JP2795208B2 - Communication device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication device, and more particularly to a communication device used in a communication system in which a transmission rate can be set for each channel, such as an ATM communication system.

[0002]

2. Description of the Related Art In an ATM (Asynchronous Transfer Mode) communication system, one communication device transmits a plurality of virtual channels (V
C) is set, and a bandwidth (transmission rate) necessary to guarantee the communication quality required by the user for each channel.
And communication is performed.

[0003] There are various types of communication devices used in such a system. For example, a plurality of hardware (rate control devices) for performing communication related to a channel having a specific transmission rate are provided. ,
Some cells perform communication by selecting a rate control device according to the channel to which the cell belongs. The rate control device itself can realize various service qualities using a plurality of types of parameters (maximum rate, average rate, burst length, scheduling priority, etc.), and select each rate control device. Is performed as follows.

In a communication device using a conventional rate control device, a representative transmission rate is fixedly set for each of a plurality of rate control devices, and as shown schematically in FIG. In the table 23, the transmission rate 2 set for the device number 21 of each rate control device is set.
2 is stored. Then, a channel setting request 2 from the user is specified by specifying the minimum value and the maximum value of the transmission rate.
When 4 is performed, a rate controller (the rate controller 2 in the case of FIG. 8) in which the transmission rate within the requested range is set is selected from the plurality of rate controllers, Used for communication on that channel.

[0005]

Although the conventional rate control device management procedure in the communication device as described above has an advantage that the processing time required for selecting the rate control device is short, it is set in advance in each rate control device. If a communication request is made at a transmission rate other than the specified transmission rate, the communicator itself has a function capable of realizing communication of different qualities equal in number to the number of rate control devices, but the communication is requested. It is not achieved with the same quality, but always with a substitute quality.

An object of the present invention is to provide a communication device capable of dynamically managing the transmission rates of a finite number of rate control devices according to a rate requested by a user.

[0007]

According to the first aspect of the present invention,
(B) a plurality of rate control devices for transmitting cells related to the assigned channel at the set transmission rate;
(B) information storage means for storing information relating to transmission rates set to the plurality of rate control devices and assigned channels; and (c) information storage means for receiving a channel setting request. When there is a rate control device that recognizes the operation state of each rate control device based on the stored information and sets a transmission rate equal to the requested rate, which is the transmission rate required for the channel. Means for allocating the requested channel to the rate control device, and (d) the first allocating means.
A second allocating means for allocating the requested channel to the unused rate control device when there is an unused rate control device when the allocation by the allocating means is not performed; Means for specifying a rate control device for which a transmission rate closest to the requested rate is set when channel assignment is not performed by the means or the second allocating means; If the transmission rate of the rate control device is higher than the requested rate, the requested channel is assigned to the rate control device. A third allocator that changes the transmission rate to the requested rate and allocates the requested channel to the rate controller that changed the transmission rate. Comprising the door.

That is, according to the first aspect of the present invention, when all the rate control devices are in use and the transmission rates of the respective rate control devices are different from the required rates, the transmission rate closest to the required rate is used. And the communication device is configured such that the rate control device for which is set is used for the requested channel, and if the transmission rate of the rate control device is lower than the requested rate, , So that the transmission rate is changed to match the requested rate.

[0009] The invention according to claim 2 provides (a) a plurality of rate control devices for transmitting cells related to assigned channels at a set transmission rate, and (b) a plurality of rate control devices. Information storage means for storing information about the transmission rate and the assigned channel, and (c) when receiving a channel setting request,
There is a rate control device that recognizes the operation state of each rate control device based on the information stored in the information storage means and sets a transmission rate equal to the requested rate that is the transmission rate required for the channel. If you have
A first allocating means for allocating the requested channel to the rate control device; and (d) when an unused rate control device is present when the allocation by the first allocating device is not performed, Allocating means for allocating a channel to the unused rate control device,
(E) first specifying means for specifying a rate control device for which a transmission rate closest to the requested rate is set when channel allocation is not performed by the first allocating means or the second allocating means; ) The first allocating means or the second
When the channel allocation is not performed by the allocating unit, the second specifying unit that specifies the two rate control devices having the smallest transmission rate difference, and (g) the rate control device that is specified by the first specifying unit. Determining means for determining a magnitude relationship between a difference between the transmission rate and the requested rate and a difference between the transmission rates of the two rate control devices specified by the second specifying means; When it is determined that the difference between the transmission rate of the rate control device specified by the means and the request rate is smaller, the transmission rate of the rate control device specified by the first specification means is higher than the request rate. If there is, the requested channel is assigned to the rate controller, and if it is lower than the requested rate, the transmission rate of the rate controller is changed to the requested rate. A third allocating means for allocating the requested channel to the rate control device having changed the transmission rate and changing the transmission rate, and a request for the transmission rate of the rate control device specified by the first specifying means by the determining means. If it is determined that the difference from the rate is greater, all channels allocated to the two rate control devices specified by the second specifying means are changed to the larger transmission rate of the two rate control devices. Is assigned to the rate control device for which the transmission rate is set, and the transmission rate of the rate control device for which the small transmission rate is set is changed to the requested rate. , Fourth allocation means for allocating the requested channel.

