminal included in the picocell 4   40  outputs UWB signals, the signal converters  140   b  converts the UWB signals into optical signals and transmits the converted optical signals to the optical signal transmission means  130   b . The optical signal transmission means  130   b  outputs the received optical signals through the first port  110   b . Then, the signal transmission apparatuses  100   a  between UWB network transmits corresponding optical signals to the central station  200  via the second port  120   a , the optical signal transmission means  130   a  and the first port  110   a.    
         [0029]    In addition to the method described above, passive switching may be performed for the switching operation in the optical signal transmission means., In particular, sensors may be utilized, or a CSMA/CA method according to communication between UWB terminals in each picocell and a signal transmission apparatus between UWB networks may be employed. Further, switching in each module may competitively occur between different picocells. Then, the central station may operate a switch in each module in a TDM method or may control the switch by using a proper protocol such as a CSMA/CA method. Thus, solving the problem of competitively occurring between picocells different from each other. According to an application of such a protocol, a network type and a service field may be changed. In the present invention, a setting regarding such switching operation and protocol is not performed.  
         [0030]    In a signal transmission apparatus between UWB networks according to the present invention as described above, UWB signals are converted into optical signals and the converted optical signals are transmitted. In this manner, the UWB signals are transmitted without the distance limitation of the prior art. Moreover, for downstream transmission, an optical switch structure can be applied to the signal transmission apparatus between UWB networks according to the present invention. This optical switch structure enables the selection of service areas by hardware, thereby providing and enhanced security environment. Furthermore, the signal transmission apparatus service is easily expanded by simply connecting it to a port of the nearest module. For example, when an error occurs or the signal transmission apparatus is temporarily congested.  
         [0031]    While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.