Multiplex communications – Pathfinding or routing – Switching a message which includes an address header
Reexamination Certificate
1998-11-02
2003-06-17
Rao, Seema S. (Department: 2666)
Multiplex communications
Pathfinding or routing
Switching a message which includes an address header
C370S434000, C370S535000
Reexamination Certificate
active
06580714
ABSTRACT:
BACKGROUND OF THE INVENTION
(a) Field of the Invention
The present invention relates to a concentrator type ATM switch for an ATM switching system and, more particularly, to a concentrator type ATM switch for use in an ATM switching system, which is capable of efficient transmission of information such as image, voice, and animation data.
(b) Description of the Related Art
An example of a typical ATM switching (network) system is shown in FIG.
1
. This system includes a plurality of (m) comparatively small-scale n×n ATM switching modules
21
each including a n×n ATM switch
23
, the ATM switching modules
21
being connected to one another through a coupling module
25
to form a large-scale ATM switching system. In this text, n×n switch as used herein means that the switch couples any one of n input ports to any one of n output ports, whereas n-to-1 selector and m-to-n multiplexer as used later mean that the selector selects any one of n inputs and the multiplexer multiplexes m signal sequences into n signal sequences.
In the ATM switching system of
FIG. 1
, a selector
22
is provided in each n×n ATM switch module
21
for selecting n cell data directly input therein or n cell data input through the coupling module
25
from another n×n ATM switch module
21
. The n cell data selected by the selector
22
are supplied to the n×n ATM switch
23
, which couples the same by switching to the output ports specified by the cell data.
The coupling module
25
receives m×n input data, or cell data supplied through m×n signal lines, which are supplied to the m ATM switch modules
21
and delivered from rout judgement blocks
24
in the ATM switch modules
21
after selecting the ATM switch modules
21
based on the destination of the data. A concentrator (or concentrator type ATM switch)
26
is provided in the coupling module
25
for each n×n ATM switch module
21
. The concentrator
26
receives the m×n input data, supplied from one of the n×n ATM switch modules
21
, to deliver the same to another of the n×n ATM switch modules
21
based on the destination of the data. That is, each concentrator
21
functions for multiplexing m×n signal sequences into n signal sequences.
The concentrator
26
may be of an output buffer type which stores all input data in output buffers after multiplexing the input data into a single signal sequence, of a knockout type which consecutively stores effective cell data in the output buffers from the first and discards the excess cell data if the number of effective cells to be processed at a time exceeds the number of the output ports, or of a switching type which functions for switching regardless of the order of the input cells and rearranges the order at the next stage of the switching.
The conventional concentrator
26
in the coupling module
25
as described above has a problem in that the transfer rate in the concentrator
26
rises along with the increase of the circuit scale that is increased by the number of ATM switch modules coupled by the coupling module
25
. The increase in the transfer rate means that the upper limit of the physical performance of the concentrator
26
in the transfer rate restricts the scale of the ATM switching system obtained by the coupling.
Especially in the case of the knockout type concentrator, when the number of effective cells to be processed at a time exceeds the number of output ports provided therein, all the effective cells are not transmitted, resulting in a blocking switching operation of the system wherein excess effective cells are discarded.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a concentrator type ATM switch, which is capable of suppressing the rise of the transfer rate therein and operating for a non-blocking switching wherein effective cells are not discarded.
It is another object of the present invention to provide an ATM switching system having the concentrator type ATM switch as described above.
The present invention provides, in one aspect thereof, a concentrator type ATM switch comprising a multiplexing block for receiving a plurality of (m) signal groups each including a plurality of (n) input signal sequences, the multiplexing block outputting n multiplexed signal sequences, a routing block for receiving the n multiplexed signals to output an assignment signal for each of effective input cells in the n multiplexed signals, and a concentration buffer block including an n×n banyan network having n input ports, n output ports and a set of switches for switching each of the effective cells supplied to the n input ports to one of the n output ports based on the assignment signal, and an output buffer block including n output buffers each for receiving effective cells through one of the output ports.
The present invention also provides, in another aspect thereof, an ATM switching system comprising:
a plurality of (m) ATM switch modules each having a plurality of (n) inputs each for receiving an input cell sequence, a routing judgement block for judging a destination of input cells in the input cell sequence to deliver a destination signal corresponding to each of the input cells, a selector for selecting n inputs from the inputs of own ATM switch module or the inputs of other ATM switch module, and a n×n ATM switch for receiving outputs from the selector; and
a coupling module having m×n input ports connected to the inputs of the m ATM switch modules, m output port groups each including n output ports, the output port group corresponding to the m ATM switch modules, at least one multiplexing block for multiplexing m×n signal sequences received from the plurality of ATM modules into n signal sequences, and m concentration buffer blocks each including a n×n banyan network and an output buffer block for receiving input cells in the n signal sequences from the multiplexing block to output the input cells through one of the output port groups to the selector of one of the ATM witch modules based on the assignment signal.
In accordance with the concentrator type ATM switch and the ATM switching system of the present invention, the rise in the transfer rate of the concentrator type ATM switch (concentrator) is suppressed, which enables a non-blocking switching operation wherein effective cells are not discarded.
The above and other objects, features and advantages of the present invention will be more apparent from the following description, referring to the accompanying drawings.
REFERENCES:
patent: 5394396 (1995-02-01), Yoshimura et al.
patent: 5412646 (1995-05-01), Cyr et al.
patent: 5414415 (1995-05-01), Ueda et al.
patent: 5555243 (1996-09-01), Kakuma et al.
patent: 5555265 (1996-09-01), Kakuma et al.
patent: 5612951 (1997-03-01), Yu et al.
patent: 5724352 (1998-03-01), Cloonan et al.
patent: 5838679 (1998-11-01), Kim et al.
patent: 6031838 (2000-02-01), Okabe et al.
patent: 6496513 (2002-12-01), Takamichi
patent: 2075027 (1996-11-01), None
patent: 0 549 122 (1992-11-01), None
patent: Hei 2-82741 (1990-03-01), None
English language translation of Japanese Office Action dated Feb. 22, Hei 11.
Canadian Office Action.
Nishihara Motoo
Nishizaki Hideki
Boakye Alexander O.
Rao Seema S.
Whitham Curtis & Christofferson, PC
LandOfFree
Concentrator type ATM switch for an ATM switching system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Concentrator type ATM switch for an ATM switching system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Concentrator type ATM switch for an ATM switching system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3113559