JP2009284140A - Communication network and ip multiplexing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To use an IP packet signal of a communication network and an IP packet signal of an RF type network through one Ethernet(R) wiring line. <P>SOLUTION: The communication network is provided with: the packet network 112 which time-division multiplexes an IP packet signal and time-division demultiplexes the transmitted IP packet signal; the RF network 111 which modulates and frequency multiplexes an IP packet signal, and frequency demultiplexes and demodulates the transmitted IP packet; and a home network 115 which packet multiplexes the IP packet signal time-division demultiplexed by the packet network 112 and the IP packet signal demodulated by the RF network 111. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a network in which an IP packet signal from an IP (Internet Protocol) packet signal source is multiplexed and transmitted on a frequency axis as an RF (Radio Frequency) signal by some modulation method, and a time axis as an IP packet signal. It is sent to the networks that are multiplexed and transmitted, and the signals from these networks are separately received and demodulated at the receiving side and output again as IP packet signals, and these IP packet signals are multiplexed and output. The present invention relates to a characteristic IP network and an IP multiplexing apparatus characterized by multiplexing and outputting IP packet signals output from the above-described two different transmission networks on the receiving side in the IP network.

  As a method for transmitting an IP packet signal in an optical access network, a GE-PON (Gigabit Ethernet (registered trademark) PON) method and a media converter method have been put into practical use. GE-PON is an Ethernet (registered trademark) packet used in a so-called PON (Passive Optical Network) form in which the topology of an optical access network is an optical splitter that is a passive component and has a 1:32 branch. Is transmitted and received (see, for example, Non-Patent Document 1). In the GE-PON system, data is transmitted and received in a digital baseband format of IM (Intensity Modulation) (pulse) in an optical fiber, and bidirectional data signals are transmitted and received at 1 Gbps. The media converter method is used in a so-called SS (single star) form in which optical fibers are arranged 1: 1. In both systems, the UNI (User Network Interface) of the line termination device arranged on the subscriber side is Ethernet (registered trademark), and the RJ45 connector is provided as the physical shape of the interface, so category 5 or higher. Thus, an IP packet signal can be transmitted and received.

  On the other hand, in the optical access network, unlike the optical pulse transmission system such as GE-PON and media converter, there is an RF system that transmits a signal modulated on the frequency axis. At present, it is transmitted together with the GE-PON system signal by WDM (Wavelength Division Multiplexing). In this method, a carrier having a bandwidth of 6 MHz in a frequency band of 90 to 2100 MHz is multiplexed with about 100 carriers or more SCM (Sub-Carrier Multiplexing), converted into an optical signal, and transmitted by IM, or optical broadband Has been put to practical use, such as a method of performing up-conversion to around 3 GHz using FM and performing FM (Frequency Modulation) batch conversion and transmission (for example, see Non-Patent Document 2). Compared to the IM transmission method, the FM batch conversion transmission method has higher resistance to reflection and noise and enables long-distance transmission. In the case of the RF method, an output interface from an ONU (Optical Network Unit) which is a line termination device is a coaxial cable. This is because the service provided by this method is a multi-channel video distribution service, and is provided for TV (Television) video machines and STB (Set Top Box) for video viewing.

  By the way, RF transmission is not limited to multi-channel video distribution. For example, a mobile phone can perform communication by modulating a carrier signal on a radio frequency, and can exchange an IP packet signal coupled to an Ethernet (registered trademark) packet or the like. Also, IP packet signals can be transmitted and received using DOCSIS (Data Over Cable Service Interface Specifications), which is a CATV (Cable Television) standard (see Non-Patent Document 3, for example).

  Currently, in the optical access network, the provision of IP packet signals is limited to the communication network based on the GE-PON system, but when the IP packet signal distribution based on the RF system is more advantageous than the communication network based on the GE-PON system. There is. IP packet signal distribution using the RF method is a case where UDP (User Datagram Protocol) packets are distributed all at once. For example, disaster information such as earthquakes and tsunamis, updating of software and firmware distributed using the carousel method, etc. In this case. When performing these distributions in a communication network, there is a limit to the processing capacity of node devices such as multicast routers in the network, so it is difficult to broadcast simultaneously on a large scale unless the number of routers is increased. . On the other hand, in the network distribution by the RF system, there is no active device such as a multicast router, and since optical amplification relay is possible, it can be provided stably and economically. Furthermore, in the case of a communication network, it is necessary to install an Ethernet (registered trademark) cable of category 5 or higher in the home, whereas in the case of the RF system, an existing coaxial cable can be used, so that the labor of wiring is unnecessary. There are also advantages. Although it is very attractive if an IP packet signal distribution service based on the RF system can be realized in the optical access network, it has not been realized at present.

