WO2007083384A1

WO2007083384A1 - One-directional transmission signal distribution method, station side device, and subscriber home side device in passive optical network system

Info

Publication number: WO2007083384A1
Application number: PCT/JP2006/300828
Authority: WO
Inventors: Haruo Yamashita; Yuichi Shimada; Tetsuya Yokomoto; Hiroshi Shouji; Masanori Yoshizawa; Toshihiko Arai
Original assignee: Fujitsu Access Limited
Priority date: 2006-01-20
Filing date: 2006-01-20
Publication date: 2007-07-26
Also published as: JPWO2007083384A1

Abstract

Provided are a one-directional transmission signal distribution method, a station side device, and a subscriber home side device in a passive optical network system. The one-directional transmission signal distribution method can easily design a signal-noise (S/N) ratio and easily perform distribution by an electric signal without requiring an expensive optical amplifier. A multiplexing unit (1-11) of the station side device (OLT) (1-1) bit-multiplexes a digital signal of one-directional transmission signal of only a downstream direction with main signal data in the passive optical network system and transmits it. A bit separation unit (1-21) of the subscriber home side device (1-2) bit-separates the digital signal of one-directional transmission signal of only the downstream direction and the main signal data in the passive optical network system, so as to extract the one-directional transmission signal of only downstream direction and process a video signal of the one-directional transmission signal by a video signal processing unit (1-22).

Description

Specification

Unidirectional transmission signal distribution method, station side apparatus, and customer premises apparatus in passive optical network system

Technical field

TECHNICAL FIELD [0001] The present invention relates to a one-way transmission signal distribution method, a station side device, and a subscriber premises side device in a passive optical network system, and, in a passive optical network (PON) system, conventionally, a wavelength of an analog signal is known. The present invention relates to a technique for distributing and distributing video signals and the like that have been performed by a multiplex system using a simple bit multiplex system using a digital signal.

[0002] A passive optical network (PON) system is a transmission method in which an optical signal transmitted through a single optical fiber is split by an optical splitter, and multiple users share a single optical fiber. Optical line terminator (OLT) sharing and optical fiber laying costs can be kept low. Until now, the G-983 series B-PON of the ITU-T and the G-984 series G — Recommended and standardized as PON!

[0003] Also, with the spread of high-speed Internet services, the IEEE 802.3 Working Group has been recommended as IEEE 802.3ah for data communication services for home (FTTH: ber To The Home) by optical fiber. As a means to provide a more economical and faster FTTH system as PON (Gigabit Ethernet (registered trademark) -PON), it has been introduced in Japan since late 2004.

[0004] However, the passive optical network (PON) system has an absolute loss of signal level due to the optical star coupler Z splitter at the branch point. This increases as the number of branches increases. For example, the fixed loss is about 17 dB for 32 branches. In this case, the telecommunications carrier must design the equipment in anticipation of this fixed loss!

[0005] In particular, when frequency-multiplexed analog transmission of an existing CAT V (Community Antenna Television) signal or the like is performed by the wavelength multiplexing method defined in ITU-T G. 983.3, noise superimposition is performed. If a signal to noise (SZN) ratio or a carrier to noise (CZN) ratio is required to be ensured, and a clean video signal is to be distributed and distributed, a high-power laser with excellent distortion characteristics is required. [0006] For this reason, an inexpensive and simple transmission means is required as an alternative to an analog transmission means for video signals by a wavelength multiplexing method or the like. In recent years, the trend of digitization has become a major trend in all fields, but there is a need for a method that can distribute and distribute video signals easily and with high quality.

Background art

[0007] In a passive optical network (PON) (hereinafter simply referred to as "PON") system, as described in ITU-T G. 983.3, only one-way in the downstream direction such as a video signal For transmission signals, analog optical transmission based on wavelength division multiplexing has been used in the wavelength band where analog optical amplifiers can be used (for example, C band 1550 nm band). This is due to the effective use and low cost of set-top boxes (STB) used for receiving broadcast waves and coaxial CA TV.

FIG. 11 shows an example of distribution / distribution of video signals and the like by analog optical transmission in a general PON system. As shown in (a) of the figure, the station side communication device (OLT) 11-1 has multiple subscriber premises side communication devices (ONU # l to # n) ll-2, Splitter 1 Connected by optical fiber branched by 1-3 and burst between station side communication equipment (OLT) 11-1 and each subscriber home side communication equipment (ONU #l to #n) ll-2 Main signal data (# 1, # 2, #n) is sent and received.

[0009] The station side communication equipment (OLT) 11-1 receives uplink burst optical signals transmitted in a time division manner from multiple subscriber premises side communication equipment (ONU # 1 to #n) 1 1-2 without collision. In order to do this, the transmission timing control instructions for each of the Caro's residential communication devices (ONU # 1 to #n) 11-2 are given. In addition, the downstream optical signal with each destination address is distributed to each subscriber premises communication device (ONU # 1 to #n) 11-2.

