JP4519014B2 - Channel assignment method for optical network - Google Patents

Description

  The present invention relates to an optical network channel assignment method, and more particularly, to an optical network channel assignment method suitable for connecting a plurality of subscriber devices by branching a plurality of optical fibers in a receiving station.

  As one of the Internet providing methods, there is a PON (Passive Optical Network) method in which an optical network is constructed by branching one optical fiber into a plurality of pieces in order to effectively use an optical fiber.

  A channel allocation method based on a conventional station apparatus installation method in the PON system (hereinafter referred to as “PON system station apparatus installation method”) is provided with two optical interfaces each having 1 to 32 ch channels. FIG. 9 shows an example in which an optical fiber is wired from one station device to eight 16-branch splitters installed on the line so that 128 subscriber devices can be connected. explain.

  The first and second station devices 111 and 112 and the first to fourth two-branch splitters 121 to 124 are installed as equipment in the communication station, and the first to eighth 16-branch splitters 131 to 138 are installed. Install on the track.

  One optical fiber to which 1 to 32 ch of one optical interface (first optical interface) of the first station apparatus 111 is allocated is assigned to the first two-branch splitter 121 by the first allocated channel range. The optical fiber is branched into one optical fiber having 1 to 16 channels of the optical interface and one optical fiber having an assigned channel range of 17 to 32 channels of the first optical interface. Then, one optical fiber whose assigned channel range is 1 to 16 ch of the first optical interface is branched from the first core wire to the 16th core wire by the first 16 branch splitter 131. Further, one optical fiber whose assigned channel range is 17 to 32 ch of the first optical interface is branched from the first core wire to the 16th core wire by the second 16-branch splitter 132.

  One optical fiber to which channels 1 to 32ch of the other optical interface (second optical interface) of the first station apparatus 111 are assigned is assigned to the second two-branch splitter 122 so that the assigned channel range is second. The optical fiber branches into one optical fiber that is 1 to 16 ch of the optical interface and one optical fiber that has an assigned channel range of 17 to 32 ch of the second optical interface. Then, one optical fiber whose assigned channel range is 1 to 16 ch of the second optical interface is branched from the first core wire to the 16th core wire by the third 16-branch splitter 133. In addition, one optical fiber whose assigned channel range is 17 to 32 ch of the second optical interface is branched from the first core line to the 16th core line by the fourth 16-branch splitter 134.

  One optical fiber to which 1 to 32 ch of one optical interface (third optical interface) of the second station apparatus 112 is assigned is assigned to an assigned channel range of 1 to 16 ch by the third two-branch splitter 123. And one optical fiber having an assigned channel range of 17 to 32 ch. Then, one optical fiber whose assigned channel range is 1 to 16 ch of the third optical interface is branched from the first core wire to the 16th core wire by the fifth 16 branch splitter 135. In addition, one optical fiber whose assigned channel range is 17 to 32 ch of the third optical interface is branched from the first core wire to the 16th core wire by the sixth 16-branch splitter 136.

  One optical fiber to which channels 1 to 32 of the other optical interface (fourth optical interface) of the second station apparatus 112 are allocated is assigned to an allocated channel range of 1 to 16 by the fourth two-branch splitter 124. And one optical fiber having an assigned channel range of 17 to 32 ch. Then, one optical fiber whose assigned channel range is 1 to 16 ch of the fourth optical interface is branched from the first core wire to the 16th core wire by the seventh 16-branch splitter 137. In addition, one optical fiber whose assigned channel range is 17 to 32 ch of the fourth optical interface is branched from the first core wire to the 16th core wire by the eighth 16-branch splitter 138.

  Thus, in the channel allocation method based on the conventional method for installing the PON station apparatus, as shown in FIG. 10, the first optical interface 1 to 32 ch, the second optical interface 1 to 32 ch, the third 1 to 32 ch of the first optical interface and 1 to 32 ch of the fourth optical interface are all assigned to subscriber devices connected to the cores branched from the first to eighth 16-branch splitters 131 to 138, respectively. .

  That is, in the channel allocation method based on the conventional PON system station apparatus installation method, an optical network is constructed so that channels can be allocated from a plurality of station apparatuses to N × M subscriber apparatuses, respectively. From the beginning, a plurality of station devices are installed as equipment in the communication station, and channels are allocated to all N × M subscriber devices connected to M N branch splitters installed on the track. I am going to go.

