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Claims  |
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What is claimed is:
1. A logical channel setting system for an asynchronous transfer mode (ATM)
network the system comprising:
a terminal adapter and corresponding terminal equipment, each operable in
conformance with a high performance parallel interface (HIPPI) and the
terminal adapter and the terminal equipment being selectively operable
respectively as a transmitting terminal adapter and a corresponding
transmitting terminal equipment and, respectively, as a receiving terminal
adapter and a corresponding receiving terminal equipment, the terminal
equipment being coupled by the corresponding terminal adapter to the ATM
network;
the transmitting terminal equipment being selectively operable for
generating and supplying, to the corresponding transmitting terminal
adapter, a request signal which, when ON, requests the setting of an
associated logical channel in the ATM network and which, when OFF,
requests the release of an associated logical channel which currently is
set in the ATM network; and
the terminal adapter further comprises:
call means, operable when the terminal adapter is a transmitting terminal
adapter and responsive to the receipt of an ON request signal from the
corresponding transmitting terminal equipment, for setting the associated
logical channel in the ATM network between the transmitting terminal
adapter and the receiving terminal adapter of a corresponding receiving
terminal equipment, thereby to enable the transfer of data from the
transmitting terminal equipment and corresponding transmitting terminal
adapter through the ATM network to the receiving terminal adapter and
thereby to the corresponding receiving terminal equipment, and
disconnect means, operable when the terminal adapter is a transmitting
terminal adapter, for releasing a logical channel, which currently is set
in the ATM network, in response to an OFF request signal received from the
corresponding transmitting terminal equipment.
2. The logical channel setting system as claimed in claim 1, wherein said
call means sets the logical channel by transmitting a call setup message
to the ATM network requesting the logical channel and a band to the
receiving terminal adapter and corresponding receiving terminal equipment
via the ATM network.
3. The logical channel setting system as claimed in claim 2, wherein said
call means requests a broad band in the order of Mbps.
4. The logical channel setting system as claimed in claim 2, wherein the
ATM network, in response to receipt of the call setup message from the
call means of the transmitting terminal adapter, transmits the call setup
message to the receiving terminal adapter and a call procedure signal to
the corresponding transmitting terminal equipment and, further, in
response to receipt of a connect message from the receiving terminal
equipment, transmitted thereto through the corresponding receiving
terminal adapter, transmits a connect ON message to the transmitting
terminal adapter and thereafter transmits a connect acknowledgement
message to the receiving terminal adapter.
5. The logical channel setting system as claimed in claim 4, wherein:
the transmitting terminal adapter, upon receipt of the connect signal from
the ATM network, transmits a connect ON signal to the corresponding
transmitting terminal equipment;
the receiving terminal adapter, in response to the connect acknowledgement
signal, enabling receipt of a data transmission by the corresponding
receiving terminal equipment; and
the transmitting terminal equipment, in response to the connect ON signal,
initiating the transmission of data through the corresponding transmitting
terminal adapter and the ATM network to the receiving terminal adapter and
corresponding receiving terminal equipment.
6. The logical channel setting system as claimed in claim 5, wherein the
transmitting terminal equipment transmits an OFF request signal when a
data transmission being performed thereby ends, and said disconnect means
transmits a disconnect message over the ATM network to the receiving
terminal adapter and corresponding receiving terminal equipment in
response to the OFF request signal.
7. The logical channel setting system as claimed in claim 2, wherein the
transmitting terminal equipment transmits an OFF request signal when a
data transmission being performed thereby ends, and said disconnect means
transmits a disconnect message over the ATM network to the receiving
terminal adapter and corresponding receiving terminal equipment in
response to the OFF request signal.
8. A logical channel setting system for an asynchronous transfer mode (ATM)
network coupled to corresponding terminal equipment via a respective
terminal adapter, the system comprising:
call means operable when the terminal adapter is a transmitting terminal
adapter, for setting a logical channel in the ATM network, said logical
channel having a narrow band in the order of Kbps;
first message transmitting means, operable when the terminal adapter is a
transmitting terminal adapter and responsive to an ON request signal from
the corresponding terminal equipment, for transmitting to the ATM network
a band change message which requests a change of the band width of the
logical channel from the narrow band to a broad band in the order of Mbps;
and
second message transmitting means, operable when the terminal adapter is a
transmitting terminal adapter and responsive to an OFF request signal
received thereby from the corresponding transmitting terminal equipment,
for transmitting to the ATM network a band release message which requests
a change of the band width of the logical channel from the broad band to
the narrow band.
