[DESCRIPTION]
[Title of Invention] COMMUNICATION DEVICE AND
TRAFFIC CONTROL METHOD
5 [Technical Field]
[OOOl]
The present invention relates to a communication device and a
traffic control method.
10 [Background Art]
[0002]
In recent years, with the advancement of informatization, demand
for data communication traffic by data communication and the like is
increasing. Accordingly, a wider bandwidth network and reduction in
15 network operation cost are required. The network configured with a
wireless link such as a Fixed broadband Wireless Access (FWA) that uses a
wireless system using a frequency of a millimeter-wave band or the like by
which a wide-band transmission can be achieved or the like is used for a
portable telephone network or the like. The communication quality of the
20 wireless link varies in accordance with a SNR (Signal to Noise Ratio) or
the like of the received signal.
[0003]
As a technology for realizing a wireless link with wider bandwidth,
the attention is focused on, for example, an adaptive modulation
25 technology. The adaptive modulation technology adaptively selects, for
example, a symbol rate or a modulation multi-value number according to a
transmission path condition (a radio condition of the wireless link) and
uses different modulation methods so as to get the best transmission
efficiency. By using the adaptive modulation technology, the most
3
suitable wireless communication can be achieved according to a radio
environment and the improvement of the frequency utilization efficiency
can be expected.
[0004]
5 Further, in order to realize a line having a wide transmission band
between transmission devices, a link aggregation technology which
virtually bundles a plurality of physical lines into one line and uses a band
that corresponds to the band obtained by totalizing the bands of the
physical lines is used.
10 [OOOS]
In the link aggregation which bundles the plurality of links, a
method by which the band can be most efficiently used is a per-packet
traffic distribution method which the link used for transmission of a packet
is determined for each packet.
15 [0006]
I-Iowever, when the traffic distribution is performed for each packet,
a packet order change occurs. For this reason, this method is not suitable
for a high priority traffic transmission for which high communication
quality is required.
20 [0007]
On the other hand, in the link aggregation in which a plurality of
wireless links whose bands vary are bundled, when the wireless link used
for transmission is fixedly determined for each flow, there is a case in
which a traffic is biased. Further, when the transmission rate of a certain
25 wireless link is decreased by an adaptation modulation function, the
communication quality of the high priority traffic using this link degrades.
[OOOS]
As the traffic control for the link aggregation, for example, in
Patent Literature 1, a traffic distribution control device which enables
4
uniform band distribution to a plurality of physical ports constituting a
logic port of the link aggregation is disclosed. In Patent Literature 2, a
method and a device by which even when a failure occurs in each of the
physical lines that are logically integrated as the link aggregation, the band
5 control corresponding to the number of the normal physical lines is
performed to a user traffic by referring to the user's band control
information for each normal physical line are disclosed. Further, in
Patent Literature 3, a packet distribution system in which a bias of a flow
rate band distributed to the physical port is found based on information
10 about a maximum flow rate band and an average flow rate band in which an
actual traffic flow rate is reflected, an amount of the flow rate band is
determined, and the packet is distributed so that the flow rate band of the
traffic having a high flow rate band is reduced by the average flow rate
band is disclosed.
15 [0009]
It is assumed that a wired link in which a link band does not vary is
used, in the disclosure of Patent Literature 1 to Patent Literature 3, which
cannot be applied to traffic distribution of wireless link considering the
case of bandwidth fluctuation caused by adaptive modulation.
[OO lo]
In Patent Literature 4, a wireless device which multiplexes and
demultiplexes a radio frame transmitted in a radio section composed of a
plurality of wireless links in which a multi-link communication is provided
in a data link layer for each radio link layer is disclosed. A wireless
25 entrance unit converts a MRL (Multi Radio Linc) frame distributed by an
aggregation switch into the radio frame and transmits it for each wireless
link of the radio section. Further, the wireless entrance unit converts the
radio frame received for each wireless link of the radio section into the
MRL frame and outputs it to the aggregation switch. Further, the
5
aggregation switch aggregates the MRL frames and reassembles them into
a network frame. In the wireless device disclosed in the Patent Literature
4, a division process and a restoration process are required for all the
frames and an overhead problem in which a used band increases by header
5 information added at the time of dividing the frame occurs.
[OOll]
Further, in Patent Literature 5, a communication device which
distributes the packet according to QoS (Quality of Service) to each
wireless system in a communication environment in which a plurality of
10 different wireless systems such as a cognitive wireless system and the like
are used is disclosed. In the communication device, the wireless link
used for transmission is determined by taking into consideration the
priority of the traffic and the quality of the wireless link. Since the
process is performed on a per-packet basis, a packet order change cannot
15 be avoided, which makes this communication device unsuitable for a high
priority traffic.
[OO 121
In the invention disclosed in Patent Literature 6, a receiver
performs a selective measurement with respect to a downlink transmission,
20 combines a past measurement value (or past channel quality estimation)
and a current measurement value (or current channel quality estimation),
predicts a channel quality at a certain time in the future, and derives a
predicted channel quality indicator (CQI). The predicted CQI is
transmitted to a transmitter and used for an update of a transmission
25 parameter. Further, the CQI represents one of a recommended transport
block size, a modulation format, the number of the codes, a power offset,
and a plurality of different types of link adaptation parameters.