  A communication network such as the GE-PON system and a multi-channel video distribution network based on the RF system have a separate terminal for each network, and terminals having different functions, that is, PCs (Personal Computers) A TV receiver is connected to each. In an optical access network using the FM batch conversion method, a WDM splitter is built in a case of a V-ONU, and optical wavelengths are separated. Accordingly, an optical fiber connected to a GE-ONU that is a line terminating device of a communication network provided by the GE-PON system is once input to the GE-ONU via the V-ONU. Recently, attempts have been made to simplify and improve convenience by making these two line termination devices into a single case. Nevertheless, at present, the IP packet signal is transmitted and received from the GE-ONU. Even if it becomes possible to transmit an IP packet signal through an RF network that transmits in the RF system, since the interface of the V-ONU is a coaxial cable, there is no Ethernet (registered trademark) standard using a coaxial cable. In view of the fact that it is not widespread, it is desirable to provide transmission of IP packet signals with a widely spread category 5 or higher cable.

  Thus, at present, the IP packet signal from the network provided by the GE-PON system is the IP packet signal from the GE-PON network line terminator, and from the RF system network considered to be possible in principle. A problem arises in that the output of IP packet signals from two different networks, such as from the line terminator of the RF network, can only be output separately from each line terminator. For this reason, since it is provided from two different networks in spite of the signal from the same IP packet as seen from the user terminal, it is necessary to receive only the IP packet signal from either network, or to multiplex Therefore, there is a problem of impairing convenience that a separate device is required.

  At present, signals provided from the two networks are output from the respective line termination devices. Therefore, user convenience is poor. This will be described with reference to FIG. FIG. 7 is a schematic diagram showing an overall image of an optical access system in which an IP packet signal is currently provided by a GE-PON system through an optical access network and a multi-channel video signal frequency-multiplexed by an RF system is provided. It is. An optical signal from a GE-PON station side transmission apparatus GE-OLT (Gigabit Ethernet (registered trademark) -Optical Line Terminal) 15 b is wavelength-multiplexed with an RF optical signal by a WDM coupler 51. At this time, in the GE-PON system, two wavelengths of 1.3 μm and 1.49 μm are used, and in the RF system, an optical wavelength of 1.55 μm is used. The wavelength-multiplexed optical signal is branched into 32 by the optical power splitter 52. The optical signal that has passed through the optical access network is first input to the V-ONU 16a, which is an RF line terminating device inside the house. The V-ONU 16a has a built-in WDM splitter 53, which separates the wavelength-multiplexed GE-PON optical signal and RF optical signal. The separated GE-PON optical signal is input to the GE-ONU 16b, which is a GE-PON line terminator. The GE-ONU 16b performs conversion processing from a PON frame to an Ethernet (registered trademark) frame, and the GE-ONU 16b outputs an Ethernet (registered trademark) packet as an Ethernet (registered trademark) interface.

On the other hand, the RF system is input from a HE (Head End) 54 facility through a multi-channel video distribution network 103 to a V-OLT (Video-Optical Line Terminal) 15a which is a transmission apparatus on the station side. In the optical access network, the optical signal of the GE-PON is multiplexed by the WDM coupler 51, branched by 32 by the optical power splitter 52, and then terminated by the V-ONU 16a which is an RF line terminating device inside the home. The output from the V-ONU 16a is a coaxial interface, and an SCM video signal frequency-multiplexed over the 90-2100 MHz band is output. Generally, there are many cases where the distribution locations of the PC 18 and the TV receiver 19 in the home are different, and if the V-ONU 16a is installed near the TV receiver 19, there is a need to input from there to the GE-ONU 16b. Optical wiring may become complicated.
IEEE802.3ah-2004, "IEEE Standard for Information technology-Telecommunications and information exchange between systems-Local and metropolitan area networks-Specific requirements Part 3: Carrier Sense Multiple Access with Collision Detection (CSMS / CD) Access Method and Physical Layer Specificaions Amendment : Media Access Control Parameters, Physical Layers, a nd Management Parameters for Subscriber Access Networks ". ITU-T J.I. 185, “Transmission equipment for transfer multi-channel television signals over optical access networks by FM conversion”. Cable Labs. , “Data over cable service interface specification DOCSIS 3.0”.