In Patent Document 1 below, a device-side optical fiber optically connected to a transmission device is accommodated in a coupler so that an optical fiber can be efficiently and economically added in response to an increase in the number of users. The optical fiber branches into a plurality of external optical fibers via a station optical coupler housed in the section, and each of the optical fibers is routed to a distribution optical coupler housed in an optical junction box. In an optical transmission system in which a plurality of distribution optical fibers are branched by a distribution optical coupler and each of these distribution optical fibers is routed to a terminal, a plurality of types of station-side optical couplers having different branch numbers are provided in the coupler housing. An optical wiring method in which the number of distribution optical couplers and the number of branches that are optically connected to one transmission device via a station-side optical coupler are different depending on the number of branches of each station-side optical coupler. It is disclosed.
JP 2005-17519 A

  However, in the channel allocation method based on the above-described conventional PON system station apparatus installation method, a plurality of station apparatuses are installed in a communication station so that channels can be allocated to all N × M subscriber apparatuses. Since the equipment was installed from the beginning of the construction of the optical network, there was a problem that the initial investment of the equipment in the communication station building was large.

  An object of the present invention is to provide an optical network channel assignment method capable of greatly reducing the initial investment of equipment in a communication station building and the space for accommodating communication equipment.

The channel assignment method for an optical network of the present invention is installed as M N-branch splitters that can be connected to N × M subscriber devices, which are installed on a line, and as equipment in a communication station. (N × M) / x station devices whose number of channels that can be allocated is x, and (N × M) / x branch splitters having x / N branch numbers, The splitter and the station apparatus can be connected via the branch splitter, and at the beginning of constructing the PON optical network, there are fewer subscriber devices than the N × M number corresponding to the subscribers. Connected to the M N-branch splitters, only some of the (N × M) / x station devices are installed, and the station device and the subscriber device are connected. After constructing the PON optical network When the number of subscriber devices connected to the N-branch splitter increases as the number of subscribers increases, a new station device and branch splitter are installed as communication station equipment, and the station device and subscriber device Is a channel allocation method for an optical network in a PON optical transmission system for connecting PON, and at the beginning of constructing a PON optical network, the number is larger than the number of subscribers and in total (N × M) / (2 A number of station devices necessary for assigning channel numbers to only one subscriber device as a facility in the communication station, and L having a larger number of branches than x / N Installing at least the same number of L branch splitters as the station equipment having the number of branches as equipment in the communication station, and M N branch splitters connected to the subscriber equipment corresponding to the subscribers Connecting each station device and each L-branch splitter with an optical fiber, and connecting the L N-branch splitters different from each L-branch splitter with an optical fiber. Determining the number of connectable subscriber devices within the range of the number of channels that can be assigned to each N branch splitter by the station devices connected to each N branch splitter; Dividing the L N-branch splitters connected to each L-branch splitter into two groups, and for each group, from a number of y channels to z channels corresponding to the number of connectable subscriber units Channel numbers that are consecutive and do not overlap with the channel numbers of the other group are added to one N-branch splitter. It is characterized by comprising the steps of assigning the incoming device in ascending order from the y channel and assigning the subscriber device connected to the other N branch splitter in descending order from the z channel.
Here, after the PON type optical network is constructed, as the number of subscribers increases, a subscriber unit connected to at least one N branch splitter among the M N branch splitters can be connected. More than the number of subscriber devices that can be connected to other N branch splitters in the same group, and more than the number of subscriber devices that can be connected to the other N branch splitters. If there are free channels, it is possible to connect to the at least one N-branch splitter so that channel numbers can be assigned to the subscriber devices exceeding the number of connectable subscriber devices. A new subscriber device that can be connected by increasing the number of subscriber devices and reducing the number of subscriber devices connectable to the other N-branch splitter by the increased number of subscriber devices. Determining a number and, for subscriber devices that exceed the number of connectable subscriber devices connected to the at least one N-branch splitter, channel numbers to the at least one N-branch splitter. Assigning channel numbers in the order in which channel numbers are assigned to connected subscriber devices.
After the PON type optical network is constructed, as the number of subscribers increases, a subscriber device connected to at least one N branch splitter among the M N branch splitters can be connected. Or the (N × M) / x station devices installed together with the required number of station devices when the number of connectable new subscriber devices is exceeded. , Installing at least one other new station device, and installing at least the same number of (L / (multiple of 2)) branch splitters as the new station device installed together with the L branch splitter. The at least one N branch splitter is connected to the new station device via an optical fiber via the (L / (multiple of 2)) branch splitter instead of the L branch splitter. Flop and may include the step of assigning the all channel numbers of the subscriber device connected to at least one of the N branch splitters.
When all the (N × M) / x station devices are installed as communication station facilities by installing the new station devices, they are installed as communication station facilities. Of the branch splitters, a step of replacing a branch splitter other than the branch splitter having the x / N branch number with a branch splitter having the x / N branch number, and the exchanged x / N branch number. Assigning channel numbers to all subscriber devices connected to the N-branch splitter connected to the branch splitter.
When the (N × M) / x station devices are station devices having two optical interfaces having channel numbers that overlap each other, the number of x / N branches is x / 2N branches. The number of L branch splitters may be twice the number of the station devices.
When the (N × M) / x station devices are station devices having two optical interfaces having channel numbers that overlap each other, the number of x / N branches is x / 2N branches. The number of the L branch splitters may be twice the number of the station devices, and the number of the (L / (multiple of 2)) branch splitters may be twice the number of the station devices.

