JP3055534B2 - Optical subscriber system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical subscriber system, and more particularly, to an optical subscriber system capable of simultaneously realizing a real-time service such as telephone and a transaction service such as data communication to enable multimedia communication. Things.

[0002]

2. Description of the Related Art Conventionally, a PON (Pass
ive Optical Network) Synchronous N-PDS system and STM-
There is a PON system or an asynchronous ATM-PON system. In particular, the ATM-PON system has attracted attention as a system for transmitting large-capacity information. ATM
-The PON system has an advantage that the bandwidth utilization efficiency can be improved due to the high speed and the statistical multiplexing effect of the ATM (asynchronous transfer system).

[0003] ATM-PON has already been standardized in ITU-T, and a document (ITU-T Recommendation G.983) is known. FIG. 10 is a conceptual diagram showing a conventional ATM-PON system. In this ATM-PON system, one fiber connected to a station is branched up to 32 on the way and connected to up to 32 subscribers.

A downlink signal from a station to a subscriber includes information for all subscribers, and the subscriber selects and obtains necessary information among them. on the other hand,
For the upstream signal from the subscriber to the station, a permission signal is given from the station side to each subscriber in advance, and a signal is transmitted from the subscriber to the station according to the content of the signal. This permission signal is realized by performing control on the station side in response to a request from the subscriber. As a result, it is possible to allocate an arbitrary band to various subscribers.

[0005]

However, in such a conventional optical subscriber system, an asynchronous ATM is used.
-In a PON system, when voice communication and data communication are to be simultaneously and simultaneously realized in the same PON system, it becomes necessary to guarantee QoS (Quality of Service). This is because the restriction on the amount of delay is different between a normal data communication service and a real-time service such as a telephone service, so that priority assignment of a cell band is required.

[0006] Also, in the access control on the station side, Qo
In addition to guaranteeing S, it is necessary to allocate a cell band to a subscriber at a predetermined cycle in order to reduce delay fluctuation. Therefore, there is a problem that control on the station side becomes complicated. SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an optical subscriber system capable of simultaneously realizing voice communication and data communication in parallel with the same PON system without complicating control on the station side. It is intended to provide.

[0007]

In order to achieve the above object, an optical subscriber system according to the present invention is provided with a station apparatus arranged on a station side for accommodating an external network, and a station apparatus arranged on a subscriber side and installed in a home. A plurality of subscriber devices accommodating terminals,
Using the PON topology, an optical signal from a station device is passively branched and transmitted to a plurality of subscriber devices, and optical signals from the respective subscriber devices are combined on the same time axis and transmitted to the station device. In an optical subscriber system, comprising an optical coupler and connecting a station device and a plurality of subscriber devices via an optical cable, the station device and the subscriber device are provided with an asynchronous external network on the station side and a plurality of subscriber side devices. Asynchronous PON signal used in the asynchronous PON system for realizing communication with the asynchronous home terminal and communication between the synchronous external network on the station side and a plurality of synchronous home terminals on the subscriber side Synchronous PON used in a synchronous PON system
A time-division multiplexing with the signal, converting the signal into an optical signal by electro-optical conversion, and then transmitting the signal to the optical coupler;
Receiving means for performing time-division separation into an N signal and a synchronous PON signal.

Therefore, in the station device, the downlink asynchronous PON signal output from each OLT device and the downlink synchronous PON signal are output.
The N signal is time-division multiplexed and transmitted as a downstream optical signal, which is equally distributed to each subscriber unit by an optical coupler. Then, the downstream optical signal received by each subscriber device is
The signal is time-division-separated into a downstream asynchronous PON signal and a downstream synchronous PON signal, and is output to each ONU. Also, in each subscriber unit, the upstream asynchronous PON signal and the upstream synchronous PON signal output from each ONU are time-division multiplexed and transmitted as upstream optical signals, which are combined by the optical coupler and transmitted to the station device. Sent. Then, after the upstream optical signal received by the station device is photoelectrically converted, the upstream asynchronous P
Time-division separated into an ON signal and an upstream synchronous PON signal,
Output to each OLT device.