In other words, according to the second aspect of the present invention, when all the rate control devices are in use and the transmission rates of the respective rate control devices are different from the required rates, the transmission rate closest to the required rate is used. Or the rate control device with the smaller transmission rate among the two rate control devices with the smallest difference in transmission rate is used for the requested channel.
The former rate controller is used because the difference (absolute value) between the transmission rate of the rate controller and the requested rate is
When the difference between the transmission rates is smaller than the difference (absolute value) between the transmission rates of the two rate controllers, and the magnitude relationship is opposite, the latter rate controller is used. Then, when the latter rate control device is used, the processing related to the channel that has been performed by that rate control device up to that point is performed by the other rate control device that is the target of calculating the transmission rate difference. Change the channel assignment.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to embodiments.

The communication device according to the embodiment is used in an ATM (Asynchronous Transfer Mode) communication system, and includes three rate control devices and a rate control device internally stored therein. It is composed of a management device that performs integrated management based on the contents of the management table.

FIG. 2 shows an outline of a rate control device management table provided in the communication device of the embodiment. As shown in the figure, the rate control device management table 11 includes, for each device number 12 of each rate control device constituting the communication system, whether or not the rate control device is used by one or more channels. , Transmission rate 14 set for the rate control device, and channel information 15 using the rate control device.

In the communication apparatus according to the embodiment, a channel is set or released in the following procedure while referring to and updating the contents of the rate control device management table.

First, the operation when a request for setting a channel with a transmission rate x is made will be described with reference to FIG. Although the communication device of the embodiment has three rate control devices as described above, FIG. 1 can also be applied to a case where the communication device has n rate control devices. A flowchart is shown.

As shown in the figure, when a request for setting a channel having a transmission rate x is made, the management device refers to the contents of the rate control device management table and requests the transmission rate x (hereinafter, referred to as a request). A rate control device a having a transmission rate equal to the rate x) is searched for (step S101).

If the rate control device a is present (step S102; yes), the communication of the requested channel is performed by the rate control device a (step S103). Also, when the rate control device a does not exist (step S102; nothing)
Search for an unused rate control device b (step S104), and if an unused rate control device b exists (step S105; yes), The transmission rate r (b) of the rate control device b is set to the requested rate x, and communication of the requested channel is performed by the rate control device b (step S106).

If there is no unused rate control device b (step S105; no), that is, if all rate control devices are used at a transmission rate different from the requested rate x, the rate control With reference to the contents of the device management table, a rate control device i in which the transmission rate closest to the request rate x is set and two rate control devices j and k in which the distance between the transmission rates is minimum are obtained. (Step S107).

The absolute value of the difference between the requested rate x and the transmission rate r (i) of the rate control device i, the transmission rates r (j) and r (k) of the two rate control devices j and k, The magnitude relation of the absolute value of the difference is compared (step S108), and when the former is smaller (Y), the communication of the requested channel is performed by the rate controller i (step S109). ). At this time, “r (i) ← max (x, r (i))” in the figure
If the requested rate x is higher than the transmission rate r (i) of the rate control device i, the transmission rate r (i) of the rate control device i is changed to x.

The requested rate x and the rate control device i
Is greater than the absolute value of the difference from the transmission rates r (j), r (k) of the rate controllers j, k (step S108; N). ), The magnitude relation between the transmission rates r (j) and r (k) is compared. If the transmission rate r (j) is smaller (step S110; Y), the rate controller j is used. Channels integrated into the rate control device k, and the transmission rate r (j) of the rate control device j.
Is set to x, and the rate controller j is in charge of the requested channel (step S111).

Conversely, if the transmission rate r (j) is higher (step S110; N), the rate controller k
Are integrated into the rate control device j, and the transmission rate r (k) of the rate control device k is x
Is set, and the rate control device k is in charge of the requested channel (step S112).

Hereinafter, with reference to FIGS. 3 to 5, the operation procedure of the communication apparatus of the embodiment described using the flowchart will be described more specifically.

For example, as shown in FIG. 3A, when all (three) rate control devices are in an unused state and a request for setting a channel 1 with a rate of “100” is issued. As described with reference to FIG. 1, the search for the rate control device set to the transmission rate “100” is performed, and since there is no corresponding rate control device, the search for the unused rate control device is further performed. Will be performed. And because there is an unused rate control device,
Step S106 is executed, and as shown in FIG. 3B, one of the unused rate control devices is
Channel 1 using the rate controller with device number "1"
Communication is performed.