9. The logical channel setting system as claimed in claim 8, wherein said
call means sets the logical channel by transmitting a call setup message
to the ATM network requesting the logical channel and the narrow band to
the receiving terminal adapter and corresponding receiving terminal
equipment via the ATM network.
10. The logical channel setting system as claimed in claim 9, wherein:
the ATM network, in response to receipt of the call setup message from the
call means of the transmitting terminal adapter, transmits a call
procedure message to the transmitting terminal adapter and, further, in
response to a connect message from the receiving terminal adapter,
transmits a connect message to the transmitting terminal adapter and a
connect acknowledge message to the receiving terminal adapter and,
further, in response to the band change message transmitted thereto by the
first transmission means, transmits a band change message to the receiving
terminal adapter;
the receiving terminal adapter transmitting an request ON message to the
corresponding receiving terminal equipment and, in response thereto, the
receiving terminal equipment transmitting a connect ON message to the
receiving terminal adapter and, in response thereto, the receiving
terminal adapter transmitting a band width confirmation message to the ATM
network; and
the ATM network transmitting the band width confirmation message to the
transmitting terminal adapter and, in response thereto, the transmitting
terminal adapter transmitting a connect ON message to the corresponding
transmitting terminal equipment, the transmitting terminal equipment
thereupon transmitting data to the corresponding transmitting terminal
adapter for transfer over the ATM network to the receiving terminal
adapter and corresponding receiving terminal equipment.
11. The logical channel setting system as claimed in claim 10, wherein the
transmitting terminal equipment transmits an OFF request signal when a
data transmission being performed thereby ends.
12. The logical channel setting system as claimed in claim 8, wherein the
transmitting terminal equipment transmits an OFF request signal when a
data transmission being performed thereby ends.
13. A logical channel setting system for a communication network carrying
fixed bit length cells over a selected one of plural routes from a
transmitting terminal to a receiving terminal and which cells contain,
respectively and selectively, plural different types of information, the
system comprising:
plural terminal adapters and plural, respectively associated terminal
equipments, each thereof operable in conformance with a high-speed digital
transmission interface for transmitting burst digital information and each
terminal adaptor and respectively associated terminal equipment being
selectively operable, in a transmit mode, as a transmitting terminal
adaptor and a respectively associated transmitting terminal equipment and,
in a receiving mode, as a receiving terminal adaptor and a respectively
associated receiving terminal equipment, each terminal equipment being
coupled by the respectively associated terminal adaptor to the
communication network;
each transmitting terminal equipment being selectively operable for
generating and supplying, to the respectively associated transmitting
terminal adapter, a request signal which, when ON, requests the setting of
an associated logical channel in the communication network and which, when
OFF, requests the release of an associated logical channel which currently
is set in the communication network; and
each terminal adapter further comprises:
call means, operable in the transmitting mode of the terminal adapter and
in response to the receipt of an ON request signal from the respectively
associated transmitting terminal equipment, for setting the associated
logical channel in the communication network between the transmitting
terminal adapter and the receiving terminal adapter of a respectively
associated receiving terminal equipment, thereby to enable the transfer of
data from the transmitting terminal equipment and respectively associated
transmitting terminal adapter through the communication network to the
receiving terminal adapter and thereby to the respectively associated
receiving terminal equipment, and
disconnect means, operable in the transmitting mode of the terminal adapter
and in response to receipt of an OFF request signal from the respectively
associated transmitting terminal equipment, for releasing a logical
channel which currently is set in the communication network.
14. The logical channel setting system as claimed in claim 13, wherein said
call means sets the logical channel by transmitting a call setup message
to the communication network requesting the logical channel and a band to
the receiving terminal adapter and respectively associated receiving
terminal equipment via the communication network.
15. The logical channel setting system as claimed in claim 14, wherein said
call means requests a broad band in the order of Mbps.
16. The logical channel setting system as claimed in claim 14, wherein the
communication network, in response to receipt of the call setup message
from the call means of the transmitting terminal adapter, transmits the
call setup message to the receiving terminal adapter and a call procedure
signal to the respectively associated transmitting terminal equipment and,
further, in response to receipt of a connect message from the receiving
terminal equipment, transmitted thereto through the respectively
associated receiving terminal adapter, transmits a connect ON message to
the transmitting terminal adapter and thereafter transmits a connect
acknowledgement message to the receiving terminal adapter.
17. The logical channel setting system as claimed in claim 14, wherein the
transmitting terminal equipment transmits an OFF request signal when a
data transmission being performed thereby ends, and said disconnect means
transmits a disconnect message over the communication network to the
receiving terminal adapter and respectively associated receiving terminal
equipment in response to the OFF request signal.
18. A logical channel setting system for a communication network carrying
fixed bit length cells over a selected one of plural routes from a
transmitting terminal to a receiving terminal and which the cells contain,
respectively and selectively, plural different types of information, the
system comprising:
plural terminal adapters and plural, respectively associated terminal
equipments operable in conformance with a high-speed digital transmission
interface for transmitting burst digital information, each terminal
equipment being coupled by the respectively associated terminal adaptor to
the communication network and each terminal adaptor and respectively
associated terminal equipment being selectively operable, in a transmit
mode, as a transmitting terminal adaptor and a respectively associated
transmitting terminal equipment and, in a receiving mode, as a receiving
terminal adaptor and a respectively associated receiving terminal
equipment;
each terminal adaptor further comprising:
call means, operable when the terminal adapter is a transmitting terminal
adapter, for setting a logical channel having a narrow band in the order
of Kbps in the communication network,
first message transmitting means, operable when the terminal adapter is a
transmitting terminal adapter and responsive to an ON request signal from
the respectively associated transmitting terminal equipment, for
transmitting to the communication network a band change message which
requests a change of the band width of the logical channel from the narrow
band to a broad band in the order of Mbps, and
second message transmitting means, operable when the terminal adapter is a
transmitting terminal adapter and responsive to an OFF request signal
received thereby from the respectively associated transmitting terminal
equipment, for transmitting to the communication network a band release
message which requests a change of the band width of the logical channel
from the broad band to the narrow band.
19. The logical channel setting system as claimed in claim 18, wherein the
call means of each respectively associated terminal adaptor sets the
logical channel by transmitting a call setup message to the communication
network requesting the logical channel and the narrow band to the
receiving terminal adapter and respectively associated receiving terminal
equipment via the communication network.
20. The logical channel setting system as claimed in claim 19, wherein:
the communication network, in response to receipt of the call setup message
from the call means of the transmitting terminal adapter, transmits a call
procedure message to the transmitting terminal adapter and, further, in
response to a connect message from the receiving terminal adapter,
transmits a connect message to the transmitting terminal adapter and a
connect acknowledge message to the receiving terminal adapter and,
further, in response to the band change message transmitted thereto by the
first transmission means, transmits a band change message to the receiving
terminal adapter;
the receiving terminal adapter transmits a request ON message to the
respectively associated receiving terminal equipment and, in response
thereto, the receiving terminal equipment transmits a connect ON message
to the receiving terminal adapter and, in response thereto, the receiving
terminal adapter transmits a band width confirmation message to the
communication network; and
the communication network transmits the band width confirmation message to
the transmitting terminal adapter and, in response thereto, the
transmitting terminal adapter transmits a connect ON message to the
respectively associated transmitting terminal equipment, the transmitting
terminal equipment thereupon transmitting data to the respectively
associated transmitting terminal adapter for transfer over the
communication network to the receiving terminal adapter and respectively
associated receiving terminal equipment.
21. The logical channel setting system as claimed in claim 18, wherein the
transmitting terminal equipment transmits an OFF request signal when a
data transmission being performed thereby ends.
22. The logical channel setting system as claimed in claim 16, wherein:
the transmitting terminal adapter, upon receipt of the connect signal from
the communication network, transmits a connect ON signal to the
respectively associated transmitting terminal equipment;
the receiving terminal adapter, in response to the connect acknowledgement
signal, enables receipt of a data transmission by the respectively
associated receiving terminal equipment; and
the transmitting terminal equipment, in response to the connect ON signal,
initiates the transmission of data through the respectively associated
transmitting terminal adapter and the communication network to the
receiving terminal adapter and respectively associated receiving terminal
equipment.
23. The logical channel setting system as claimed in claim 22, wherein the
transmitting terminal equipment transmits an OFF request signal when a
data transmission being performed thereby ends, and said disconnect means
transmits a disconnect message over the communication network to the
receiving terminal adapter and respectively associated receiving terminal
equipment in response to the OFF request signal.