  FIG. 8 shows an image in which the IP packet signal provided by the GE-PON system and the IP packet signal provided by the RF system are received by the PC 18 which is the user terminal device. Here, it is assumed that an IP packet signal based on the RF system is provided by modulating, for example, a carrier signal in a VHF (Very High Frequency) band on the frequency axis and being superimposed in a unidirectional form only in the downlink direction. is doing. As described above, in the form of the optical access network as shown in FIG. 8, the IP packet signal transmission by the RF method is not practically used at present, but is possible in principle, and is shown for comparison with FIG. . On the coaxial interface output from the V-ONU 16a, an SCM multi-channel video signal and an IP packet signal (RF system) are superimposed. It is input to a device 55 that separates it into a multi-channel video signal and an IP packet signal (RF system), is separated into a multi-channel video signal and an IP packet signal (RF system), and is input to the PC 18 and TV receiver 19 respectively. To do. Since IP packet signals by GE-PON are also provided, there is a trouble for the user that the same IP packet signal is provided but provided by two different line terminators and routes.

  As described above, there is a problem that the signals of the respective networks are output from the respective line terminating devices. In addition, as described above, the distribution of IP packet signals on the RF network is suitable for simultaneous broadcast distribution, and it is advantageous in that the existing coaxial wiring in the house can be used as it is because the network load is not applied for the distribution. However, at present, there is a problem that the distribution of the IP packet signal by the RF method has not been put into practical use. Even if IP packet signal distribution by the RF method is provided, it cannot be handled at present except for being provided from the V-ONU 16a through a coaxial interface. Since there is no separation device 55 for separating the SCM multi-channel video signal and the IP packet signal (RF system), the device for separating the SCM multi-channel signal and the IP packet signal (RF system) is required. There was a problem of being.

  Therefore, an object of the present invention is to make it possible to use an IP packet signal from a communication network and an IP packet signal from an RF network on a single Ethernet (registered trademark) wiring.

  In order to solve the above-described problems, a communication network according to the present invention is characterized in that two networks of an IP packet signal distribution network and a communication network using an RF system are used as communication networks for IP packet distribution. Here, as an example of the modulation method of the RF signal SCM on the frequency axis, there are a QAM method such as 64QAM (Quadrature Amplitude Modulation) and 256QAM, a PSK modulation method such as QPSK (Quadrature Phase Keying), and 8PSK. In the present invention, modulation other than these modulation methods may be used.

  Specifically, the communication network according to the present invention transmits an IP packet signal by time division multiplexing and transmits the IP packet signal in a time division manner, and modulates and frequency multiplexes the IP packet signal. An RF network for frequency-separating and demodulating the transmitted IP packet signal, and an IP packet for time-division separation of the packet network and a demodulated IP packet signal for the RF network packet-multiplexed for transmission And a network.

Since the IP multiplexer receives signals from the RF network and the packet network separately to make an IP packet signal, and multiplexes and outputs the IP packet signal, the IP packet signal and the RF multi-channel video signal are combined into one. It can be made available on the home network. Therefore, the IP packet signals provided separately from the two networks appear as if they are provided from one network when viewed from the user.
That is, even in an RF network which has been mainly used for multi-channel video distribution, an IP packet signal is modulated and transmitted in frequency, and the SCM video signal and the IP packet signal (RF system) are superimposed in the IP multiplexer of the present invention. It is necessary to switch between the IP packet signal from the GE-PON network and the network by separating the modulated carrier signal that has been modulated, re-IP packet signal, and packet multiplexing the IP packet signal (RF method) And seamless reception. Thereby, for example, an IP packet signal including broadcast information is provided by the RF network, and both IP packet signals can be provided by a single Ethernet (registered trademark) wiring as viewed from the user. An attractive service can be easily deployed.

  Furthermore, even if IP packet signals are provided from two different networks, they are output from the respective line terminators, so that the two different networks are solved in order to solve the very inconvenient situation. An IP multiplexing apparatus is provided that can multiplex IP packet signals provided from the network and provide them to a user terminal such as a PC or TV receiver as one interface. In other words, the transmission signal multiplexed and transmitted on the frequency axis as an RF signal is provided from two different networks, an RF network that transmits an IP packet signal and a communication network that transmits it as a signal on the time axis such as GE-PON. Provided is an IP multiplexer that can multiplex IP packet signals to be provided and provide them to a user terminal as one interface.

Specifically, the IP multiplexing device according to the present invention modulates an IP packet signal, frequency-multiplexes and transmits an RF signal from an RF network that is transmitted as an RF signal, and demodulates the RF signal to an IP packet signal. A signal reception conversion unit, an IP packet signal from a packet network for time-division multiplexing and transmitting the IP packet signal, and time-division separating the transmitted IP packet signal, and an IP packet signal from the RF signal reception conversion unit And an IP packet multiplexing unit for packet multiplexing.
Since the RF signal reception conversion unit converts the signal from the RF network into an IP packet signal, and the IP packet multiplexing unit multiplexes and outputs the IP packet signal, the IP packet signal and the RF multi-channel video signal are combined into one Ethernet. (Registered trademark) can be used in wiring.