In the state of FIG. 3B,
When the setting request for the channel 2 of the rate "100" is made, the rate control device of the device number "1" is operating at that rate, so that step S103 is executed, and FIG. ), The device number “1”
Will be in charge of communication on channel 1 and channel 2.

Subsequently, when a request for setting the channel 3 at the rate "110" is made, there is no rate controller operating at that rate and there is an unused rate controller. Then, as shown in FIG. 3 (D), the communication of the channel 3 is performed using the rate control device of the device number “2”.

As described above, in the communication apparatus according to the embodiment, when a channel setting request is made while an unused rate control apparatus is present, or the same transmission rate as the requested transmission rate is set. If there is a rate control device that is running,
The rate control device used by the requested channel is determined.

The processing after step S107 is performed when all the rate control devices are in use and the transmission rate of each rate control device is different from the requested rate. In such a case, The rate control device used by the request channel is determined based on the transmission rate and the request rate set for each rate control device.

For example, let us consider a case where a request for setting a channel 5 of rate "270" is made while all the rate control devices are in use, as shown in FIG. 4A. In this case, step S107 is executed, and in that step, the requested rate “27” is set.
The rate control device 3 is specified as the rate control device to which the transmission rate closest to “0” is set, and the rate control devices 1 and 2 are specified as the two rate control devices with the minimum difference between the transmission rates. In the state shown in Fig. 4A, there are two combinations of rate control devices that minimize the difference between the transmission rates, but in such a case, the combination is determined in advance. According to the ordering rule, one of the combinations is selected.

Then, x = 270, r (3) = 300, r (1)
= 100 and r (2) = 200, the absolute value (= 30) of the difference between the request rate x and the transmission rate r (3) is equal to the absolute value of the difference between the transmission rates of the rate controllers 1 and 2 (= 100)
In step S108, branching is performed on the Y side. As a result, as shown in FIG. 4B, the rate control device 3 takes charge of channels 4 and 5. In this case, since x <r (3), the transmission rate of the rate control device 3 is not changed. For example, when the requested rate is “310”, the rate control device 3 Transmission rate is "310"
Is changed to

When all the rate control devices are in use, as shown in FIG.
When the setting request of the channel 5 of “00” is made, in step S107, the rate control device 2 is specified as the rate control device in which the transmission rate closest to the requested rate “200” is set, and the transmission rate of the transmission rate is determined. The rate control devices 1 and 2 are specified as the two rate control devices having the minimum distance.

Then, in this case, x = 200, r
Since (1) = 100 and r (2) = 110, the required rate x
The absolute value (= 30) of the difference between the transmission rate and the transmission rate r (2) is the absolute value (= 10) of the difference between the transmission rates of the rate controllers 1 and 2.
In step S108, branching is performed on the N side.

Therefore, the difference between the transmission rates is small.
Since the two rate control devices 1 and 2 are integrated, and the rate control device for which a small transmission rate is set is the rate control device 1, as shown in FIG. Up to now, the channels 1 and 2 assigned to the rate control device 1 are assigned to the rate control device 2, and the requested rate "200" is newly set in the rate control device 1, and the channel 5 becomes Assigned.

As described above, in the communication device according to the embodiment, the transmission rates of the finite number of rate control devices are dynamically managed,
Assignment of the requested channel to the rate controller is performed. At this time, if necessary, the rate control device used by the existing channel is also changed, so that a plurality of channels are always assigned to a finite number of rate control devices and to each channel. The distribution is performed in such a manner as to best satisfy the required communication quality.

Even if the communication device is configured not to change the rate control device used by the existing channel (that is, in step S107 in FIG. 1, only the search for the rate control device i is performed. Then, step S109 is directly performed), and a communication device that can realize a better communication state than the conventional communication device can be obtained.

Finally, the operation of the communication apparatus according to the embodiment when a channel release is requested will be described with reference to FIGS. 6 and 7. FIG. 6 is a flowchart showing an operation procedure when a channel release is requested, and FIG. 7 is a diagram showing an example of the contents of the rate control device management table before and after the channel release.

As shown in FIG. 6, when a channel release request is issued, the management device refers to the contents of the rate control device management table, specifies the rate control device used by the channel, and Then, it is determined whether or not there is another channel using the rate control device (step S201). If another channel exists (step S202; Y), the channel information relating to the rate control device is changed (step S2).
03), if there is no other channel (step S202; N), the rate control device is unused (step S204).

For example, as shown in FIG. 7 (A), when five channels such as channels 1 to 5 are set and channel 3 is requested to be released,
Since other channels are not assigned to the rate control device 2 to which the channel 3 is assigned, step S203 in FIG. 6 is executed, and as shown in FIG. Is changed to unused.