[0010] As shown in FIG. 4B, the wavelength allocation in wavelength division multiplexing (WDM) according to ITU-T G. 983.3 is performed in the upstream direction with respect to the PON main signal data. The signal band [1260nm-1360nm, the downstream signal band [1480-150 Onm] is commonly used for G-PON and GE-PON! The 1550nm wavelength band can be overlaid for video signal distribution. For this reason, signals such as video signals have a wavelength different from the transmission wavelength of the main signal data of the PON system. And transmitted as an analog signal.

FIG. 12 shows a configuration example of a transmission / reception circuit of a station side communication device (OLT) and a customer premises side communication device (ONUZONT) in a conventional PON system. (A) in the figure shows the transmission / reception circuit configuration in GE-PON compliant with IEEE802.3ah, and (b) in the figure shows the transmission / reception circuit configuration in G-PON compliant with ITU-T G. 984.x. Yes.

[0012] In the figure, 12-1 is an interface unit with Ethernet (registered trademark), 12-2 is a priority class (QoS) control unit in the MAC layer, 12-3 is a PON that performs address processing of the PON layer, etc. Processing unit, 12-4 is a laser diode, 12-5 is a photodetector or avalanche chef detector, 12-6 is a wavelength multiplexing / demultiplexing unit that wavelength-multiplexes and separates optical signals in the upstream wavelength band and downstream wavelength band, 7 is a video signal extraction circuit, 12-8 is a distributed feedback laser diode, 12-9 is an interface with Ethernet (registered trademark) ATMZT DM, 12-10 is priority class (QoS) control Part.

[0013] As shown in the figure, the video delivery signal is delivered by overlaying the PON main signal output from the wavelength multiplexing / demultiplexing unit 12-6 of the station side communication equipment (OLT) by wavelength multiplexing. In the subscriber premises communication device (ONUZONT), the signal is separated by the wavelength multiplexing / separation unit 12-6, extracted by the video signal extraction circuit 12-7, and output as a video signal.

On the other hand, there is a form of video signal distribution by multicast type data distribution (Video on Dem and etc.) as video signal distribution 'distribution. The video signal in this form is transmitted in a format multiplexed with the main signal data signal in response to a request from a distribution candidate. FIG. 13 shows an example of spectrum arrangement of signals such as analog video to be multiplexed. 13-1 is the upstream channel according to <3 to 31 ^, 13-2 is the downstream channel by AM VSB or QAM, and 13-3 is the additional channel for video signal distribution by VOD.

[0015] As prior art documents related to the present invention, Ethernet (registered trademark) passive optical network for fusion of broadcasting and communication is described in Patent Documents 1 to 3 below.

Patent Document 1: Japanese Patent Laid-Open No. 2005-210715

Patent Document 2: JP-A-2005-110247

Patent Document 3: Japanese Patent Laid-Open No. 2005-27302

Disclosure of the invention Problems to be solved by the invention

[0016] As described above, in the distribution and distribution of video signals and the like by analog optical transmission in a PON system, it is necessary to design a troublesome signal-to-noise (SZN) ratio for the loss of optical branching peculiar to PON. There is also a need for expensive optical amplifiers for the distribution of analog optical signals. In addition, in multicast type data distribution, the video signal is multiplexed into the main signal data upon request, and in the multicast type data distribution, the video signal is transmitted in a unidirectional transmission format only in the downlink direction, that is, the main signal. Since it is not transmitted as a separate signal, the main signal data band is used.

[0017] The present invention employs a digital transmission method for distributing and distributing video signals and the like in a PON system, thereby making it easier to design a signal-to-noise (SZN) ratio than an analog transmission method. It is an object of the present invention to provide a one-way transmission signal distribution method that can be performed easily and that does not require an expensive optical amplifier and that can be easily distributed with an electric signal.

Means for solving the problem

[0018] A one-way transmission signal distribution method in a passive optical network system according to the present invention includes: (1) a subscriber-side device, and a station-side device connected to the subscriber-side device by an optical fiber via an optical splitter. And the station side device performs a transmission timing control instruction of the subscriber home side device for receiving, without collision, an upstream burst optical signal transmitted in a time division manner from a plurality of subscriber home side devices. And a passive optical network system provided with a means for distributing a downstream optical signal with a destination address for each subscriber premises equipment, and the station side equipment is a digital signal of a unidirectional transmission signal only in the downstream direction. The main signal data of the passive optical network system is bit-multiplexed and transmitted, and at the subscriber premises equipment, the digital signal of the unidirectional transmission signal only in the downlink direction and the main signal of the passive optical network system Bit separation of data and And extracting the one-way transmission signals only in the direction Ri.

[0019] (2) The passive optical network system is an uplink signal / downstream signal lGbps bidirectional transmission system that is a standardized system defined in IEEE 802.3ah, and includes the bit multiplexing and demultiplexing. The downstream unidirectional transmission signal is a signal having the same information rate and code conversion format as the bidirectional transmission system.