  In the IP multiplexing device according to the present invention, the RF signal reception conversion unit separates, from the RF signal, an RF frequency separation unit that separates a frequency carrier on which an IP packet signal is frequency-multiplexed, and an output of the RF frequency separation unit A bandpass processing unit that performs bandpass filtering of the signal, an IF generation unit that generates an intermediate frequency component from the output signal of the bandpass processing unit, and an AD that converts the output signal of the IF generation unit into a digital signal A conversion unit, a Nyquist filter unit that suppresses a signal component in a frequency band greater than a half of the Nyquist frequency, and a phase that corrects a phase error of the output signal of the Nyquist filter unit. A rotation control unit; a demodulation unit that demodulates a carrier modulated on the frequency axis from an output signal of the phase rotation control unit; and the demodulation From the output signal, and the error correction code decoding section for decoding an error correcting code, an output signal from said error correction code decoding portion, an IP packet converting unit that IP packet signal is preferably provided with a.

  In the IP multiplexing apparatus according to the present invention, the IP packet multiplexing unit includes a first receiving unit that receives an IP packet signal from the RF signal reception conversion unit, and a first receiving unit that receives an IP packet signal from the packet network. 2 receiving units, a buffer unit for temporarily storing IP packet signals input to the first receiving unit and the second receiving unit, an IP packet signal from the first receiving unit, and the second receiving unit A switch unit for packet-multiplexing the IP packet signal, an address registration memory for registering and storing the address of the IP packet signal, the priority of the IP packet signal and the address stored in the address registration memory, and the switch unit And a control unit that multiplexes the IP packet signal and a packet multiplexed IP packet signal from the switch unit. A multiplexing signal transmitting unit is preferably provided with a.

  The IP multiplexing apparatus according to the present invention includes a plurality of ports that output IP packet signals from the IP packet multiplexing unit, and the IP packet multiplexing unit transmits the packet-multiplexed IP packet signal to any one of the ports or It is preferable to forward to all.

  In the IP multiplexing device according to the present invention, it is preferable to further include a line termination unit of the RF network and the packet network.

  According to the present invention, an IP packet signal from a communication network and an IP packet signal from an RF network can be used with one Ethernet (registered trademark) wiring.

  Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiment described below is an example of the configuration of the present invention, and the present invention is not limited to the following embodiment.

(Embodiment 1)
FIG. 1 is a diagram schematically showing the overall configuration of a communication network according to the present embodiment. The communication network according to the present embodiment transmits an IP packet signal by time division multiplexing and transmits the IP packet signal to the packet network 112 for time division separation, modulates the IP packet signal, and transmits it by frequency multiplexing. RF network 111 for frequency-demultiplexing and demodulating the transmitted IP packet signal, and home network for packet-multiplexing and transmitting the time-separated IP packet signal of packet network 112 and the demodulated IP packet signal of RF network 115.

The packet network 112 includes a router 14a, a packet transmission network 102, a router 14b, a GE-OLT 15b, a GE-ONU 16b, and an IP multiplexer 17. The RF network 111 includes an SCM device 13, an RF transmission network 101, a V-OLT 15 a, a V-ONU 16 a, and an IP multiplexing device 17. The home network 115 includes an IP multiplexer 17 and a PC 18.
An IP packet signal from the IP source 11 can be input to the RF network 111 and the packet network 112 by the switch device 12. At this time, as described above, it is advantageous that the broadcast IP packet signal is distributed by the RF network 111. Therefore, if the address of the UDP / IP packet signal or the like is a broadcast address. The switch device 12 performs distribution to the SCM device 13. Then, the SCM device 13 frequency-multiplexes the IP packet signal into an RF signal and sends it to the RF transmission network 101. In the case of one-to-one communication, the switch device 12 distributes to the router 14a so as to see the IP address of the IP packet signal and input it to the packet network 112. Then, the router 14a sends the IP packet signal to the packet transmission network 102.

  The IP packet signals transmitted through both networks are received by the respective line termination devices 16. The RF signal via the RF transmission network 101 is received by the V-ONU 16a that receives the RF signal via the V-OLT 15a, and is input to the IP multiplexer 17 via the coaxial interface. Then, the IP multiplexer 17 generates an IP packet signal from the RF signal. The IP packet signal via the packet transmission network 102 is received by the GE-ONU 16b that receives the packet signal via the GE-OLT 15b, and is input to the IP multiplexer 17 via the Ethernet (registered trademark) interface. The IP multiplexer 17 multiplexes IP packet signals from both networks, and provides them to the user's PC 18 via one Ethernet (registered trademark) interface.

