Note: Descriptions are shown in the official language in which they were submitted.
12~Z~S
The invention relates to an opti.cAl. main
clistributor.
At present there are no practicable means for
jo.ining information streams of diferent services on an
optical subscriber line.
The solutions which are presently known allow
only ~Eor metallic conductors in the main distributor and
include only mechanical jumpers which are al.located in a
fixed manner. Therefore the main distributors which are
presently ]cnown are largely extended because they include
a large amount oE components which are allocated to
individual subscribers.
It is accordingly an object of the invention to
provide an optical main distributor which includes only a
few elements Eixedly allocated to the subscriber. Thereby
the components in the main distributor may be
substanti.ally reduced according to the invention.
~ c~ording to the present invention, there is
provided an optical main distributor which provides a
junction between the local lines which join together from
all directions of a local network communication switching
means, wherein the optical main distributor comprises, an
electrical switching network allocating multiplexing means
including 64 kbit/s-channel to a PCM 30-system and
allocating a PCM 30-system to a PCM l9~0-system for the
dur~tion oE a connection and having at least one output
signal and a second, optical switching network being
connected to receive the output signals of the electrical
switching network and controlling a plural.ity of opto-
electrical converters as well as a plurality o:E lambda-
multiplexing means which are also a:Llocal:ed to a
connectlon for the duration oE a communication, wherein a
sequential switching o the switching networks is used to
connect the optical terminal lines with the terminals of
different wide band- and narrow band exchange systems.
The present invention further provides a main
distribution frame for message switching systems for
optional connection of incoming and outgoing connecting
YJ~
~24Z13S
- la -
lines, to serving and ofEerlng trunk groups compri.si.ng, a
PCM 30 system, a t.ime-space recognition device, a scanner,
an electric~l switching network, an electro-optical
converter, and a computer, wherein all incoming connecting
lines are assembled into PCM 30 systems from a narrow-band
switching exchange X, the time-space recognition clevice
and the scanner are allocated to each PCM 30 system within
a coupl;ng means to trigqer setting instructions via a
- computer, by means of which the transmission oE an
incoming or outgoing time space to the serving trnllk group
or oEfering trunk qroup can be con-trolled by means oE the
electrical switching network during the period oE time a
connection required by a subscriber is being created, and
the serving trunk group or offering trunk group is
connected to the optical switching network by means of the
electro-optical converter whose connecting elements are
controlled by the computer on the basis of detector
signals during the period o time the connection is being
formed .
~n embodiment of the invention is described
below with reference to the accompanying drawings, in
which:
Figure 1 shows the basic construction oE the
optical
4~2~5
main distributor;
Fig. 2 shows a coupling means;
Fig. 3 shows a sequential coupling means; and
Fig. 4 shows the in-tegration of narrow band and
wide band serv:ices.
The optical main distributor which is shown in
Fig. 1 consists of two switching matrix networks l and
2.
- The electric switching matrix l includes multi-
plexing means allocatin~ a 64 kbit/s-channel to a PCM 30-
system (pulse coded multi channel system including 30
channels) and if additional wide band dialogue services
are requiredr allocating a PCM 30-system to a PCM 1920-
system within the time duration of a communication. The
second optical switching network 2, which is connected
after the first switching network, control a plurality
of opto-electrical converters o/e as well as lambda-
multiplexing mearls ~-MUX in the same manner. A lambda-
multiplexing me~ans is a device which distributes in~orma~
tion on optical communication lines which are operated
with different optical wavelengths~ The sequentially
coupled switching matrix networks operate on all optical
terminal lines AsLs as well as on the terminals of the
different wide band and narrow band switching systems of
each of the subscribers in the di~ferent switching stations.
The elements of the electrical and opticaL switch-
ing matrix networks 1 and 2 can be regarded to be available
for the connection set-up procedure which can be al:Located
to the connection within the time duration of a comrnunica-
tion by a computer and a marking control instruction~ i.e.almost all elements of the Gptical main distributor are
available independent of the subscriber and are not alloca-
ted to the subscriber as in present main distributors;
the allocation is effected by a computer. Therefore jumpers
no longer need to be re-arranged.
As it is shown in Fig. 2 all offering trunk groups
of a narrow band switching station X which are supposed
~4~t3S
to be in space-division multiplex are joined together in
PCM 30-systemsO By this measure the line numbers a:re re-
duced by the Eactor 30 and the information streams are
handled within the time range which facilitates the employ-
ment of large scale integrated circuits.
For t;he outbound traffic a time slot detec-tor
(TSAC) and a scanner which is allocated to each of the
PCM 30-systems detect which time slots of the PCM 30-system
can be reservecl. The TSAC time slot detector and the
scanner are used for the inbound traffic to trace requests.
The time slot cletector TSAC provides the re-transmission
of the contents of the reserved time slots from one switch-
ing matrix network from or to a serving trunk.
There are two operational principles:
a) For one incoming request of a subscriber a
PCM 30-system is reserved in which all further service
requests are established in a defined manner, or
b) individual time slots are reserved on the
serving trunk with optional reservation.
Both methods, however, require an identif:ication
word (not shown) accompanying the information within the
duration of the communication. Thereby the method b) is
advantageous because a high usage factor of the serving
trunk is achieved. However, there can arise complications
in the successive switching means which loop in the wide
band services.
Fig. 3 shows that the coupling means being pro-
vided for a narrow band service can be connected serially
to further coupling means E. Thereby it is possible to
integrate in one PCM 30-system the informations of a
plurality of narrow band switching stations.
The reservation of a PCM 30-system or of parts
thereof during a communication is advantageous in that
thereexists at the end of the serving trunk information
streams which are clearly assigned to a subscriber.
As it is shown in Fig. 4 the information streams
for the integration of wide band and narrow band services
Z85
(ss- and Ss-services) are supplied to electro-optical con-
verters 3 so that the optical signals which are provided
by the converters 3 can be supplied to an optical, swi-tch-
ing network 2 and afterwards to the terminal lines ~sI,s
the information streams are assigned to. One path in the
switching network remains connected through during the
communication so that also low speed elements can be used.
The opto-electrical elements in this branch also se:rve
to detect requests from the subscriber terminal lines AsLs.
By integrating a plurality of dialogue services
the narrow band signals of the PCM 30-systems can be mixed
with wide band.dialogue signals (e.g. video telephone).
Thereby an information stream according to PCM 1920 is
generated. This information stream can be supplied if
necessary together with further TV information to a wave-
length multiplexing device set WD-MUX which is also not
allocated to a subscriber. If a corresponding multiplicity
of wavelength is used in this wavelength multiplexing
device set WD-MUX a TV switching system is dispensible
in the future.
It is necessary to allocate the wavelength multi-
plex because of its general employment temporarily to each
of the subscriber terminal lines in the successive optical
switching network 2. Therefore elements are necessary
which remain switched through during the communicat:ion
time.
The invention is further advantageous in that
movement of mechanical connections between all elements
is not required, so that predetermined damping cond:itions
can be provided especially for the optical range. Thereby
it is remarkable tha.t an extension in the direction of
a network with integrated services is possible without
problems and that the operation of narrow band and wide
band subscribers in parallel at any time is ensured~. The
mechanical re-arranging of subscriber terminal lines as
it is presently known can be fully avoided (this is also
true for de~ective devices) also if the optical swit:ching
networks are extended with reserve fibers.