[0020] Further, (3) the passive optical network system is an upstream signal defined in ITU-T G. 984.3. Downlink signal 1. A 2448 Gbps bidirectional transmission method, in which the unidirectional transmission signal in the downlink direction that is multiplexed and separated is a signal having the same information rate and code conversion format as the bidirectional transmission method. It is characterized by being.

[0021] (4) The passive optical network system is an uplink signal / downlink signal defined in ITU-T G. 984.3. The downstream unidirectional transmission signal is a signal having the same information rate as the bidirectional transmission system and a signal of a code conversion format different from the bidirectional transmission system.

[0022] Further, (5) the passive optical network system includes a receiving unit that reproduces the bit-multiplexed one-way transmission signal only in the downlink direction. It is a passive optical network system in which a subscriber's premises equipment equipped with a receiving unit that reproduces transmission signals is mixed.

[0023] (6) In the station side device, an identifier indicating that the signal is a unidirectional transmission signal only in the downlink direction is added to the bit-multiplexed unidirectional transmission signal only in the downlink direction. Then, the subscriber premises apparatus determines whether or not the identifier is normally received, and controls the bit separation position according to the determination result.

[0024] (7) The subscriber premises apparatus determines whether or not the main signal data of the bit-separated passive optical network system has been normally received, and the main signal data is determined for a predetermined time. Control is made so that the bit separation position is changed when the signal data is not normally received.

[0025] (8) The one-way transmission only in the downlink direction from the station-side device is a signal obtained by bit-multiplexing a plurality of transmission signals. The unidirectional transmission signal is bit-separated into a plurality of transmission signals.

[0026] (9) The passive optical network system includes: a subscriber premises apparatus that does not include a receiving unit that reproduces a unidirectional transmission signal in a downward direction in which the plurality of transmission signals are bit-multiplexed. Further, the present invention is characterized in that a passive optical network system in which a plurality of types of subscriber premises apparatuses having different numbers of receiving units for reproducing the one-way transmission signal are mixed.

[0027] (10) The station side apparatus wavelength-multiplexes the digital signal of the unidirectional transmission signal only in the downlink direction obtained by bit-multiplexing a plurality of transmission signals and the main signal data of the passive optical network system. Unidirectional transmission signal only in the downlink direction at the subscriber premises apparatus The digital signal and the main signal data of the passive optical network system are wavelength-separated, and the unidirectional transmission signal only in the downlink direction is extracted by bit separation.

[0028] Further, (11) the downstream signal of the passive optical network system is a downstream signal lGbps transmission signal that is a standardized method defined in IEEE 802.3ah, and is downstream of the bit multiplexing and demultiplexing. The unidirectional transmission signal having only the direction is a signal having the same information rate and code conversion format as the transmission signal.

[0029] (12) The downstream signal of the passive optical network system is a downstream signal defined in ITU-T G. 984.3, which is a transmission signal of 2448 Gbps, and is multiplexed and demultiplexed. The downward unidirectional transmission signal is a signal having the same information rate and code conversion format as the transmission signal.

[0030] (13) The downstream signal of the passive optical network system is a downstream signal defined in ITU-T G. 984.3, which is a 1448 Gbps transmission signal, and is multiplexed and demultiplexed. The unidirectional transmission signal only in the downward direction is a signal having the same information rate as that of the transmission signal and having a code conversion format different from that of the transmission signal.

[0031] (14) In the station side device, an identifier indicating that the signal is a unidirectional transmission signal only in the downlink direction is added to the bit-multiplexed unidirectional transmission signal in the downlink direction. The subscriber premises apparatus determines whether the identifier has been normally received, and controls the bit separation position according to the determination result.

[0032] (15) The passive optical network system includes a subscriber premises apparatus that does not include a receiving unit that reproduces a unidirectional transmission signal only in the downlink direction in which a plurality of transmission signals are bit-multiplexed; It is a passive optical network system in which a plurality of types of subscriber-side devices with different numbers of receiving units that reproduce the one-way transmission signal are mixed.

[0033] (16) In the station side device, an identifier for each transmission signal is added to a unidirectional transmission signal only in the downlink direction in which a plurality of transmission signals are bit-multiplexed, and transmitted. The home side device determines whether the identifier of the specific transmission signal is normally received, and controls the bit separation position according to the determination result.

In addition, the station side device of the passive optical network system of the present invention is (17) connected to a plurality of subscriber home devices via an optical splitter via an optical fiber, and a plurality of subscriber home side devices are connected. Time division Means for instructing the transmission timing control of the subscriber premises equipment to receive the transmitted upstream burst optical signal without collision, and means for distributing the downstream optical signal with the destination address for each subscriber premises equipment A bit multiplexing means for bit-multiplexing a digital signal of a unidirectional transmission signal only in the downlink direction and main signal data of the passive optical network system, and Means for transmitting the downlink signal multiplexed by the multiplexing means to the subscriber premises apparatus.