  FIG. 2 is a diagram schematically showing functional blocks of the IP multiplexer 17 according to the present embodiment. The IP multiplexing apparatus according to the present embodiment includes an RF signal reception conversion unit 23 that demodulates an RF signal from an RF network (reference numeral 111 shown in FIG. 1) into an IP packet signal, and a packet network (FIG. 1). And an IP packet multiplexing unit 25 that multiplexes the IP packet signal from the RF signal reception conversion unit 23 and the IP packet signal from the RF signal reception conversion unit 23.

  Corresponding to two inputs from V-ONU (reference numeral 16a shown in FIG. 1) and GE-ONU (reference numeral 16b shown in FIG. 1), a coaxial connector 22 and an RJ45 connector 24 are provided. An RF signal obtained by multiplexing the IP packet signal on the frequency axis is input to the coaxial connector 22. An IP packet signal is input to the RJ45 connector 24. The RF signal input to the coaxial connector 22 is demodulated into an IP packet signal by the RF signal reception conversion unit 23 for RF signal reception processing and packetization. The IP packet signal from the RF signal reception conversion unit 23 is packet-multiplexed with the IP packet signal input from the GE-ONU to the RJ45 connector 24 and the IP packet multiplexing unit 25. When the IP multiplexing apparatus includes a plurality of ports that output the IP packet signal from the IP packet multiplexing unit 25, the IP packet multiplexing unit 25 selects the desired IP packet signal from among the plurality of ports or Forward to all ports. The IP packet signal packet-multiplexed by the IP packet multiplexing unit 25 is output from an Ethernet (registered trademark) interface 26 such as an RJ45 connector or an optical fiber. Here, the Ethernet (registered trademark) interface such as the RJ45 connector 24 and the Ethernet (registered trademark) interface 26 can be provided by a category 5 cable, but in the future, the Ethernet (registered trademark) standard based on optical fiber, for example, 1000BaseSX or the like. It is preferable that an Ethernet (registered trademark) interface such as the RJ45 connector 24 and the Ethernet (registered trademark) interface 26 can be attached and detached in preparation for the case where 1000BaseLX or the like is provided.

  FIG. 3 is a diagram schematically illustrating functional blocks of the RF signal reception conversion unit 23 according to the present embodiment. The RF signal reception conversion unit according to the present embodiment includes an RF frequency separation unit 23-1, a BP (bandpass) processing unit 23-2, an IF generation unit 23-3, an AD conversion unit 23-4, and a Nyquist. Filter units 23-5a and 23-5b, a phase rotation control unit 23-6, a demodulation unit 23-7, an error correction code decoding unit 23-8, and an IP packet conversion unit 23-9 are provided.

  The RF frequency separation unit 23-1 separates the frequency carrier on which the IP packet signal is superimposed from the RF signal from the coaxial connector (reference numeral 22 shown in FIG. 2). As a result, only the frequency carrier on which the IP packet signal is superimposed is selected in the RF frequency separation unit 23-1 as the IP packet signal that is SCM-modulated on the frequency axis. The BP processing unit 23-2 extracts a frequency component in which the IP packet signal is multiplexed from the output signal of the RF frequency separation unit 23-1. As a result, the selected carrier is subjected to bandpass filter processing in the BP processing unit 23-2 and input to the IF generation unit 23-3. In IF generator 23-3, the carrier frequency is down-converted to an IF frequency by a local oscillator (not shown). The down-converted signal is subjected to AD (Analog to Digital) conversion for digital processing in the AD conversion unit 23-4, and then converted into an I component which is an amplitude component of modulation and a Q component which is a phase component.

  The converted signals are subjected to Nyquist processing by Nyquist filters 23-5a and 23-5b for suppressing ISI (Inter Symbol Interference), respectively. The Nyquist filter units 23-5a and 23-5b suppress the signal component in the frequency band larger than half of the Nyquist frequency from the output signal of the output signal of the AD conversion unit 23-4. In order to minimize the influence of the phase noise, the phase rotation control unit 23-6 performs a phase rotation control process. For example, the phase rotation control unit 23-6 detects and corrects a phase error between the I component and the Q component of the output signal of the Nyquist filter units 23-5a and 23-5b. The demodulator 23-7 demodulates the output signal from the phase rotation controller 23-6 into a baseband signal. The demodulated signal is decoded by a subsequent error correction code decoding unit 23-8 that has been subjected to error correction coding. Since the signal is a baseband signal when the error correction code is decoded, in order to packetize the signal, a process of converting the output signal from the error correction code decoding unit 23-8 into an IP packet signal Is performed in the IP packet conversion unit 23-9. The converted IP packet signal is passed to an IP packet multiplexing unit (reference numeral 25 shown in FIG. 2) which is a subsequent processing block.

