Abstract:
A wireless transceiving system capable of processing multi-channel broadcast signals and Ethernet signals from an Ethernet PON (Passive Optical Network), the wireless transceiving system includes a wireless STB (Set-top Box) transmitter for wirelessly transmitting broadcast signals which are multi-channel image signals and Ethernet signals; and at least one wireless STB receiver for receiving the broadcast signals and the Ethernet signals transmitted from the wireless STB transmitter to output image signals and audio signals corresponding to the received broadcast signals, and to support an Ethernet port based on the received Ethernet signals.

Description:
CLAIM OF PRIORITY 
     This application claims priority to an application entitled “Wireless Transceiving System,” filed in the Korean Intellectual Property Office on Feb. 16, 2005 and assigned Serial No. 2005-12805, the contents of which are hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an Ethernet Passive Optical Network, and more particularly to the wireless transceiving system capable of receiving and processing both multi-channel broadcast signals and Ethernet signals. 
     2. Description of the Related Art 
     In order to effectively provide a mass storage, high speed data service, and a real time digital broadcast/image service to subscribers, a data transmission speed of more than 100 Mb/s is generally required for those services. Therefore, it is impossible to provide such services through a conventional xDSL or a cable modem which has only a maximum 50 Mb/s of the data transmission rate. Accordingly, in recent years, there has been a demand for a high speed transmission network capable of providing the mass storage, high speed data service, and real time digital broadcast/image service. In order to meet this demand, several optical networks are already proposed. Among them, Passive Optical Network (PON) has prevailed because of its low construction costs. PON include for example, ATM-PON based on the ATM (Asynchronous Transfer Mode), WDM-PON based on the WDM (Wavelength Division Multiplexing), Ethernet-PON based on the Ethernet and etc. 
     The Ethernet PON scheme has been developed mainly in pursuit of receiving and processing the communication data therein. In order to transmit data in a Ethernet PON, gigabit Ethernet signals of 1.25 Gb/s are transmitted in the direction from an Optical Line Terminal (OLT) to Optical Network Unit/Optical Network Terminals (ONU/ONTs) by using a signal at a wavelength of 1550 nm, while the gigabit Ethernet signal of 1.25 Gb/s are transmitted in the direction from the ONTs to the OLT by using a signal at a wavelength of 1310 nm. 
       FIG. 1  illustrates the structure of a typical Ethernet Passive Optical Network according to the prior art. As shown, the typical Ethernet PON includes an OLT (Optical Line Terminal)  100  functioning as a sub-system located between users and service nodes for receiving broadcast signals and communication signals transmitted from a broadcast provider and a communication service provider, converting the received broadcast signals and the received communication signals into broadcast optical signals and communication optical signals, respectively, and then combining the converted broadcast and communication optical signals into single optical signals to be transmitted, a beam splitter  110 , a plurality of ONTs (Optical Network Terminals)  120  and  122  functioning as users&#39; devices for receiving information from the OLT  100  and relaying the received information to the users, a plurality of set-top boxes (hereinafter referred to as “STB”)  130 ,  133 ,  134  and  135 , and optical fiber lines connecting the OLT  100  with the plurality of ONTs  120  and  122 . 
     More specifically, the OLT  100  receives the broadcast signals via a broadcast network and transmit the light-converted and light-amplified signals to the beam splitter  110 , while the OLT  100  also receives data information from an IP (Internet Protocol) router  111  via an IP network, and light-converts the received data signals into optical data signals to transmit the optical data signals to the beam splitter  110 . Furthermore, the OLT  100  receives data signals from the ONTs  120  and  122  via the beam splitter  110  and transmits the received data signals to the IP network through the IP router  111 . 
     ONTs  120  and  122  receive broadcast signals through the broadcast receivers to transmit the received broadcast signals to the users via the broadcast STBs (Set-top Box)  130 ,  133 ,  134  and  135 . Furthermore, the ONTs  120  and  122  receive the communication data through communication receivers to transmit the received communication data to the users via an E-PON ONT function processor (not shown), while the ONTs  120  and  122  receive also communication data from the users via the E-PON ONT function processor to transmit the communication data to the OLT  100  via a burst-mode transmitter (not shown). 
