JP2002152239A - Stm-pds transmission system and subscriber device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an STM-PDS(synchronous transfer mode-passive double star) transmission system and a subscriber device, that can be compatible with a contract reaching the agreement between a station and a subscriber and effectively utilize the capacity of transmission line between the station and the subscriber. SOLUTION: A subscriber device 10 transmits a continuous transmission permission request repeatedly by each frame, until the data transmission quantity reaches a continuous data transmission quantity A proportional to a minimum warrant transmission capacity on the contract to a station device 20 and informs the device 20 of the end of the continuous transmission permission request, when the transmission quantity reaches the continuous data transmission quantity A. The station device transmits a transmission permission continuously to the subscriber device which transmits the continuous transmission permission request, until the subscriber device informs the station device of the end of the continuous transmission permission request by each frame.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a point-multipoint type STM-PDS (Synchronous Transfer M
The present invention relates to an ode-Passive Double Star) transmission system and a subscriber device, and more particularly, to the allocation of a shared band for an upstream frame transmitted from the subscriber device to the station device.

[0002]

2. Description of the Related Art Generally, in an STM-PDS transmission system, a subscriber line terminal (SLT) which is a terminal device for a subscriber side of a station side device;
A plurality of network terminating units (ONU: Optical Netw
An optical coupler is placed between the SLT and the optical coupler, and one optical fiber is connected between the SLT and the optical coupler.
Optical fibers are individually arranged between them, and S
The optical signal between the LT and the ONU is multiplexed and separated. For this reason, multiplexing is performed between the SLT and the optical coupler, and the transmission capacity is limited. Therefore, when a large amount of data is transmitted in an upstream direction by one ONU, data transmission by another ONU is inhibited.

Therefore, as a conventional method (conventional example 1) for preventing this problem, Japanese Patent Laid-Open Publication No. Hei 10-336186 and "Study of STM-PDS band sharing method suitable for high-speed IP access" are reported. 4 (1998-04) In p24-28, the station accumulates the transmission permission request of the shared band from the subscriber side and allocates the shared band to each fixed area for each request source, or a fixed amount for each reception time. There has been proposed a method of allocating each request, or allocating a fixed amount to each request source and reception time. As another conventional method (conventional example 2), Japanese Patent Laid-Open No. 11-341037 discloses that a subscriber notifies a station of a transmission permission request and a transmission data amount, and the station dynamically allocates an unused area. A method has been proposed.

[0004]

By the way, in such an STM-PDS transmission system, usually, a unit time per unit time when transmission is performed between the station side and the subscriber side in the upward direction from the subscriber side to the station side. In some cases, a contract is established that defines the minimum guaranteed transmission amount and the maximum transmission amount of the data transfer amount, or the subscriber side simply agrees with the predetermined line capacity. Note that contracts, agreements, agreements, and the like between the office and the subscriber are collectively referred to as contracts. However, since the transmission capacity (band) is allocated to each fixed area in the above-mentioned conventional example 1, and the unused area is simply dynamically allocated in the conventional example 2, it corresponds to the contract between the station side and the subscriber side. There is a problem that cannot be done.

The present invention has been made in view of the above-described problems of the prior art, and is capable of coping with a contract between a station and a subscriber.
In addition, STM- which can effectively use the optical transmission line
An object of the present invention is to provide a PDS transmission system and a station device thereof.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides a point-to-point connection between an optical line terminal and a plurality of subscriber units via an optical transmission line based on a contract for data transmission capacity.・ Multipoint type ST for two-way communication
In the M-PDS transmission system, a request for permitting continuous transmission of a shared band is issued for one frame until the subscriber unit transmits a continuous data transmission amount proportional to the contractual minimum guaranteed transmission capacity to the station unit. Repeatedly transmitted every time, when the continuous data transmission amount has been reached, the end of the continuous transmission permission request is notified, and the station apparatus receives the continuous transmission permission request for the subscriber apparatus, The transmission permission is continuously transmitted every frame until the end of the continuous transmission permission request is notified (claim 1). According to the above configuration, it is possible to cope with a contract concluded between the station side and the subscriber side, and it is possible to effectively use the optical transmission line.

Further, according to the present invention, after the subscriber side device notifies the station side device of the end of the continuous transmission permission request, if transmission data remains, the transmission permission request is transmitted in the next frame. When the station apparatus receives the transmission permission request, the station apparatus transmits a transmission permission to the subscriber apparatus when there is no transmission permission request from another subscriber apparatus. Item 2). With the above configuration,
A plurality of subscriber units can effectively use the shared band.

The present invention is also directed to a case where the subscriber unit transmits the last data having a capacity equal to or less than the capacity of the shared band, the number of areas obtained by dividing the shared band, and the number of areas capable of transmitting the required capacity. (Claim 3).
According to the above configuration, the required amount is not the number of bytes or the like but the number of areas obtained by dividing the shared band, so that the optical transmission path can be effectively used.

Further, the present invention is configured such that when the subscriber side device reaches the continuous data transmission amount, if there is a free space in the shared band, data is transmitted to the free space. 4). With the above configuration, the optical transmission path can be used effectively.

In the present invention, when the subscriber unit transmits data to the empty area, a transmission permission request is sent from the continuous data transmission amount to the data transmission of the empty area when the next continuous data transmission is performed. The transmission is repeated for each frame until the amount is subtracted (claim 5). With the above configuration, the optical transmission path can be used effectively, and the minimum guaranteed transmission capacity can be guaranteed for all the subscribers.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS <First Embodiment> An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a first embodiment of the STM-PDS transmission system according to the present invention.

In FIG. 1, a plurality of subscriber units 10
Each of (10-1, 10-2 to 10-n) is constituted by a network termination unit (ONU) or the like, and is connected to a telephone terminal, a personal computer, or the like. The optical line terminal 20 comprises a subscriber line terminal (SLT) and an operating system. Subscriber-side devices 10-1, 10
Between each ONU of −2 to 10-n and the star coupler 30,
The optical couplers are connected via optical fibers 31-1, 31-2 to 31-n, respectively.
Between T, they are connected via one optical fiber 31.

In the case where optical communication is performed between each ONU of the subscriber unit 10 and the SLT of the optical line terminal 20, the optical line terminal 20 transmits a downstream frame in the first half of one burst period (frame). 10, and in the latter half, the subscriber-side device 10 transmits an upstream frame to the station-side device 20 so that transmission is performed in a ping-pong system. The upstream frame and the downstream frame are composed of a fixed band (also referred to as an area or a time slot) allocated in a time-division manner in the order of the subscribers and a shared band shared by all the subscribers.
The present invention is not limited to the ping-pong transmission method, but can be applied to a WDM (Wavelength Division Multiplexing) method and an SDM (Space Division Multiplexing) method.

The internal blocks of the subscriber unit 10 and the central unit 20 in FIG. 1 only show those relating to the transmission of an upstream frame from the subscriber unit 10 to the central unit 20. Each of the subscriber devices 10 includes a data storage unit 11
, A data transmitting unit 12 and a frame assembling / disassembling unit 13
, The minimum guaranteed bandwidth storage unit 14, and the transmission permission request transmission unit 1.
5 and a transmission permission receiving unit 16. The optical line terminal 20 includes a frame assembling / disassembling unit 21 and a transmission permission request accumulating unit 22.
And a scheduling unit 23 for allocating a shared band (see FIG. 14), and a transmission permission transmitting unit 24.

The minimum guaranteed bandwidth storage unit 14 stores a minimum guaranteed bandwidth [Mbps] based on a contract with the station side and a continuous data transmission amount α (the number of areas obtained by dividing a shared bandwidth described later).
Is stored in advance. The continuous data transmission amount α is
It is determined according to the uplink shared bandwidth capacity, all subscribers and the minimum guaranteed bandwidth of the subscriber, and in proportion to the minimum guaranteed bandwidth of the subscriber. That is, assuming that the continuous data transmission amount of the i-th subscriber device 10-i is αi, the following minimum guaranteed capacity [Mbps] is guaranteed for the subscriber device 10-i. Minimum guaranteed capacity = Upstream shared bandwidth capacity × (αi / Σαi)

When transmission data exceeding the uplink shared band capacity occurs, the subscriber unit 10-i repeats the continuous transmission permission request for each frame until the continuous data transmission amount αi is reached, and When the transmission is performed up to the continuous data transmission amount αi, the end of the continuous transmission permission request is notified. At this time, the optical line terminal 20 continuously grants the transmission permission for each frame to the subscriber-side apparatus 10-i that has notified the continuous transmission permission until receiving the end notification of the continuous transmission permission request.

FIG. 2 shows a transmission procedure using the shared band of the subscriber unit 10, and FIG.
The communication procedure between 0 is shown. 2 and 3, 1
When the optical line terminal 20 transmits the shared band transmission permission to the subscriber side device 10 in the first half downlink frame of the burst frame, the subscriber side device 10 performs the shared band data transmission processing (the second half upstream frame of one burst frame). Step S1) is executed to transmit data, and transmission permission request processing for the shared band is executed (step S2) to transmit a transmission permission request. This is repeated for each burst frame. The transmission permission → data transmission → transmission permission request in one burst frame is merely an example, and the transmission permission request → transmission permission → data transmission may be performed.

FIG. 4 shows the data transmission processing in step S1 of FIG. 2 in detail, and FIG. 5 shows the transmission permission request processing in step S2 in detail. In the data transmission process shown in FIG. 4, first, it is determined whether or not there is a shared band assigned to itself based on the presence or absence of transmission permission from the optical line terminal 20 (step S11). The process proceeds to the following, on the other hand, if there is none, the process ends (step S12). In step S13 and subsequent steps, it is determined whether or not the previous request was a “continuous transmission permission request” (step S13). If No, the process proceeds to step S14.
On the other hand, if Yes, the process branches to step S17.

In step S14, it is determined whether or not the quota amount ≧ the transmission permission request amount.
Then, if No, the process branches to step S17. In step S17, the quota is transmitted, and then the amount of transmitted data = the amount of transmitted data up to the previous time + the amount of data transmitted this time is set (step S18), and the process is terminated (step S19). In step S15, since the quota ≧ the transmission permission request amount, the previous transmission permission request amount is transmitted, and then the transmitted data amount is set to 0 (step S1).
6) Then, the process ends (step S19).

In the transmission permission request process shown in FIG.
"Preset continuous data transmission amount A [byte]
It is determined whether or not ≧ transmitted data amount + untransmitted accumulated data amount ”(step S21). Here, the continuous data transmission amount A is a value [byte] proportional to the continuous data transmission amount α (the number of areas into which the shared band is divided). Step S2
In the case of Yes in 1, the process proceeds to step S22, where a is set to a = the amount of accumulated data, and then the process proceeds to step S24. On the other hand, if No in step S21,
In step S23, a = continuous data transmission amount A-transmitted data amount is set.

In step S24, it is determined whether or not the transmission capacity of the shared band in one frame is equal to or larger than a. If the determination is No, the process proceeds to step S25, and the transmission permission request amount is set to "continuous transmission permission request". On the other hand, if Yes in step S24, the process proceeds to step S26, where the transmission permission request amount is set to a. At this time, the transmission permission request amount “a” indicates “end of the continuous transmission permission request”. Also, "End of continuous transmission permission request"
Is transmitted, if transmission data remains, transmission permission is requested in the next frame.

The above process will be described with a specific example. FIG.
Will be described in order to simplify the explanation.
1 shows a system having 1 and 10-2 (and an optical line terminal 20). FIG. 7 shows the subscriber unit 10-1 shown in FIG.
FIG. 8 shows an example of a communication sequence between 10-2 and the optical line terminal 20, and FIG. 8 shows an assignment process. Here, the shared band in one uplink frame is divided into four regions # 1 to # 4, and 2.56 Mbps per divided region × 4 divided regions = 10.24 Mbps in total. The cycle of one burst frame is 1 ms, and the data amount of one divided area is 320 bytes. One of the subscriber units 10-1 and 10-2 exclusively uses the divided areas # 1 to # 4, and the subscriber units 10-1 and 10-2 use the divided areas # 1 to # 4. 4 can be used separately.

Here, the minimum bandwidth guaranteed capacity and the continuous data transmission amount α1 of the subscriber unit 10-1 are 6.144, respectively.
Mbps, 12 (A = 12 × 320 bytes = 3840 bytes), the minimum bandwidth guaranteed capacity of the subscriber unit 10-2, and the continuous data transmission amount α2 are 4.096 Mbps, 8, respectively.
(A = 8 × 320 bytes = 2560 bytes). It is also assumed that the subscriber-side devices 10-1 and 10-2 have transmission data accumulation amounts exceeding the continuous data transmission amounts α1 = 12 and α2 = 8, respectively.

At this time, the subscriber unit 10-1 sets No in step S21 shown in FIG. 5, so a is set to a = A-0 (the amount of transmitted data) in step S23, and then No in step S24. Therefore, in step S25, the transmission permission request amount is set to “continuous transmission permission request” (four or more divided areas, hereinafter “four or more”).

When the subscriber unit 10-1 transmits a transmission permission request of "4 or more" and the subscriber unit 10-2 transmits a transmission permission request of "4 or more", the station device 2
In this case, “0” indicates that the transmission permission of the four-divided area (hereinafter, “4”) is transmitted to the subscriber unit 10-1 according to a predetermined selection rule (FIG. 14) (transmit to the subscriber unit 10-2). Do not grant permission). At this time, since the request from the subscriber unit 10-1 is not "4" but "4 or more",
Judge that there is the next request. Upon receiving the transmission permission, the subscriber unit 10-1 performs data transmission of "4" to the four divided areas # 1 to # 4 of the shared band at timing A1 in FIG.

At this time, the subscriber unit 10-1 transmits the “continuous transmission permission request” in step S13 shown in FIG.
Therefore, the allocated amount = 4 is transmitted in step S17, and the transmitted data amount = 0 in step S18.
(Transmitted data amount up to the previous time) +4 (data amount transmitted this time) = 4 is calculated. Step S shown in FIG.
Since it is No at 21, a = A-4 is set at step S23, and then the transmission permission request amount is set to "4 or more" at No at step S24.

Next, similarly, the subscriber units 10-1 and 10-1
When 0-2 transmits a transmission permission request of "4 or more", the optical line terminal 20 determines that the previous transmission permission request from the subscriber side device 10-1 is a continuous request of "4 or more". The transmission permission of "4" is transmitted to the apparatus 10-1 (the transmission permission is not given to the subscriber apparatus 10-2). Upon receiving the transmission permission, the subscriber unit 10-1 performs data transmission of "4".

At this time, the subscriber unit 10-1 transmits the "continuous transmission permission request" in step S13 shown in FIG.
Therefore, the allocated amount = 4 is transmitted in step S17, and the transmitted data amount = 4 in step S18.
+ 4 = 8 is calculated. Step S21 shown in FIG.
At step S23, a = a at step S23.
A-8 (the amount of transmitted data), and since yes is determined in step S24, the transmission permission request capacity =
4 (= a).

Next, when the subscriber units 10-1 and 10-2 transmit transmission permission requests of "4" and "4 or more", respectively, the station unit 20 similarly sends a request to the subscriber unit 10-1. Transmit the transmission permission of "4" (subscriber side device 10-2)
Is not given permission to send). Upon receiving the transmission permission, the subscriber unit 10-1 performs data transmission of "4". At this time, the optical line terminal 20 determines that the request from the optical line terminal 10-1 is "4".
Since it is "4" instead of "above", it is determined that one continuous transmission permission request (hereinafter, continuous request) has been completed.

Next, the subscriber units 10-1 and 10-2
Transmit a transmission permission request of “4 or more”, the station side device 20 determines that the previous transmission permission request from the subscriber side device 10-1 is the end of the continuous request of “4”. The transmission permission of "4" is transmitted to the subscriber side device -2 (the transmission permission is not given to the subscriber unit 10-1). Next, when the subscriber units 10-1 and 10-2 transmit transmission permission requests of "4 or more" and "4", respectively, the optical line terminal 20 transmits "4" to the subscriber unit 10-2. The permission is transmitted (the transmission permission is not given to the subscriber unit 10-1). At this time, since the request from the subscriber unit 10-2 is not "4 or more" but "4", it is determined that the continuous request is completed. Next, both the subscriber units 10-1 and 10-2 are set to “4”.
When the transmission permission request described above is transmitted, the optical line terminal 20 transmits “4” to the subscriber side device 10-1 because the previous transmission permission request from the subscriber side device 10-2 is the end of the continuous request. (The transmission permission is not given to the subscriber unit 10-2).

Therefore, according to such processing, the minimum guaranteed amount of the subscriber unit 10-1 is 10.24 Mbp.
s × 12 / (12 + 8) = 6.144 Mbps Minimum guaranteed amount of the subscriber unit 10-2 = 10.24 Mbps
s × 8 / (12 + 8) = 4.096 Mbps can be realized.

<Second Embodiment> Here, in step S26 shown in FIG. 5, if the transmission permission request amount a in the last frame of the continuous data transmission amount is transmitted in bytes or bits, the overhead due to the information a (Information amount) is increased, and transmission efficiency is reduced. FIG. 9 shows a process for preventing this, and step S26 shown in FIG. 5 is replaced by step S26-1 and step S26-2. The other steps are the same.

That is, in step S26-1, the transmission permission request amount a [byte] is divided by the divided area capacity of the shared band to round up the decimal point, and the subsequent step S26-2
, The calculation result b is set as the transmission permission request amount (the number of requested divided areas). According to such processing, when the number of divided regions of the shared band = 4, the transmission permission request amount b is 0,
Since there are six types of 1, 2, 3, 4, 4 or more (continuous transmission permission request), it can be expressed by 3 bits. Also,
The same is true for the transmission permission amount from the optical line terminal 20 to the subscriber side device 10.

<Third Embodiment> By the way, the continuous data transmission amount A does not always coincide with the capacity of the shared band and its multiple. Therefore, assuming that the transmission amount in the last frame is the previous transmission permission request amount a in step S15 shown in FIG. 4, an empty area (useless area) is generated as shown in FIG.
FIG. 10 shows that there is a free area β in the fourth divided area # 4.

FIG. 11 shows a process for preventing this. Step S15 shown in FIG. 4 is replaced by step S15-1, and in step S15-1, the transmission amount in the last frame is calculated by the previous transmission permission request amount. not b
Even if the continuous data transmission amount A is exceeded, the transmission data can be packed in the empty area β within the allocated amount of the station side device 20, thereby preventing the transmission efficiency from being deteriorated. The other steps are the same as those in FIG.

<Fourth Embodiment> By the way, as shown in FIG. 11, if the allocation amount of the optical line terminal 20 is packed into an empty area, the continuous data transmission amount A will be exceeded. The minimum guaranteed transmission amount cannot be guaranteed.
That is, if the above-mentioned stuffed transmission by the j-th subscriber side device occurs continuously and transmission is performed by the stuffing amount β, the minimum transmission amount of the other i-th subscriber side device is the minimum transmission amount = Upstream shared bandwidth capacity × ｛αi / (Σαi +
β)｝, which is smaller than the minimum guaranteed transmission amount.

FIGS. 12 and 13 show a data transmission process and a transmission permission request process according to the fourth embodiment for solving the above problems. In the transmission process shown in FIG. 12, steps S15 and S16 shown in FIG.
1. In the transmission permission request process shown in FIG. 13, steps S21 and S23 shown in FIG. 5 are replaced with steps S21-1 and S23, respectively.
Has been replaced by -1. Other processes are the same. The values in FIGS. 12 and 13 are shown below. α (0) = initial value of continuous transmission data amount A β (n) = data transmission amount in n-th allocation−α
(N) γ (n) = counter for managing the correction value of the continuous transmission data amount, and is the total sum of β (γ (0) = 0).

First, in step S15-1 shown in FIG. 12, the transmission amount in the last frame is packed in the free area β as the allocation amount of the optical line terminal 20. Next, the amount of transmitted data = the amount of transmitted data up to the previous time + the amount of data transmitted this time is calculated (step S16-1), and then the number of times of packing n is incremented (step S16-
2).

Next, β (n) = transmitted data amount− {α (0) −γ (n)} at the n-th time is calculated (step S16-3), and then γ (n + 1) = γ (n) + β ( n) is calculated (step S16-4). Next, the transmitted data amount is set to 0 (step S16-5), and the process is terminated.

In step S21-1 shown in FIG.
It is determined whether (α (0) −γ (n + 1)) ≧ transmitted data amount + untransmitted accumulated data amount, and if No, a =
(Α (0) −γ (n + 1)) − the transmitted data amount (step S23-1). Then, the transmission permission request amount in the last frame is set to a.

Finally, referring to FIG.
The assignment process of the (scheduling unit 23) will be described.
The values in FIG. 14 are shown below. The mask signal MASK
j = 1 indicates the subscriber-side device j for which transmission permission assignment has been completed.
Is a signal for preventing the assignment from being performed until the assignment of the transmission permission to the other subscriber's device is completed, whereby the transmission permission is sequentially transmitted to the plurality of subscriber's devices. be able to. i, j: subscriber device number (1 ≦ i, j ≦ subscriber device number y) REQ1j: request for permitting transmission of shared band from subscriber device j REQ2j: result of capturing REQ1j REQ3j: result of capturing REQ2j Result of masking with mask signal MASKj REQ3j = REQ2j and (not MASKj) RNDj: Number of transmission permission requests for divisional area from subscriber unit j # 1 to # 4: Divisional area per unit time x: Division currently assigned Area number (1 ≦ x ≦ 4)

The allocation process shown in FIG. 14 is executed once for each burst frame, and first, the subscriber unit j (= 1, 2 to 2)
When the transmission permission request REQ1j and the transmission permission request number RNDj are generated from y) (step S31), the division area number x is set to 1 (step S32). Next, the mask result REQ3j
Is determined to be all 0 (step S3).
3) If YES, proceed to step S34 and below, and if NO, proceed to step S38 and below. In step S34 and subsequent steps, first, the mask signal MASKj is set to all 0s.
To update the mask result REQ3j (step S3
4) Then, the request presence / absence check order is exchanged (step S35). Next, the transmission permission request REQ1j is fetched and REQ2j = REQ1j is set (step S36). Next, it is determined whether or not the mask result REQ3j is all 0 (step S36), and in the case of YES, this allocation processing is terminated,
On the other hand, in the case of NO, the process proceeds to step S38 and thereafter.

In step S38 and subsequent steps, the mask result REQ3
The one having the highest check order among j = 1 is assigned to the divided area #x (step S38), and then the number of transmission permission requests RNDj is changed to the continuous transmission permission request (transmission permission request number RNDj =
(4 or more) is determined (step S39). If the determination is No, the process proceeds to step S40. If the determination is Yes, the process jumps to step S43. Step S40
Then, the number RNDj of transmission permission requests is decremented by one, and then it is determined whether or not the number RNDj of permission requests = 0 (step S4).
1) If YES, proceed to step S42,
If NO, the process jumps to step S43. In step S42, the mask signal MASKj is set to 1 to update the mask result REQ3j, and then the division area number x is incremented by one (step S43). Next, it is determined whether or not the divided area number x> 4 (step S44). If NO, the process returns to step S33. On the other hand, if YES, the allocation process ends.

[0044]

As described above, according to the present invention, the continuous band of the shared band is transmitted until the subscriber unit transmits a continuous data transmission amount proportional to the contractual minimum guaranteed transmission capacity to the station unit. The transmission permission request is repeatedly transmitted for each frame, and when the continuous data transmission amount is reached, the end of the continuous transmission permission request is notified, and the optical line terminal sends the continuous transmission permission request to the subscriber side device that has received the continuous transmission permission request. Therefore, the transmission permission is transmitted continuously for each frame until the end of the continuous transmission permission request is notified, so that it is possible to cope with the contract between the station side and the subscriber side, and In addition, the capacity of the optical transmission line between the station and the subscriber can be effectively used.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of an STM-PDS transmission system according to the present invention.

FIG. 2 is a flowchart showing an uplink shared bandwidth control process of the subscriber unit of FIG. 1;

FIG. 3 is an explanatory diagram showing an example of execution timing of an uplink shared band control process of FIG. 2;

FIG. 4 is a flowchart showing the data transmission process of FIG. 2 in detail;

FIG. 5 is a flowchart showing a transmission permission request process of FIG. 2 in detail;

FIG. 6 is an explanatory diagram showing an example of a continuous data transmission amount;

FIG. 7 is an explanatory diagram showing an example of a continuous data transmission sequence.

FIG. 8 is an explanatory diagram showing an example of a shared band allocation process.

FIG. 9 is a flowchart illustrating a transmission permission request process according to the second embodiment in detail;

FIG. 10 is an explanatory diagram showing a case where a shared band has a free space when a continuous data transmission amount is reached;

FIG. 11 is a flowchart showing details of a data transmission process according to the third embodiment;

FIG. 12 is a flowchart illustrating details of a data transmission process according to the fourth embodiment;

FIG. 13 is a flowchart showing details of a transmission permission request process according to the fourth embodiment;

FIG. 14 is a flowchart showing details of an assignment process of the optical line terminal in FIG. 1;

[Explanation of symbols]

 10, 10-1 to 10-n subscriber-side device 20 station-side device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Mikito Sugiura 4-3-1 Tsunashima Higashi, Kohoku-ku, Yokohama-shi, Kanagawa Prefecture Inside Matsushita Communication Industrial Co., Ltd. (72) Kazuhiro Shinsako Tsunashima, Kohoku-ku, Yokohama-shi, Kanagawa Prefecture Matsushita Communication Industrial Co., Ltd. 4-3-1 Higashi (72) Inventor Junki Miki 2-3-1 Otemachi, Chiyoda-ku, Tokyo F-term (reference) 5K002 AA05 BA04 DA03 DA04 DA12 FA01 5K030 GA19 HA01 HB11 LA17 5K051 AA05 DD14 HH01

Claims (10)

[Claims] 1. A point-multipoint type bidirectional communication between an optical line terminal and a plurality of subscriber side devices via an optical transmission path based on a contract for a data transmission capacity.
In the TM-PDS transmission system, a request for permitting continuous transmission of a shared band for one frame is transmitted until the subscriber unit transmits a continuous data transmission amount proportional to the contractual minimum guaranteed transmission capacity to the station side device. Repeatedly transmitted every time, when the continuous data transmission amount is reached, the end of the continuous transmission permission request is notified, and the station apparatus receives the continuous transmission permission request to the subscriber side apparatus, An STM-PDS transmission system wherein transmission permission is continuously transmitted for each frame until the end of the continuous transmission permission request is notified. 2. After the subscriber unit notifies the station side device of the end of the continuous transmission permission request, if a transmission data remains, a transmission permission request is transmitted in a next frame; 2. The transmission apparatus according to claim 1, wherein, when the station apparatus receives the transmission permission request, transmission permission is transmitted to the subscriber apparatus when there is no transmission permission request from another subscriber apparatus. STM-PDS transmission system. 3. When the subscriber unit transmits last data having a capacity equal to or less than the capacity of the shared band, the subscriber apparatus requests the number of areas obtained by dividing the shared band, the number being capable of transmitting the required capacity. The STM according to claim 1 or 2, wherein
A PDS transmission system. 4. When the subscriber side device has reached the continuous data transmission amount and the shared band has a free space,
The STM-PDS transmission system according to any one of claims 1 to 3, wherein data is transmitted to the empty area. 5. When the subscriber unit transmits data to the empty area, a transmission permission request is subtracted from the continuous data transmission amount by the data transmission amount of the empty area when the next continuous data transmission is performed. 5. The transmission method according to claim 4, wherein the transmission is repeatedly performed for each frame until the transmission amount becomes smaller.
TM-PDS transmission system. 6. A point / multipoint type bidirectional communication between an optical line terminal and a plurality of subscriber side devices via an optical transmission line based on a contract for data transmission capacity.
In the subscriber unit of the TM-PDS transmission system, a request for permitting continuous transmission of a shared band for one frame is transmitted to the station side device until a continuous data transmission amount proportional to the contracted minimum guaranteed transmission capacity is transmitted. The subscriber-side apparatus repeatedly transmits the data each time, and notifies the end of the continuous transmission permission request when the continuous data transmission amount is reached. 7. A transmission means for transmitting a transmission permission request in the next frame when transmission data remains after notifying the station side apparatus of the end of the continuous transmission permission request. The subscriber-side device according to claim 6, wherein 8. When transmitting the last data having a capacity equal to or less than the capacity of the shared band, a request is made for the number of areas obtained by dividing the shared band, the number being capable of transmitting the required capacity. The subscriber device according to 6 or 7. 9. The method according to claim 6, wherein, when the continuous data transmission amount is reached, if there is a vacancy in the shared band, data is transmitted to the vacant area. Subscriber side equipment. 10. When data is transmitted to the empty area, a transmission permission request is sent for one frame until the amount of data transmission of the empty area is subtracted from the continuous data transmission amount when the next continuous data transmission is performed. 10. The subscriber-side device according to claim 9, wherein the transmission is repeated every time.