  FIG. 4 is a diagram schematically illustrating functional blocks of the IP packet multiplexing unit 25 according to the present embodiment. The IP packet multiplexing unit 25 includes a reception unit 1a as a first reception unit, a reception unit 1b as a second reception unit, a switch unit 3, a transmission unit 4c as a multiplexed signal transmission unit, and a transmission IP. A receiving unit 1c as a packet signal receiving unit, a transmitting unit 4b as a transmitting IP packet signal transmitting unit, and buffer units 2a, 2b for buffering IP packet signals inputted to the receiving units 1a, 1b and 1c, respectively 2c. The IP packet multiplexing unit 25 includes a priority control unit 5a that performs priority control of the IP packet signal input to the reception unit 1a, and a priority control unit 5b that performs priority control of the IP packet signal input to the reception unit 1b. And a priority control unit 5c that performs priority control of the IP packet signal input to the reception unit 1c.

  The IP packet signal superimposed on the IP packet signal from the GE-ONU 16b and the RF signal from the V-ONU 16a shown in FIG. 1 and subjected to IP packet conversion processing is both input to the IP packet multiplexing unit 25 as an IP packet signal. Is done. For this reason, the input system has two inputs of the receivers 1a and 1b. The IP packet signal from the RF signal reception conversion unit 23 is input to the reception unit 1a. An IP packet signal from the RJ45 connector 24 shown in FIG. 2 is input to the receiving unit 1b. Reception processing is performed by the reception units 1a and 1b in the IP packet multiplexing unit 25, and the address and priority of the IP packet signal are detected and input to the switch unit 3 via the buffers 2a and 2b. The switch unit 3 multiplexes the IP packet signal from the receiving unit 1a and the IP packet signal from the receiving unit 1b. Since the switch unit 3 receives control, buffers 2a and 2b are provided in order to prevent packet discard during the waiting time for the processing. The switch unit 3 multiplexes the IP packet signals of the two input systems and sends them to the output side transmission unit 4c. The transmission unit 4 c transmits the multiplexed IP packet signal from the switch unit 3. The signal of the output IP packet from the transmission unit 4c is received by a PC or the like. FIG. 4 shows a case where the output side port of the switch unit 3 is one port. However, it is possible to provide two or more output ports, and an external control signal input from the external control signal input unit 6 can be used. The transfer destination can be set by the external control signal control unit 7.

  In the case of transmission from the PC 18 shown in FIG. 1, an IP packet signal for transmission is input to the receiving unit 1c from the Ethernet (registered trademark) interface 26 shown in FIG. An IP packet signal for transmission from the PC is input to the switch unit 3 via the receiving unit 1c. At this time, it is preferable that the priority control unit 5c detects the address and priority of the transmission IP packet signal and performs transfer control in the switch unit 3. At the time of transfer control, control of port A or port B of the switch unit 3 is performed, and the data is transferred to the corresponding port. For example, if the port B is a port connected to the GE-ONU 16b shown in FIG. 1, the priority control unit 5c performs transfer control so that the upstream transmission IP packet signal selects the port B. Then, the switch unit 3 outputs the transmission IP packet signal input to the reception unit 1c to the transmission unit 4b. In addition, when an IP packet signal with a small delay is to be transferred in the upstream direction, if the external control signal control unit 7 is set in advance so that the packet is transferred to the port B with a high priority, the delay is low and the priority is given. Control to perform the transfer process is performed. Thereby, the transmission unit 4b outputs the transmission IP packet signal input to the reception unit 1c to the RJ45 connector 24 shown in FIG. In this example, it is assumed that the uplink IP packet signal for transmission is transmitted only to the packet network of the GE-PON system (reference numeral 112 shown in FIG. 1). Therefore, in this example, the RF network (FIG. 1) is used. The transmission unit 4a of the port A connected to the reference numeral 111) can stop the function. When IP packet signals are simultaneously input to port A and port B, processing similar to that for a general switch or the like may be performed.

  FIG. 5 illustrates an example in which an IP packet signal is distributed to a user's PC using the communication network and the IP multiplexer 17 according to the present embodiment. As shown in FIG. 5, for example, an IP packet signal from a simultaneous broadcast information distribution server connected to the HE 54, such as software download or emergency notification, is transmitted by the switch device 12, for example, to a multi-channel video distribution network or the like. The signal is transmitted to the RF transmission network 101, modulated as a signal on an RF carrier by a transmission device in the HE 54, and SCM is performed together with other signals (for example, video signals). Thereafter, it is provided to the RF transmission network 101 by the FM batch conversion method or the like. An IP packet signal modulated on the frequency axis and superimposed on the RF signal is input from the V-ONU 16a to the RF signal reception conversion unit 23 through the coaxial interface. The IP packet signal from the V-ONU 16a is converted from an RF signal to an IP packet signal by the RF signal reception conversion unit 23.