[00 131
In Patent Literature 7, a device which predicts the degradation in
6
line quality due to rain from rainfall information, performs band priority
control in advance, so that it transmits information that cannot be
transmitted by an interruption due to rain in advance, thereby reducing
degradation in throughput due to line quality degradation of the wireless
5 line is disclosed.
[Citation List]
[Patent Literature]
[00 1 41
[PTL 11 Japanese Patent Application Laid-Open No. 2006-5437
[PTL 21 Japanese Patent Application Laid-Open No. 2007-67586
[PTL 31 Japanese Patent Application Laid-Open No. 20 1 1 - 1036 14
[PTL 41 Japanese Patent Application Laid-Open No. 201 0-258606
[PTL 51 Japanese Patent Application Laid-Open No. 2009- 14 143 8
15 [PTL 61 Japanese Unexamined Patent Application Publication
(Translation of PCT Application) No. 2006-505221
[PTL 71 Japanese Patent Application Laid-Open No. 2004-363679
[Non Patent Literature]
[00 151
20 [NPL 11 Jun Nishioka, Satoru Yamano, "A Study on Routing over
AMC-enabled FWA Mesh Network", IEICE technical report, January 2009,
vol. 108, no. 392, NS2008-134, pp. 49 - 54
[Summary of Invention]
[Technical Problem]
[OO 1 61
The related technologies will be analyzed below.
[00 171
In traffic transmission between the communication devices
7
connected by a plurality of wireless links, it is difficult to perform a traffic
processing which satisfies both of the following conditions:
- the communication quality of the high priority traffic can be
guaranteed; and
5 - the link band can be effectively used.
[0018]
Further, in the technology disclosed in Patent Literature 1 to Patent
Literature 3, it is assumed that a wired link in which the link band does not
vary is used. Therefore, this technology cannot distribute the traffic of
10 the wireless link considering the case of the band fluctuation caused by
adaptation modulation. Further, in the technology disclosed in Patent
Literature 4, a division process and a restoration process are required for
all the frames and an overhead problem in which a used band increases by
adding header information at the time of dividing the frame occurs. The
15 technology disclosed in Patent Literature 5 determines the wireless link
used for transmission by taking into consideration the priority of the traffic
and the quality of the wireless link. However, since the process is
performed on a per-packet basis, a packet order change cannot be avoided,
which makes this technology unsuitable for the high priority traffic.
20 [0019]
The present invention is made in view of the above problem. The
object is to provide a device and a method which can secure the
communication quality of the high priority traffic and efficiently
accommodate the traffic in the link aggregation in which a plurality of
25 wireless links is bundled.
[Solution to p~oblem]
[0020]
According to the present invention, a traffic control method in
8
which a plurality of wireless links between nodes for use, and the wireless
link used by a traffic is determined from a stability of a band for each
modulation method used for each wireless link and a traffic pattern for
each priority of a path is provided.
5 [002 l ]
According to the present invention, a communication device
comprises a means for bundling a plurality of wireless links between the
communication devices for use it, and determining the wireless link used
by a traffic from a stability of a band for each modulation method used for
10 each wireless link and a traffic pattern for each priority of a path is
provided.
[Advantageous Effects of Invention]
[0022]
15 An exemplary advantage according to the invention, in the link
aggregation in which a plurality of wireless links are bundled, the
communication quality of the high priority traffic can be secured and the
traffic can be efficiently accommodated.
20 [Brief Description of Drawings]
[0023]
[Fig. 11 Fig. 1 is a figure showing one example of a configuration
of a network system according to one exemplary embodiment of the present
invention.
25 [Fig. 21 Fig. 2 is a flowchart showing an operation procedure of
one exemplary embodiment of the present invention.
[Fig. 31 Fig. 3 is a figure for explaining a first exemplary
embodiment of the present invention.
[Fig. 41 Fig. 4 is a figure for explaining a second exemplary
9
embodiment of the present invention.
[Fig. 51 Fig. 5 is a figure showing a configuration of a
communication device according to one exemplary embodiment of the
present invention.
5
[Description of Embodiments]
[0024]
First, a principle of the present invention will be described. Next,
an exemplary embodiment will be described as an example. Although not
10 restricted in particular, in the following exemplary embodiment and the
like, an explanation will be made about a route control in a mobile
backhaul network, in particular, will be made in line with an application
example for a network composed of the wireless link having an adaptation
modulation function.
15 [0025]
When the traffic is distributed to a plurality of wireless links, an
influence on the communication quality of the traffic caused by a change in
transmission rate of the wireless link by the adaptation modulation has to
be considered. The change in transmission rate by the adaptation
20 modulation occurs by, for example, a change in band due to weather or the
like. A certain amount of band remains even when the transmission rate
is reduced by the adaptation modulation except for a case in which a
wireless link failure occurs.
[0026]
2 5 It is desirable to predict (estimate) the modulation method used by
the wireless link and allocate the band which can be stably provided even
when the low modulation method (low transmission rate) is used to the
high priority traffic which requires the high commui~icationq uality.
[0027]
10
On the other hand, for a traffic with a strong burst characteristic
like a data traffic, available band is more important than the
communication quality. Thus, the band (which, for example, cannot be
used temporarily with high probability) that is provided by using the high
5 modulation method (high transmission rate) may be allocated to the low
priority traffic which does not require a relatively high communication
quality.