The optical network channel assignment method of the present invention has the following effects.
(1) Even when M N-branch splitters are installed on the line and N × M subscriber units are connected, the initial construction of the optical network is (N × M) / (multiple of 2). It is sufficient to install as many station equipment as necessary for allocating channels to only the subscriber equipment of the existing equipment as equipment in the communication station, greatly increasing the initial investment of the equipment in the communication station and the space for accommodating the communication equipment. Can be reduced.
(2) Allotting y consecutive channels out of x channels to subscriber units connected to one N branch splitter of M N branch splitters according to a predetermined allocation direction, The subscriber unit connected to one N-branch splitter transmits z (z is less than or equal to xy) of the remaining (xy) channels out of the x channels to the above-described channel. Even if it becomes impossible to assign a channel to a subscriber apparatus with y channels in the one N-branch splitter by assigning according to an assignment direction opposite to a predetermined assignment direction, the other one N An empty channel in the branching splitter can be delivered efficiently.

  At the beginning of the construction of the optical network, the initial investment of the equipment in the communication station building and the purpose of greatly reducing the communication equipment accommodation space are (N × M) / (2 of N × M subscriber devices). Multiple)) Only the number of station devices necessary for assigning channels to each of the subscriber devices is installed as equipment in the communication station, and one of the necessary number of station devices is installed. Assigning y consecutive channels of x channels to a subscriber device connected to one N branch splitter of M N branch splitters from a station device according to a predetermined assignment direction; The subscriber unit connected to the other one of the M N-branch splitters is connected to z of the remaining (xy) channels of the x channels (z is xy or less) This is realized by assigning subsequent channels according to an assignment direction opposite to a predetermined assignment direction.

Embodiments of an optical network channel assignment method according to the present invention will be described below with reference to the drawings.
An optical network channel allocation method according to an embodiment of the present invention includes 8 (M = 8) units installed on a line from two station apparatuses each including two optical interfaces each having 1 to 32 ch channels. The optical fiber is wired up to 16 branch splitters (N branch splitter: N = 16) so that 128 (= N × M) subscriber devices can be connected.

  In the channel assignment method for an optical network according to the present embodiment, 64 (= (N × M) / 2) subscriptions out of 128 (= N × M) subscriber units are initially constructed when the optical network is constructed. Only one station device necessary for assigning a channel only to each user device is installed as equipment in the communication station.

  That is, as shown in FIG. 1, station equipment 11 having first and second optical interfaces each having 1 to 32 ch channels, and first and second four-branch splitters as equipment in a communication station (L branch splitter: L = 4) 21 and 22 are installed.

  Then, one optical fiber to which channels 1 to 32 of the first optical interface of the station apparatus 11 are allocated is assigned by the first four-branch splitter 21 so that the allocated channel range is 1 to 8 channels of the first optical interface. One optical fiber, one optical fiber whose assigned channel range is 9 to 16 ch of the first optical interface, and one optical fiber whose assigned channel range is 17 to 24 ch of the first optical interface Then, the assigned channel range branches to one optical fiber having 25 to 32 ch of the first optical interface.

  One optical fiber whose assigned channel range is 1 to 8 ch of the first optical interface is branched from the first core wire to the 16th core wire by the first 16-branch splitter 31. One optical fiber whose assigned channel range is 9 to 16 ch of the first optical interface is branched from the first core line to the 16th core line by the second 16-branch splitter 32. One optical fiber whose assigned channel range is 17 to 24 ch of the first optical interface is branched from the first core wire to the 16th core wire by the third 16-branch splitter 33. One optical fiber having an allocated channel range of 25 to 32 ch of the first optical interface is branched from the first core line to the 16th core line by the fourth 16-branch splitter 34.

  In addition, one optical fiber to which channels 1 to 32 of the second optical interface of the station apparatus 11 are allocated is allocated to the channel range 1 to 8 of the second optical interface by the second four-branch splitter 22. One optical fiber, one optical fiber whose assigned channel range is 9 to 16 ch of the second optical interface, and one optical fiber whose assigned channel range is 17 to 24 ch of the second optical interface Then, the assigned channel range branches to one optical fiber having 25 to 32 ch of the second optical interface.

  One optical fiber whose assigned channel range is 1 to 8 ch of the second optical interface is branched from the first core line to the 16th core line by the fifth 16-branch splitter 35. One optical fiber whose assigned channel range is 9 to 16 ch of the second optical interface is branched from the first core wire to the 16th core wire by the sixth 16-branch splitter 36. One optical fiber whose assigned channel range is 17 to 24 ch of the second optical interface is branched from the first core wire to the 16th core wire by the seventh 16-branch splitter 37. One optical fiber having an allocated channel range of 25 to 32 ch of the second optical interface is branched from the first core line to the 16th core line by the eighth 16-branch splitter 38.

  In this case, although 16 subscriber devices can be connected to the first to eighth 16-branch splitters 31 to 38, respectively, the inputs of the first to eighth 16-branch splitters 31 to 38 are input. Since only 8 channels are assigned to each of the optical fibers connected to the side, the channel can only be assigned to only 8 subscriber devices. However, there is no particular problem because the number of subscribers is small at the beginning of the construction of the optical network.

  Thus, in the optical network channel assignment method according to the present embodiment, as shown in FIG. 2, the channels 1 to 32ch of the first optical interface of the station apparatus 11 are connected to the first to fourth 16-branch splitters. Assigned only to the subscriber devices connected to 8 of the 16 core wires branched from 31 to 34 (1st core wire to 16th core wire), respectively, as shown in FIG. As described above, the 16 core wires (the first core wire to the 16th wire) are branched from the first to 32nd channel channels of the second optical interface of the station apparatus 11 from the fifth to eighth 16 branch splitters 35 to 38, respectively. Each of them is assigned only to a subscriber unit connected to eight of the cores).

  Further, in the optical network channel assignment method according to the present embodiment, a subscriber unit connected to eight of the 16 cores branched from the first 16-branch splitter 31 includes a station. While the channels are assigned in the order of 1ch to 8ch of the first optical interface of the optical device 11, they are connected to 8 of the 16 cores branched from the second 16-branch splitter 32. Channels are assigned to the subscriber apparatus in the order of 16 ch to 9 ch of the first optical interface of the station apparatus 11. The subscriber apparatus connected to 8 of the 16 cores branched from the third 16-branch splitter 33 has channels 17 to 24 of the first optical interface of the station apparatus 11. On the other hand, the subscriber apparatus connected to eight of the 16 cores branched from the fourth 16-branch splitter 34 is assigned to the first of the station apparatus 11. Channels are assigned in the order of 32 ch to 25 ch of the optical interface.

  That is, as indicated by the arrows in FIG. 2, for the first optical interface of the station apparatus 11, the channel allocation direction allocated to the subscriber apparatus is reversed between 1-8ch and 9-16ch, and , 17-24ch and 25-32ch, the channel allocation direction allocated to the subscriber apparatus is reversed.

  Similarly, the subscriber apparatus connected to eight of the 16 cores branched from the fifth 16-branch splitter 35 is connected to 1ch of the second optical interface of the station apparatus 11. While the channels are assigned in the order of 8 channels, the subscriber apparatus connected to 8 of the 16 cores branched from the sixth 16-branch splitter 36 has the number of stations of the station apparatus 11. Channels are assigned in the order of 16 ch to 9 ch of the second optical interface. The subscriber apparatus connected to 8 of the 16 cores branched from the seventh 16-branch splitter 37 is connected to the second optical interface 17ch to 24ch of the station apparatus 11. On the other hand, the subscriber apparatus connected to 8 of the 16 cores branched from the eighth 16-branch splitter 38 is assigned to the second of the station apparatus 11. Channels are assigned in the order of 32 ch to 25 ch of the optical interface.

  That is, as indicated by the arrows in FIG. 3, the channel allocation direction allocated to the subscriber apparatus is reversed between 1-8 ch and 9-16 ch for the second optical interface of the station apparatus 11, and , 17-24ch and 25-32ch, the channel allocation direction allocated to the subscriber apparatus is reversed.

  Thereafter, for example, when the number of subscribers increases in the area where the first 16-branch splitter 31 is installed and more than 8 channels are required, 8 of the 16 core wires branched from the second branch splitter 32 are used. When 9 to 14 ch of 9 to 16 ch assigned to the core wire remain as unused channels (see FIG. 2), as shown in FIG. 4, for example, among the unused channels 9 to 14 ch, 9 to 12 ch are assigned to 1 to 8 ch to the remaining 4 cores of the 16 cores that are not assigned to the 16 cores branched from the first branching splitter 31. Allocation is performed in the same allocation direction (that is, the order of 9ch to 12ch). For the 16 core wires branched from the second branching splitter 32, only four channels 13 to 16ch can be assigned.

  As described above, the first and second 16 branches of the first optical interface of the station apparatus 11 are made by reversing the allocation directions of the channels allocated to the subscriber apparatuses in 1 to 8 ch and 9 to 16 ch. The channel can be easily transferred between the splitters 31 and 32.

  Similarly, for example, when the number of subscribers increases in the area where the fourth 16-branch splitter 34 is installed and 8 or more channels are required, 8 of the 16 core wires branched from the third branch splitter 33 are used. When 19 to 24 ch of 17 to 24 ch assigned to the core are left as unused channels (see FIG. 2), as shown in FIG. 4, of the unused channels 19 to 24 ch, For example, 22 to 24 ch are assigned to 3 to 3 of the remaining 8 cores of the 16 cores that are branched from the fourth branching splitter 34, and are assigned to 25 to 32 ch. Are assigned in the same assignment direction (that is, the order from 24 ch to 22 ch). For the 16 core wires branched from the third branching splitter 33, only five channels 17 to 21ch can be assigned.

  As described above, the third and fourth 16 branches are made by reversing the channel assignment directions assigned to the subscriber devices in the first optical interface of the station apparatus 11 in 17-24 ch and 25-32 ch. The channel can be easily transferred between the splitters 33 and 34.

  Thereafter, the number of subscribers increases in the area where the first and seventh 16-branch splitters 31 and 37 are installed, and 12 channels and 8 channels or more are required (that is, 128 subscriber units are required only for the station unit 11). 5), and the other stations having the third and fourth optical interfaces respectively having channels 1 to 32ch as shown in FIG. Device 12 and one optical fiber to which channels 32 to 32 of the third optical interface of other station devices 12 are assigned one optical fiber whose channel assignment range is 1 to 16 channels of the third optical interface. A first optical fiber for branching into one optical fiber whose channel allocation range is 17 to 32 ch of the third optical interface. Channel allocation range of the two-branch splitter 41 ((L / 2) branch splitter: L = 4) and one optical fiber to which channels 1 to 32ch of the fourth optical interface of the other station apparatus 12 are allocated. A second two-branch splitter 42 for branching to one optical fiber that is 1 to 16 ch of the fourth optical interface and one optical fiber that has a channel allocation range of 17 to 32 ch of the fourth optical interface ((L / 2) branch splitter: L = 4) is newly installed as equipment in the communication station.

  And, as shown by the dotted line in FIG. 5, the end of the optical fiber whose channel allocation range is 1 to 12ch of the first optical interface is removed from the first four-branch splitter 21, Connect to the newly installed first two-branch splitter 41. Similarly, the end of the optical fiber whose channel allocation range is 17 to 24 ch of the second optical interface is removed from the second four-branch splitter 22 and the newly installed first 2 Connect to branch splitter 41.

  Further, as shown in the bottom table of FIG. 6, the channel assignment range of the optical fiber that is disconnected from the first four-branch splitter 21 and connected to the first two-branch splitter 41 is represented by 1 to 1 of the first optical interface. 12 ch is changed to 1 to 16 ch of the third optical interface of another newly installed station apparatus 12. Similarly, the channel allocation range of the optical fiber disconnected from the second four-branch splitter 22 and connected to the first two-branch splitter 41 is for other newly installed stations from 17 to 24ch of the second optical interface. Change to 17 to 32 ch of the third optical interface of the device 12.

  Note that the first optical interface 1 to 12 ch of the station apparatus 11, which was the channel allocation range of the optical fiber removed from the first four-branch splitter 21, and the light removed from the second four-branch splitter 22. 17 to 24ch of the second optical interface of the station apparatus 11 that is the fiber channel allocation range is an empty channel as shown in the uppermost and middle table of FIG.

  Thereafter, the number of subscribers increases in the areas where the second, fourth, fifth and sixth 16-branch splitters 32, 34, 35 and 36 are installed, and 4 channels, 11 channels, 8 channels and 8 channels or more are required. Then, the following processing is performed.

  As shown by a dotted line in FIG. 7, for the fourth 16-branch splitter 34, the end on the communication station equipment side of the optical fiber whose channel allocation range is 22 to 32 ch of the first optical interface is Disconnect from the 4-branch splitter 21 and connect to the second 2-branch splitter 42. Similarly, for the fifth 16-branch splitter 35, the end of the optical fiber whose channel allocation range is 1 to 8 ch of the second optical interface on the communication station equipment side is removed from the second 4-branch splitter 22. To the second two-branch splitter 42.

  Further, as shown in the lowermost table of FIG. 8, the channel assignment range of the optical fiber that is disconnected from the first four-branch splitter 21 and connected to the second two-branch splitter 42 is defined as 22 to 21 of the first optical interface. The channel number is changed from 32 ch to 17 to 32 ch of the fourth optical interface of the other station apparatus 12. Similarly, the channel assignment range of the optical fiber that is disconnected from the second four-branch splitter 22 and connected to the second two-branch splitter 42 is changed from 1 to 8ch of the second optical interface to the first of the other station devices 12. It changes to 1-16ch of 4 optical interfaces.

  For the second 16-branch splitter 32, the channel allocation range of the optical fiber (indicated by a one-dot chain line in FIG. 7) connected to the second 16-branch splitter 32 is shown in the uppermost table of FIG. Thus, the first optical interface is changed from 13 to 16 ch to the first optical interface from 1 to 16 ch. Similarly, for the sixth 16-branch splitter 36, the channel assignment range of the optical fiber (shown by a one-dot chain line in FIG. 7) connected to the sixth 16-branch splitter 36 is shown in the second table of FIG. As shown in FIG. 9, the second optical interface is changed from 9 to 16 ch to the second optical interface from 1 to 16 ch.

  As a result, since only two optical fibers are connected to the 16-branch splitter in the first and second 4-branch splitters 21 and 22, a third and fourth 2-branch splitter (not shown) is newly added. The two optical fibers connected to the first four-branch splitter 21 are removed from the first four-branch splitter 21 and connected to the newly installed third two-branch splitter. The two optical fibers connected to the four-branch splitter 22 are disconnected from the second four-branch splitter 22 and connected to the newly installed fourth two-branch splitter.

  In addition, as shown in the uppermost table of FIG. 8, the channel allocation range of the optical fiber connected from the newly installed third two-branch splitter to the third sixteen-branch splitter 33 is changed to that of the first optical interface. Change from 17 to 21 ch to 17 to 32 ch of the first optical interface. Similarly, the channel assignment range of the optical fiber connected from the newly installed fourth two-branch splitter to the eighth sixteen-branch splitter 38 is changed from 25 to 32ch of the second optical interface to 17 of the second optical interface. Change to ~ 32ch.

In the above description, 64 (= (N × M) / 2) subscribers out of 128 subscriber units connected to 8 (M = 8) 16-branch splitters (N = 16). Initially, the first and second 4-branch splitters 21 and 22 were installed as equipment in the communication station so that channels were allocated only to the devices, but they can be serviced as described below. The number of new subscriber devices may be increased by a multiple of two.
(1) 64 (= (N × M) / (2 × 2)) subscriptions out of 256 subscriber units connected to 16 (M = 16) 16 branch splitters (N = 16) Instead of the first and second four-branch splitters 21 and 22, first and second eight-branch splitters are installed so that channels can be assigned only to the user devices.
(2) 64 of 512 subscriber devices connected to 32 (M = 32) 16 branch splitters (N = 16) (= (N × M) / (2 × 2 × 2)) Instead of the first and second four-branch splitters 21 and 22, the first and second 16-branch splitters are installed so that channels are assigned only to the subscriber devices.

  Further, the case where a 16-branch splitter is installed on the line has been described as an example. However, for example, when an 8-branch splitter and a 32-branch splitter are installed, N × M at the beginning of constructing an optical network in the same manner. Only the number of station devices necessary for allocating channels only to (N × M) / (multiple of 2) subscriber devices among the subscriber devices are installed as equipment in the communication station. You can just leave it.

  Furthermore, as shown in FIGS. 2 and 3, at the beginning of the construction of the optical network, the channel allocation range of the four optical fibers branched by the same four-branch splitter is set to 8 consecutive channels. , It does not have to be continuous.

  Furthermore, as shown in FIGS. 2 and 3, at the beginning of the construction of the optical network, the channel allocation range of the four optical fibers branched by the same four-branch splitter was set to 8 channels each. The number of channels in the channel allocation range of these four optical fibers may be changed according to the number of subscribers at the beginning of the construction of the optical network in the installed area.

  As described above, the channel assignment method for an optical network according to the present invention can be used, for example, to connect a plurality of subscriber devices by branching one optical fiber into a plurality of branches in a accommodating station.

FIG. 3 is a diagram for explaining an optical network channel assignment method according to an embodiment of the present invention; Example 1 It is a figure which shows the relationship between the 1st thru | or 4th 16 branch splitters 31-34 shown in FIG. 1, and an allocation channel range. Example 1 It is a figure which shows the relationship between the 5th thru | or 8th 16 branch splitters 35-38 shown in FIG. 1, and an allocation channel range. Example 1 The channel delivery between the first and second 16-branch splitters 31 and 32 shown in FIG. 1 and the channel delivery between the third and fourth 16-branch splitters 33 and 34 shown in FIG. 1 will be described. FIG. Example 1 It is a figure for demonstrating the change of the connection of an optical fiber, and the allocation channel range when another station apparatus is newly installed in the channel allocation method for optical networks by one Example of this invention. Example 1 It is a figure which shows the relationship between the 1st thru | or 8th 16 branch splitters 31-38 after the change shown in FIG. 5, and an allocation channel range. Example 1 It is a figure for demonstrating the change of the connection of an optical fiber, and the allocation channel range after newly installing another station apparatus in the channel allocation method for optical networks by one Example of this invention. Example 1 It is a figure which shows the relationship between the 1st thru | or 8th 16 branch splitters 31-38 after the change shown in FIG. 7, and an allocation channel range. Example 1 It is a figure for demonstrating the channel allocation method based on the installation method of the conventional apparatus for PON system stations. It is a figure which shows the relationship between the 1st thru | or 8th 16 branch splitters 131-138 shown in FIG. 9, and an allocation channel range.

Explanation of symbols

11 station apparatus 12 other station apparatuses 21, 22 4 branch splitters 31 to 38 16 branch splitter 41, 42 2 branch splitter

Claims (6)

M number of N-branch splitters that can be connected to N × M subscriber units installed on the track and the number of channels that can be allocated as equipment in the communication station are x (N (M) / x station devices and (N × M) / x branch splitters having x / N branches, and the N branch splitter and the station device are the branch splitters. Can be connected through
At the beginning of constructing a PON optical network, fewer than N × M subscriber devices corresponding to subscribers are connected to the M N-branch splitters, and the (N × M) / x units are connected. Install only some of the station devices, connect the station device and the subscriber device,
After building the PON optical network, as the number of subscribers connected to the N-branch splitter increases as the number of subscribers increases, a new station device and branch splitter are installed as equipment in the communication station. An optical network channel allocation method in a PON optical transmission system for connecting a station apparatus and a subscriber apparatus,
In the initial stage of constructing a PON optical network, channel numbers can be assigned to only one (N × M) / (multiple of 2) subscriber devices in addition to the number of subscribers. Installing the necessary number of station equipment as equipment in the communication station,
Installing at least the same number of L branch splitters as the station apparatus having the number of branches of L greater than x / N as the number of branches as the equipment in the communication station;
Installing M N-branch splitters connected to subscriber devices corresponding to subscribers on the line;
Connecting each station device and each L branch splitter with an optical fiber;
Connecting each of the L branch splitters to the L different N branch splitters by optical fibers;
Determining, for each N branch splitter, the number of connectable subscriber devices within a range of the number of channels that can be allocated by the station devices connected to each N branch splitter;
Dividing the L N-branch splitters connected to each L-branch splitter into two groups;
For each group, a channel number corresponding to the number of connectable subscriber devices from the y-channel to the z-channel and not overlapping with the other channel numbers is assigned to one N-branch splitter. Allocating in ascending order from the y channel to subscriber devices connected to, and assigning in descending order from the z channel to subscriber devices connected to the other N-branch splitter;
An optical network channel assignment method comprising the steps of: After constructing the PON optical network, as the number of subscribers increases, subscriber devices connected to at least one of the M N-branch splitters are connected to the connectable subscriber devices. The number of subscriber devices that can be connected to other N branch splitters in the same group exceeds the number of subscriber devices that can be connected to the other N branch splitter. If there are numbers,
Increasing the number of subscriber devices connectable to the at least one N-branch splitter so that channel numbers can be assigned to the subscriber devices exceeding the number of connectable subscriber devices; Reducing the number of subscriber devices connectable to other N-branch splitters by the increased number of subscriber devices to determine the number of new subscriber devices connectable;
For subscriber devices that exceed the number of connectable subscriber devices connected to the at least one N-branch splitter, channel numbers are assigned to subscriber devices connected to the at least one N-branch splitter. Assigning channel numbers in the order of assigning channel numbers to
The channel assignment method for an optical network according to claim 1, comprising: After the construction of the PON optical network, as the number of subscribers increases, a subscriber device connected to at least one N-branch splitter among the M N-branch splitters can be connected. Or when the number of new subscriber devices that can be connected is exceeded,
Installing at least one other new station device among the (N × M) / x station devices installed together with the required number of station devices;
Installing at least as many (L / (multiple of 2)) branch splitters as new station devices installed with the L branch splitter;
Connecting the at least one N branch splitter to the new station device via an optical fiber via the (L / (multiple of 2)) branch splitter instead of the L branch splitter;
Assigning a channel number to all of the subscriber devices connected to the at least one N-branch splitter.
3. The channel assignment method for an optical network according to claim 1, wherein the channel assignment method is for an optical network. When all the (N × M) / x station devices are installed as equipment in the communication station by installing the new station devices,
A step of replacing a branch splitter other than the branch splitter having the x / N branch number among the branch splitters installed as equipment in the communication station building with the branch splitter having the x / N branch number;
Assigning a channel number to all subscriber devices connected to the N-branch splitter connected to the branch splitter having the exchanged x / N branch number.
4. The channel assignment method for an optical network according to claim 3, wherein: When the (N × M) / x station devices are station devices having two optical interfaces having channel numbers that overlap each other, the number of x / N branches is x / 2N branches. 3. The channel assignment method for an optical network according to claim 1, wherein the number of the L branching splitters is twice as many as that of the station apparatus. When the (N × M) / x station devices are station devices having two optical interfaces having channel numbers that overlap each other, the number of x / N branches is x / 2N branches. The number of L branch splitters is twice as many as the station devices, and the number of (L / (multiple of 2)) branch splitters is twice as many as the station devices. An optical network channel assignment method according to claim 3 or 5.

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