  On the other hand, an IP packet signal provided from a VOD (Video On Demand) server 57 or the like is input to the packet transmission network 102 such as the Internet by the switch device 12, and via a GE-OLT 15b in a GE-PON optical access network. The GE-ONU 16b is input to the IP multiplexer 17 through the Ethernet (registered trademark) interface. The IP packet signals provided from the two networks described above are multiplexed in the IP multiplexer 17 and output to the user side via the Ethernet (registered trademark) interface. The output IP packet signal is input to the PC 18, for example. As shown in FIG. 5, the user can receive information such as an emergency broadcast provided simultaneously from the broadcast information distribution server 56 while viewing the video from the VOD server 57. Note that broadcast transmission information, etc., consumes a large amount of network resources when the communication packet transmission network 102 is used, and depending on the accommodation design, it may become congested and packet discard may occur, making it impossible to receive it. There is also. On the other hand, when an IP packet signal of such information is provided using the RF transmission network 101, there is no concern about congestion and the possibility that the PC 18 cannot receive the information is low.

  FIG. 6 is a schematic diagram showing an example of another form of the IP multiplexing apparatus according to the present embodiment. The IP multiplexing apparatus shown in FIG. 6 includes an ONU unit 17a and a CAS (Communication Adaptation System) unit 17b. The ONU unit 17a is equipped with a V-ONU unit 16c as a line termination unit of the RF network and a GE-ONU unit 16d as a line termination unit of the packet network, and the CAS multiplexing unit 17b has the IP multiplexer 17 shown in FIG. A connector 36 and an RJ45 connector 41 are mounted. The IP multiplexer 17 includes a coaxial connector 35 and RJ45 connectors 39 and 40. As described above, the V-ONU 16a and the GE-ONU 16b shown in FIG. 1 are accommodated in the ONU unit 17a, the IP multiplexer 17 is accommodated in the CAS unit 17b, and these are accommodated in one casing 58. Even if IP packet signals are provided from two different networks, the RJ45 connector 41 can be provided as an interface to a user terminal such as a PC or a TV receiver.

  The optical fiber from the optical access network is input from the optical fiber input terminal 31 of the housing, and the WDM splitter 32 in the housing 58 uses the RF wavelength of 1.55 μm and the GE-PON of 1.3 / 1.49 μm. Are separated from each other. The separated wavelengths of light are input to the V-ONU unit 16c and the GE-ONU unit 16d, respectively. Each of the ONU units 16c and 16d performs line termination of the optical access network. The RF signal terminated at the V-ONU unit 16c is superimposed with a video signal and an IP packet signal (RF system) that are SCMed on the coaxial interface on the frequency axis. Therefore, the output from the coaxial connector 34 of the V-ONU unit 16c is branched into two, and one is input to the RF signal reception conversion unit 23 from the coaxial connector 35 mounted on the CAS unit 17b. The RF signal on which the input IP packet signal is superimposed is converted into an IP packet by the RF signal reception conversion unit 23 and input to the IP packet multiplexing unit 25 separately from the IP packet signal from the GE-ONU unit 16d. . The IP packet multiplexing unit 25 packet-multiplexes the IP packet signals from the two ONU units, and outputs the multiplexed IP packet signal from the RJ45 connector 40 that is an output terminal. By mounting the IP multiplexing device 17 on the CAS unit 17b, it is possible to use it in a small size so that the user is not aware of the network.

  The present invention can be used for an IP packet distribution service using an RF multi-channel video distribution network.

It is the figure which represented typically the whole structure of the communication network which concerns on this embodiment. It is the figure which represented typically the functional block of the IP multiplexing apparatus which concerns on this embodiment. It is the figure which represented typically the functional block of the RF signal reception conversion part which concerns on this embodiment. It is the figure which represented typically the functional block of the IP packet multiplexing part which concerns on this embodiment. It is one of the Examples by which an IP packet signal is delivered to a user's PC using the communication network and IP multiplexing apparatus which concern on this embodiment. It is a schematic diagram which shows an example of another form of the IP multiplexing apparatus which concerns on this embodiment. FIG. 1 is a schematic diagram illustrating an overall image of an optical access system in which an IP packet signal is provided by a GE-PON system through an optical access network and a multi-channel video signal frequency-multiplexed by an RF system is provided. It shows an image in which an IP packet signal provided by a GE-PON system and an IP packet signal provided by an RF system are received by a PC which is a user terminal device.