[0035] Further, the subscriber premises apparatus of the passive optical network system of the present invention is (18) connected to the station apparatus via an optical fiber via an optical splitter, and in response to a transmission timing control instruction from the station apparatus. Means for transmitting upstream burst optical signals in a time division manner without collision, and means for receiving downstream optical signals with destination addresses attached from station side devices, and a subscriber home side device constituting a passive optical network system; A bit separation means for bit-separating a digital signal of a unidirectional transmission signal only in the downlink direction bit-multiplexed from the downlink signal and the main signal data of the passive optical network system, and the bit separation Means for extracting a unidirectional transmission signal only in the downlink direction separated by the means.

The invention's effect

[0036] According to the present invention, in the distribution of the one-way transmission signal only in the downstream direction such as the video signal in the passive optical network system, the main signal data of the passive optical network system and the digital one-way transmission signal are distributed. Signals are multiplexed by bit multiplexing and transmitted by digital transmission method, so that one-way transmission signals such as video signals only in the downstream direction can be distributed and distributed using inexpensive passive optical network systems. It is possible to increase the functionality of the wide area network and to reduce the price.

[0037] Further, by simple bit multiplexing and separation, it is possible to distribute and distribute a unidirectional transmission signal only in the downlink direction such as a video signal as a separate signal from the main signal data of the passive optical network system. Therefore, it is possible to distribute a unidirectional transmission signal only in the downstream direction such as a video signal without affecting the band of the main signal system data signal.

Brief Description of Drawings

FIG. 1 is a diagram showing a configuration of first to fifth embodiments of the present invention.

FIG. 2 is a diagram showing a sixth embodiment of the present invention. FIG. 3 is a diagram showing a seventh embodiment of the present invention.

FIG. 4 is a diagram showing an eighth embodiment of the present invention.

FIG. 5 is a diagram showing a ninth embodiment of the present invention.

FIG. 6 is a diagram showing tenth and eleventh embodiments of the present invention.

FIG. 7 shows a twelfth embodiment of the present invention.

FIG. 8 shows a thirteenth embodiment of the present invention.

FIG. 9 is a diagram showing a fourteenth embodiment of the present invention.

FIG. 10 shows fifteenth and sixteenth embodiments of the present invention.

FIG. 11 is a diagram showing an example of distribution / distribution of video signals and the like by analog optical transmission in a general PON system.

FIG. 12 is a diagram showing a transmission / reception circuit configuration example of a station side communication device (OLT) and a customer premises side communication device (ON U / ONT) in a conventional PON system.

FIG. 13 is a diagram showing an example of spectrum arrangement of signals such as analog video to be multiplexed. Explanation of symbols

[0039] 1-1 station side equipment (OLT)

1-2 Subscriber premises equipment (ONU)

1-3 optical splitter

1-11 bit multiplexing part

1-21 bit separator

1-22 Video signal processor

12-5 Avalanche Chef Od Detector

12-6 Wavelength multiplexing / separation section

12-8 Distributed Feedback Laser Diode (DFB— LD)

12-9 Ethernet (registered trademark) Interface part with ATMZTDM

12-10 Priority Class (QoS) Control Unit

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 shows the configuration of the first embodiment of the present invention. As shown in the figure, the PON system consists of multiple subscriber premises equipment (ONU: Optical Network Unit / ONT: Optical Network). Terminal) 1-2 and a station side device (OL T: Optical Line Terminator) 1-1 connected by an optical fiber via an optical splitter 1-3.

[0041] The station side equipment (OLT) 1-1 is a subscriber home for receiving uplink burst optical signals transmitted in a time division manner from a plurality of subscriber home equipment (ONU) 1-2 without collision. A means to send transmission timing control instructions (ONTZO NU) 1-2 (not shown) and a means to distribute downstream optical signals with destination addresses for each subscriber premises equipment (Ο NT / ONU) 1 2 (Not shown). In the subscriber premises equipment (ONTZONU) 1-2 and the station equipment (OLT) 1-1, the same components as those in the conventional configuration shown in FIG. Is omitted.

[0042] In the above-mentioned デジタル system, the digital signal of the unidirectional transmission signal only in the downstream direction, such as a video signal, is transmitted to the 主 main signal data by the bit multiplexing unit 1-11 of the station side device (OLT) 1-1. And bit-multiplexed, converted to an optical signal by a distributed feedback laser diode (DFB—LD) 12-8, and transmitted.

[0043] In the subscriber premises equipment (ONTZONU) 1 2, the received optical signal is converted into an electrical signal by the photo detector or avalanche photo detector 12-5, and the video signal etc. Only one-way transmission signal digital signal and PON main signal data are bit-separated, and the video signal processing unit 122 demodulates the digital signal of the one-way transmission signal only in the downstream direction. Distribute video and other signals.

[0044] As a second embodiment of the present invention, the PON system described above is an uplink signal / downstream signal lGbps bidirectional transmission system that is a standardized system defined in IEEE 802.3ah (the optical transmission speed is 8B10B code converted). 1. A unidirectional transmission signal in the downstream direction that is bit-multiplexed / separated at the same information rate as the bidirectional transmission method and the same code conversion format signal (optical The transmission speed is 8B10B converted to 1.25Gbps).

[0045] As a third embodiment of the present invention, the above-mentioned PON system has an upstream signal / downstream signal defined by a recommendation document such as ITU-T G. 984.3. The speed is 155.52 XN (N: integer); in this case, N = 8), and the unidirectional transmission signal in the downlink direction that is bit-multiplexed and separated is the same information speed as the above bidirectional transmission system ( Koden The transmission speed is a downlink signal (1.2448 Gbps) and can be a signal of the same code conversion format.

[0046] As a fourth embodiment of the present invention, the above-mentioned PON system has an upstream signal / downstream signal defined by a recommendation such as ITU-T G. 984.3. The speed is 155.52 XN (N: integer); in this case, N = 8), and unidirectional transmission signals in the downlink direction that are bit-multiplexed and separated are transmitted at the same transmission speed as the above-mentioned bidirectional transmission system. It can be a signal of different code conversion format (usually 8B10B code conversion used in Ethernet (registered trademark)) (optical transmission rate is downlink signal 1.2448Gbps).

[0047] As a fifth embodiment of the present invention, in the above-described PON system, only the customer premises equipment (ONTZONU) 1 2 provided with the video signal processing unit 122 and the bit-multiplexed downlink direction only. The means up to the bit separation unit 121 for separating the unidirectional transmission signal bits and the PON main signal data has a receiving unit for reproducing the video signal of the unidirectional transmission only in the downstream direction.できる It can be applied to PON systems that have both subscriber premises equipment (ONTZONU) (not shown). With the video signal processing unit 1-22, the subscriber premises equipment (ONTZONU) receives only the data service in the PON system without receiving the distribution and distribution of downstream video.

FIG. 2 shows a sixth embodiment of the present invention. In the sixth embodiment, an identifier indicating that a unidirectional transmission signal only in the downlink direction such as a video signal is a special packet signal in a unidirectional transmission signal only in the downlink direction such as a bit multiplexed video signal. First, the subscriber premises equipment (ONTZONU) 1-2 inputs the signal that has been bit-separated by the bit separation unit 1 21 to the video signal processing unit 1-22, and the video signal processing unit 1-22 Input signal power It is determined whether the above-mentioned identifier is normally received, and a bit separation control signal corresponding to the determination result is generated by the video signal processing unit 122, and the bit separation unit is generated by the bit separation control signal. It is designed to control the bit separation position of 1-21.

That is, if the above-mentioned identifier is normally received by the video signal processing unit 1-22, the bit extraction position of the unidirectional transmission signal only in the downstream direction in the bit separation unit 122 is left as it is. If the bit separation control signal to be generated is not successfully received, the bit separation position of the one-way transmission signal only in the downlink direction in the bit separation unit 121 and the PO Generate a bit separation control signal that swaps the bit extraction position of N main signal data.

[0050] A seventh embodiment of the present invention is shown in FIG. In the seventh embodiment, the customer premises equipment (ON TZONU) 1-2, the signal separated by the bit separation unit 1-21 is input to the PON processing unit 12-3, and the PON processing unit 12- 3 determines whether or not the input PON signal has been normally received, generates a bit separation control signal corresponding to the determination result in the PON processing unit 12-3, and performs bit separation by the bit separation control signal. The bit separation position of the conversion unit 121 is controlled.

[0051] When the PON signal is normally received by the PON processing unit 12-3, the bit extraction Lf standing of the unidirectional transmission signal only in the downlink direction in the bit separation unit 1-21 is left as it is. If a bit separation control signal is generated and it is not successfully received, the bit separation position of the unidirectional transmission signal only in the downlink direction in the bit separation section 1-21 and the main signal data of the PON A bit separation control signal for exchanging the bit extraction position is generated.

[0052] FIG. 4 shows an eighth embodiment of the present invention. In the eighth embodiment, a unidirectional transmission signal only in the downstream direction, such as a video signal to be bit-multiplexed, is bit-multiplexed with a plurality of transmission signals in the bit multiplexing unit 41, and the station side device (OLT ) Downlink-only unidirectional transmission signal bit-multiplexed with the above-mentioned multiple transmission signals on the downstream PON signal from 1-1 is bit-multiplexed by bit multiplexing section 1-11, and distributed feedback laser diode (DFB) — LD) 12 8 Converts to optical signal and transmits.

[0053] In the subscriber premises equipment (ONTZONU) 1 2, the received optical signal is converted into an electrical signal by the photo detector or avalanche photo detector 12-5, and the bit separation unit 1-21 downloads the video signal or the like in the downstream direction. Only one-way transmission signal digital signal and PON main signal data are bit-separated, and further, the one-way transmission signal only in the downstream direction is separated into a plurality of transmission signals by the bit separator 4-2. Each digital signal is demodulated by the video signal processor 1 2 2 so that a plurality of video signals can be distributed and received. In Fig. 4, video signals etc. that have undergone 1: 4 bit multiplexing are further subjected to 1: 2 bit multiplexing, and the customer side equipment (ONTZONU) 1-2 performs reverse bit separation. An example is shown. [0054] Fig. 5 shows a ninth embodiment of the present invention. In this embodiment, as in the eighth embodiment, the unidirectional transmission signal only in the downlink direction such as a bit-multiplexed video signal is obtained by bit-multiplexing a plurality of transmission signals. (ONTZONU) 1-2 as a bit separation unit 1-21, which separates the double-bit multiplexed downstream signal, but receives a unidirectional transmission signal in the downstream direction and receives a video signal. Video signal processing unit 1-22 (a) with three reception / reproduction units, (b) with two reception / reproduction units, and (c) one reception / reproduction unit Multiple types of customer premises equipment (ONTZONU) 1-2 with different numbers of receiving / playback units such as (d) those without video signal processing unit 1-22 This is applied to the PON system.

[0055] FIG. 6 shows a tenth embodiment of the present invention. In Fig. 6, the PON system is the same as that shown in Fig. 1 and the like. This embodiment is an embodiment in which a unidirectional transmission digital signal only in the downstream direction such as a video signal is multiplexed with a downstream PON signal from the station side device (OLT) 1-1 by a wavelength multiplexing method. As a one-way transmission digital signal only in the downstream direction, a plurality of transmission signals are bit-multiplexed by the bit multiplexer 6-1 and transmitted, and the video signal extraction circuit of the subscriber premises equipment (ONTZONU) 1-2 is 6-2. Thus, by separating the plurality of transmission signals into bits, it is possible to distribute and receive unidirectional digital signals only in the downlink direction such as video signals.

[0056] The eleventh embodiment of the present invention is a standardized method prescribed in IEEE 802.3ah for the unidirectional transmission digital signal only in the downlink direction such as the video signal of the tenth embodiment. Transmission system (optical transmission rate is 1.25 Gbps with 8B10B code conversion), and only one-way transmission digital signals in the downstream direction that are bit-multiplexed / separated have the same information rate and the same It is a code conversion format signal (the optical transmission speed is 1.25 Gbps after 8B10B conversion).

FIG. 7 shows a twelfth embodiment of the present invention. In this embodiment, the unidirectional transmission digital signal only in the downlink direction such as the video signal in the tenth embodiment described above is converted into a downlink signal 1.2448Gbps specified in the recommendation of ITU-T G. 984.3. The transmission method (optical transmission rate is 155.52 XN (N: integer); in this case N = 8). And the same code conversion format (The optical transmission rate is downlink 1. 2448 Gbps system).

FIG. 8 shows a thirteenth embodiment of the present invention. In this embodiment, a unidirectional transmission digital signal only in the downlink direction such as a video signal in the tenth embodiment described above is used as a downlink signal defined by a recommendation such as TU-TG. The transmission method (optical transmission rate is 1 55.52 XN (N integer); in this case N = 8). Bit-multiplexed and demultiplexed unidirectional transmission digital signals only in the downstream direction have the same transmission rate. Signals of different code conversion formats (normally 8B10B code format signals used in Ethernet (registered trademark) (optical transmission speed is downlink 1.2448 Gbps system)).

A fourteenth embodiment of the present invention is shown in FIG. In this embodiment, an identifier indicating that the signal is a unidirectional transmission signal only in the downstream direction such as a video signal is added to the bit multiplexed digital signal in the tenth embodiment described above as a special packet signal. In the subscriber premises equipment (ONTZONU) 1-2, the signal separated by the bit separation unit 1-21 is input to the video signal processing unit 1-22, and the video signal The signal power input by the processing unit 1-22 determines whether or not the above-mentioned identifier has been normally received, generates a bit separation control signal corresponding to the determination result by the video signal processing unit 122, and outputs the bit The bit separation position of the bit separation unit 121 is controlled by the separation control signal.

FIG. 10 shows a fifteenth embodiment of the present invention. In this embodiment, a unidirectional transmission digital signal only in the downstream direction such as a video signal is wavelength-multiplexed, and a unidirectional transmission signal only in the downstream direction such as a bit-multiplexed video signal is transmitted in a plurality of transmissions. In a PON system that distributes bit-multiplexed signals, a bit separation unit 1-2-1 that performs bit separation of the double-bit multiplexed downstream signal is used as the subscriber premises equipment (ONTZONU) 1-2. As a video signal processing unit 1-22 that receives a unidirectional transmission signal only in the downstream direction and reproduces the video signal, (a) a receiver with three playback units, (b) a receiver Receiving / reproducing unit equipped with two playback units, (c) One receiving / reproducing unit, (d) One without video signal processing unit 1-22. Applicable to PON systems with multiple types of customer premises equipment (ONTZONU) 1 2 with different numbers It is what.

[0061] In the sixteenth embodiment of the present invention, in the fifteenth embodiment described above, the subscriber premises equipment (ONTZONU) 12 can reproduce the video signal desired by the user. In this case, the identifier (packet signal, etc.) of the signal is superimposed on the unidirectional transmission digital signal in the downstream direction, such as a bit-multiplexed video signal, and transmitted to the subscriber premises equipment (ONTZON U) 1-2. Then, the signal separated by the bit separation unit 1-21 is inputted to the video signal processing unit 1-22, and the video signal desired by the user is input from the signal inputted by the video signal processing unit 1-22. It is determined whether the identifier is normally received, a bit separation control signal is generated based on the determination result, and the bit separation position of the bit separation unit 121 is controlled by the bit separation control signal. is there.

[0062] The first to sixteenth embodiments described above are based on IEEE802.3ah speed of 1.25 Gbps and IT UT G. 984.3 speed of 1.2448 Gbps (= 155.52 Mbps x 8 times). However, the speed combination is not limited to this, and any integer multiple of the Ethernet (registered trademark) interface (transmission speed: 125 Mbps, information speed: 100 Mbps) and SDH frame speed 155. 52 Mbps It can also be applied to speeds combining speeds of any integer multiple of.

Further, the tenth to sixteenth embodiments described above can be configured based on the wavelength arrangement defined in ITU-T G. 983.3 (see FIG. 11 (b)) as the wavelength arrangement. However, the wavelength when multiplexing the unidirectional transmission digital signals such as video signals only in the downstream direction is not limited to the 1550 η m band (C band), but also includes the 1600 nm band L band that will be available in the future. Is possible.

Claims

The scope of the claims

[1] A plurality of subscriber premises devices, and a station premises device connected to the subscriber premises devices via an optical splitter via an optical fiber, the station side devices comprising a plurality of subscriber premises devices Distributes the transmission timing control instruction of the subscriber premises equipment to receive the upstream burst optical signal transmitted in a time-sharing manner without collision, and the downstream optical signal with the destination address for each subscriber premises equipment In a passive optical network system having means for

In the station side device, the digital signal of the unidirectional transmission signal only in the downlink direction and the main signal data of the passive optical network system are bit-multiplexed and transmitted,

The subscriber premises equipment performs bit separation of the digital signal of the unidirectional transmission signal only in the downlink direction and the main signal data of the passive optical network system to extract the unidirectional transmission signal only in the downlink direction. A unidirectional transmission signal distribution method in a passive optical network system.

[2] The passive optical network system is an uplink signal / downstream signal lGbps bidirectional transmission system, which is a standardized system defined in IEEE 802.3ah, and is used only in the downstream direction where the bit multiplexing and demultiplexing is performed. 2. The unidirectional transmission signal distribution method in the passive optical network system according to claim 1, wherein the unidirectional transmission signal is a signal having the same information rate and code conversion format as the bidirectional transmission system.

[3] The passive optical network system is an upstream signal / downstream signal 1.2448 Gbps bidirectional transmission system defined in ITU-T G. 984.3, and is configured to transmit the bit multiplexed and separated signals. 2. The unidirectional transmission signal distribution method in the passive optical network system according to claim 1, wherein the unidirectional transmission signal of only direction is a signal having the same information rate and code conversion format as the bidirectional transmission system.

[4] The passive optical network system is an upstream signal / downstream signal 1.2448 Gbps bidirectional system stipulated in ITU-T G. 984.3, and the downstream direction in which the bit multiplexing and separation are performed. 2. The single-way transmission signal in the passive optical network system according to claim 1, wherein the single-way transmission signal is a signal having the same information rate as that of the bidirectional transmission system and a code conversion format different from that of the bidirectional transmission system. Directional transmission signal distribution method.

[5] The passive optical network system is configured such that the bit-multiplexed one-way transmission only in the downlink direction. A passive optical network system in which a subscriber premises equipment and a subscriber premises equipment equipped with a receiver for reproducing the one-way transmission signal are mixed. The unidirectional transmission signal distribution method in the passive optical network system according to claim 1, wherein:

[6] The station side device transmits the bit-multiplexed downlink only one-way transmission signal with an identifier indicating that the signal is a downlink only one-way transmission signal, and 2. The piece of passive optical network system according to claim 1, wherein the subscriber premises apparatus determines whether or not the identifier is normally received, and controls the bit separation position according to the determination result. Directional transmission signal distribution method.

[7] To the subscriber premises equipment! Then, it is determined whether or not the main signal data of the bit-separated passive optical network system has been normally received, and the bit separation position is set when the main signal data is not normally received for a predetermined time! The unidirectional transmission signal distribution method in the passive optical network system according to claim 1, wherein the unidirectional transmission signal distribution method is controlled so as to be changed.

[8] The unidirectional transmission signal only in the downlink direction from the station side device is a signal obtained by bit-multiplexing a plurality of transmission signals, and the unidirectional transmission signal only in the downlink direction in the subscriber premises device. 2. The method for distributing a one-way transmission signal in a passive optical network system according to claim 1, wherein the bit is separated into a plurality of transmission signals.