24. The logical channel setting system as claimed in claim 20, wherein the
transmitting terminal equipment transmits an OFF request signal when a
data transmission being performed thereby ends.
25. A terminal adaptor for coupling a respectively associated terminal
equipment to a communication network, the terminal adapter being operable
selectively in a transmitting mode, as a transmitting terminal adapter,
and in a receiving mode, as a receiving terminal adapter, the transmitting
terminal adapter coupling data from a respectively associated transmitting
terminal equipment to a communication network for transmission thereover
and the receiving terminal adapter receiving data transmitted over a
communication network and coupling the received data to a respectively
associated receiving terminal equipment, the communication network
carrying data in fixed bit length cells over a selected one of plural
routes, the terminal adapter comprising:
call means, operable in the transmitting mode of the terminal adapter and
in response to the receipt of an ON request signal from a respectively
associated transmitting terminal equipment, for setting an associated
logical channel in the communication network thereby to enable the
coupling of data from the respectively associated transmitting terminal
equipment to the communication network for transmission thereover; and
disconnect means, operable in the transmitting mode of the terminal adapter
and in response to receipt of an OFF request signal from the respectively
associated transmitting terminal equipment, for releasing a logical
channel which currently is set in the communication network.
26. The terminal adapter as claimed in claim 25, wherein said call means
sets the logical channel by transmitting a call setup message to the
communication network requesting the logical channel and a band to a
remote, receiving terminal adapter and a respectively associated and
remote receiving terminal equipment via the communication network.
27. The terminal adapter as claimed in claim 26, wherein said call means
requests a broad band in the order of Mbps.
28. The terminal adapter as claimed in claim 26, wherein the communication
network, in response to receipt of the call setup message from the call
means of the transmitting terminal adapter, transmits the call setup
message to the remote receiving terminal adapter and a call procedure
signal to the respectively associated transmitting terminal equipment and,
further, in response to receipt of a connect message from the remote,
receiving terminal equipment, transmitted thereto through the respectively
associated and remote receiving terminal adapter, transmits a connect ON
message to the transmitting terminal adapter and thereafter transmits a
connect acknowledgement message to the remote, receiving terminal adapter.
29. The terminal adapter as claimed in claim 26, wherein the transmitting
terminal equipment transmits an OFF request signal when a data
transmission being performed thereby ends, and said disconnect means
transmits a disconnect message over the communication network to the
remote, receiving terminal adapter and respectively associated, remote
receiving terminal equipment in response to the OFF request signal.
30. A terminal adaptor for coupling a respectively associated terminal
equipment to a communication network, the terminal adapter and
respectively associated terminal equipment being operable, selectively, in
a transmitting mode and in a receiving mode respectively for transmitting
data over the communication network to a remote receiving terminal adapter
and a respectively associated, remote terminal equipment and for receiving
data, transmitted over the communications network from a remote,
transmitting terminal adapter and a respectively associated and remote
terminal equipment, the communication network carrying fixed bit length
cells over a selected one of plural routes selectively interconnecting a
transmitting terminal adapter and a receiving terminal adapter designated
by the transmitting terminal adapter, each terminal adaptor comprising:
call means, operable when the terminal adapter is a transmitting terminal
adapter, for setting a logical channel having a narrow band in the order
of Kbps in the communication network;
first message transmitting means, operable when the terminal adapter is a
transmitting terminal adapter and responsive to an ON request signal from
the respectively associated terminal equipment, for transmitting to the
communication network a band change message which requests a change of the
band width of the logical channel from the narrow band to a broad band in
the order of Mbps; and
second message transmitting means, operable when the terminal adapter is a
transmitting terminal adapter and responsive to an OFF request signal
received thereby from the respectively associated transmitting terminal
equipment, for transmitting to the communication network a band release
message which requests a change of the band width of the logical channel
from the broad band to the narrow band.
31. The terminal adapter as claimed in claim 30, wherein the call means
sets the logical channel by transmitting a call setup message to the
communication network requesting the logical channel and the narrow band
to a remote receiving terminal adapter and respectively associated, remote
receiving terminal equipment via the communication network.