[0028]
Further, in the traffic distribution to a plurality of wireless links,
10 when the packet is distributed to the plurality of wireless links by the
round robin method (the method in which the resource is allocated in turns),
a packet order change occurs. Therefore, the round robin method is not
suitable for the traffic that requires a high communication quality.
[0029]
15 It is desirable to determine the wireless link used for transmission
on a per-flow basis in which each flow is identified by a pair of a
transmission source (a packet transmission source) and a transmission
destination (a destination of the packet) or the like.
[0030]
20 As described above, when the traffic is fixedly allocated to the
wireless link used for transmission on a per-flow basis, by the traffic
amount difference between the flows or the like, the bias of the total traffic
amount that flows in the wireless link may occur. For this reason, the
plurality of wireless links cannot be efficiently used.
25 [003 11
As mentioned above, according to the communication quality
required for the traffic, the most suitable method is different from each
other with respect to the band of the wireless link used for transmission,
the traffic distribution method, or the like.
[0032]
Accordingly, in the present invention, according to the
communication quality required for the traffic, the traffic is distributed by
taking into consideration the difference of the band of the wireless link
5 used for transmission and the difference of the traffic distribution method.
[0033]
For example, according to an exemplary embodiment shown as an
example, referring to Fig. 1, two communication devices (1 01 and 102) are
connected to destination communication devices (102 and 101) by a
10 plurality of wireless links (1 11 and 112), respectively, and the most
suitable band allocation and the traffic distribution are performed based on
a state of the wireless link of the communication device itself (1 01 or 102)
and information of the traffic that flows.
[0034]
15 Fig. 2 is a flowchart for explaining a process procedure according
to an exemplary embodiment shown as an example. The process
procedure according to the exemplary embodiment shown as an example
will be described with reference to Fig. 1 and Fig. 2.
[0035]
20 The communication devices (101 and 102) check the states of the
wireless links through which the communication devices (10 1 and 102) are
connected to the destination communication devices (1 02 and 101),
respectively (Step 201). At the time, the communication devices (101
and 102) acquire, for example, a history of the modulation method used in
25 the past, weather information, or the like and calculate the stability for
each band with respect to the band (the increased band) provided by using
each modulation method used for the wireless link. The stability of a
modulation method c indicates a percentage of the use of the modulation
method c or the modulation method having a higher transmission rate than
12
that of the modulatioll method c. For example, the stability is calculated
for each interval (time interval) Ti,,t,,,,l and a stability St[c] of the
modulation method c during a t-th interval is given by the following
equation. Where, M is a set of the modulation methods used for the
5 wireless link and c is included in M (refer to equation (3) described in N
on- Patent Literature 1).
100361
A final stability FSt[c] can be obtained by reflecting the value
10 obtained in the past by using the moving average or the like of the stability
St[c] for each interval (refer to equation (4) shown in Non - Patent
Literature I).
[0037]
Further, refer to the above-mentioned Patent Literature 7 and
15 another document with respect to the control of the wireless line based on
the weather information or the like.
[0038]
Although not restricted in particular, as the modulation method
selected by the adaptation modulation includes, for example, QPSK
20 (Quadrature Phase Shift Keying), 16QAM (Quadrature Amplitude
Modulation), 32QAM, 128QAM, and the like. According to the
modulation method used for the wireless link, the transmission rate
increases. For example, when QPSK i s used as the modulation method,
the transmission rate is 40 Mbps (Mega bits per second) and when 16QAM
25 is used as the modulation method, the transmission rate is 80 Mbps. The
difference between the transmission rate of l6QAM and transmission rate
of QPSK that is a step lower modulation method than 16QAM is 40 Mbps
13
(= 80 Mbps - 40 Mbps). In the adaptation modulation, when the
modulation method is changed from QPSK to 16QAM, the band of the
wireless link increases by 40 Mbps. This band of 40Mbps is a band
provided by 16QAM. Because this band can be used when the modulation
5 method whose transmission rate is greater than that of 16QAM is used, the
stability of 16QAM is equal to the stability of the band.
[0039]
After that, when a path through which the traffic flows is set to the
communication devices (1 01 and 102) by an external routing control device
10 (not shown) or the like, the communication devices (101 and 102) check
the traffic information (Step 202).
[0040]
The communication devices (1 01 and 102) obtain the band which
can be used by the high priority traffic based on the stability for each band
15 (Step 203).
[004 11
For example, the stability of the band that is required for each
priority is designated in advance with respect to the entire network
including the communication devices (1 0 1 and 102). The communication
20 devices (101 and 102) check the band to which the high priority traffic or
the low priority traffic can be allocated from among the bands which meet
the stability required for each priority. Further, the communication
devices (101 and 102) grasp the priority (for example, high priority, low
priority, or the like) of the traffic from the priority information described
25 in the header of each frame. Further, for example, the designation of the
priority is performed in advance by the operator based on a type of traffic.
For example, the priority is designated based on a QCI (QoS Class
Identifier) of the 3GPP (3rd Generation Partnership Project). Further, in
a case in which by the external routing control device (not shown), the
14
communication devices (101 and 102) are notified of an amount of the high
priority traffic that flows on the basis of path flow in advance, the
communication devices (1 0 1 and 102) may determine the wireless link used
when transferring the high priority traffic based on the traffic amount and
5 the band that is allocated to the high priority traffic. On the other hand,
in a case in which the traffic amount of the high priority traffic cannot be
obtained for each flow, as will be described later, the communication
devices (101 and 102) may determine the wireless link used for
transmission by taking into consideration a ratio of an unused band in the
10 band with high reliability.
[0042]
Next, the communication devices (1 01 and 102) determine the
process to the low priority traffic (Step 204).
[0043]
15 In case of the low priority traffic, the communication devices (101
and 102) distribute the traffic by taking into consideration the unused band
of each wireless link including the band with low reliability. As an
example of this method, a per-packet traffic distribution method in which
the wireless link used for transmission is changed for each packet
20 according to the ratio of the unused band for each wireless link is used.
[0044]
Usually, one of the following two alternatives has to be selected:
(I) fixedly using the same wireless link for the traffic on the same
path; and
25 (11) distributing all the traffics on a per-packet basis. Therefore,
one of the communication quality and the efficiency cannot be
satisfied.
[0045]
In contrast, by using the present invention, the followings are made
15
possible:
(A) maintaining the communication quality of the high priority
traffic for which the high communication quality is required; and
(B) using efficiently the band of a plurality of wireless links.
5 [0046]
An exemplary embodiment 1 of the present invention will be
described below. The exemplary embodiment 1 is applied to a
communication device which is connected to the same communication
device (the same connection destination) via a plurality of wireless links.
10 As shown in Fig. 1, the communication device 101 is connected to the
communication device 102 via a plurality of wireless links 11 1 and 112.
In the exemplary embodiment 1, the communication devices 10 1 and 102
determine how to use wireless links 11 1 and 112 for distributing the traffic
flowing between the communication devices 101 and 102. This process
15 will be described.
COO471
The communication devices 101 and 102 check wireless link states
of themselves that are held in a storage device (not shown) and calculate
the stability for each band for each modulation method from the past
20 history and statistical information (for example, trend information such as
an average value, a maximum value, a minimum value, or the like) (Step
201 of Fig. 2).
[0048]
The communication devices 101 and 102 measure the traffic
25 flowing through the communication devices 101 and 102 and classify the
traffic into a path and a flow within the recognition capability of the
communication devices 101 and 102, respectively (Step 202 of Fig. 2).
The communication devices 101 and 102 identify the traffic for each path
or flow based on the header information of the frame that is accessible by
16
the commuilication devices 101 and 102. In Step 202 of Fig. 2, tlie
communication devices 101 and 102 further classify the path or the flow in
detail based on the priority.
[0049]
5 Next, the communication devices 10 1 and 102 allocate the traffic to
one of the wireless links according to the pathlflow and the priority (Steps
203 and 204 of Fig. 2).
[OOSO]
With respect to the allocation of the high priority traffic to the
10 wireless link (Step 203 of Fig. 2), the communication devices 101 and 102
determines the wireless link used for transmission so as to transmit the
traffic by using the same wireless link and the band with high stability
preferably. Here, when the traffic granularity which can be recognized
by the communication devices 10 1 and 102 is a path unit such as an LSP
15 (Label Switched Path) or the like of a MPLS (Multi-Protocol Label
Switching), the path is recognized in a label. unit and when it is a VLAN
(Virtual Local Area Network), the communication devices 101 and 102
recognize the path based on a VLAN ID and set the link in the path unit.
When the communication devices 101 and 102 can read an IP (Internet
20 Protocol) header of each packet, the communication devices 10 1 and 102
recognize it in a flow unit whose granularity is more fine by a set of the IP
address of the transmission source and the IP address of the destination or
the like and set the link in a flow unit. The communication devices 101
and 102 grasp the priority of the traffic from the priority (MPLS: EXP bit,
25 VLAN: bit PCP (Priority Code Point) showing the order of priority, and IP:
TOS (Type Of Service) showing the priority of the IP packet) of each
header.
[005 11
Next, with respect to the allocation of the low priority traffic to the
17
wireless link (Step 204 of Fig. 2), when a granularity level recognized by
the communication devices 101 and 102 is a path unit that is rough, the
communication devices 101 and 102 change the wireless link used for
transmission of the packet on a per-packet basis based on the ratio of the
5 unused band of each wireless link and transmit it.
[0052]
Here, the unused band which is taken into consideration by the
communication devices 101 and 102 i s the band that can be used by each
wireless link from which the band considered as the band used for the high
10 priority traffic is excluded and in order to maximally use the band of each
link, the wireless link used for transmission is changed on a per-packet
basis.
[0053]
Further, when the granularity level which can be recognized by the
15 communication devices 101 and 102 is a flow unit that i s more fine, the
communication devices 101 and 102 set the link used for communication
based on the ratio of the unused band on a per-flow basis and change the
wireless link used for transmission according to the change of the traffic
amount of each flow.
20 [0054]
Fig. 5 is a figure showing an example of a configuration of the
wireless communication device (the communication devices 10 1 and 102
shown in Fig. 1) which performs the link aggregation which bundles a
plurality of wireless links. Further, because the communication devices
25 101 and 102 have the same configuration, only the communication device
101 will be described below. The communication device 101 includes
communication units 5 1 1, 5 12, 5 13, and 5 14 that are connected to a
plurality of wireless links and perform wireless communication with a
destination communication device, a frame processing unit 501, a link
18
information management unit 502, a resource management unit 503, and a
traffic information management unit 504.