Explanation of symbols

1a, 1b, 1c receiving unit 2a, 2b, 2c buffer 3 switch unit 4a, 4b, 4c transmitting unit 5a, 5b, 5c priority control unit 5-1a, 5-1b, 5-1c address / priority detection unit 5- 2a, 5-2b, 5-2c control unit 5-3a, 5-3b, 5-3c address registration memory 6 external control signal control unit 7 external control signal input unit 11 IP source 12 switch 13 SCM device 14a, 14b router 15a V-OLT
15b GE-OLT
16a V-ONU
16b GE-ONU
17 IP multiplexer 17a ONU unit 17b CAS unit 18 PC
19 TV receiver 22 Coaxial connector 23 RF signal reception conversion unit 23-1 RF frequency separation unit 23-2 BP processing unit 23-3 IF generation unit 23-4 AD conversion unit 23-5a, 23-5b Nyquist filter unit 23- 6 Phase Rotation Control Unit 23-7 Demodulation Unit 23-8 Error Correction Code Decoding Unit 23-9 IP Packet Conversion Unit 24 RJ45 Connector 25 IP Packet Multiplexing Unit 26 Ethernet (Registered Trademark) Interface 31 Optical Fiber Input Terminal 32 WDM Splitter 33 Optical fiber input terminal 34, 35, 36 Coaxial connector 37 Optical fiber input terminal 38, 39, 40, 41 RJ45 connector 51 WDM coupler 52 Optical power splitter 53 WDM coupler 54 Head end (HE)
55 SCM signal / IP packet signal separation device 56 Broadcast information distribution server 57 VOD server 58 Case 101 RF transmission network 102 Packet transmission network 103 Multi-channel video distribution network 104 Internet network 111 RF network 112 Packet network 115 Home network

Claims (6)

A packet network that transmits time-division multiplexed IP (Internet Protocol) packet signals, and time-division-separates the transmitted IP packet signals;
An RF (Radio Frequency) network that modulates an IP packet signal, frequency multiplexes and transmits, and frequency-separates and demodulates the transmitted IP packet signal;
A communication network, comprising: a home network that multiplexes and transmits an IP packet signal that is time-division-separated in the packet network and an IP packet signal that is demodulated in the RF network. An RF signal reception conversion unit that modulates an IP packet signal, frequency-multiplexes and transmits the RF signal from the RF network as an RF signal, and frequency-separates the signal into an IP packet signal;
An IP packet signal is transmitted by time-division multiplexing an IP packet signal, and an IP packet signal from a packet network for time-division separating the transmitted IP packet signal and an IP packet signal from the RF signal reception conversion unit are packet-multiplexed. A packet multiplexing unit;
An IP multiplexing apparatus comprising: The RF signal reception conversion unit is
An RF frequency separation unit for separating a frequency carrier in which an IP packet signal is frequency-multiplexed from the RF signal;
A bandpass processing unit for performing a bandpass filter process on the output signal of the RF frequency separation unit;
An IF (Intermediate Frequency) generation unit that generates an intermediate frequency component from an output signal of the bandpass processing unit;
An AD (Analog-to-Digital) converter that converts an output signal of the IF generator into a digital signal;
A Nyquist filter unit that suppresses a signal component in a frequency band larger than half of the Nyquist frequency, the output signal of the output signal of the AD conversion unit;
A phase rotation control unit for correcting a phase error of the output signal of the Nyquist filter unit;
A demodulator that demodulates the carrier modulated on the frequency axis from the output signal of the phase rotation controller;
An error correction code decoding unit for decoding an error correction code from an output signal of the demodulation unit;
An IP packet conversion unit that converts an output signal from the error correction code decoding unit into an IP packet signal;
The IP multiplexer according to claim 2, further comprising: The IP packet multiplexing unit includes:
A first receiver that receives an IP packet signal from the RF signal reception converter;
A second receiver for receiving an IP packet signal from the packet network;
A buffer unit for temporarily storing IP packet signals input to the first receiving unit and the second receiving unit;
A switch unit that packet-multiplexes the IP packet signal from the first receiving unit and the IP packet signal from the second receiving unit;
An address registration memory for registering and storing an IP packet signal address;
In accordance with the priority of the IP packet signal and the address stored in the address registration memory, the control unit causes the switch unit to multiplex the IP packet signal;
A multiplexed signal transmission unit for transmitting a packet-multiplexed IP packet signal from the switch unit;
The IP multiplexer according to claim 2 or 3, further comprising: A plurality of ports for outputting IP packet signals from the IP packet multiplexing unit;
5. The IP multiplexing apparatus according to claim 2, wherein the IP packet multiplexing unit transfers a packet-multiplexed IP packet signal to any or all of the ports. 6.   6. The IP multiplexing apparatus according to claim 2, further comprising a line termination unit for the RF network and the packet network.

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