[0009]

Next, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an optical subscriber system according to a first embodiment of the present invention. This embodiment is directed to an ATM used in an asynchronous ATM-PON system.
-By multiplexing and transmitting the PON signal and the STM-PON signal used in the synchronous STM-PON system, the ATM-PON system and the STM-PON system can be realized in parallel on the same PON system at the same time. It was done.

In FIG. 1, each of the subscriber units 11 to 1N
(N is an integer of 2 or more) is connected to the station device 10 via the optical coupler 108, and further connected from the station device 10 to the external networks 121 and 122 of the ATM-PON and the STM-PON, respectively. The OLT for terminating the asynchronous external network 121 is provided on the station device 10 side.
(Optical Line Termination) device 101 and OLT device 104 for terminating synchronous external network 122 are provided.

Also, as a transmitting unit of the station device 10, the downstream ATM-PON from each of the OLT devices 101 and 104 is used.
Time-division multiplexing circuit (multiplexing means) 102 for time-division multiplexing of signal 131 and downlink STM-PON signal 132
And the downlink multiplex P generated by the time-division multiplexing circuit 102.
An optical transmission circuit (optical transmission means) that converts the ON signal 133 into a downstream optical signal 134 by electro-optical conversion and transmits the optical signal to the optical coupler 108 side.
103 are provided.

Further, as a receiving section of the station apparatus 10, an optical receiving circuit (optical receiving means) 106 for performing optical-to-electrical conversion of the upstream optical signal 135 received from the optical coupler 108 side to perform signal reproduction and clock extraction, and A time-division demultiplexing circuit (separating means) 105 that demultiplexes the upstream multiplexed PON signal 136 from the receiving circuit 106 into time-division bits and outputs the upstream ATM-PON signal 137 and the upstream STM-PON signal 138 to the respective OLT devices 101 and 104. Is provided.

The optical transmission circuit 103 and the optical reception circuit 106 of the station device 10 are connected to an optical coupler 107 via optical fibers, respectively. Further, the optical coupler 10
7 is connected to an optical coupler 108 via an optical fiber, where it is passively branched and each of the subscriber units 11 to 1N
Is distributed equally to.

On the other hand, the subscriber units 11 to 1N are connected to the asynchronous home network 12 to which the asynchronous terminals are connected.
(Optical Network Unit) device 11 that terminates 3
2 and an ONU device 115 that complains about the synchronous home network 124 to which the synchronous terminal is connected.

Also, as receiving units of the subscriber units 11 to 1N, the downstream optical signal 141 received from the optical coupler 108 side.
Receiving circuit (optical receiving means) 110 for performing optical-to-electrical conversion, signal regeneration and clock extraction, and this optical receiving circuit 11
The multiplexed PON signal 142 from 0 is time-division-separated into bits, and the obtained downlink ATM-PON signal 143 and downlink STM-PON signal 144 are respectively transmitted to the ONU 11
Time division separation circuit (separation means) for separation and output to 2,115
111 are provided.

Further, a time division multiplexing circuit (multiplexing) for performing time division bit multiplexing on the upstream ATM-PON signal 145 and the upstream STM-PON signal 145 output from each of the ONU units 112 and 115 as a transmission unit of the subscriber units 11 to 1N. Means) 114, and an optical transmitting circuit (optical transmitting means) 1 for converting the upstream multiplexed PON signal 147 from the time division multiplexing circuit 114 into an upstream optical signal 148 and transmitting it to the optical coupler 108 side.
13 are provided.

Optical transmission circuit 11 on the side of subscriber units 11-1N
3 and the optical receiving circuit 110 are connected to the optical coupler 109 via optical fibers, respectively. Further, the optical coupler 109 is connected to the optical coupler 108 via an optical fiber.
, Where the optical signals from the respective subscriber units 11 to 1N are multiplex-coupled on the same time axis and transmitted to the station device 10 side.

In the present invention, a wavelength division multiplexing (WDM) system is used. In the section from the optical coupler 107 to the optical coupler 109, downstream optical signals and upstream optical signals having different wavelengths are transmitted.
They are transmitted simultaneously in the same optical cable. In this case, a laser beam having a light wavelength in the 1.3 μm band is used as the upstream optical signal, and a laser beam having a light wavelength in the 1.5 μm band is used as the downstream optical signal. The optical coupler 1
At 07 and 109, the optical signal is split according to the wavelength band of the laser light, and at the optical coupler 108, it is split to each subscriber side with the same optical power.

Next, an operation according to the first embodiment of the present invention will be described with reference to FIG. First, the station device 1
Downlink signals received by the OLT devices 101 and 104 on the 0 side from the external networks 121 and 122 to the home networks 123 and 124 on the subscriber side, respectively, are downlink AT
M-PON signal 131 and downlink STM-PON signal 1
32 is output.

The downstream ATM-PON signal 131 and the downstream STM-PON signal 132 are time-division multiplexed by the time-division multiplexing circuit 102 to form a downstream multiplex PON signal 1.
33. Then, this downlink multiplexed PON signal 133
Is converted into a downstream optical signal 134 by the optical transmission circuit 103,
The signals are distributed to each of the subscriber units 11 to 1N via the optical couplers 107, 108, and 109.

FIG. 2 is an explanatory diagram showing an optical signal transmission system based on the PON topology according to the present invention.
An optical signal transmission system similar to the system is used. In the downstream direction from the station side to the subscriber side, as shown in FIG. 2A, the downstream optical signal 134 transmitted from the station apparatus 10 is passively transmitted to each of the subscriber apparatuses 11 to 1N by the optical coupler 108. Evenly distributed, the downstream optical signals 1
41 is received.

The downstream optical signal 141 is transmitted to the subscriber unit 11
-1 PON received by the optical receiving circuit 110
It is output as a signal 142. The downlink multiplexed PON signal 142 is converted by the time division demultiplexing circuit 111 into a downlink ATM-PO
The N signal 143 and the downstream STM-PON signal 144 are separated. Then, the corresponding ONU devices 112, 1
15 and the respective home networks 123,
It is transmitted to the corresponding asynchronous home terminal and synchronous home terminal via 124.

Also, from each of the home networks 123 and 124 received by the ONU devices 112 and 115,
The upstream signal to the side is an upstream ATM-PON signal 1 respectively.
45 and the uplink STM-PON signal 146 are output to the time division multiplexing circuit 114. Then, the multiplexed PON signal 147 is time-division multiplexed into an upstream multiplexed PON signal 147, and is converted into an upstream optical signal 148 by the optical transmission circuit 113.
The data is transmitted to the station device 10 through 9, 108 and 107.

In the upward direction from the subscriber side to the office side, FIG.
As shown in (b), each upstream optical signal 148 transmitted from each of the subscriber units 11 to 1N is multiplex-coupled on the same time axis by the optical coupler 108, and the upstream optical signal 13
5 is received. The upstream optical signal 135 is received by the optical receiving circuit 106 of the station device 10 and output as an upstream multiplexed PON signal 136.

The upstream multiplexed PON signal 136 is separated by the time division separation circuit 105 into an upstream ATM-PON signal 137 and an upstream STM-PON signal 138. And
The data is output to the corresponding OLT devices 101 and 104 and transmitted to the external networks 121 and 122, respectively.

FIGS. 3A and 3B are explanatory diagrams showing examples of the frame structure of the PON signal. FIG. 3A shows an ATM-PON signal, and FIG.
Indicates an STM-PON signal. In the case of the ATM-PON signal shown in FIG. 3A, a frame having a predetermined cycle length is provided with a large number of cells CEL1, CEL2,... An ATM cell exchanged with an asynchronous home terminal connected to the home network 123 and a header section containing various control information are stored.

In the case of the ATM-PON system, the assignment of time slots to the respective subscriber units 11 to 1N is performed by the OLT device 101 of the station device 10 in response to a request from the respective subscriber units 11 to 1N. Subscriber device 1
Using the control information (PID) in the header section and the OAM cell for control, the available time slots, that is, cells, are dynamically specified for the 1 to 1N ONUs 112 according to the situation.

On the other hand, in the case of the STM-PON signal, FIG.
As shown in (b), a frame having a predetermined cycle length includes:
Are provided with a number of time slots TS1, TS2,..., And frame data exchanged between the synchronous external network 122 on the station side and the synchronous home terminal connected to the subscriber home network 124; A header section including various control information is stored. In this case, available time slots are fixedly designated by the predetermined permission signal from the station device 10 to the respective subscriber devices 11 to 1N at the start of communication.

In the present invention, a new frame structure different from these frame structures is used to
The N signal and the STM-PON signal are bit-multiplexed. FIG. 4 is an explanatory diagram showing an example of a frame configuration according to the present invention, in which “A” indicates bits of an ATM-PON signal, “B” indicates bits of an STM-PON signal, and each PON signal shown in FIG. Are alternately multiplexed in bit units.

Therefore, in the downstream direction, the time division multiplexing circuit 102 of the station device 10 generates the downstream multiplexed PON signal 133 having the frame format shown in FIG. 4, and this is transmitted from the optical transmission circuit 103 as the downstream optical signal 134. You. Then, as shown in FIG. 2A, distribution is equally performed from the optical coupler 108 to each of the subscriber units 11 to 1N based on the PON topology.

On the other hand, in the up direction, the subscriber units 11 to 1
The N time-division multiplexing circuit 114 generates an upstream multiplexed PON signal 147 having the frame format shown in FIG. 4 and outputs the downstream multiplexed PON signal 147 from the optical transmission circuit 113 at a timing different from that of another predetermined subscriber. Sent. Then, as shown in FIG. 2B, based on the PON topology, the optical coupler 108 is coupled on the same time axis and transmitted to the station device 10.

Therefore, according to the present invention, two P Ps can be provided by a relatively simple circuit configuration for the station side and the subscriber side.
The ON systems can be realized independently and in parallel at the same time. This eliminates the need to provide services such as telephones in an asynchronous ATM-PON system, and eliminates the need for priority control of cell bandwidth and control for reducing delay fluctuations for QoS guarantee, thereby complicating control on the station side. Voice communication and data communication can be integrated without the need for communication.

In the above description, two PON systems, ATM-PON and STM-PON, have been described by way of example. However, the present invention is not limited to this.
Needless to say, it can be realized by the ON system. Although the bit multiplexing method has been described as an example, various multiplexing methods such as byte multiplexing can be used.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a block diagram of an optical subscriber system according to a second embodiment of the present invention.
The same or equivalent parts as those described above (see FIG. 1) are denoted by the same reference numerals. In the present embodiment, in addition to the above-described first embodiment (see FIG. 1), a power control circuit 201 for controlling the optical power of the optical signal in the upstream direction on each of the subscriber units 11 to 1N is provided. It is provided.

In the above-described first embodiment, when signals from the subscriber units 11 to 1N are received by the station unit 10,
Since optical signals having various optical powers arrive due to a difference in distance, an optical receiving circuit 106 capable of receiving signals having different threshold levels is required. In the present embodiment, each of the subscriber devices 11 to 11 is previously set in the optical receiving circuit 106 of the station device 10.
The optical power of the optical signal 135 from 1N is measured, and the
The station device 10 notifies each of the subscriber units 11 to 1N of individual optical power information so that the optical power of the signal received at 0 becomes constant.

In each of the subscriber units 11 to 1N, optical power information from the optical network unit 10 is detected by the optical receiving circuit 110, and based on the optical power information, the power control circuit 201 transmits the optical power information from the optical transmitting circuit 113 to the optical network unit 10. The output optical power of the optical signal 148 to be transmitted is adjusted. Therefore, each subscriber device 11
When the optical signal 135 from １1N is received by the optical network unit 10, the threshold level becomes almost the same, the optical signal 135 can be received stably, and the configuration of the optical receiving circuit 106 can be simplified.

Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 6 is a block diagram of an optical subscriber system according to a third embodiment of the present invention.
The same or equivalent parts as those described above (see FIG. 1) are denoted by the same reference numerals. In this embodiment, in addition to the above-described first embodiment (see FIG. 1), a digital broadcast signal is multiplexed on a downlink multiplexed PON signal from a station side to a subscriber side.

In FIG. 6, the station apparatus 10 is provided with a broadcast signal receiving circuit 221 for receiving a digital broadcast, and a broadcast signal accommodating circuit 222 for accommodating the output of the broadcast signal receiving circuit 221 in the multiplexing circuit 102. ing. In addition, the subscriber units 11 to 1N include a time-division separating circuit 111.
A broadcast signal terminating circuit 223 for extracting a digital broadcast signal from the signal separated by the above is provided.

In this case, in the station device 10, the output of the broadcast signal receiving circuit 221 is input to the time division multiplexing circuit 102 via the broadcast signal accommodating circuit 222, and each OLT device 10
Multiplexed with the PON signals 131 and 132 from the first and the first 104. As a multiplexing method, a bit for a digital broadcast signal may be provided and bit multiplexing may be performed as shown in FIG. 2, for example, or another multiplexing method may be used.

The subscriber units 11-1N are connected to the central office 10
The digital broadcast signal multiplexed with the signal from the receiver is separated by the time-division multiplexing / demultiplexing circuit 111 and the broadcast signal terminating circuit 223
Is output to the home via Accordingly, in addition to synchronous and asynchronous communication services, broadcast-type services, such as satellite television broadcasting and cable television broadcasting, can be realized on the PON system using the same optical fiber.

Next, a fourth embodiment of the present invention will be described with reference to FIG. FIG. 7 is a block diagram of an optical subscriber system according to a fourth embodiment of the present invention.
The same or equivalent parts as those described above (see FIG. 1) are denoted by the same reference numerals. In this embodiment, similarly to the first embodiment (see FIG. 1), the ATM-PON system and the STM-PON system are realized in parallel on the same PON system at the same time. .

In this case, instead of the time division multiplexing circuit 114 (see FIG. 1), each of the ONUs
Each PON signal 14 output from the devices 112 and 115
Buffer memory (first buffer memory) 2 for temporarily storing 5,146, and outputting at an arbitrary timing and speed
14 and a timing control circuit 215 for controlling the operation of the buffer memory 214.

The station device 10 includes a time-division separating circuit 1.
05, a buffer memory (second buffer memory) 205 that temporarily stores the upstream multiplexed PON signal 136 output from the optical receiving circuit 106 and outputs the multiplexed PON signal 136 at an arbitrary timing and speed. A timing control circuit 206 for controlling is provided.

FIG. 8 is an explanatory diagram showing a frame format of an upstream signal according to the fourth embodiment. The height of the optical signals 148 and 135 from each of the subscriber units 11 to 1N indicates the magnitude of the optical power. Is shown. Here, a plurality of sub-frames for individually storing signals of each PON system are provided in one frame, and each subscriber unit 11 to 1N provides an uplink AT.
M-PON signal 145 and STM-PON signal 146
Are multiplexed on a subframe basis.

First, in each of the subscriber units 11 to 1N, each O
Up PON signals 145 and 145 from the NU units 112 and 115
146 is temporarily stored in the buffer memory 214. Under the control of the timing control circuit 215, the buffer memories are controlled at different timings specified in advance by the station device 10 so that the signals output from the individual subscriber devices 11 to 1N do not collide with other subscribers. The data is read out from 214 and output to the optical transmission circuit 113.

At this time, the timing control circuit 215
For example, the downstream ATM-P detected by the ONU 112
On the basis of the frame of the ON signal 143, the ATM-PO
The PON signal corresponding to each subframe is specified at a timing designated in advance by the station device 10 by defining a delay time of a predetermined time measured by the ranging function of the N system as a frame start point of the uplink multiplex PON signal 147. 145,14
6 is read from the buffer memory 214.

As a result, each subframe has an uplink ATM
-Frame of PON signal 145 and upstream STM-PO
An upstream optical signal 148 in which the frames of the N signal 146 are multiplexed on a frame basis as subframes is generated. On the other hand, in the station device 10, the uplink multiplexed PON signal obtained from the optical receiving circuit 106 is temporarily stored in the buffer memory 205.

Under the control of the timing control circuit 206, the PON signal stored in the buffer memory 205 at the time position of the ATM-PON sub-frame is output as an upstream ATM-PON signal 137, and S
The PON signal stored at the time position of the TM-PON subframe is output as the uplink STM-PON signal 138.

Therefore, as in the first embodiment, real-time communication and exchange of transaction data signals can be performed. In addition, in each of the subscriber units 11 to 1N, since a multiplex is performed for each subframe provided corresponding to each PON system, a clock that is different for each PON system is switched by switching the clock for each subframe. It is possible to use the same clock in each PON system.

Note that, instead of the frame format of FIG. 8, another frame format as shown in FIG. 9 may be used. FIG. 9 is an explanatory diagram showing another frame format of the uplink signal according to the fourth embodiment. The heights of the optical signals 148 and 135 from each of the subscriber units 11 to 1N indicate the magnitude of the optical power. ing.

Here, a plurality of subframes for individually storing the PON signals of the respective subscriber units 11 to 1N are provided in one frame, and each subscriber unit 11 to 1N provides an upstream ATM-
The PON signal 145 and the STM-PON signal 146 are multiplexed in subframe units. Each subframe is provided with a fixed band region in which a fixed band signal such as voice flows and a variable band region in which information such as data communication flows in a burst manner.
The signal 146 is multiplexed in the fixed band area and the ATM-PON
The signal 145 is multiplexed in the variable band region.

As a result, the band can be freely handled for each subscriber. When a signal is received by the station apparatus 10, the upstream optical signal 135 is input with the same optical power in the subframe section allocated to each subscriber apparatus. As a result, the upstream optical signal 135 can be received stably, and the configuration of the optical receiving circuit 106 can be simplified.

[0053]

As described above, the present invention provides an asynchronous communication system for realizing communication between an asynchronous external network on the office side and a plurality of asynchronous home terminals on the subscriber side. Asynchronous PON Used in Mobile PON System
Signal and synchronous PO for realizing communication between the synchronous external network on the station side and a plurality of synchronous home terminals on the subscriber side
A synchronous PON signal used in the N system is time-division multiplexed, converted into an optical signal by electro-optical conversion and transmitted, and the received optical signal is photoelectrically converted.
The N signal and the synchronous PON signal are time-division-separated.

Therefore, as in the prior art, the asynchronous A
In the TM-PON system, as compared with the case where voice communication and data communication are simultaneously realized in parallel in the same PON system, the asynchronous and synchronous PON systems can be realized independently. Control such as QoS guarantee and priority allocation of cell bandwidth is not required, and voice communication and data communication can be simultaneously realized in parallel in the same PON system without complicating control on the station side.

[Brief description of the drawings]

FIG. 1 is a block diagram of an optical subscriber system according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a PON signal transmission system.

FIG. 3 is an explanatory diagram illustrating an example of a frame configuration of a PON signal.

FIG. 4 is an explanatory diagram showing a frame format of a multiplexed PON signal.

FIG. 5 is a block diagram of an optical subscriber system according to a second embodiment of the present invention.

FIG. 6 is a block diagram of an optical subscriber system according to a third embodiment of the present invention.

FIG. 7 is a block diagram of an optical subscriber system according to a fourth embodiment of the present invention.

FIG. 8 is an explanatory diagram illustrating a frame configuration example of a multiplexed PON signal.

FIG. 9 is an explanatory diagram showing another example of a frame configuration of a multiplexed PON signal.

FIG. 10 is a conceptual diagram showing a conventional ATM-PON system.

[Explanation of symbols]

10 station device, 11-1N subscriber device, 101 OL
T device (ATM-PON), 102, 114: time division multiplexing circuit, 103, 113: optical transmission circuit, 104: OLT
Apparatus (ATM-PON), 105, 111: time-division demultiplexing circuit, 106, 110: optical receiving circuit, 107-109 ...
Optical coupler, 112 ... ONU (ATM-PON), 11
5: ONU (STM-PON), 121: Asynchronous external network, 122: Synchronous external network, 12
3 asynchronous home network, 124 synchronous home network, 131, 143 downstream ATM-PON signal, 132, 144 downstream STM-PON signal, 13
3, 142: Downlink multiplexed PON signal, 134, 141: Downlink optical signal, 135, 148: Uplink optical signal, 136, 14
7: Uplink multiplexed PON signal, 137, 145: Uplink ATM
-PON signal, 138, 146 ... Upstream STM-PON signal, 201 ... power control circuit, 205, 214 ... buffer memory, 206, 215 ... timing control circuit, 22
1: Broadcast signal receiving circuit, 222: Broadcast signal accommodation circuit, 2
23 Broadcast signal termination circuit.

Claims (7)

(57) [Claims] 1. A station device arranged on a station side for accommodating an external network, a plurality of subscriber devices arranged on a subscriber side for accommodating a home terminal, and a passive optical signal from the station device using a PON topology. An optical coupler for transmitting the signal to a plurality of subscriber units and transmitting the signal to the station device by combining the optical signals from the respective subscriber devices on the same time axis. In an optical subscriber system in which devices are connected via an optical cable, a station device and a subscriber device realize communication between an asynchronous external network on the office side and a plurality of asynchronous home terminals on the subscriber side. Asynchronous PON
A time-division multiplexing of an asynchronous PON signal used in a system and a synchronous PON signal used in a synchronous PON system for realizing communication between a synchronous external network on a station side and a plurality of synchronous home terminals on a subscriber side. Transmitting means for converting the optical signal into an optical signal by electro-optical conversion, and then transmitting the signal to the optical coupler; and photoelectrically converting the optical signal received from the optical coupler, and then time-division-divided into an asynchronous PON signal and a synchronous PON signal. An optical subscriber system comprising: 2. The optical subscriber system according to claim 1, wherein the transmitting means of the station device and the subscriber device has multiplexing means for time-division multiplexing the asynchronous PON signal and the synchronous PON signal in 1-bit units. An optical subscriber system, wherein the receiving device of the station device and the subscriber device has a separating device for time-division separating into an asynchronous PON signal and a synchronous PON signal in 1-bit units. 3. The optical subscriber system according to claim 1, wherein the transmitting means of the station device and the subscriber device transmits an asynchronous PON signal and a synchronous PON signal in N (N is an integer of 2 or more) bits. An optical subscriber unit having multiplexing means for performing time division multiplexing, wherein the receiving means of the station apparatus and the subscriber apparatus has separating means for performing time division separation into an asynchronous PON signal and a synchronous PON signal in N-bit units. System. 4. The optical subscriber system according to claim 1, wherein the transmitting means of the station device comprises: a downlink signal from the station side to the subscriber side of the asynchronous PON signal and the synchronous PON signal; A multiplexing unit for performing time-division multiplexing with a downstream signal from the network side, wherein the receiving unit of the subscriber unit transmits the downstream signal from the subscriber side to the station side of the asynchronous PON signal and the synchronous PON signal and broadcasts 1. An optical subscriber system, comprising: separating means for performing time-division separation into a downstream signal to a mobile terminal. 5. The optical subscriber system according to claim 1, wherein the transmitting means of the subscriber unit converts the upstream signal of the asynchronous PON signal into a frame having a predetermined cycle length based on a timing designated in advance. The multiplexed signal is multiplexed at a predetermined time position in the provided asynchronous signal period, and an uplink signal of the synchronous PON signal is placed at a predetermined time position in the synchronous signal period provided in the frame based on a timing designated in advance. Multiplexing means for multiplexing, wherein the receiving means of the station device separates the upstream signal of the asynchronous PON signal from the asynchronous signal period provided in the frame of the signal obtained by the photoelectric conversion, and An optical subscriber system, comprising: separating means for separating an uplink signal of a synchronous PON signal from a provided synchronous signal period. 6. The optical subscriber system according to claim 1, wherein the transmitting means of the subscriber unit comprises: an uplink signal of an asynchronous PON signal and a synchronous PO signal.
A multiplexing means for multiplexing an uplink signal of the N signals at a predetermined time position within a period exclusive for the own subscriber provided in a frame having a predetermined cycle length based on respective timings specified in advance; The receiving means includes a separating means for separating an uplink signal of the asynchronous PON signal and an uplink signal of the synchronous PON signal from each subscriber-only period provided in the frame of the signal obtained by the photoelectric conversion. An optical subscriber system, comprising: 7. The optical subscriber system according to claim 1, wherein the transmission means of the subscriber unit comprises: a first buffer memory for storing an upstream PON signal of the asynchronous PON signal and the synchronous PON signal; Control means for reading each of the upstream PON signals from the first buffer memory based on a timing designated in advance, and electro-optical conversion of the upstream signal read from the first buffer memory into an optical signal to the optical coupler. Optical transmitting means for transmitting, optical receiving means for receiving optical signals from the respective subscriber units coupled on the same time axis by an optical coupler, and performing optical-electrical conversion; A second buffer memory for storing an output from the optical receiving means, and an asynchronous PO based on a predetermined timing.
Control means for reading an upstream signal of the N signal and the synchronous PON signal from the second buffer memory, respectively.