[0055]
The traffic information management unit 504 manages traffic
5 amount information on the basis of path flow or the like in addition to a
routing table for each destination. Namely, the traffic information
management unit 504 manages for example, a used band, a destination
communication device, and a traffic amount for each priority as the traffic
information that flows in the wireless link.
10 [0056]
The frame processing unit 501 identifies the traffic on the basis of
path flow, measures the traffic amount, and stores information including
information of a next destination in the traffic information management
unit 504 in addition to a frame transmission based on the destination
15 information stored in the traffic information management unit 504.
[0057]
The communication quality of the wireless link is measured by the
communication units 5 1 1 to 5 14 and stored in the link information
management unit 502. Further, when the frame processing unit 501
20 acquires weather information from the outside through the communication
units 5 11 to 5 14, the frame processing unit 501 records the information in
the link information management unit 502.
[0058]
The link information management unit 502 manages for example, a
25 stability of each modulation method, a BER (Bit Error Rate), a SNR
(Signal to Noise Ratio), and a modulation method that is currently used as
link quality information. For example, the resource management unit 503
calculates a traffic allocation setting based on the traffic information
periodically recorded in the traffic information management unit 504 and
19
the link information of the link information management unit 502 and
updates the routing table for each destination of the traffic information
management unit 504.
[0059]
5 Further, the stability calculation in step 201 of Fig. 2 is performed
by the link information management unit 502 shown in Fig. 5, the traffic
information check in step 202 of Fig. 2 is performed by the frame
processing unit 501 shown in Fig. 5 , and the results are recorded in the
traffic information management unit 504. The settings of the high
10 priority traffic transmission process in step 203 and the low priority traffic
transmission process in step 204 of Fig. 2 are performed by the resource
management unit 503 shown in Fig. 5 and the frame processing unit 501 .
transmits the frame based on the settings. Hereinafter, these processes
will be explained in line with a specific example.
15

In an exemplary embodiment 1, an explanation will made about an
example of a case in which the traffic granularity which can be recognized
by the communication device is a path unit that is relatively rough.
20 Further, of course, the value used in the exemplary embodiment 1 is shown
as an example. Therefore, the value should not be interpreted as a
limitation of a scope of the present invention.
[0060]
The communication devices 101 and 102 shown in Fig. 1 are
25 connected to each other by two wireless links 11 1 and 112. It is assumed
that the bands of the wireless links 11 1 and 112 are as follows (further, in
the following description, the reliability may be used instead of the
stability).
[0061]
2 0
The wireless link 11 1 : the maximum transmission speed is 155
Mbps and the stability is better than 99.99 % when the transmission speed
is up to 40 Mbps.
LO0621
The wireless link 1 12: the maximum transmission speed is 155
Mbps and the stability is better than 99.99 % when the transmission speed
is up to 80 Mbps.
[0063]
It is assumed that the following traffic flows from the
10 communication device 101 to the communication device 102.
[0064]
A path A (VLAN ID = 0): The transmission speed of the high
priority traffic is 30 Mbps (maximum) and the transmission speed of the
low priority traffic i s 70 Mbps (average).
15 [0065]
A path B (VLAN ID = 1): The transmission speed of the high
priority traffic is 70 Mbps (maximum) and the transmission speed of the
low priority traffic is 110 Mbps (average).
LO0661
Here, the communication device 101 (102) transmits the traffic as
follows.
[0067]
First, the wireless link used for the high priority traffic of the paths
A and B is determined.
25 [0068]
The best match band allocation setting is determined from a size of
the band in which the stability is better than 99.99 % and the traffic amount
of each wireless link. As a result, the high priority traffic of the path A
uses the band of the wireless link 11 1 in which the stability is better than
2 1
99.99 % and the high priority traffic of the path B uses the band of the
wireless link 112 in which the stability is better than 99.99 %.
[0 0 6 91
Next, the low priority traffic of each path is distributed to the
5 wireless link on a per-packet basis and transmitted. At this time, the
wireless link used for transmission of the low priority traffic is determined
according to the ratio of the unused band from which the band through
which the high priority traffic will be transmitted is excluded.
[0070]
The unused band of the wireless link 11 1 i s 125 Mbps (= 155 - 30).
The unused band of the wireless link 112 is 85 Mbps (= 155 - 70).
Accordingly, the ratio of the unused band of the wireless link 11 1
to the unused band of the wireless link 112 that are used for transmission
of the packet is calculated as follows.
15 The unused band of the wireless link 11 1 : the unused band of the
wireless link 112 = 125 : 85 = 25 : 17.
[007 11
The low priority traffic of the path A and the path B is distributed
to the wireless link 11 1 and the wireless link 112 at a ratio of 25:17. Fig.
20 3 is a figure schematically showing a result of a traffic control performed
in the exemplary embodiment 1. In Fig. 3, it is schematically shown that
the low priority traffic of the paths A and B is distributed to the wireless
link 11 1 at a ratio of 25:42 and to the wireless link 112 at a ratio of 17:42.

In the exemplary embodiment 2, the high priority traffic is
transmitted in the same manner as the above-mentioned exemplary
embodiment 1. With respect to the low priority traffic, an average traffic
amount of the low priority traffic of each path is compared with the unused
band (a remaining portion of the band after allocating to the high priority
22
traffic) in each link and a combination of the average traffic amount and
the unused band is found out that gives the minimum difference (absolute
value) between them.
[0072]
5 As a result, when the low priority traffic of the path A uses the
wireless link 1 12 (difference = 11 25 - 1 101 = 15) and the low priority traffic
of the path B uses the wireless link 11 1 (difference = 185 - 701 = 15), the
difference is minimum.
[0073]
10 The communicatioil devices 10 1 and 102 perform a setting so that
each low priority traffic is transmitted through the wireless link different
from the wireless link used for the high priority traffic. The wireless link
used by each traffic is shown below.
[0074]
15 The path A: The high priority traffic is transmitted through the
wireless link 11 1 and the low priority traffic is transmitted through the
wireless link 1 12.
The path B: The high priority traffic is transmitted through the
wireless link 112 and the low priority traffic is transmitted through the
20 wireless link 1 11.
As a result, the link setting of each traffic is shown in a part 401
surrounded by a dashed line of Fig. 4(A).
[0075]
After this process, the communication devices 101 and 102
25 periodically measure the average traffic amount of the low priority traffic
of each path and at the same time, check the most suitable link for
transmission of the low priority traffic. For example, it is assumed that
the average traffic amount of the low priority traffic of each path changes
as follows.
23
the path A: from 70 Mbps to 85 Mbps
the path B: from 110 Mbps to 30 Mbps
In this case, when the low priority traffic of the path A uses the
wireless link 11 1 and the low priority traffic of the path B uses the wireless
5 link 112, the difference between the unused band and the average traffic
amount is small. Therefore, the communication devices 101 and 102
change the wireless link used for the low priority traffic. That is,
(1) when the wireless links 11 1 and 112 are used for transmission of
the low priority traffics of the paths A and By respectively, the difference
10 between the unused band and the average traffic amount is calculated as
follows; 1125 - 851 = 40 when the wireless link 112 i s used for the path B
and 185 - 301 = 55 when the wireless link 11 1 is used for path A.
(2) when the wireless links 112 and 11 1 are used for transmission of
the low priority traffics of the paths A and By respectively, the difference
15 between the unused band and the average traffic amount is calculated as
follows; 1125 - 301 = 95 when the wireless link 112 is used for path A and
185 - 851 = 0 when the wireless link 11 1 is used for path B. Therefore, the
combination is changed to the combination of ( I ) giving smaller maximum
absolute value of difference between the unused band and the average
20 traffic amount.
[0 0 7 6 1
The link setting of each traffic after the change is shown in a part
402 surrounded by a dashed line of Fig. 4(B). Referring to Fig. 4(B), the
wireless link 11 1 is used for the low priority traffic of the path A and the
25 wireless link 112 is used for the low priority traffic of the path B.
[0077]
Thus, by using the exemplary embodiment 2, when the traffic
amount of the low priority traffic varies, the link band can be efficiently
used without affecting the high priority traffic.
[0078]
While two wireless links 11 1 and 112 are used in the
above-mentioned exemplary embodiment, the number of the wireless links
bundled by the link aggregation is not limited to two.
5 [0079]
According to the above-mentioned exemplary embodiment, by
employing the traffic control taking into consideration both the priority of
the traffic and the band whose stability in the wireless link is different
from others, the communication quality of the high priority traffic can be
10 guaranteed and also the link band can be efficiently used.
[OOSO]
The whole or part of the exemplary embodiments disclosed above
can be described as, but not limited to, the following supplementary notes.
15 (Supplementary note 1)
A traffic control method characterized by comprising the steps of:
bundling a plurality of wireless links between nodes for use, and
determining the wireless link used by a traffic from a stability of a
band for each modulation method used for each wireless link and a traffic
20 pattern for each priority of a path.
(Supplementary note 2)
The traffic control method described in Supplementary note 1
characterized in that a traffic distribution is performed to the traffics on
the same path so as to satisfy the communication quality required by each
25 traffic according to the traffic pattern and the priority of the path.
(Supplementary note 3)
The traffic control method described in Suppleinentary note 1 or
Supplementary note 2 characterized in that the traffic pattern is a pattern
indicating a characteristic of the traffic that includes at least one of an
2 5
average traffic amount, a maximum traffic amount, and a burst
characteristic.
(Supplementary note 4)
The traffic control method described in any one of Supplementary
5 notes 1 to 3 characterized in that the modulation method used for the
wireless link is predicted and the stability of the band for the modulation
method used for the wireless link is calculated based on the predicted
modulation method.
(Supplementary note 5)
10 The traffic control method described in any one of Supplementary
notes 1 to 4 characterized in that the stability of the band for the
modulation method used for the wireless link is calculated based on a
history of the modulation method used for the wireless link and a history of
information indicating a radio wave environment of the wireless link.
15 (Supplementary note 6)
The traffic control method described in any one of Supplementary
notes 1 to 5 characterized in that from a size of the band in which the
stability of the wireless link is equal to or greater than a predetermined
value set in advance and a traffic amount of each path,
20 the band of the wireless link in which the stability is equal to or
greater than the predetermined value set in advance and which has a band
equal to or greater than the traffic amount is allocated to at least a first
traffic which has a higher priority of each path, and
a plurality of wireless links on a per-packet basis based on a ratio
25 of an unused band from which the band used by the first traffic of each
wireless link is excluded are allocated to at least a second traffic which has
a lower priority of each path.
(Supplementary note 7)
The traffic control method described in any one of Supplementary
26
notes 1 to 5 characterized in that from a size of the band in which the
stability of the wireless link is equal to or greater than a predetermined
value set in advance and a traffic amount of each path,
the band of the wireless link in which the stability is equal to or
5 greater than the predetermined value set in advance and which has a band
equal to or greater than the traffic amount is allocated to at least the first
traffic which has a higher priority of each path, and
an average traffic amount of the second traffic of each path and the
unused band in each wireless link are compared with each other and the
10 wireless link is allocated to at least the second traffic which has a lower
priority of each path based on the difference between the unused band and
the average traffic amount.
(Supplementary note 8)
A communication device characterized in that the communication
I5 device comprises a means for
bundling a plurality of wireless links between the communication
devices for use and
determining a wireless link used by a traffic from a stability of a
band for each modulation method used for the wireless link and a traffic
20 pattern for each priority of a path.
(Supplementary note 9)
The communication device described in Supplementary note 8
characterized in that a traffic distribution is performed to the traffics on
the same path so as to satisfy the communication quality required by each
25 traffic according to the traffic pattern and the priority of the path.
(Supplementary note 10)
The communication device described in Supplementary note 8 or
Supplementary note 9 characterized in that the traffic pattern is a pattern
indicating a characteristic of the traffic that includes at least one of an
2 7
average traffic amount, a maximum traffic amount, and a burst
characteristic.
(Supplementary note 1 1)
The communication device described in any one of Supplementary
5 notes 8 to 10 characterized in that the modulation method used for the
wireless link is predicted and the stability of the band for the modulation
method used for the wireless link is calculated based on the predicted
modulation method.
(Supplementary note 12)
10 The communication device described in any one of Supplementary
notes 8 to 11 characterized in that the stability of the band for the
modulation method used for the wireless link is calculated based on a
history of the modulation method used for the wireless link and a history of
information indicating a radio wave environment of the wireless link.
15 (Supplementary note 13)
The communication device described in any one of Supplementary
notes 8 to 12 characterized in that from a size of the band in which the
stability of the wireless link is equal to or greater than a predetermined
value set in advance and a traffic amount of each path,
20 the band of the wireless link in which the stability is equal to or
greater than the predetermined value set in advance and which has a band
equal to or greater than the traffic amount is allocated to at least a first
traffic which has a higher priority of each path, and
a plurality of wireless links on a per-packet basis based on a ratio
25 of an unused band from which the band used by the first traffic of each
wireless link is excluded are allocated to at least a second traffic which has
a lower priority of each path.
(Supplementary note 14)
The communication device described in any one of Supplementary
28
note 8 to 13 characterized in that from a size of the band in which the
stability of the wireless link is equal to or greater than a predetermined
value set in advance and a traffic amount of each path,
the band of the wireless link in which the stability is equal to or
5 greater than the predetermined value set in advance and which has a band
equal to or greater than the traffic amount is allocated to at least the first
traffic which has a higher priority of each path, and
an average traffic amount of the second traffic of each path and the
unused band in each wireless link are compared with each other and the
10 wireless link is allocated to at least the second traffic which has a lower
priority of each path based on the difference between the unused band and
the average traffic amount.
(Supplementary note 15)
A communication system characterized in that a plurality of
15 wireless links between node devices are bundled for use and
the node device determines the wireless link used by a traffic from a
stability of a band for each modulation method used for the wireless
link
and a traffic pattern for each priority of a path.
(Supplementary note 16)
The communication system described in Supplementary note 15
characterized in that the node device performs a traffic distribution to the
traffics on the same path so as to satisfy the communication quality
required by each traffic according to the traffic pattern and the priority of
25 the path.
(Supplementary note 17)
The cominunication system described in Supplementary note 15 or
Supplementary note 16 characterized in that the traffic pattern is a pattern
indicating a characteristic of the traffic that includes at least one of an
29
average traffic amount, a maximum traffic amount, and a burst
characteristic.
(Supplementary note 18)
The communication system described in any one of Supplementary
5 notes 15 to 17 characterized in that the node device predicts the
modulation method used for the wireless link and calculates the stability of
the band for the modulation method used for the wireless link based on the
predicted modulation method.
(Supplementary note 19)
10 The communication system described in any one of Supplementary
notes 15 to 18 characterized in that the node device calculates the stability
of the band for the modulation method used for the wireless link based on a
history of the modulation method used for the wireless link and a history of
information indicating a radio wave environment of the wireless link.
15 (Supplementary note 20)
The communication system described in any one of Supplementary
notes 15 to 19 characterized in that from a size of the band in which the
stability of the wireless link is equal to or greater than a predetermined
value set in advance and a traffic amount of each path,
20 the node device allocates the band of the wireless link in which the
stability is equal to or greater than the predetermined value set in advance
and which has a band equal to or greater than the traffic amount to at least
a first traffic which has a higher priority of each path and
allocates a plurality of wireless links on a per-packet basis to at
25 least a second traffic which has a lower priority of each path based on a
ratio of an unused band from which the band used by the first traffic of
each wireless link is excluded.
(Supplementary note 2 1 )
The communication system described in any one of Supplementary
30
notes 15 to 19 characterized in that from a size of the band in which the
stability of the wireless link is equal to or greater than a predetermined
value set in advance and a traffic amount of each path,
the node device allocates the band of the wireless link in which the
5 stability is equal to or greater than the predetermined value set in advance
and which has a band equal to or greater than the traffic amount to at least
the first traffic which has a higher priority of each path and
compares an average traffic amount of the second traffic of each
path with the unused band in each wireless link and allocates the wireless
10 link to at least the second traffic which has a lower priority of each path
based on the difference between the unused band and the average traffic
amount.
[008 11
Further, each disclosure of the above-mentioned patent literature
15 and non - patent literature is hereby incorporated by reference in its
entirety. Modification and adjustment of the exemplary embodiment can
be made within the scope of the overall disclosure (including claims) of the
present invention and based on the basic technical concept of the present
invention. Moreover, various combinations or selections of the various
20 disclosed elements (including each element of each supplementary note,
each element of each exemplary embodiment, and each element or the like
of each drawing) are possible within the scope of the claims of the present
invention. Namely, various deformations or modifications that may be
made by those skilled in the art according to the overall disclosure
25 including the claims and the technical concept are included in the present
invention.
[0082]
The invention of the present application has been described above
with reference to the exemplary embodiment. However, the invention of
3 1
the present application is not limited to the above mentioned exeinplary
embodiment. Various changes in the configuration or details of the
invention of the present application that can be understood by those skilled
in the art can be made without departing from the scope of the invention of
5 the present application.
[0083]
This application claims priority based upon and claims the benefit
of priority from Japanese Patent Application No. 20 12-03 5 844, filed on
February 22, 2012, the disclosure of which is incorporated herein in its
10 entirety by reference.
[Reference Signs List]
[0084]
101 and 102 communication device
11 1 and 1 12 wireless link
401 used link setting of each traffic in initial stage
402 used link setting of each traffic after resetting
501 frame processing unit
502 link information management unit
503 resource management unit
504 traffic information management unit
5 1 1, 5 12, 5 13, and 5 14 communication unit

We Claim:
[Claim 11
A traffic control method characterized by comprising the steps of:
bundling a plurality of wireless links between nodes for use, and
determining the wireless link used by a traffic from a stability of a
band for each modulation method used for each wireless link and a
traffic pattern for each priority of a path.
[Claim 21
The traffic control method described in claim 1 characterized in
10 that a traffic distribution is performed to the traffics on the same path so as
to satisfy the communication quality required by each traffic according to
the traffic pattern and the priority of the path.
[Claim 31
The traffic control method described in claim 1 or claim 2
15 characterized in that the traffic pattern is a pattern indicating a
characteristic of the traffic that includes at least one of an average traffic
amount, a maximum traffic amount, and a burst characteristic.
[Claim 41
The traffic control method described in any one of claims 1 to 3
20 characterized in that the modulation method used for the wireless link is
predicted and the stability of the band for the modulation method used for
the wireless link is calculated based on the predicted modulation method.
[Claim 51
The traffic control method described in any one of claims 1 to 4
25 characterized in that the stability of the band for the modulation method
used for the wireless link is calculated based on a history of the modulation
method used for the wireless link and a history of information indicating a
radio wave environment of the wireless link.
[Claim 61
33
The traffic control method described in any one of claims 1 to 5
characterized in that from a size of the band in which the stability of the
wireless link is equal to or greater than a predetermined value set in
advance and a traffic amount of each path,
5 the band of the wireless link in which the stability is equal to or
greater than the predetermined value set in advance and which has a band
equal to or greater than the traffic amount is allocated to at least a first
traffic which has a higher priority of each path, and
a plurality of wireless links on a per-packet basis based on a ratio
lo of an unused band from which the band used by the first traffic of each
wireless link is excluded are allocated to at least a second traffic which has
a lower priority of each path.
[Claim 71
The traffic control method described in any one of claims 1 to 5
15 characterized in that from a size of the band in which the stability of the
wireless link is equal to or greater than a predetermined value set in
advance and a traffic amount of each path,
the band of the wireless link in which the stability is equal to or
greater than the predetermined value set in advance and which has a band
20 equal to or greater than the traffic amount is allocated to at least the first
traffic which has a higher priority of each path, and
an average traffic amount of the second traffic of each path and the
unused band in each wireless link are compared with each other and the
wireless link is allocated to at least the second traffic which has a lower
25 priority of each path based on the difference between the unused band and
the average traffic amount.
[Claim 81
A communication device characterized in that the communication
device comprises a means for
3 4
bundling a plurality of wireless links between the coinmunication
devices for use and
determining a wireless link used by a traffic from a stability of a
band for each modulation method used for the wireless link and a traffic
5 pattern for each priority of a path.
[Claim 91
The communication device described in claim 8 characterized in
that a traffic distribution is performed to the traffics on the same path so as
to satisfy the communication quality required by each traffic according to
10 the traffic pattern and the priority of the path.
[Claim 101
The communication device described in claim 8 or claim 9
characterized in that the traffic pattern is a pattern indicating a
characteristic of the traffic that includes at least one of an average traffic
15 amount, a maximum traffic amount, and a burst characteristic.