     Conventional broadcast TV service system, based on IP, receive broadcasting signals provided by an apparatus connected to a broadcast TV headend and/or provided by the content or program provider. Received broadcast signals are encoded into MPEG2/4 frames, and corresponding image services are provided to subscriber terminals based on the encoded MPEG2/4 frames. Such image data can be received through the subscriber&#39;s TV or computer terminal connected to the STB at the home according to a corresponding channel selected by the subscriber. 
     Such a structure as that disclosed in the prior art requires that subscribers wishing to have access to broadcast services in multiple locations in their home necessitate locating STBs in each room or part of rooms in the home. Each STB would then need to be interconnected and/or connected to corresponding terminals with physical wires. Such physical wires have brought about a variety of restrictions to construct a home network for transmitting the broadcast signals and the Ethernet signals through the wires. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention has been made to solve the above-mentioned problems and provides additional advantages, by providing a wireless transceiving system including a wireless STB transmitter and a plurality of wireless STB receivers, so that a plurality of STBs can be easily set up to construct a home network on an economical basis. 
     Another aspect of the present invention is to provide a wireless STB transmitter and wireless STB receivers which can be interlinked with mobile multimedia devices. 
     In one embodiment, there is provided a wireless transceiving system capable of receiving and processing multi-channel broadcast signals and Ethernet signals from an Ethernet PON (Passive Optical Network), the wireless transceiving system includes a wireless STB (Set-top Box) transmitter for wirelessly transmitting broadcast signals which are multi-channel image signals and Ethernet signals; and at least one wireless STB receiver for receiving the broadcast signals and the Ethernet signals transmitted from the wireless STB transmitter to output image signals and audio signals corresponding to the received broadcast signals, and to support an Ethernet port based on the received Ethernet signals. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  illustrates a structure of a typical Ethernet passive optical network according to a prior art; 
         FIG. 2  illustrates the structure of a wireless STB (Set-top Box) transceiving system according to one embodiment of the present invention; 
         FIGS. 3   a - 3   b  illustrates data structures provided for explaining the data flow of the wireless STB according to one embodiment of the present invention; and 
         FIG. 4  is a flow chart for explaining an operation process of a 1394 to 802.1 In PAL according to one embodiment of the present invention 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. For the purposes of clarity and simplicity, a detailed description of known functions and configurations incorporated herein will be omitted as it may make the subject matter of the present invention unclear. 
     According to one embodiment of the present invention, a wireless transceiving system includes a STB (Set-top Box) transmitter and wireless STB receivers, wherein the transceiving system can receive multi-channels broadcast signals as well as Ethernet signals at the same time through a single STB transmitter, and provide the received broadcast signals and Ethernet signals to the users through a plurality of STB receivers located through out a house or a building. The terminology “broadcast signal” herein used is regarded as being HD (High Definition) grade hereinafter. 
       FIG. 2  illustrates the structure of a wireless multi-channel STB (Set-top Box) or a multi-channel wireless transceiving system according to one embodiment of the present invention. 
     Referring to  FIG. 2 , the multi-channel wireless STB transceiving system includes a wireless STB transmitter  200  and a plurality of wireless STB receivers  210 ,  212  and  214 . In this embodiment of the present invention, the number of the wireless STB receivers is three for illustrative purposes. However, the number of the STB receivers is not limited to the three, but can be extended further without limitation in accordance with the teachings of the present invention. 
     The wireless STB transmitter  200 , transmits wirelessly broadcast signals which are multi-channel image signals, and Ethernet signals, whereas the wireless STB receivers  210 ,  212  and  214  are coupled to image and audio ports of a TV and/or Ethernet port located at a certain space in a home or office. The STB receivers  210 ,  212  and  214  receive the signals transmitted from the transmitter  200  and transmit the received signals to the TV, computers or other electronic devices. 
     Now, a more detailed description is provided regarding the internal structure of the wireless STB transmitter  200 . 
     Referring to  FIG. 2 , the wireless transmitter  200  includes a plurality of HD tuners  202 , an Ethernet switch  204 , a 1394 LLC (Logical Link Control)/PHY (Physical Layer)  206 , a 1394 to 802.11n PAL (Protocol Adaptation Layer)  208  and a 802.11n MAC (Medium Access Control)/PHY  209 . 
     HD tuners  202  are able to receive not only ground wave signals, cable signals and satellite broadcast TV signals, but also analog and/or digital TV signals. When such HD tuners  202  receives a digital broadcast signal of, for example, ATSC (Advanced Television System Committee) scheme, the HD tuners  202  demodulate the received digital broadcast signal into a signal of MPEG2-TS (Motion Picture Expert Group 2—Transport Streams) type which is then output to the external part thereof. Also, in case that the HD tuners  202  receive analog signals to be then output in the form of CVBS (Composite Video Baseband Signal) and/or SIF (Sound Interface), this requires an apparatus for converting the analog image and audio signals to digital image and audio signals such as ITU656 and I2S. 
     The Ethernet switch  204  provides an interface between an external network and an internal network of the STB. Also, the Ethernet switch  204  has one WAN (Wide Area Network) and at least two LAN (Local Area Network) Ports in order to provide Ethernet ports via a plurality of STBs to the subscriber. 
     The wireless STB transmitter  200  disclosed according to the present invention uses an IEEE 1394 protocol in order to send not only real time and multi-channel broadcast signals of HD grade, but also a plurality of Ethernet signals to the wireless STB receivers  210 ,  212  and  214  at the same time. Such an IEEE 1394 protocol has a wide bandwidth of 800 Mbps so that both the isochronous data like the real time broadcast signals and the asynchronous data like the Ethernet data can be transmitted simultaneously therewith. 
     According to one embodiment of the present invention, the IEEE 1394 LLC (Logical Link Control)/PHY (Physical Layer)  206  receives the multi-channel broadcast signals and the Ethernet signals shown in  FIG. 3   a  through the HD tuners  202  and the Ethernet switch  204 , respectively. Thereafter, the IEEE 1394 LLC/PHY  206  performs data-encapsulation of both the received multi-channel broadcast signals and the received Ethernet signals through the isochronous channels and the asynchronous channels to then add a header to the resultant encapsulated data as shown in  FIG. 3   b . As a result, the IEEE 1394 LLC/PHY  206  outputs the encapsulated data shown in  FIG. 3   b  to the 1394 to 802.11n PAL  208 . 
     The 1394 to 802.11n PAL  208  has the function of overcoming some differences between the IEEE 1394 protocol and the 802.11n protocol. Specifically, the differences rated to the protocol&#39;s clock speed. IEEE 1394 LLC/PHY  206  provide a Service Data Unit (SDU), an expire time and a window size which are different from those of the 802.11n PAL  208 . A buffer such as the FIFO (First Input First Output) is necessary to overcome the differences by matching the clock speed of the IEEE 1394 and the 802.11n protocols. 
     The IEEE 1394 LLC/PHY  206  outputs the data-encapsulated broadcast signals and Ethernet signals to the PAL  208  in which the IEEE 1394 protocol and the 802.11n protocol are matched with each other and added with a PAL header to output the resultant signals as shown in  FIG. 3   c  to the 802.11n MAC (Medium Access Control)/PHY (Physical Layer)  209 . Then, the 802.11n MAC/PHY  209  adds an 802.11n header to the signals shown in  FIG. 3   c  to transmit wirelessly the final resultant data of  FIG. 3   d  to the wireless STB receivers  210 ,  212  and  214 . 
     Hereinafter, a description will be provided about the operation of the 1394 to 802.11n PAL  208  more concretely, referring to the  FIG. 4  which is a flow chart for explaining the operation procedure thereof. 
     Referring to  FIG. 4 , firstly in step  400 , the 1394 to 802.11n PAL  208  uses an MSDU (Maximum Service Data Unit) and a clock which is different from those of the 1394 LLC/PHY  206  and the 802.11n  209 . 
     Next, in step  402 , the 1394 to 802.11n PAL  208  prepares a buffer in order to overcome a difference in packet transmission rate between the 1394 LLC/PHY  206  and the 802.11n MAC/PHY  209 . Specifically, because the 1394 LLC/PHY  206  has a 125 μs of the packet transmission rate and the 802.11n MAC/PHY  209  has a 1 ms of the packet transmission rate, there is that difference between the LLC/PHY  206  and the PAL  209  which should be matched with each other. The buffer used in the PAL  209  has a size determined depending on the packet transmission periods of the 1394 MSDU and the 802.11n. Specifically, the buffer has a size range from the minimum 1394 MSDU to the maximum PAL MSDU. The maximum PAL MADU, PAL max  is calculated by multiplying the maximum 1394 MSDU, 1394 max  by the maximum aggregation number of the 1394 MSDU, 1394 agg-max . The maximum aggregation number, agg max  is a value calculated by dividing the 802.11n packet transmission period, 802.11n per  by the 1394 packet transmission period, 1394 per  and taking only integer number from the resultant value of the division. For example, assuming that 802.11n per =1 ms, and 1394 per =125 μs, therefore maximum aggregation number, agg max =“8”. 
     Next, in step  404 , the 1394 to 802.11n PAL  208  forms the PAL packet. Such a PAL packet includes a PAL header and a PAL Payload. The PAL header has representative numbers of the PAL MSDU, a whole size of the PAL MSDU, an effective time of the PAL MSDU and etc., and the PAL payload has an aggregation packet composed of one 1394 MSDU or more than two 1394 MSDUs to which serial numbers are allocated, respectively. 
     Next, in step  406 , the 1394 to 802.11n PAL  208  encapsulates the PAL header and the PAL payload into a 802.11n header and a 802.11n payload which are then sent to the 802.11n MAC/PHY  209 . 
     Referring back to  FIG. 2 , the wireless STB receiver  210 , receives the broadcast signals and the Ethernet signals transmitted from the wireless STB transmitter  200  disclosed in  FIG. 2 . The internal structure of the wireless STB receiver  210  is identical to those of the other wireless STB receiver  212  and  214  disclosed in  FIG. 2 . Therefore, for simplicity and to avoid redundancy, the internal structure about only the wireless STB receiver  210  will be described, referring to  FIG. 2 . According to one embodiment of the present invention, the wireless STB receiver  210  includes a 802.11n MAC/PHY  216 , a 1394 to 802.11n PAL (Protocol Adaptation Layer)  218 , a 1394 LLC/PHY  219 , an MPEG decoder  212  and an Ethernet PHY  214 . 
     When the wireless STB transmitter  200 , in  FIG. 2 , transmits wirelessly the broadcast signals and the Ethernet signals, the 802.11n MAC/PHY  216  in the wireless STB receiver  210  receives the broadcast and Ethernet signals which are then sent to the 1394 to 802.11n PAL  218 . Then the 1394 to 802.11n PAL  218  extracts the data-encapsulated IEEE 1394 data from the received broadcast and Ethernet signals through a process of which sequence is reversed with respect to the process of the PAL  208  of the STB transmitter  200  disclosed in  FIG. 2 . Thereafter, the data-encapsulated IEEE 1394 data are output to the 1394 LLC/PHY  219  in which the data-encapsulated IEEE 1394 data are divided into the MPEG-TS broadcast signals and the Ethernet signals. Finally, the divided broadcast signals are output to the MPEG decoder  222 , the divided Ethernet signals are output to the Ethernet PHY  224 , respectively. 
     The MPEG-TS broadcast signals received in the MPEG decoder  222  are then converted into the image signals and the audio signals through which the users can watch the image pictures and listen to the audio sounds, accordingly. Also, the Ethernet signals received in the Ethernet PHY  224  provide the Ethernet ports to users. 
     As mentioned above, a signal for controlling the tuners is essentially in order to transmit and receive the signals between the wireless STB transmitter  200  and the wireless STB receiver  210  by wireless communication. Typically, the tuners are controlled by a I2C (Inter IC Communication) signal. Especially, in the present invention, the wireless STB receiver  210  encapsulates the I2C signals with an IEEE 1394 asynchronous packet to transmit the encapsulated I2C signals. Then the encapsulated I2C signals are de-capsulated in the wireless STB transmitter  200  which controls the tuners with the de-capsulated I2C signals. 
     As mentioned above, the present invention provides an easy solution to setting up a wireless STB transmitter and a plurality of wireless STB receivers in a various locations, such as in the home. Furthermore, the present invention can facilitate and accelerate to establish future home networks with lower cost by using the wireless STB transmitter and the wireless STB receivers which can be wirelessly communicated with each other, and also which can be wirelessly interlinked with mobile multimedia players. 
     Although preferred embodiments of the present invention have been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims, including the full scope of equivalents thereof.