[9] The passive optical network system includes a subscriber premises apparatus that does not include a receiving unit that reproduces a unidirectional transmission signal only in the downlink direction in which the plurality of transmission signals are bit-multiplexed, and the unidirectional transmission. 9. The one-way transmission signal in the passive optical network system according to claim 8, wherein a plurality of types of subscriber premises apparatuses having different numbers of receiving units for reproducing signals are mixed passive optical network systems. Distribution method.

[10] A plurality of subscriber premises devices, and a station premises device connected to the subscriber premises devices via an optical splitter via an optical fiber, the station side devices being a plurality of subscriber premises devices Distributes the transmission timing control instruction of the subscriber premises equipment to receive the upstream burst optical signal transmitted in a time-sharing manner without collision, and the downstream optical signal with the destination address for each subscriber premises equipment In a passive optical network system having means for

The station side device wavelength-multiplexes the digital signal of the unidirectional transmission signal only in the downlink direction obtained by bit multiplexing of a plurality of transmission signals and the main signal data of the passive optical network system. Send

At the subscriber premises equipment, the digital signal of the one-way transmission signal only in the downlink direction and the main signal data of the passive optical network system are wavelength-separated, and the one-way transmission signal only in the downlink direction is bit-separated. Unidirectional transmission signal distribution method in a passive optical network system, characterized in that

[11] The downstream signal of the passive optical network system is a downstream signal IGbps transmission signal, which is a standardized method defined in IEEE 802.3ah, and is transmitted in the unidirectional direction only in the downstream direction where the bit multiplexing and separation are performed. 11. The one-way transmission signal distribution method in a passive optical network system according to claim 10, wherein the signal is a signal having the same information rate and code conversion format as the transmission signal.

[12] The downstream signal of the passive optical network system is a downstream signal defined in ITU-T G. 984.3, which is a 2448 Gbps transmission signal, and is a single piece of the downstream direction that is bit-multiplexed and separated. 11. The unidirectional transmission signal distribution method in the passive optical network system according to claim 10, wherein the directional transmission signal is a signal having the same information rate and code conversion format as the transmission signal.

[13] The downstream signal of the passive optical network system is a downstream signal defined in ITU-T G. 984.3, which is a transmission signal of 2448 Gbps, and is only one piece of the downstream direction to be multiplexed and separated. 11. The unidirectional transmission signal distribution method in the passive optical network system according to claim 10, wherein the directional transmission signal is a signal of a code conversion format different from the transmission signal at the same information rate as the transmission signal.

[14] The station side device transmits the bit-multiplexed downlink only unidirectional transmission signal with an identifier indicating that the signal is a downlink only unidirectional transmission signal, 11. The one-way in the passive optical network system according to claim 10, wherein a subscriber premises apparatus determines whether the identifier is normally received and controls a bit separation position according to the determination result. Transmission signal distribution method.

[15] The passive optical network system includes: a subscriber premises apparatus that does not include a receiving unit that reproduces only a unidirectional transmission signal in a downlink direction in which a plurality of transmission signals are bit-multiplexed; and the unidirectional transmission signal Multiple types of subscriber premises equipment with different numbers of receivers 11. The one-way transmission signal distribution method in the passive optical network system according to claim 10, wherein the one-way transmission signal distribution method is used in the passive optical network system.

[16] In the station side device, an identifier is added for each transmission signal to the unidirectional transmission signal only in the downlink direction in which a plurality of transmission signals are bit-multiplexed, and transmitted.

16. The passive optical network according to claim 15, wherein the subscriber premises apparatus determines whether an identifier of a specific transmission signal has been normally received, and controls a bit separation position according to the determination result. A one-way transmission signal distribution method in a system.

[17] Subscriber premises for receiving uplink burst optical signals transmitted in a time-division manner without any collision, connected to multiple subscriber premises equipment via an optical fiber via an optical splitter In the station side device constituting the passive optical network system, comprising means for instructing the transmission timing of the side device and means for distributing the downstream optical signal with the destination address for each subscriber home side device,

Bit multiplexing means for bit-multiplexing the digital signal of the unidirectional transmission signal only in the downlink direction and the main signal data of the passive optical network system;

Means for transmitting the downlink signal multiplexed by the bit multiplexing means to the subscriber premises apparatus;

A station apparatus for a passive optical network system, comprising:

[18] Means for transmitting an upstream burst optical signal in a time-division manner without collision in accordance with a transmission timing control instruction from the station-side device power, connected to the station-side device via an optical splitter, and from the station-side device to the destination Means for receiving a downstream optical signal to which an address is attached, and the subscriber premises equipment constituting the passive optical network system,

Bit separation means that separates a digital signal of a unidirectional transmission signal that is bit-multiplexed only from the downlink and the main signal data of the passive optical network system from the downlink signal, and the bit separation means Means for extracting the transmitted unidirectional transmission signal only in the downstream direction,

A subscriber-side device for a passive optical network system, comprising: