Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02409220 2003-10-O1
OPTICAL FIBER CORDS
BACKGROUND OF THE INVENTION
This is a divisional application of Canadian Patent Application Serial No.
2,278,259 filed on July 21, 1999.
Field of the Invention
The present invention relates to an optical fiber distribution module for
connecting
or exchanging connections of mufti-core optical fibers, a single-fiber optical
cord and a
set-type optical fiber cords, and an optical fiber distribution system for
managing
operating information of a network connecting outdoor optical facilities with
optical
communication equipment in a telecommunication equipment center so that the
system
may be operated at its peak efficiency.
The subject matter of this divisional is directed to optical fiber cords
having a
sheathing with identifying marks and identifying colors. The subject matter of
the parent
application was restricted to an optical fiber distribution module, system and
board.
However, it should be understood that the expression "the invention" and the
like
encompasses the subject matter of both the parent and the divisional
application.
Description of the Related Art
Conventional optical fiber distribution modules have a connection board with
an
array of connector adaptors, and a holding board for storing those fiber cords
with
connector plugs that are not in use, and connections or switching requires the
following
three basic operations.
( 1 ) Connect a plug of a stored optical fiber cord to a desired adaptor on
the
connection board.
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(2) Change a connection by disconnecting a plug from the connection board and
connecting it to another adaptor.
(3) Disconnect a plug connected to an adaptor on the connection board and
store the
plug on the holding board.
However, when such operations are repeatedly performed, many fiber cords
become
tangled, such that
(1) Entangled cords are hard to handle and the effective length becomes too
short to
reach the desired location of the adaptor;
(2) The weight of many fiber cords hanging from each other tends to load the
fiber
cord to distort the shape of the optical fiber inside the cord; and
(3) The force applied to a fiber is transmitted to the connection section of
the plug
attached to the end of the cord to increase optical signal attenuation;
thus resulting in di~culty of achieving higher Eber density for the optical
fiber distribution
module.
Also, in some case, a set-type fiber cords, such as optical cable, are used
for
distribution of light signals on the fiber distribution board.
A set-type fiber cord is produced by bundling a plurality of fiber units, each
unit
containing several fiber cords.
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Such set-type fiber cords are given identifying markings to enable to identify
individual fiber cords within the cord unit, and such markings may be
imprinted directly on
the sheath for the cord, or indicated on a ring attached to the cord.
With the expansion of the optical fiber communication network, needs for
switching
the tangled fibers arise frequently, and a serious fiber congestion is
experienced in the
vicinity of the fiber sorting board, which is used to retain individual cords
of the set-type
fiber cords by the congregation of in-use fibers and not-in-use fibers which
are stored in the
holding board. Therefore, it is essential that individual fiber cords be
clearly identifiable,
particularly for the set-type fiber cords.
However, conventional set-type fiber cords allows identification of individual
fiber
cords within a given cord unit, but because the markings are the same for
different units, it
has been difficult to identify a particular fiber cord when the fiber units
are debundled.
Especially, when such set-type fiber cords are used for fiber distribution
purposes,
fiber connections and fiber switching are made to different locations on the
connection
board on the basis of individual fibers, the bundle must be released before
any particular
fiber can be connected or switched to a specific adaptor.
Also, in equipment centers in a high density optical network, external fibers
must be
connected to internal fibers within the center using fiber termination modules
(FTMs); and
a distribution system is used to mange such fiber connections inside the
centers.
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Some examples of conventional FTMs will be presented in the following.
In general, FTMs are installed at the connection points between outdoor
optical fiber
cables in the subscriber loops and the indoor optical fiber cables in the
central office.
Examples of the conventional FTMs are reported in references (N. Tomita et al;
"High-
Speed & High-Capacity Technologies of Optical Fiber Line Testing System",
TECHNICAL REPORT OF IEICE (T~ INSTTTUT E OF ELECTRONICS
INFORMATION AND COMMUNICATION ENGINEERS), CS95-50, pp59-66 ).
Figure 29 shows an example of the configuration of the center equipment
including
the conventional FTM. The system comprises: FTM 1; optical coupler 2; fiber
selector
(FS); test light introducing fibers 4 to the optical coupler 2; optical
splitter 5; center-side
optical filter 6; center communication equipment 7; center imaging equipment
8;
transmission equipment units 9; star coupler units 10; test equipment modules
11; test
instruments 12; fiber testing and equipment selection apparatus (FTES) 13; FS
master-side
optical fiber 14; fist indoor optical fiber cable 15; second indoor optical
fiber cable 16;
subscriber optical fiber cable 17; user-side optical filter 18; user-side data
terminating unit
19; and user-side image terminating unit 20.
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Figure 29 shows a communication service system used for transmission of data
and
images. To provide high reliability, the equipment centers are provided with
FTMs 1,
transmission equipment units 9, star coupler modules 10, and TEMs 11.
Center communication equipment 7 used for data communication operate on signal
light of a 1.3 pm band and a 1.55 ~cn band for imaging signals output from
center image
equipment 8 are injected in the star coupler module 10 through the first
internal fiber cable
15. The optical sputter 5 in the star coupler 10 wavelength multiplexes the
1.3 pm and 1.55
pm band signals, and wavelength multiplexed signal is distributed to a
plurality of output
ports. Signal light output from the ports of the splitter S is input in the
FTM 1 through the
second internal cable 16. Signal Iight input in the FTM 1 passes through the
optical coupler
2 which multildemultiplexes test light, and is wavelength multiplexed to user-
side data
terminating unit 19 and user-side image terminating unit 20 through the
subscriber cable 17,
to be delivered as data and image transmission service:
Tests to be conducted from the equipment center when installing or maintaining
optical cable will be explained in the following. The fiber selector 3 in the
fiber test
module 1 selectively couples test light splitting fibers 4 and the fiber
selector master-side
fiber 14 connected to the test apparatus 12 in the test equipment module 11.
The fiber
testing and equipment selection apparatus 13 in the FEM 11 selects the optical
pulse tester
in the test apparatus 12. By this process, test light from the optical pulse
tester is injected in
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the subscriber cable 17, and signal loss distribution measurements and problem
location
searching are performed.
When performing the tests, to prevent test light from entering in the user-
side data
terminating unit 19 and user-side image terminating unit 20, the user-side
optical filter 18
for blocking the test light and transmitting the signal light is disposed just
ahead of the user-
side data terminating unit 19 and the user-side image terminating unit 20.
Also, to prevent
test light and reflected light of the 1.55 pm band output from the center
image equipment 8
from entering in the center communication equipment 7, a center-side optical
filter 6 for
blocking test light and 1.55 pxn band light and transmitting the 1.3 pm signal
light is
disposed in the signal light input port.
Figure 31 shows an example of ~nfiguration of the conventional FTM 1, and
those
parts that correspond to Figure 29 are referred to by the same reference
numerals. The FTM
1 includes an excess cord length holder 21, and an excess cable length storage
shelves 22,
and on the left of FT'M 1, there. are optical couplers 2 in each shelf, and
the test light
splitting fibers 4 separated from each coupler 2 are connected to FS 3
disposed at the
bottom section. On the right side, there is an excess cable length storage
space having an
excess cable length holder 21 and an excess cable length shelves 22 for
storing excess cable
length of primarily second optical fibers 16.
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Figure 32 shows the structure of a connection section in the conventional FT'M
1,
and those parts that are the same as those in Figures 29, 30 are referred to
by the same
reference numerals. It includes: optical connector adaptor 23; optical
connector 24; single
core tape connection section 25. A single-core tape connection section 25 and
optical
connector 24 are attached to the optical coupler 2.
When transmission service is to be commenced, subscriber cable 17 and FS
master
side fiber 14 are connected to the coupler 2. Next, the optical connector 24
of the second
internal fiber cable 16 is connected to the optical connector adaptor 23
connected to the
coupler 2, thereby commencing transmission service.
With increasing access to optical network, more optical fibers are needed to
meet
the demand of subscribers, and the service centers are required to increase
the number of
cable per unit floor area in the center. Also, the cable connections are
closely meshed for
connecting center equipment modules (on-fiber- transaction modules, OLT,
modules), star
coupler modules and FTM modules. The congestion of cable presents serious
operational
and maintenance problems.
Also, the lengths of the second internal cable 16 for connecting from the
excess
cable length assigning holder 21 to the optical coupler 2 are not uniform,
excess cable
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length is inevitably created for the second internal cable 16, and a high
cable density in the
FTM cannot be achieved without solving the problem posed by excess cable
length.
In the conventional FTM, the excess cable length holder 21 and excess cable
length
storage shelves 22 are used to store excess lengths of second internal cable
16. For new
installations and repair of existing optical network, in-use fibers must be
separated and
untangled from other fibers for switching and connecting operations, and this
aspect of the
operation was extremely laborious and time-consuming.
SUMMARY OF TIC INVENTION
It is a first object of the present invention to provide an optical fiber
distribution
module that can prevent cord tangling caused by repeated
connection/disconnection so that
more fiber cords can be introduced to the module to accommodate high density
of
connecting fibers.
A second object is to provide a cord unit that enables to identify individual
cords
within a cord unit and a set-type fiber cable based on a group of such fiber
cords.
A third object is to provide optical fiber distribution system to enable
efficient fiber
distribution and switching while providing high density optical fiber cables
for the central
office as well as for the users.
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These objects are enabled by using an optical fiber distribution module
comprised
by: a connection board with an array of optical connector adaptors for
connecting in-use
optical fiber cords, and a storage section for storing not-in use optical
fiber cords, wherein a
plurality of cord sorting boards having a plurality of fiber cord passageways
for
accommodating and retaining at least one optical fiber cord is arranged
between said
connection board and said storage section.
The board sorts a pluality of fiber cords in groups so that in-use cords can
be
separated by not-in-use cords.
Also, because the load on the cords is suitably supported, tangling of cords
is
prevented and other fiber cords are protected from being loaded.
Accordingly, high density fibers can be achieved without introducing signal
distortions.
Further, because the sorting board prevents cord tangling, work efficiency of
fiber
connecting and switching operations is improved, and the fiber density on the
board can be
increased by using miniature connector adaptors and fine fiber cords withe
miniature plugs.
These improvement would contribute significantly to the future expansion of
optical
networks.
An optical fiber cord to be used for the distribution board is provided with
identifying marks and identifying colors provided on a sheathing.
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More specifically, the present invention provides an optical fiber cord,
comprising
an optical fiber cord, and a sheathing for covering the optical fiber cord,
wherein
identifying marks and identifying colors are provided on the sheathing, and
the identifying
marks are comprised of one of digits, letters and a combination of digits and
letters such
that the marks are oriented along the sheathing, and neighboring marks
separated at a
given spacing are inverted relative to one another.
The present invention also provides an optical fiber cable or a set-type
optical fiber
cord comprising a plurality of cord units, each of the cord units having a
plurality of
optical fiber cords, each of the optical fiber cords comprising an optical
fiber cord, and a
sheathing for covering the optical fiber cord, wherein identifying marks and
identifying
colors are provided on the sheathing, and the identifying marks comprise one
of digits,
letters and a combination of digits and letters such that the marks are
oriented along the
sheathing, and neighboring marks separated at a given spacing are inverted
relative to one
another, wherein the identifying colors provided on the sheathing are
different for
different cord units, and the identifying marks are different at least within
a given cord
unit.
The present invention also provides an optical fiber cord, comprising an
optical
fiber cord, a sheathing for covering the optical fiber cord, and an 1D tag
attached to the
sheathing, wherein identifying marks and identifying colors au-e provided on
the >D tag.
The present invention also provides an optical fiber cable or a set-type
optical fiber
cord comprising a plurality of cord units, each of the cord units having a
plurality of
optical fiber cords, each of the optical fiber cords comprising an optical
fiber cord, a
sheathing for covering the optical fiber cord, and an ID tag attached to the
sheathing,
wherein an identifying mark and an identifying color are provided on the
sheathing and on
the ID tag, and the identifying color provided on the sheathing is different
for different
cord units, and the identifying mark on the sheathing is different at least
within a given
cord unit.
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The set-type fiber cords is comprised by bundling a group of such cords, and
said
identifying colors provided on said fiber cords are different for different
cord units, and said
identifying marks are different at least within a given cord unit.
Therefore, by differentiating different cord units by different color dots
given to the
fiber cords, and differentiating each fiber cord in a given cord unit by
different numeric
identifying marks, even if the sheath is removed or the cord units are
debundled, fiber cords
in a desired cord unit can be identified clearly among the many cords,
according to the
identifying color dots, and a desired fiber cord, containing the target fiber,
can be identified
among the many fiber cords on the basis of the numeric identifying marks.
Thus, the
efficiency of working on the fiber distribution board is significantly
improved, and fiber
switching service to the subscriber can be provided quickly and correctly to
enhance future
development of optical communication technology.
The distribution board and the cord units of the present invention are most
effectively used in an optical fiber distribution system comprised by: a
center-side
terminating section for terminating a plurality of first fiber cables
connected to center
terminal equipment; a user-side terminating section for terminating a
plurality of second
fiber cables connected to a plurality of subscriber terminal equipment; a
cross connecting
section for switching any optical fiber of said first fiber cable with any
optical fiber of said
second fiber cable; a fiber distributing section for connecting any optical
fiber from said
center-side terminating section to said cross connecting section; and a fiber
distribution
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module having a test accessing section for operating said first fiber cable
and said second
fiber cable, and a fiber switching section for switching input/output ports
for operating said
test accessing section.
The present optical fiber distribution system enables to organize the internal
cables
in the equipment center for efficient management of providing communication
services by
preventing congested fiber passages.
BRIEF DESCRIPTIONS OF THE DRAWINGS
Figure 1 is a perspective view of a fiber distribution board in Embodiment 1.
Figure 2 is a perspective view of a sorting board in Embodiment 1.
Figure 3 is a perspective view of another sorting board in Embodiment 1.
Figure 4 is a perspective view of still another sorting board in Embodiment 1.
Figure 5 is an external view of a fiber cord in Embodiment 2.
Figure 6A,, 6B are schematic representations of set-type fiber cords based on
the
fiber cord shown in Figure 5.
Figure 7 is a front view of a fiber distribution board for the set-type fiber
cords
shown in Figure 6.
Figure 8 is an external view of a variation of the fiber cord in Embodiment 2.
Figure 9 is an external view of another variation of the fiber cord in
Embodiment 2.
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Figure 10 is an external view of yet another variation of the fiber cord in
Embodiment 2.
Figure 11 is an external view of still another variation of the fiber cord in
Embodiment 2.
Figure 12 is an external view of further variation of the fiber cord in
Embodiment 2.
Figure 13 is an external view of still further variation of the fiber cord in
Embodiment 2.
Figure 14 is an external view of yet further variation of the fiber cord in
Embodiment 2.
Figure 15 is a schematic diagram of the equipment configuration in a center of
optical fiber distribution system in Embodiment 3.
Figure 16 is an illustration of the distribution system and the connection
with other
equipment inside the center in Embodiment 3.
Figure 17 is an illustration of the system in Example 3, Embodiment 3.
Figure 18 is an illustration of the system in Example 3, Embodiment 3.
Figure 19A 19E are illustrations of the fiber jumper method of fiber switching
in
Embodiment 3.
Figure 20 is a front view of a part of the connection board in Example 9,
Embodiment 3.
Figure 21 is a schematic diagram of the system in Example 9, Embodiment 3.
Figure 22 is a schematic diagram of the system in Example 10, Embodiment 3.
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Figure 23 is a schematic diagram of the system in Example 10, Embodiment 3.
Figure 24A, 24B are schematic diagrams of a splitting jumper section in the
system
in Example 10, Embodiment 3.
Figure 25A, 25B are schematic diagrams of a non-splitting jumper section in
the
system in Example 10, Embodiment 3.
Figure 26 is a schematic diagram of the system in Example 11, Embodiment 3.
Figure 27 is a schematic diagram of the system in Example 12, Embodiment 3.
Figure 28 is a schematic diagram of the system in Example 13, Embodiment 3.
Figure 29 is a block diagram of a center based on the conventional FTM.
Figure 30 is an illustration of a center based on the conventional equipment.
Figure 31 is a front view of the conventional FTM with optical couplers and
FS.
Figure 32 is a perspective view of the connection section of a conventional
FTM.
i
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments will be presented with reference to the drawings for
three
groups of embodiirients: ~in Embodiment 1, examples are related to optical
fiber distribution
modules; in Embodiment 2, examples are related to types of fibers and groups
of fibers and
their identification means; in Embodiment 3, examples are related to optical
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communication systems using the fiber distribution boards and cable presented
in
Embodiments 1 and 2.
Embodiment 1
Figure 1 shows a configuration of an optical fiber distribution module in
Embodiment 1, and includes a distribution MODULE 101, a connector board 102, a
holding board 103 disposed in a separate location of the MODULE, an optical
fiber cords
104 having a connector plug 105 at one end, a trunk entry section 106 for
admitting optical
fiber cords 104 (or fiber cable) into the MODULE 101, a cord sorting board 107
disposed
between the connector board 102 and the holding board 103.
The connector board 102 is an array of optical connector adaptors 108 for
making
plug-to-plug connection of optical connector plugs 105. The holding board 103
has a
plurality of engaging sections (not shown) for engaging the connector plugs
105, and is
used to hold those cords 104 that are drawn in through the trunk entry section
106 but are
not being used.
The cord sorting board 107 is an array of sorting clips 110 arranged
vertically on the
sorting clip attachment frame 109.
Figure 2 shows details of the sorting clips 110, each clip being u-shaped, and
each
right and left arm members 111, 112 has respective fiber cord entry/exit
passageways 113,
114 for receiving/retaining at least one fiber cord in approximately
horizontal position. Slot
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openings (or open/close type slots) 113a, 114a are formed contiguously with
the
passageways 113, 114 to enable inserting or disconnecting the fiber cord 104
in the cord
passageways 113, 114.
It means that the cord sorting board 107 has a plurality of fiber cord
passageways
113, 114 arranged in a vertical array.
In this configuration, all the fiber cords 104 drawn from the trunk entry
section 106
into the distribution MODULE 101 are passed through suitable cord entry
passageway 113
on the cord sorting board 107, and the fiber cords 104 that are to be
connected (in-use) are
passed through the cord exit passageway 114 and are looped towards the
connector board
102 to be connected to the connector adaptor 108. On the other hand, those
fiber cords 104
that are to be stored are not inserted into the cord exit passageway 114 and
are looped
towards the holding board 103 to be stored as spare cords.
When a fiber cord 104 held in the holding board 103 is to be connected, the
connector plug 105 is disengaged from the engaging device on the holding board
103, and
the fiber cord 104 is manually pulled in the vicinity of the cord sorting
board 107 and after
disentangling from other cords, and the connector plug 105 is connected to a
desired
connector adaptor 108 on the connector board 102. The newly connected fiber
cord 104 is
inserted through the slot opening 114a into the cord exit passageway 114.
In a similar manner, any fiber cord 104 that is connected to the connector
board 102
can be switched to other connector adaptor 108 or removed to the holding board
103.
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The design of assigning the fiber cords 104 from one cable in one sorting clip
110,
fiber cords in one cable can be separated from those in other cable, and
tangling of fiber
cords 104 can be prevented. Also, by providing many sorting clips 110 to a
cord sorting
board 107, cords are not subjected to undue stresses, and consequently light
transmission
quality of the fibers can be maintained so that, compared with the MODULES of
conventional designs, more cable can be stored thus increasing the density of
fiber cords in
the distribution board.
Figure 3 shows another example of the sorting board. In this design, the exit
arm
121 of the sorting clip is provided with two exit passageways. The sorting
clip 120 is u-
shaped, and the entry arm 121 has the same entry passageway 123 while the
opposing exit
anm 122 has two exit passageways 124, 125. Slot openings 123a, 124a, 125a are
provided
contiguously to reach the cord passageways 123, 124,125.
In this configuration, all the fiber cords 104 drawn into the distribution
MODULE
101 from the trunk entry section 106 are passed through suitable cord entry
passageway
123, and of the fiber cord 104, those that are to be connected (in use) are
passed through the
first cord exit passageway 124 and are looped towards the connector board 102
to be
connected to the connector adaptor 108. On the other hand, those fiber cords
104 that are to
be stored are passed through the second cord exit passageway 125 and are
looped towards
the holding board 103 to be stored as spare cords.
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When a fiber cord 104 held in the holding board 103 is to be connected, the
connector plug 105 is disengaged from the engaging device on the holding board
103, and
the fiber cord 104 is manually pulled in the vicinity of the cord sorting
board 107 until the
connector plug 105 reaches the location of the second cord exit passageway
125, and after
disentangling from the bunched cords, the cord 104 is removed from the second
cord exit
passageway 125 through the slot opening 125x, and then the connector plug 105
is
connected to a desired connector adaptor 108 on the connector board 102. The
fiber cord
104 is inserted through the slot opening 124a into the first cord exit
passageway 124.
In a similar manner, any fiber cord 104 that is connected to the connector
board 102
can be switched to other connector adaptor 108 or removed to the holding board
103.
Figure 4 shows another example of the sorting board, which is shaped as a
frame,
and the cords enter the distribution MODULE from the rear of the frame, and
exit to the
front of the frame. A sorting clip 130 has a cord entry frame 131, which has a
cord entry
passageway 133, and an opposing cord exit flame 132 has cord exit passageways
134,135.
Slot openings 133a, 134a, 135a are provided respectively for the passageways
133, 134,
135.
In this example, the cord exit passageways 134, 135 correspond to the first
and
second cord exit passageways 124,125 shown in Figure 3, and their
function/effects are the
same as those presented for Figure 3.
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Optical fiber cords that can be used with the sorting board include those
optical fiber
cords that connect to optical component parts. In such a case, a number of
cords that
connect various component parts can be bundled into one cable and arranged
using the
sorting board to achieve the same operation.
As explained above, by using the sorting board for connection and switching of
connection, optical fiber cords are prevented from becoming tangled, and those
cords in use
can be clearly separated from those cords that are in storage. Therefore, even
if connecting
and switching are repeated many times, tangling of fiber cords can be avoid.
Embodiment 2
Embodiment 2 presents optical fiber cords and a fiber cord bundles that
include a
number of fiber cords.
Figure 5 shows an example of the external appearance of an optical fiber cord
210
and Figure 6 shows examples of type of fiber cord bundles in Embodiment 2, and
Figure 7
shows a view of the connections made in the distribution MODULE by using the
set-type
fiber cords shown in Figure 6.
As shown in Figure 5, an optical fiber cord 210, having an optical fiber
packaged
inside, is identified by numeric identifying marks 212 imprinted along the
longitudinal
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sheath 211 at a suitable spacing (preferably about 2050 mm apart). These marks
212
consist of two digits and are imprinted transversely in such a way that each
pair of digits is
inverted with respect to its neighboring pair. Also, identifying color dots
213 are imprinted
on the sheath 211 at a suitable spacing (preferably about 2050 mm apart) in
the
longitudinal direction at a suitable spacing (preferably about 2050 mm apart).
Several such optical fiber cords 210 are bundled to form a cord unit 300, as
shown
in Figure 6, and such cord units are bundled to form a fiber cord set 310
(refer to Figure
6A), or a fiber cable 320, which is a fiber cord set 310 encased in a sheath
321 (refer to
Figure 6B).
Therefore, by differentiating different cord units 300 by different color dots
213
given to the fiber cords 210, and differentiating each fiber cord 210 in a
given cord unit 300
by different numeric identifying marks 212, even if the sheath 321 is removed
or the cord
units 300 are debundled, fiber cords 210 in a desired cord unit 300 can be
identified clearly
among the many cords 210, according to the identifying color dots 213, and a
desired fiber
cord 210, containing the target fiber, can be identified among the many fiber
cords 210 on
the basis of the numeric identifying marks 212.
The fiber distribution board and the coded fiber cords 210, shown in Figure 7,
are
used in the following manner to achieve quick fiber switching. Cable 320 are
brought into
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the board, and in-use fiber cord sets 310 are routed to external service side
while not-in-use
fiber cord sets 310 in the same cable 320 are stored in the holding board 204.
The in-use
fiber cords 210 in a fiber cord set 310 are extended and individually plugged
into the
connection board 202 of the fiber distribution board 201 while retaining the
fiber cords 210
from the same fiber cord set 310 in the sorting board 203. When a fiber on the
connected
board 210 is to be switched, a desired core fiber among the many fiber cords
210 can be
ident~ed quickly according to the color dots 213 and numeric identifying marks
212.
Thus, the efficiency of working on the fiber distribution board 201 is
significantly
improved, and fiber switching service to the subscriber can be provided
quickly and
correctly to enhance future development of optical communication technology.
Also, as shown in Figure 5, because the color dots 213 and numeric identifying
marks 212 are repetitively imprinted along the longitudinal sheath 211 of each
fiber cord
210, each cord can be identified at any point along the length of the cord.
Also, as shown in Figure S, because the color dots 213 and numeric identifying
marks 212 are imprinted transversely and every other marks 212 are inverted, a
desired cord
210 can be identified visually from any angle of view of the worker.
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Further, in the present embodiment, although the color dots 213 are imprinted
on the
cord 210 longitudinally, but as shown in Figure 8, a fiber cord 220 may have a
longitudinally extending color fiber 223 imprinted on the sheath 211.
Also, as shown in Figure 9, a fiber cord 230 may have color patches 213 and
numeric identifying marks 212 imprinted transversely (preferably at two
equidistant
locations) or, as shown in Figure 10, a. fiber cord 240 may have color fibers
223 and
numeric identifying marks 212 imprinted transversely (preferably at two
equidistant
locations). Such fiber cords 230, 240 can be easily identified visually even
if they become
twisted in use.
Also, the fiber cord 210, 220 are easily identified from any direction by
having
inverting numeric identifying marks 212 that are right side up and transverse
to the sheath
211, but as shown in Figure 11, fiber cords 250, 260 may numeric marks 252
that are
arranged on a fiber along the sheath 211 and neighboring digits are inverted
so that each
fiber cord can be identified visually from any longitudinal direction.
In the foregoing examples, color dots 213 and color fiber 223 are imprinted
along
the sheath 211, but other arrangements for identification are possible, for
example, as
shown in Figures 13, 14. Such fiber cords 270, 280 have a sheath 271 made of a
colored
polymeric resin for identification.
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Also, in the present embodiment, fiber cord 210 has numeric identifying marks
212
consisting of two digits on the sheath 211, but alpha-numeric marks can be
used on the
sheath for identification purposes.
Also, it is sufficient that the numeric identification (ID) marks 212 are
different
within a given fiber unit 300, but the fiber cords in all the fiber units may
be given different
IDs.
Embodiment 3
Embodiment 3 presents various examples of the optical fiber distribution
system of
the present invention.
Example 1
Figure 15 shows a configuration of an equipment center that includes an
integrated
fiber distribution system, and Figure 16 shows a method of connecting the
integrated fiber
distribution system with other equipment within the equipment center.
The integrated distribution module 401 includes: an optical coupler 402;
optical
fiber selection device (FS) 403; center communication equipment 407; center
CATV
equipment 408; center equipment frame 409; star coupler frame 410; test
equipment
module (TEM) 411; first internal cable 415; subscriber cable 417; test
accessing section
426; cross connecting section 427; splitting section 428; fiber distributing
section 429;
CA 02409220 2002-11-28
23
optical fiber switching section 430; portable terminal 431; intermediate
distribution
managing section 432; integrated distribution managing section 433; data
communication
network 434; external equipment operating systems 435; integrated distribution
module
(IDM) 436; fiber distribution managing section 437 for managing distribution
information,
components information and circuit information within the IDM; equipment
interface 439;
test equipment selecting section 471 for selecting optical testing section,
monitoring section
or optical power comparing section; fiber testing section 472 for testing
fibers in cable;
monitoring section 473 for testing signal light and test light; optical power
comparing
section 474 for comparing optical fibers; center-side terminating section 480;
and user-side
terminating section 481.
The first internal cable 415 extending from the center equipment termination
unit
center equipment is connected to the first terminal of the integrated
distribution module
401, and the subscriber cable 417 is connected to the second terminal of the
integrated
distribution module 401. The integrated distribution module 401 is connected
to TEM 411
through the equipment interface 439.
The fiber distributing section 429 distributes the first internal cable 415 to
a number
of cross connecting sections 427 and splitting sections 428 provided in the
IDM 436. The
splitting section 428 distributes signal light from the center communication
equipment 407;
408 to several output ports. The cross connecting section 427 switches any
optical fibers of
CA 02409220 2002-11-28
24
fiber distributing section 429 and splitting section 428 to any optical fibers
of second fiber
cable 417. The test accessing section 426 injects light into optical fibers in
the first internal
cable 415 and the second fiber cable 417. The fiber switching section 430
selects
input/output ports for the test accessing section 426.
The integrated distribution module 401 of such a design enables not only to
integrate several separate functions that exist in the conventional system,
but also simplifies
the distribution paths within the equipment center by newly providing the
fiber distributing
section 429, and achieves economy in equipment by integrating various
functions.
In other words, as explained with reference to Figure 29, in the conventional
design,
a plurality of signal paths exist in the internal fiber distribution
connecting the OLT module
9, a star coupler frame 10 and FTM 1. Therefore, a large number of first and
second
internal fiber cable 416, 415 is required, resulting in serious cable
congestion. In contrast,
in the examples shown in Figures 15,16, the fist internal cable 415 from the
OLT frame
409 is totally accommodated in the fiber distributing section 429 of the mM
436, enabling
simpler connections based on multi-fiber first internal cable 415. Also,
inside-center
connections between the star coupler 10 and FTM 1 in the conventional design
are
integrated within the mM 436 in the present design, and are under the
management of the
integrated distribution module 401.
CA 02409220 2002-11-28
Example 2
In this example, the optical fiber switching section 430 is connected to test
equipment module 411 comprised by fiber testing section 472, monitoring
section 473,
optical power comparing section 474 and test equipment selecting section 471
for selecting
the optical testing section, monitoring section or power comparing section.
The fiber
testing section 472 has a capability of monitoring the signal light and test
light, and the
optical power comparing section 474 has a capability of comparing optical
fibers. This
system design enables to test the quality of newly installed subscriber cable
417 and
maintenance of existing cable.
Example 3
Figures 17,18 show a system comprised by: a base module 440 of IDM 436;
addition modules 44I of 1DM 436; test accessing unit 442; sorting board 443;
holding
board unit 444; coupling fibers 445; fiber distribution unit 446; connection
board 447;
internal cable fixatioa section 448; holding board 449; and third internal
cable 450.
The IDM base module 440 of the )DM 436 is comprised by: test accessing section
426; cross connecting section 427; splitting section 428; fiber distributing
section 429; fiber
switching section 430. The addition module 441 is comprised by: test accessing
unit 426;
cross connecting section 427; splitting section 428; and optical fiber
switching section 430.
The test accessing unit 442 is comprised by: test accessing section 426; and
fiber switching
CA 02409220 2002-11-28
26
section 430, and the cross connecting section 427 is comprised by coupling
fibers 445 and
connection board 447; and the fiber distribution unit 446 has a capability of
connecting one
IDM base module 440 to a plurality of addition modules 441. By including the
addition
module 441 in the design, it becomes possible to maintain the managing
capability of
optical fiber distribution functions regardless of increases in the number of
core fibers in the
cable.
Fiber switching is carried out by the cross connecting section 427 in
conventional
IDM 436, but, in this case, this is achieved by switching the coupling fibers
445 connected
to the connection board 447. Because the number of cores that can be
accommodated in the
conventional FTM is limited, there is possibility of encountering some
switching events
that cannot be handled within a single FTM, but in the present example, such a
problem
does not arise because the inside-center optical fibers are managed totally by
the integrated
distribution module 401.
Also, in the present example, the fiber distributing section 429 is able to
switch
fibers beyond the cross connecting section 427, so that any fiber connections
between the
subscriber data terminal device 407 and the subscriber cable 417, as well as
any
connections between the center CAT'V equipment 408 and the subscriber cable
417 can be
selected and connected freely. Also, because the star coupler unit 10 and FTM
1 are
CA 02409220 2002-11-28
27
integrated in the present system, the space requirement is lessened, and the
density of core
fibers that can be accommodated within the center can be increased.
Figure 18 shows a method for connecting the IDM 436 of the present
distribution
system to various conventional equipment within the center. Conventional FTM 1
is
connected to the optical multi/demultiplexer in the star coupler frame 410
through the
second internal fiber cable 416, and the star coupler frame 410 is connected
to the fiber
distribution unit 446 in the IDM base module 440 through the third internal
fiber cable 450.
The present system incorporates conventional inside-center equipment so that
the
integrated distribution module 401 is able to offer total control including
those internal fiber
cable connecting conventional inside-center equipment, thereby simplifying the
distribution
system inside the equipment center, and avoiding fiber congestion of data
fibers inside the
center.
Example 4
In this system, the fiber distribution managing section 437 is provided with
the
portable terminal 431, intermediate distribution managing section 432 and
integrated
distribution managing section 433. The intermediate distribution managing
section 432 has
databases to manage distribution information inside the IDM 436, components
information
and circuit information, and has a capability to command fiber switching
tasks. The
CA 02409220 2002-11-28
28
portable terminal 431 has a capability to exchange information on work content
(such as
fiber switching) by referencing the databases in the intermediate distribution
managing
section 432, and provides support to the workers performing the task of fiber
switching.
The integrated distribution managing section 433 compiles and manages
distribution
information from a plurality of intermediate distribution managing sections
432, and
manages connections to external operating systems 435. The fiber distribution
managing
section 437 of the present system enables effective management of equipment
information
and interfacing with external operating systems 435, as well as provide
operational support
to workers carrying out operational tasks.
Example 5
In this system, the cross connecting section 427 uses a sorting board based on
the
jumper method. Figure 19 shows the system configuration which includes:
optical
connector adaptor 423; optical connector 424; sorting board 443; coupling
fibers 445;
connection board 447; holding board 449; cord stopper 451; and excess length
storage
section 454.
A method of switching of coupling fiber 445 on the sorting board 443 will be
explained in the following. The coupling fibers 445 are supported loosely on
the sorting
board 443 so as to permit sliding so that the excess cord length of the
coupling fibers 445 is
stored in the excess length storage section 454 provided in the front and back
surfaces of
CA 02409220 2002-11-28
29
the system apparatus. When fiber switching is required, and even if there is a
long excess
length of coupling fiber 445, the optical connector 424 can be pulled right up
to the front of
the sorting board 443, so that the required work can be carried out
effectively and with
visual confirmation. Switching of the coupling fiber 445 is carned out by
disconnecting the
optical connector 424 of the coupling fiber 445 inserted in the first optical
connector
adaptor 423 on the connection board 447 and inserting into the second optical
connector
adaptor 423 provided on the connection board 447.
Figure 19A shows a schematic representation of the optical connector 424 of
the
coupling fiber 445 coupled on the first optical connector adaptor 423. In
Figure 19B, the
optical connector 424 is decoupled from the first optical connector adaptor
423. Tn Figure
19C, the coupling fiber 445 having the decoupled connector 424 is pulled from
the back of
the sorting board 443 until the stopper is in the vicinity of a viewing hole
provided on the
sorting board 443. This step enables to select?? conErm?? a desired optical
connector 424
from the excess length front storage section 454, which stores excess length
of many cords.
Figure 19D shows the excess length of the coupling Fiber 445 being pulled to
the
front side to a required length to grasp the connector 424 so that the
coupling Bber 445 can
be pushed through the slot opening, Located next to the decoupled fiber on the
sorting board
443, and the optical connector 224 is then connected to the second optical
connector
adaptor 423 on the connection board 447. Figure 19E illustrates balancing of
the excess
length in the front and back storage sections 454.
CA 02409220 2002-11-28
EXPLANATION DOES NOT MAKE SENSE
The present system enables to select the cord and connector visually even if
there is
excess length of cords so that coupling fibers and connectors can be easily
identified and
selected to shorten the time required for fiber switching.
Example 6
In this system, the coupling fiber 445 shown in Figure 19A is identified by
bar codes
imprinted at a location 453 of the fiber 445, which are read by a portable
terminal 431.
This system thus enables to shorten the time required for searching for a
correct coupling
fiber 445 to improve the work efficiency and decrease erroneous selection of
coupling fiber
445.
Example 7
In this system, the connection board 447 and the holding board unit 444 are
provided with a display section for displaying instruction data from the
intermediate
distribution managing section 432. Figure 20 shows a part of the connection
board 447,
and an array of connector adaptors 423 is identified by the corresponding LED
indicators
452 provided in the vicinity. The indicators 452 indicate the coupling
terminals to be
serviced on the connection board 447, and the indicators 452 provided on the
holding board
unit 444 indicate the coupling fiber 445 to be serviced. This system enables
to search the
connection sections on the connection board reliably and quickly so that fiber
switching
CA 02409220 2002-11-28
31
operation can be carried out efficiently and prevent errors in selecting the
cords to be
switched.
Example 8
In this system, a visible light source is provided for the fiber switching
section 430,
and the coupling fiber 445 is provided with a light deflection section to
transmit visible
light. The light from a visible light source is injected in a FS master side
fiber, and
propagates to the coupling fiber 445 through the connection board 447, and the
light is
leaked externally through the deflection section provided on the coupling
fiber 445 stored in
the front and back excess length storage sections. This leaked light is
observed visually to
identify a desired coupling fiber 445. This system enables to select a desired
coupling fiber
445 from the back side of the sorting board 443 to improve the work efficiency
of fiber
switching and prevent erroneous switching.
The visible light source includes semiconductor lasers, He-Ne lasers.
Example 9
In this system, an error-free switching method is applied on the cross
connecting
section 427. Figure 21 shows the configuration that includes: optical fiber
selector (FS)
403; subscriber cable 417; holding board unit 444; coupling fiber 445;
connection board
447; first optical coupler 455; second optical coupler 456; optical coupler A
port 457;
optical coupler B port 458; optical coupler C port 459; optical coupler D port
460; optical
CA 02409220 2002-11-28
32
pulse tester 461; visible light source 462; optical monitor device 463; #1
connector 464;
and #2 connector 465.
Signal light exiting from the coupling fiber 445 reaches subscriber cable 417
after
successively propagating through the #1 connector 464, port B 458 and port A
457 of the
first optical coupler 455. Optical couplers 455, 456 produce splitting, so
that: light entering
from port A 457 is split to port B 458 and port C 459; light entering from
port B 458 is split
to port A 457 and port D 460; light entering from port C 459 is split to port
A 457 and port
D 460; and light entering from port D 460 is split to port B 458 and port C
459. Each port
A 457 is connected to the subscriber cable 417.
In the initial stage, the coupling fiber 445 is connected to the #1 connector
464, and
the following explanation relates to a case of switching the coupling fiber
445 to the #2
connector 465.
First, the operator at the equipment center enters change items for the
structure of
the network, including subscriber information, service information, to the
portable terminal
431, intermediate distribution managing section 432 or integrated distribution
managing
section 433. Next, all the request for connection switching made to sections
other than the
intermediate distribution managing section 432 are all transferred to the
intermediate
distribution managing section 432. The intermediate distribution managing
section 432,
CA 02409220 2002-11-28
33
referring to its own database, determines the coupling fiber 445, #1 connector
464 and #2
connector 466 involved in the fiber switching operation. Identifying
information for the
coupling fiber 445, #1 connector 464 and #2 connector 465 are forwarded to the
portable
terminal 431 so that the worker may work according to the information
provided.
Next, the intermediate distribution managing section 432 issues a command to
FS
403 to connect port D 460 on the first coupler 455 and the optical monitor
device 463, and
when the FS 403 executes the command in response, the monitor device 463
begins
monitoring signals from the coupling fiber 445 in the current condition.
Next, the center worker selects the fist connector 464 indicated on the
portable
terminal 431, and confirms the coupling fiber 445 attached to the connector
464. In this
case, reading the bar codes provided on the coupling fiber 445 with the
portable terminal
431 would enable to carry out the task more reliably. When there is no error
in selection of
the coupling fiber 445, the portable terminal 431 outputs disconnect
instruction for the fiber
445, and the worker, upon confirming the instruction, carries out the
disconnection
operation of the coupling fiber 445.
When the coupling fiber 445 is decoupled, the signal being monitored by the
monitor device 463 is disconnected. The monitor device 463 reports the signal
disconnection to intermediate distribution managing section 432. Upon
receiving the
CA 02409220 2002-11-28
34
report, intermediate distribution managing section 432 issues a command to FS
403 to
connect the port D 460 on the second coupler 456 to the monitor device 463.
When the FS
403 executes this operation, visible light emitted from the visible light
source 462 is
emitted from the port B 458 on the second coupler 456, that is, from the #2
connector 465.
The worker confirms the connector 465 because of the light emitted from the
connection
board 447, and reports confirmation to the portable terminal 431. Confirmation
report is
transferred from the portable terminal 431 to the intermediate distribution
managing section
432.
Next, the intermediate distribution managing section 432 issues a command to
the
FS 403 to connect port D 460 on the second coupler 456 to the monitor device
463, and
when FS 403 executes the operation in response, the monitor device 463 waits
for signal to
be transmitted from the #2 connector 465. Further, the intermediate
distribution managing
section 432 issues a connection instruction for the #2 connector 465 to the
worker. The
worker connects the coupling Bber 445 to the #2 connector 465 according to the
instruction
on the portable terminal 431.
When the coupling fiber 445 is correctly connected to the #2 connector 465,
the
monitor device 463 receives signal light from the coupling fiber 445, and
reports the
connection event to the intermediate distribution managing section 432. Upon
receiving
connection report, the intermediate distribution managing section 432 notifies
the worker
CA 02409220 2002-11-28
through the portable terminal 431 that connection has been made, and commands
FS 403 to
return to the initial position, and make changes to own database. This system
thus assures
reliable and quick operation.
Example 10
Figure 22 shows the a view of the distribution system in Example 10, comprised
by:
distribution board SOl; cross connecting section 502; fiber sorting section
503; fiber storage
section 504; splitting jumper section 505; cord storage section 506; user-side
terminating
section 507; non-splitting jumper section 508; fiber sorting section S09
having a plurality of
fiber sorting sections 503; center-side terminating section 510; first
internal cable 511;
subscriber cable S 12; center terminals frame S 13 housing center
communication equipment
and center imaging equipment; connector plug 551; and splitter SS2.
However, Figure 23 shows a case of using splitting jumper section SOS, but
instead
of this jumper section SOS, non-splitting jumper section 508 may be used.
The center-side terminating section S10 houses the first internal cable 511
connected to a plurality of subscriber center devices, and is connected to the
jumper section
508. Jumper section is broadly divided into those that have splitting
capability (Figure 24)
and those that do not (Figure 2S). A splitter divides signal light transmitted
from a
subscriber center to several ports, and although the number of divisions is
not specially
limited, four, eight and sixteen ports are useful in relation to center
capabilities.
CA 02409220 2002-11-28
36
Here, Figure 24 shows a schematic diagram of the splitting jumper section 505
and
Figure 25 shows a schematic diagram of the non-splitting jumper section 508,
and include
input port 560; splitter 561; output-side port 562; and optical filter 563.
Splitter 561
divides signal from the center-side to a plurality of ports.
Signal light may be comprised by different wavelengths for the data fibers and
imaging fibers, and they may be combined suitably to suit the number of ports
to be sent out
from the output ports. Non-splitting jumper section 508 is used to transmit
signal light
from the center terminals frame 513 to a particular subscriber without
splitting, and is
comprised by a plurality of input ports and respective output ports. Splitting
jumper section
505 and non-splitting jumper section 508 are both made in the same shape so as
to enable to
be installed in any desired area in the jumper fiber sorting section 509.
The fiber sorting section 503 provides the following functions:
(I) houses optical fibers having connector plugs connected to the output ports
of the
jumper section 505, 508 and separates the in-use fibers from the in-storage
fibers;
(2) provides entry/exit passageways for in-use fibers and storing fibers;
(3) maintains a certain bending arc of the fibers in the storage section;
(4) able to switch in-use fibers with storing fibers in the openings;
(5) restrains sorted fibers so as not be detached easily;
(6) has a fiber pulling capability including a rotary capability;
CA 02409220 2002-11-28
37
(7) provides a space for enabling to visually identify imprinted ID marks.
Furthermore, the fiber sorting section 503 is designed to completely separate
the in-
use fibers from the storing fibers so that the stored fibers do not adversely
affect the
properties of the in-use fibers. Also, because the pulling means and visual
observation
means are provided, even if another fiber sorting section 503 is over laid on
the existing
fiber sorting section 503, in-use fibers from any sorting section 503 can be
visually
distinguished from the storing fibers. These functions are used to identify a
desired fiber
cord and the connector plug attached at the cord end can be pulled up to the
face of the fiber
sorting section 503 to confirm the identification.
The connector plug pulled in closer for confirmation can now be connected to
the
new connection position in the cross connecting section 502. This approach
enables to
avoid generating twisting of the fibers. In the conventional approach, fiber
storing density
could not be increased, because repeated switching causes the fibers to become
twisted over
time.
Optical fibers connected to output port of the jumper sections 505, 508 need
to be
protected with sheathing of certain tensile strength and bending elasticity,
therefore, a
sheathing structure comprised by a stretch resistant material and a polymeric
material is
suitable. Sheathing polymeric materials used were anti-flammatory polymers,
which
CA 02409220 2002-11-28
38
included: non-halogenic polymers such as polyolefin group resins; polyamide
group resins;
polyester group resins. Anti-flammatory polymers included anti-flammatory
agents not
containing organic phosphorous group substances.
In order to increase the fiber density in the distribution board, optical
cords having a
diameter of the order of 1 mm are satisfactory. Those fibers housed in the
jumper section
505 (SO8) having core fibers in a range of 3264 cores exhibit superior
handling and storing
characteristics.
Methods of visual identification of fibers include identifying marks having
numeric
information. Identification was improved by using a combination of
symbols/numerals
markings pertaining to a cord, and colored sheathing or color printed
sheathing to identify a
particular fiber core in a mufti-core cord. Marking information was provided
transversely
across the sheath singly or in multiple markings or along the sheath
longitudinally spaced
apart at a given spacing so that any location along the cord can be identified
from any
position along the cord, and when the marking information was provided in
various
orientations with respect to the sheath, the cord can be identified from any
viewing angle.
The fiber sorting section 509 can contain several jumper sections 505 (508).
Storing
methods include vertical or horizontal accommodation, and the fibers can be
arranged in
each of these method so that a single fiber of fibers or multiple fibers of
fibers can be stored
in a horizontal or slanted orientation.
CA 02409220 2002-11-28
39
The length of jumper fibers in the jumper sections SOS (S08) should be made a
constant length to reach any part of the cross connecting section 502. This is
most easily
achieved by a vertical single fiber storing method. In such a method, the
jumper sections
SOS (S08) can be incorporated in the fiber sorting section 503, and arranging
the fiber
sorting section S09 from the bottom to the top region of the MODULE. This
method
allows to increase the number of jumper sections SOS {508) without adversely
affecting the
in-use fibers.
To store the excess lengths for the in-use fibers in the fiber storage section
using the
vertical single fiber storing method, the positions of the cross connecting
section S02 and
fiber sorting section S09 should be higher than the middle of the fiber
distribution unit.
The cross connecting section S02 is connected to the subscriber by connecting
one
end of the cross connecting section 502 to the subscriber cable. Therefore, by
incorporating
the various jumper section SOS (S08) in the fiber sorting section 503,
transmission service
to subscribers can be provided by switching at the cross connecting section
502.
Example 11
Figure 26 shows an example of the fiber distribution system storing the first
internal
cable directly in the fiber sorting section.
After storing several first internal cable S 11 distributed from the center
terminals
frame S 13 inside the center-side terminating section S 10, the fibers from
the first internal
CA 02409220 2002-11-28
cable 511 are stored in the fiber sorting section 503. The fibers are single
core fibers and an
optical connector is attached to one end.
This fiber sorting section 503 performs the same function as the fiber sorting
section
shown in Figure 22. However, because each fiber has a connector plug attached
at the end,
when storing them in the fiber sorting section 503, it is necessary to provide
entry/exit
passageway for the fiber so that the fibers would not come loose from the
clips, by
providing properly shaped slot opening or open/close type slots. This system
is useful
when it is desired to provide a dedicated service at the center on a one-on-
one basis, or
when the subscriber cable time-shares signal light with subscribers.
Example 12
Figure 27 shows a configuration of an integrated fiber distribution system
provided
with IDM distribution board A (520) and IDM distribution board B (521), and
has a
distribution managing function and a testing function.
It is obvious that a distribution system may be comprised only with IDM
distribution board A (520) and IDM distribution board B (521), and in such a
system, one
IDM distribution board B (521) can accommodate many IDM distribution boards A
(520).
IDM distribution board B (521) is situated between a plurality of subscribers
linked
to the IDM distribution board A (520) and a plurality of center terminals
frames 513, and
has a function of assigning the fibers. In a system that does not have an IDM
distribution
CA 02409220 2002-11-28
41
board B (521), there will be not only a need for providing an extensive
network of fiber
cable between the IDM distribution board A (520) and many subscriber
equipment, but also
a need to have on-hand a large variety of fiber cable, those having a low
number of cores
and those having a high number of cores. By providing the IDM distribution
board B (521),
mufti-core fiber cable can be installed in the fore-stage of the system to
avoid the difficulty
of dealing with congestion of fiber cable.
IDM distribution board A (520) has the equivalent functions as the board 50I
shown
in Figure 22, and mM distribution board B (521) has the equivalent functions
as the board
501 shown in Figure 26. B3M distribution board A (520) and IDM distribution
board B
(521) are connected with 1DM cable 516. IDM distribution board B (521) has a
fiber sorting
section 503 for the IDM cable 516 and IDM distribution board A (520) has a
jumper
section.
This configuration is sufficient for a fiber distribution system, but by
incorporating a
testing function in the distribution system, operational status of the fibers,
from the center
equipment to subscribers, can be maintained and monitored in the system.
Testing function
includes a test accessing section 514 having an optical coupler for injecting
test light from
the vicinity of the cross connecting section 502 into fibers on the center-
side or fibers on the
subscriber side. Other testing components include fiber switching section 530
for switching
test light to be injected into a plurality of test accessing section 514 and
an optical testing
533 for measuring and analyzing forward and return test light.
CA 02409220 2002-11-28
42
The system may further include a monitoring section 535 for monitoring signal
light, an optical power comparing section 536 for comparing the performance of
cores.
Parts for the optical testing section can be accommodated in the lower section
of either the
cross connecting section or the IDM distribution board B (521).
The test accessing section S 14 is connected to the subscriber cable at one
end, and at
other end, to the cross connecting section 502 having many receptacles. These
receptacles
have traditionally been SC type, but the fiber density on the distribution
board can be
increased by using a smaller MU type 16-string receptacle so that the capacity
of cross
connection may exceed 4,000 terminals.
For connecting to the subscriber cable, an 8-core multioore connector (MT
type)
may be used. For example, two 8-core multicore connectors may be joined at
about 10 mm
width in a I6-string receptacle to increase the fiber density. Excess length
portion of the
tape type ire fibers of the subscriber fiber cable may be stored by providing
a 10-mm wide
partition plate in the center of the test accessing section SI4, and storing
the tapes on left
and right sides of the partition plate. Connection to the fiber switching
section may be
made using a 16-core multicore connector.
Test light wavelength is different than signal light wavelength so as not to
affect
communication functions. Also, optical filters are used in the distribution
system to avoid
affecting the communication equipment adversely. In the present system,
optical filters are
CA 02409220 2002-11-28
43
inserted on the transmission side of the jumper section 508, in order to
reduce the number
of required filters.
Additional functions can be provided to the present system. For example, by
incorporating the distribution managing section 525 in the system, complex
distribution of
fibers can be performed by computation using database system 524 shown in
Figure 27.
Further, it enables to use a bar-code reader 522 provided for the fiber
distributing section
517 to read two-dimensional identifying marks 519, optical fibers, cross
connecting section
502, and to register the operating status of the system in the database DB.
Such an
arrangement facilitates the task of managing the system, and increases the
efficiency of
fiber distribution operation.
Two-dimensional identification codes may be imprinted or bonded on removable
tags to be attached to the fiber sheath. One-dimensional codes are typically
bar-codes, but a
high density distribution system such as those presented in the present
invention requires
fine diameter fibers, and the identifying marks must also be miniaturized.
Such micro-sized two-dimensional codes are capable of registering 30x30 alpha-
numeric markings inside a 5-mm square, and much more information can be
represented
compared with one-dimensional markings. Such micro-sized markings can also be
used for
product inventory purposes.
Information regarding the locations of receptacles and adaptors for the cross
connecting section 502 and fiber distributing section 517 can be obtained by
imprinting or
attaching two-dimensional marks on respective protective caps or displaying
visual
CA 02409220 2002-11-28
44
identifying marks on a monitor. Two-dimensional markings are advantageous for
automatic registering or altering in databases.
Example 13
Figure 28 shows an example of the configuration of a fiber distribution system
having an integrated jumper section SOS and fiber sorting section 503.
IDM cable 515 is connected to input port of the jumper section 505, and
optical
fibers distributed by a splitter 547 are inserted in the fiber sorting section
503. Those fibers
are stored as spare fibers 543 on the fiber storing board 504.
On the other hand, one end of the test accessing section 514 is connected to
subscribers through the subscriber cable 512. Other end of the test accessing
section 514
serves as the cross connecting section 502.
To provide communication service to a subscriber, a spare fiber is connected
to the
cross connecting section 502. In this case, the fiber to be connected is
identified visually in
the identification space 544.
The fiber sorting section 503 has a rotation pulling section 545 to facilitate
visual
identification of the fibers using identifying marks S50 and color markings
549. Those in-
use fibers connected to the cross connecting section 502 are separated
completely, from the
CA 02409220 2002-11-28
in-storage fibers so that there is no problem of becoming tangled??? with the
in-storage
fibers.
By attaching two-dimensional identifying marks 519 on the fiber and cross
connecting section 502, information regarding connection status can be
automatically
registered in the databases. For example, identification process is enhanced
by attaching an
ID tag 541 on the fiber sheath as illustrated.
In this case, a round shape of the ID tag 541 is suitable to prevent other
fibers to
catch on the tags. Such identification codes are placed in the vicinity of the
connector plug
540, and the ID tag 541 should be made movable along the fiber sheath for
adaptability.
It should be noted that the various examples presented above are for
illustrative
purposes and are not meant to be limiting the invention in any manner. The
present
invention can be modified within the scope of the claims disclosed.