32. The terminal adapter as claimed in claim 31, wherein:
the communication network, in response to receipt of the call setup message
from the call means of the transmitting terminal adapter, transmits a call
procedure message to the transmitting terminal adapter and, further, in
response to a connect message from the remote, receiving terminal adapter,
transmits a connect message to the transmitting terminal adapter and a
connect acknowledge message to the remote, receiving terminal adapter and,
further, in response to the band change message transmitted thereto by the
first transmission means, transmits a band change message to the remote,
receiving terminal adapter;
the remote, receiving terminal adapter transmits a request ON message to
the respectively associated and remote receiving terminal equipment and,
in response thereto, the remote receiving terminal equipment transmits a
connect ON message to the remote receiving terminal adapter and, in
response thereto, the remote receiving terminal adapter transmits a band
width confirmation message to the communication network; and
the communication network transmits the band width confirmation message to
the transmitting terminal adapter and, in response thereto, the
transmitting terminal adapter transmits a connect ON message to the
respectively associated transmitting terminal equipment, the transmitting
terminal equipment thereupon transmitting data to the respectively
associated transmitting terminal adapter for transfer over the
communication network to the remote receiving terminal adapter for
coupling thereby to the respectively associated and remote receiving
terminal equipment.
33. The terminal adapter as claimed in claim 30, wherein the transmitting
terminal equipment transmits an OFF request signal when a data
transmission being performed thereby ends.
34. The terminal adapter as claimed in claim 28, wherein:
the transmitting terminal adapter, upon receipt of the connect signal from
the communication network, transmits a connect ON signal to the
respectively associated transmitting terminal equipment;
the remote receiving terminal adapter, in response to the connect
acknowledgement signal, enables receipt of a data transmission by the
respectively associated and remote receiving terminal equipment; and
the transmitting terminal equipment, in response to the connect ON signal,
initiates the transmission of data through the respectively associated
transmitting terminal adapter and the communication network to the remote
receiving terminal adapter and the respectively associated and remote
receiving terminal equipment.
35. The terminal adapter as claimed in claim 34, wherein the transmitting
terminal equipment transmits an OFF request signal when a data
transmission being performed thereby ends, and said disconnect means
transmits a disconnect message over the communication network to the
remote, receiving terminal adapter and the respectively associated and
remote receiving terminal equipment in response to the OFF request signal.
36. The terminal adapter as claimed in claim 32, wherein the transmitting
terminal equipment transmits an OFF request signal when a data
transmission being performed thereby ends. |
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Description |
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BACKGROUND OF THE INVENTION
The present invention generally relates to logical channel setting systems,
and more particularly to a logical channel setting system for an
asynchronous transfer mode (ATM) network.
Recently, there is active research to realize a broadband integrated
services digital network (B-ISDN) using the ATM. On the other hand, a high
performance parallel interface (HIPPI) has been proposed to transfer a
large amount of data at a high speed between computers such as
supercomputers or between a terminal and a computer. A method has also
been proposed to convert HIPPI data into ATM cells at a terminal adapter
(TA) on the transmitting side, to switch and transmit the ATM cells within
an ATM network, and to convert the ATM cells back into the HIPPI data at a
TA on the receiving side. However, in order to transmit the HIPPI data via
the ATM network, it is necessary to reserve a band in which the large
amount of data can be transmitted, as a virtual channel (VC, or logical
channel), and the network and the like are greatly affected thereby.
FIG. 1 shows a communication system using a HIPPI interface provided by an
ATM network. In FIG. 1, an ATM network 80 which is a B-ISDN is coupled to
a plurality of terminal adapters (HIPPI-TA) 81 of the HIPPI interface. A
HIPPI terminal equipment (TE) is coupled to each HIPPI-TA 81. In addition,
the ATM network 80 is coupled to one or a plurality of terminal adapters
(not shown) of other interfaces.
FIG. 2 shows the frame structure of the HIPPI protocol. As shown in line A
of FIG. 2, a group of data received from a host unit, such as a computer
and a TE, is called a packet, and a maximum length of this packet is 4
Gbytes. In the TE 82 of the HIPPI interface, the packet is divided into
units called bursts, as shown in line B of FIG. 2, and each burst has a
fixed length of 1 kbytes. The packet is transferred between the TE 82 and
the HIPPI-TA 81 via parallel buses made up of a data bus, a control bus,
an address bus and the like. The HIPPI-TA 81 converts the bursts into the
ATM protocol. According to the ATM protocol, ATM cells having a total
length of 53 octets (bytes) are generated as shown in line C of FIG. 2.
Out of the 53 octets, the first 5 octets form a header and the remaining
48 octets form an information part, and the burst data are successively
transmitted in division in this information part.
FIG. 3 is a diagram for explaining the HIPPI interface. As shown in FIG. 3,
when making a data transfer in one direction between a HIPPI terminal (or
computer) "TE" and a TA, various kinds of control signals are exchanged.
Although the HIPPI interface is used for making data communication in one
direction, the control signals are exchanged, that is, the control signals
are transmitted in both directions. The principal signals exchanged
between the transmitting side HIPPI TE 82 and a transmitting side HIPPI-TA
81 (or between a receiving side HIPPI-TA 81 and a receiving side HIPPI TE
82) include a 32-bit parallel data signal, a 4-bit parity signal with
respect to the data, a request signal, a connect signal, a ready signal, a
burst signal, a packet signal and the like. The request signal is ON when
requesting a data transmission and becomes OFF when the data transmission
ends. The connect signal indicates a state where the power source is
turned ON, and the ready signal indicates that a necessary preparations
are completed and the system is ready for a data transmission. The burst
signal indicates the breakpoint of the burst information, and the packet
signal indicates the breakpoint of the packet.
Because the HIPPI interface shown in FIG. 3 is provided between each HIPPI
TE 82 and the corresponding HIPPI-TA 81, it is necessary to convert the
HIPPI protocol into the ATM network protocol at the transmitting (or
receiving) side HIPPI-TA 81 for transmission within the ATM network 80 and
to reproduce the HIPPI protocol at the receiving (or transmitting) side
HIPPI-TA 81.
Conventionally, in order to transmit normal data, a VC (FIG. 1) is set
between the HIPPI-TA 81 (#1) and the other HIPPI-TA 81 (#2) at the time
when a call setup request is made by the man-machine- interface (MMI) of
the HIPPI-TA 81 (#1). In addition, this VC is released at the time when
the disconnect request is made by the MMI of the HIPPI-TA 81 (#1).
In order to enable data transmission at the HIPPI interface, a procedure is
carried out in which a request signal, which is ON, is transmitted from
the transmitting side HIPPI TE 82 and a connect signal, which is ON, is
returned from the receiving side HIPPI TE 82. In addition, when ending the
data transmission, a procedure is carried out in which a request signal,
which is OFF, is transmitted from the transmitting side HIPPI TE 82 and a
connect signal, which is OFF, is returned from the receiving side HIPPI TE
82. As shown in FIG. 1, the connection of the two HIPPI TEs 82 (#1 and #2)
is formed via the HIPPI-TAs 81 and the ATM network 80 in the state in
which the VC is set. As described above, the VC is conventionally set at
the time when the call setup request is made by the MMI of the HIPPI-TA
81, and the VC is released at the time when the disconnect request is made
by the MMI of the HIPPI-TA 81.
As another example of the conventional system, there is also a system which
sets the VC at a reserved time. According to such HIPPI interfaces, a
broad band of 600 Mbps, for example, is declared and set to the ATM
network 80 as the band which will be used when setting the VC with respect
to the ATM network 80. However, after the HIPPI-TA 81 makes the call
setup, responsive to the request by the MMI, there is a problem in that
the VC is constantly maintained even when no data is actually transmitted
from the HIPPI TE 82.
In this case, the ATM network 80 must allocate the broad band of the
transmission line for the VC which is not used, and a transmission request
from other HIPPI TEs 82 may not be accepted because there may not be
enough margin when the available band is calculated. On the other hand, in
the case where the VC is set by time reservation, the VC having the broad
band is set in waste if the time in which the data is actually transmitted
occupies only a short time interval of the reserved time span.
SUMMARY OF THE INVENTION
Accordingly, it is a general object of the present invention to provide a
novel and useful logical channel setting system in which the problems
described above are eliminated.
Another and more specific object of the present invention is to provide a
logical channel setting system for an asynchronous transfer mode (ATM)
network which is coupled to terminal equipments, which are in conformance
with a high performance parallel interface (HIPPI), via respective
terminal adapters which likewise are in conformance with the HIPPI,
wherein the logical channel setting system comprises call means, provided
in a transmitting terminal adapter, for setting a logical channel in the
ATM network in response to a request signal which is ON and which is
received from a transmitting terminal equipment which is coupled to the
transmitting terminal adapter, and disconnect means, provided in the
transmitting terminal adapter, for releasing the logical channel which is
previously set in the ATM network in response to a request signal which is
OFF and is received from the transmitting terminal equipment which is
coupled to the transmitting terminal adapter. According to the logical
channel setting system of the present invention, it is possible to improve
the utilization efficiency of the ATM network because the broad band will
not be wasted when providing the HIPPI by the ATM network.
Still another object of the present invention is to provide a logical
channel setting system for an asynchronous transfer mode (ATM) network
which is coupled to terminal equipments which are in conformance with a
high performance parallel interface (HIPPI) via respective terminal
adapters which are in conformance with the high performance parallel
interface (HIPPI), wherein the logical channel setting system comprises
call means, provided in a transmitting terminal adapter, for setting a
logical channel in the asynchronous transfer mode (ATM) network, and
wherein the logical channel has a narrow band of a Kbps order, first
message transmitting means, provided in the transmitting terminal adapter,
for transmitting to the asynchronous transfer mode (ATM) network a band
change message which requests a change of the band of the logical channel
from the narrow band to a broad band of Mbps order in response to a
request signal which is ON and is received from a transmitting terminal
equipment, and second message transmitting means, provided in the
transmitting terminal adapter, for transmitting to the asynchronous
transfer mode (ATM) network a band release message which requests a change
of the band of the logical channel from the broad band to the original
narrow band in response to a request signal which is OFF and is received
from the transmitting terminal equipment. According to the logical channel
setting system of the present invention, the broad band is not fixedly
used and the band can be changed depending on the request from the
terminal equipment. For this reason, it is possible to effectively manage
the band at the terminal equipment and/or the ATM network.
Other objects and further features of the present invention will be
apparent from the following detailed description when read in conjunction
with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a system block diagram showing a communication system having a
HIPPI interface provided by an ATM network;
FIG. 2 shows the frame structure of the HIPPI protocol;
FIG. 3 is a block diagram for explaining the HIPPI interface;
FIG. 4 is a system block diagram for explaining the operating principle of
a first embodiment of a logical channel setting system according to the
present invention;
FIG. 5 is a system block diagram for explaining the operating principle of
a second embodiment of the logical channel setting system according to the
present invention;
FIG. 6 shows a control sequence used in the first embodiment;
FIG. 7 is a system block diagram showing an embodiment of a HIPPI-TE used
in the first embodiment;
FIG. 8 shows a control sequence used in the second embodiment;
FIGS. 9(A) to 9(C) show embodiments of messages used in the second
embodiment;
FIG. 10 is a system block diagram showing an embodiment of a HIPPI-TE used
in the second embodiment; and
FIG. 11 is a flow chart for explaining an operation of a terminal adapter
of the first embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First, a description will be given of the operating principles of first and
second embodiments of a logical channel setting system according to the
present invention, by referring to FIGS. 4 and 5. FIG. 4 shows an
essential part of the first embodiment for explaining the operating
principle thereof, and FIG. 5 shows an essential part of the second
embodiment for explaining the operating principle thereof. In FIG. 5,
those parts which are basically the same as those corresponding parts in
FIG. 4 are designated by the same reference numerals, and a description
thereof will be omitted.
In FIG. 4, a HIPPI TE 1 and a HIPPI TA 2 are coupled as shown, and the TA 2
includes a call unit 20 and a disconnect unit 21. The TA 2 on the
transmitting side sets a VC (logical channel) by calling an ATM network
(not shown) in response to a request signal which is ON and is received
from the TE 1 on the transmitting side. The TA 2 on the transmitting side
releases the VC in response to a request signal which is OFF and is
received from the TE 1 on the transmitting side.
In the first embodiment, the TA 2 does not make a call in response to a
call setup request by the MMI. When the TE 1 generates a control signal
indicating the request signal which is ON, the call unit 20 of the TA 2 is
started and sends call setup information with respect to the ATM network.
A broadband VC of 600 Mbps, for example, which is specified in advance is
included within the call setup information. The ATM network receives the
call setup information and sets up a call, if the call can be accepted, to
enable a communication. Thereafter, when the data transmission from the TE
1 ends, the request signal becomes OFF. The disconnect unit 21 of the TA 2
is started in response to this request signal which is OFF, and the
disconnect means 21 sends a signal for releasing the set VC with respect
to the ATM network.
In FIG. 5, a call is made to the ATM network and a VC of a narrow band is
set when the power is turned ON at the TA 2. A message for changing the
band to the broad band is sent when a request signal which is ON is
received from the TE 1. On the other hand, a message for changing the band
to the narrow band is sent when a request signal which is OFF is received
from the TE 1.
In the second embodiment, the call unit 20 is started when the call setup
request is generated by the MMI at the TA 2, and the call setup
information is sent with respect to the ATM network, similarly to the
first embodiment. But in this case, a narrow band of 64 Kbps, for example,
is set in advance for the band of the VC. The ATM network receives the
call setup information and sets up a call, if the call can be accepted, to
enable a communication. Thereafter, if a data transmission is to be made
from the TE 1, the request signal is turned ON. When the TA 2 detects the
ON state of the request signal, a band change message transmitting unit 22
is started. The band change message transmitting unit 22 transmits the
band change message which requests the change of the band of the VC,
previously set at the narrow band, to the broad band. When the ATM network
receives this message, it becomes possible to transmit the data from the
TE 1 using the broad band.
When the data transmission ends, the TE 1 turns the request signal OFF.
When the TA 2 detects the OFF state of the request signal, a band release
message transmitting unit 23 is started. This band release message
transmitting unit 23 transmits a message which has a content opposite to
that of the message transmitted from the band change message transmitting
unit 22. In other words, the band release message transmitting unit 23
transmits the above described message which requests the change of the
band of the VC, previously set at the broad band, to the narrow band. As a
result, a large part of the broad band is released, and only a part of the
broad band remains.
Next, a more detailed description will be given of the first embodiment, by
referring to FIGS. 6 and 7. FIG. 6 shows a control sequence of the first
embodiment, and FIG. 7 shows an embodiment of the TA which is used in the
first embodiment. It will be assumed for the sake of convenience that this
embodiment is applied to the system shown in FIG. 1.
The control sequence shown in FIG. 6 will be described with reference to
the following three basic procedures.
According to a first procedure, the TE #1 transmits a request signal which
is ON (REQUEST ON) to the TA #1 in a step 30. The TA #1 which receives the
request signal which is ON (REQUEST ON) makes a call setup (SET UP) by
requesting a VC and a broad band of 600 Mbps, for example, with respect to
the TA #2 and the TE #2 via the ATM network 80 in a step 31. Then, a HIPPI
interface is made between the TA #2 and the TE #2. In other words, the
request signal which is ON (REQUEST ON) is transmitted from the TA #2 to
the TE #2 in a step 32, and a connect signal which is ON (CONNECT ON) is
returned from the TE #2 to the TA #2 in a step 33. Thereafter, a layer 3
(network layer) procedure is carried out between the ATM network 80 and
the TAs #2 and #1. More particularly, a call procedure signal (CALL PROC)
is transmitted from the ATM network 80 to the TA #1 in a step 34, a
connect message (CONN) is transmitted from the TA #2 to the TA #1 via the
ATM network 80 in a step 35, and a connection acknowledge message (CONN
ACK) is transmitted from the ATM network 80 to the TA #2 in a step 36. The
data transfer between the TEs #1 and TE #2 is enabled when the connect
signal which is ON (CONNECT ON) is returned from the TA #1 to the TE #1 in
a step 37.
According to a second procedure, a request signal which is OFF (REQUEST
OFF) is transmitted from the TE #1 to the TA #1 in a step 38 when the data
transfer ends. The TA #1 which receives this request signal which is OFF
(REQUEST OFF) starts to transmit a disconnect message (DISC) to the TA #2
and the TE #2 via the ATM network 80 in a step 39. The TA #2 transmits the
request signal which is OFF (REQUEST OFF) to the TE #2 in a step 40 in
response to the disconnect message (DISC). The TE #2 transmits a connect
signal which is OFF (CONNECT OFF) to the TA #2 in a step 41, and the TA #2
transmits a release message (REL) to the TA #1 via the ATM network 80 in
response to the connect signal which is OFF (CONNECT OFF). In addition, a
release communication message (REL COM) is transmitted from the TA #1 to
the TA #2 via the ATM network 80 in a step 43. The VC and the band is
released by the layer 3 clearing procedure of the steps 42 and 43, and the
TA #2 t | | |
