Multiplex communications – Fault recovery – Bypass an inoperative switch or inoperative element of a...
Reexamination Certificate
1998-03-18
2002-07-09
Olms, Douglas (Department: 2732)
Multiplex communications
Fault recovery
Bypass an inoperative switch or inoperative element of a...
C370S221000
Reexamination Certificate
active
06418115
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to an exchange and, more particularly, to an exchange which changes a route of a transmission path, when a malfunction occurs in one of a plurality of switches, so as to bypass the malfunctioning switch.
In an exchange or a transmission apparatus which communicates information including audio data and image data, a switch network is provided with a plurality of inputs and outputs so that any one of the inputs can be connected to any one of the outputs so as to arbitrarily change a route of a communication path formed in the switch network.
2. Description of the Related Art
A description will now be given of a conventional method for avoiding influence of a malfunction occurring in one of a plurality of switches which constitute a switch network in an exchange.
FIGS. 1
,
2
and
3
show a first, second and third conventional exchange, respectively.
The first conventional exchange shown in
FIG. 1
comprises a working switch network
101
, a spare switch network
102
having the same structure as the working switch network
101
, an input switching unit
103
and an output switching unit
104
. The working switch network
101
comprises a plurality of switches, and has a plurality of inputs and a plurality of outputs. The input switching unit
103
and the output switching unit
104
change a transmission path formed through the exchange so that the transmission path is formed in the spare switch network
102
instead of the working switch network
101
when a malfunction occurs in one of the switches in the working switch network
101
which is actually being used.
When a malfunction occurs in one of the switches constituting the working switch network
101
, the first conventional exchange bypasses the malfunctioning switch by switching the actually used switch network from the working switch network
101
to the spare switch network
102
. This switching operation is performed by the input switching unit
103
and the output switching unit
104
. Transmission paths formed after the switching operation are also formed in the spare switch network
102
.
The second conventional exchange shown in
FIG. 2
comprises a switch network
111
, an input switching unit
112
, an output switching unit
113
and a header changing table circuit
114
. The switch network
111
comprises a plurality of switches and a plurality of spare switches reserved for spare use. The switch network
111
has a plurality of inputs and a plurality of outputs, and also has a plurality of spare inputs and a plurality of spare outputs. The input switching unit
112
and the output switching unit
113
change a route of a transmission path formed through the exchange so that the transmission path is formed between one of the spare inputs and one of the spare outputs when a malfunction occurs in one of the switches included in the transmission path in the switch network. The header changing table circuit
114
changes input address information, which is included in communication information to be transmitted, to input address information of one of the spare inputs.
When a malfunction occurs in one of the switches in the switch network
111
, the second conventional exchange bypasses the malfunctioning switch by changing a route of the transmission path including the malfunctioning switch to a route formed between one of the spare switches and one of the spare inputs.
The third conventional exchange shown in
FIG. 3
comprises a switch network
121
including a plurality of switches. The switch network
121
has a plurality of inputs and a plurality of outputs. When a malfunction occurs in one of the switches constituting the switch network
121
, the malfunctioning switch is detected so that a transmission path routing the malfunctioning switch is changed to a transmission path routing a spare switch instead of the malfunctioning switch.
However, each of the above-mentioned conventional exchanges has the following problems.
In the first conventional exchange, since a detection of the malfunctioning switch in the actually used working switch network
101
is not performed, a transmission path routing the malfunctioning switch cannot be distinguished. Thus, all transmission paths including normal transmission paths must be switched to transmission paths formed in the spare switch network
102
when a malfunction occurs in one of the switches in the working switch network
101
.
In the first, second and third conventional exchanges, since the spare switch network or the spare switch must be reserved for spare use which is not used in a normal condition, weight and size of the entire system is increased and also manufacturing cost of the exchange is increased.
SUMMARY OF THE INVENTION
It is a general object of the present invention to provide an exchange in which the above-mentioned problems are eliminated.
A more specific object of the present invention is to provide an exchange in which, when a malfunction occurs in one of a plurality of switches, a transmission path bypassing the malfunctioning switch can be formed in the absence of a spare switch in the exchange so as to decrease weight and size of the entire system.
In order to achieve the above-mentioned objects, there is provided according to the present invention an exchange setting a transmission path for transmitting communication information through a switch network comprising a plurality of switches, the switch network provided with a plurality of inputs and a plurality of outputs so that the transmission path is formed between one of the inputs and one of the outputs by routing the switches in the switch network, the exchange changing a route of the transmission path when a malfunction occurs in one of the switches included in the transmission path so as to bypass the malfunctioning switch, the exchange comprising:
a malfunctioning switch detecting unit detecting a location of the malfunctioning switch in the switch network; and
changing means for changing the route of the transmission path by switching one of the inputs and outputs connected to the transmission path based on predetermined routing information so as to bypass the malfunctioning switch.
According to the above-mentioned invention, when a malfunction occurs in one of the switches constituting the switch network, the location of the malfunctioning switch is detected and the location information is supplied to the changing means. The location information may include an address of the malfunctioning switch and information indicating a position of the malfunctioning switch with respect to the inputs and outputs of the switch network. For example, if the switches in the switch network are arranged in a matrix, the location information may include indication of a column (stage) in which the malfunctioning switch is included. When the changing means receives the location information, the changing means changes the route of the transmission path by changing one of the inputs which is connected to the transmission path or changing one of the outputs connected to the transmission path. That is, the input or the output connected to the transmission path is changed to another input or output based on the routing information which indicates a route which bypasses the malfunctioning switch. That is, the route of the transmission path can be changed to a route which bypasses the malfunctioning switch by merely changing the input or output of the switch network.
Accordingly, the exchange according to the present invention discriminate the transmission path including the malfunctioning switch, and the route of the transmission path is changed by changing the input or the output of the switch network based on the location of the malfunctioning switch. Thus, the exchange according to the present invention does not need a spare switch which is not used when the exchange is operated in a normal condition. Therefore, the weight and size of the entire system is reduced which is advantageous for reducing manufacturing
Iino Toshiyuki
Shirai Hiroaki
Fujitsu Limited
Katten Muchin Zanis Rosenman
Olms Douglas
Vanderpuye Ken
LandOfFree
Exchange for changing a route of a transmission path to... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Exchange for changing a route of a transmission path to..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Exchange for changing a route of a transmission path to... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2817531