[0038]

As described in detail above, claim 1 is as follows.
According to the described invention, when all the rate control devices are in use and the transmission rate of each rate control device is different from the request rate, the rate at which the transmission rate closest to the request rate is set When the control device determines that the transmission rate is lower than the required rate, the transmission rate is changed to match the required rate and used for the requested channel, and so on. Since the transmission rate is dynamically controlled, it is possible to appropriately respond to various communication requests from the user.

Further, when the communication device is configured so that the rate control device used by the existing channel is changed when a predetermined condition is satisfied, as in the second aspect of the present invention. Multiple channels are allocated to a finite number of rate control devices in a manner that better satisfies the communication quality required for each channel, so that various communication requests from users can be handled more accurately. You can do it.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating a response procedure to a channel setting request of a communication device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a rate control device management table used in the communication device according to the embodiment.

FIG. 3 is a diagram illustrating an operation procedure when a request channel is set when an unused rate control device is present in the communication device according to the embodiment, based on a change in the content of a rate control device management table. FIG.

FIG. 4 is an explanatory diagram showing an example of an operation procedure in a case where a request channel is set without integration of existing channels in the communication device according to the embodiment by changing the content of a rate control device management table. is there.

FIG. 5 is an explanatory diagram showing an example of an operation procedure in a case where a request channel is set with the integration of existing channels in the communication device according to the embodiment, based on a change in the content of a rate control device management table.

FIG. 6 is a flowchart illustrating a response procedure to a channel release request of the communication apparatus according to the embodiment.

FIG. 7 is a flowchart showing a response procedure to a channel release request of the communication device according to the embodiment.

FIG. 8 is an explanatory diagram showing an outline of an operation of a conventional communication device including a rate control device.

[Explanation of symbols]

 11 Rate control device management table 12, 21 Device number 13 Status information 14, 22 Transmission rate 15 Channel information 23 Management table 24 Channel setting request

Claims (2)

(57) [Claims] 1. A plurality of rate control devices for transmitting cells related to assigned channels at a set transmission rate, and information on transmission rates set for the plurality of rate control devices and assigned channels. And an information storage unit for storing the operation status of each rate control device based on the information stored in the information storage unit when a channel setting request is received. If there is a rate control device for which a transmission rate equal to the requested rate, which is the transmission rate, is set, first allocating means for allocating the requested channel to the rate control device; If there is an unused rate controller when there is no allocation by Allocating means for allocating to the rate control apparatus, and a rate control apparatus which sets a transmission rate closest to the requested rate when channel allocation is not performed by the first allocating means or the second allocating means. Specifying means for specifying, and if the transmission rate of the rate control device specified by the specifying means is higher than the requested rate, assigning the requested channel to the rate control device, A third allocating means for changing the transmission rate of the rate control device to the requested rate if the transmission rate is lower, and allocating a requested channel to the rate control device having changed the transmission rate. A communication device, characterized in that: 2. A plurality of rate controllers for transmitting cells related to assigned channels at a set transmission rate, and information on transmission rates set for the plurality of rate controllers and assigned channels. And an information storage unit for storing the operation status of each rate control device based on the information stored in the information storage unit when a channel setting request is received. If there is a rate control device for which a transmission rate equal to the requested rate, which is the transmission rate, is set, first allocating means for allocating the requested channel to the rate control device; If there is an unused rate controller when there is no allocation by A second allocating means for allocating to the rate control apparatus, and a rate control apparatus to which a transmission rate closest to the requested rate is set when no channel is allocated by the first allocating means or the second allocating means. First specifying means for specifying, and second specifying means for specifying two rate control devices having the smallest difference in transmission rate when channel allocation is not performed by the first allocating means or the second allocating means. Determining a magnitude relationship between a difference between the transmission rate of the rate control device specified by the first specifying unit and the request rate and a difference between the transmission rates of the two rate control devices specified by the second specifying unit. And a determining unit that determines that the difference between the transmission rate of the rate control device specified by the first specifying unit and the requested rate is smaller. In this case, when the transmission rate of the rate control device specified by the first specifying means is higher than the requested rate, the requested channel is allocated to the rate control device and the requested channel is lower than the requested rate. In some cases, the transmission rate of the rate control device is changed to the request rate, and a third allocation unit that allocates a requested channel to the rate control device that has changed the transmission rate. When it is determined that the difference between the transmission rate of the specified rate control device and the requested rate is larger, all channels assigned to the two rate control devices specified by the second specifying unit are set to those Of the two rate control devices, the one assigned to the larger transmission rate is assigned to the one with the smaller transmission rate. And a fourth allocating means for changing the transmission rate of the rate control apparatus to which the rate is set to the request rate and allocating the requested channel to the rate control apparatus having changed the transmission rate. A communication device, characterized in that: