Technical Field]
5 [0001]
The present invent ion relates to a communicat ion system, a base
stat ion device, a control device, and a communicat ion method in a radio
communicat ion network.
[Background Ar t ]
10 [0002]
In recent years, communicat ion services have been more diversi fied,
as the network has started to be used in more appl icat ions. This trend has
caused various changes in the network environment .
[0003]
15 First , provision of services such as traffic control and remote
medicine that require high rel iabi l i ty, i .e. , mission cri t ical service (MCS),
has been considered.
[0004]
Secondly, devices to be connected to a base stat ion have been more
20 and more diversi fied. Speci fical ly, in addi t ion to general mobi le
terminals, such devices as moni toring cameras may be connected to a base
stat ion.
[0005]
Thirdly, appl icat ion of a system that incorporates therein mobi le
25 edge comput ing (MEC) has been considered. Non Patent Li terature 1
descr ibes a communicat ion system that incorporates therein a technology
of MEC. Incorporat ion of a technology of MEC makes i t possible to
provide services that require real -t ime processing and analysis of vast data,
whi le restraining the burden on core networks. Consequent ly, services
2
are expected to be provided wi th lower latency and broader bandwidth than
ever before.
[0006]
On the other hand, in accordance wi th such changes in network
environments, var ious methods to detect system abnormal 5 i t ies due to
unauthorized accesses or the l ike have started to be considered. In
par t icular, as devices to be connected to a base stat ion device have been
diversi fied, poor ly secured devices may be connected to base stat ion
devices. In view of this, there is a heightened demand for protect ing a
10 system from unauthorized accesses.
[0007]
For example, Patent Li terature 1 describes a technology of
protect ing a system from abnormal i t ies due to an unauthor ized access or
the l ike. Patent Li terature 1 describes an abnormal i ty detect ion system
15 that detects an abnormal i ty occurring in a cont rol system, and isolates the
control system found to be abnormal .
[Ci tat ion List ]
[Patent Li terature]
[0008]
20 [PTL 1] Japanese Patent Appl icat ion Publ icat ion No. 2012-168755
[Non Patent Li terature]
[0009]
[NPL 1] Mobi le-Edge Comput ing- Introductory Technical Whi te Paper
September 2014
25 [Summary of Invent ion]
[Technical Problem]
[0010]
In the future, int roduct ion of a technology of MEC or the l ike may
make a single base stat ion device in a communicat ion system provide a
3
user terminal wi th a plural i ty of services di ffering in priori ty levels.
When an abnormal i ty is detected in such communicat ion system,
appl icat ion of the technology in Patent Li terature 1 wi l l stop al l the
services provided by the base stat ion device included in the communicat ion
system. Here, when an MCS is included among the services 5 provided by
the base stat ion device, the MCS service also stops. On the other hand, i f
the abnormal i ty in the communicat ion system is left unat tended, the MCS
wi l l stop funct ioning normal ly, which may resul t in serious accidents.
[0011]
10 In view of the above, one object ive which the example embodiment s
disclosed in the present descript ion at tempts to achieve is to provide a
communicat ion system, a base stat ion device, a cont rol device, and a
communicat ion method, which can protect the communicat ion system
detected to be abnormal , whi le restraining the deteriorat ion in a vai labi l i ty
15 of services provided by the base stat ion device.
[Solut ion to Problem]
[0012]
A communicat ion system of the present embodiment includes: a
fi rst server that provides a first service; a second server that provides a
20 second service; and a first base stat ion device that communicates wi th the
fi rst server and the second server, wherein when the second service has a
higher pr iori ty level than the first service, and when an abnormal i ty is
detected in the first server, a communicat ion path between the first base
stat ion device and the fi rst server is blocked.
25 [0013]
A base stat ion device of the present embodiment in a
communicat ion system includes: a means that communicates wi th a fi rst
server that provides a fi rst service; a means that communicates wi th a
second server that provides a s econd service; and
4
a means that stops communicat ion wi th the first server, when an
abnormal i ty is detected in the first server when the second service has a
higher priori ty level than the first service.
[0014]
A control device of the present embodiment is a control 5 device in a
communicat ion system, wherein the communicat ion system includes: a fi rst
server that provides a first service; a second server that provides a second
service; and a fi rst base stat ion device that communicates wi th the first
server and the second server, and when the second service has a higher
10 priori ty level than the fi rst service, and when an abnormal i ty is detected in
the first server, the control device controls whereby a communicat ion path
between the fi rst base stat ion device and the first server is blocked.
[0015]
A communicat ion method of the present embodiment is a
15 communicat ion method in a communicat ion system, wherein the
communicat ion system includes: a first server that provides a first service;
a second server that provides a second service; and a first base stat ion
device that communicates wi th the first server and the second server, the
communicat ion method comprising: blocking a communicat ion path
20 between the first base stat ion device and the first server, when an
abnormal i ty is detected in the fi rst server in cases where the second service
has a higher pr ior i ty level than the first service.
[Advantageous Effects of Invent ion]
[0016]
25 The above-described example embodiments can protect the
communicat ion system detected to be abnormal , whi le restraining the
deteriorat ion in avai labi l i ty of services provided by the base stat ion
device.
[Br ief Descript ion of Drawings ]
5
[0017]
Fig.1 is a block diagram i l lustrat ing a configurat ion of a
communicat ion system according to a fir st example embodiment .
Fig. 2 is a flowchart for explaining an operat ion of the
communicat ion system according to the fi rst example 5 embodiment .
Fig. 3 is a block diagram i l lustrat ing a configurat ion of a
communicat ion system according to a second example embodiment .
Fig. 4 is a flowchart for explaining an operat ion of the
communicat ion system according to the second example embodiment .
10 Fig. 5 is flowchart for explaining an operat ion of a communicat ion
system according to a third example embodiment .
Fig. 6 is a block diagram i l lustrat ing a configurat ion of a
communicat ion system according to a fourth example embodiment .
Fig. 7 is a flowchart for explaining an operat ion of the
15 communicat ion system according to the fourth example embodiment .
Fig. 8 is a block diagram i l lust rat ing another example of the
configurat ion of the communicat ion system according to the fourth
example embodiment .
Fig. 9 is a flowchar t for explaining another example of the
20 operat ion of the communicat ion system according to the four th example
embodiment .
[Descript ion of Embodiments ]
[0018]
The fol lowing describes speci fic example embodiments wi th
25 reference to the drawings , in detai l . The same or corresponding elements
in each drawing are assigned the same reference numerals . For
clar i ficat ion purposes, overlapping explanat ion is omi t ted where necessary.
[0019]
The plural i ty of example embodiments described below can be
6
implemented independent ly or in appropriate combinat ion. These
plural i ty of example embodiment s have mutual ly di fferent novel
characterist ics. Therefore, these plural i ty of example embodiments
contribute to solut ion of mutual ly di fferent object ives or problems, and
contribute to achievement of mutual ly 5 di fferent effects.
[0020]
[Fi rst example embodiment ]
A configurat ion of a communicat ion system according to a first
example embodiment of the present invent ion is described below wi th
10 reference to Fig. 1.
[0021]
The communicat ion system 10 according to the present example
embodiment includes a server 100, a server 101, and a base stat ion device
102. The server 100 provides a first service. The server 101 provides a
15 second service. The base stat ion device 102 communicates wi th the
server 100 and the server 101.
[0022]
Next , an operat ion of the communicat ion sys tem 10 according to the
present example embodiment is described below wi th reference to Fig. 2.
20 Note that , in the present example embodiment , i t is assumed that the
second service provided by the server 101 has a higher priori ty level than
the fi rst service provided by the server 100. The pr iori ty level of a
service is determined, for example, based on the required level of
rel iabi l i ty; however, the pr iori ty level of a service may be determined
25 based on di fferent cri teri a.
[0023]
The base stat ion device 102 according to the present example
embodiment communicates wi th the server 100 and the server 101 (Step
S1). Then, when any abnormal i ty is detected in the server 100 (Step S2),
7
the communicat ion path between the base stat ion device 102 and the server
100 is blocked (Step S3) .
By doing so, provision of the first service by the base stat ion device 102
wi l l stop. On the other hand, the communicat ion path between the base
stat ion device 102 and the server 101 wi l l not be blocked. 5 Accordingly,
provision of the second service by the base stat ion device 102 can
cont inue.
[0024]
As described above, according to the present example embodiment ,
10 when the server 100 that provides the first service is detected to be
abnormal , the communicat ion path between the server 100 and the base
stat ion device 102 wi l l be blocked. Therefore, whi le stopping the
communicat ion wi th the server 100, the base stat ion device 102 does not
have to stop provision of the second service having a higher prior i ty level
15 than the fi rst service. In this way, in the communicat ion system 10
according to the present example embodiment , the communicat ion system
10 detected to be abnormal can be protected, whi le the deteriorat ion in
avai labi l i ty of services provided by the base stat ion device 102 being
rest rained.
20 [0025]
Note that , the operat ion in the present example embodiment is
descr ibed by way of a case in which an abnormal i ty is detected in the
server 100 that provides the first service having a lower priori ty level than
the second service. When, on the other hand, an abnormal i ty is detected
25 in the server 101 that provides the second service, a di fferent operat ion
may be per formed. That is, when an abnormal i ty is detected in the server
101, the system of the operat ion and maintenance (O&M) may be not ified
that an abnormal i ty has been detected, instead of blocking the
communicat ion path between the server 101 and the base stat ion device
8
102.
[0026]
[Second example embodiment ]
Next , a second example embodiment of the present invent ion is
descr ibed below. Fig. 3 i l lustrates a configurat ion 5 of a communicat ion
system according to the present example embodiment . The
communicat ion system 20 according to the present example embodiment
includes an MEC server 200, an MEC server 201, a swi tch 202, a base
stat ion device 203, a base stat ion device 204, a moni toring device 205, a
10 control device 206, a communicat ion terminal 207, and a communicat ion
terminal 208.
[0027]
The MEC server 200 provides a first service. The MEC server 201
provides a second service. The second service has a higher priori ty level
15 than the first service. In the present example embodiment , the priori ty
level is determined based on the required level of rel iabi l i ty. Speci fical ly,
the second service is an MCS that require s a high rel iabi l i ty, for example,
remote medicine or traffic control . The fi rst service requi res low
rel iabi l i ty compared wi th the MCS, for example, a heal thcare service for
20 heal th care using a passometer or the l ike.
[0028]
The swi tch 202 relays the communic at ion paths among the MEC
servers 200, 201, and the base stat ion devices 203, 204, respect ively.
[0029]
25 Each of the base stat ion devices 203 and 204 can communicate wi th
the MEC servers 200 and 201, and can provide the fi rst service and the
second service.
[0030]
The moni toring device 205 detects an abnormal i ty in the MEC
9
servers 200 and 201. The moni toring device 205 is, for example, an
intrusion detect ion system ( IDS) apparatus.
[0031]
The control device 206 controls the swi tch 202 and per forms
handover control over the base stat ion devices 203 and 5 204. The control
device 206 also manages informat ion on the type s of servers wi th which
the base stat ion device 203 and the base stat ion device 204 can
communicate. The control device 206 is, for example, a sel f -organizing
network (SON) server for use in a SON.
10 [0032]
The communicat ion terminal 207 is a terminal that subscribes to the
fi rst service. In addi t ion, the communicat ion terminal 207 is located in a
posi t ion where coverage of cel l 209 of the base stat ion device 203 over laps
wi th coverage of cel l 210 of the base stat ion device 204, in the present
15 example embodiment . The communicat ion terminal 208 is a terminal that
subscribes to the second service, and is located wi thin a range of the
coverage of cel l 210 of the base stat ion device 204.
[0033]
The communicat ion terminals 207 and 208 are devices that
20 communicate wi th a base stat ion device, and may be a mobi le terminal such
as a por table telephone and a smartphone, as wel l as a communicat ion
terminal such as a moni toring camera, an environment sensor, and a
connected car.
[0034]
25 An operat ion of the communicat ion system 20 according to the
present example embodiment is descr ibed below wi th reference to Fig. 4.
First of al l , the moni tor ing device 205 detects an abnormal i ty caused in the
MEC server 200 (Step S11) . Abnormal i t ies of the MEC server 200 may
be caused when, for example, the MEC server 200 receives an unauthorized
10
access via the communicat ion terminal 207.
[0035]
A method of detect ing an abnormal i ty by the moni toring device 205
is descr ibed in detai l below. Fi rst , the moni toring device 205 moni tors
the resul t of the service provision by the base stat ion devices 5 203 and 204.
The relevant service whose provision resul t is to be moni tored is a service
having a high priori ty level , i .e. , the second service being an MCS.
Speci fical ly, the moni toring device 205 counts the number of t imes at
which the base stat ion devices 203 and 204 provide the second service to
10 the communicat ion termina l located in i ts own cel l , and manages i t as a
counted value. Then, it moni tors the amount of traffic between the base
stat ion device whose counted value is a predetermined value or more and
the MEC server to which this base stat ion device is connected. Here, the
counted value may be the one wi thin a predetermined period of t ime. For
15 example, the number of t imes at which the second service is provided
wi thin past one month may be counted.
[0036]
In the present example embodiment , i t is assumed that the number
of t imes at which the second service is provided by the base stat ion device
20 204 is a predetermined counted value or more. On the other hand, i t is
assumed that the number of t imes at which the second service is provided
by the base stat ion device 203 is less than the predetermined counted value.
This includes a case in which no second service has been provided by the
base stat ion device 203. In this case, the moni toring device 205 moni tors
25 the amount of traffic among the base stat ion device 204 and the MEC
servers 200 and 201 to which this base stat ion device 204 is connected.
Then, the moni toring device 205 detects an abnormal i ty in the MEC servers
200 and 201 based on this amount of traffic. For example, the amount of
generated traffic may be stat ist ical ly managed, and a case in which there is
11
traffic in an amount way over a normal amount of traffic may be
determined to be abnormal .
[0037]
When the moni toring device 205 detects an abnormal i ty in the MEC
server 200, the control device 206 determines the communicat 5 ion path to
be blocked, based on the pr iori ty level of the services provided by the base
stat ion devices 203 and 204 communicat ing wi th the MEC server 200 (Step
S12) . Speci fical ly, the base stat ion device that is providing a service
having a higher pr iori ty level than the service provided by the MEC server
10 200 is extracted, and the communicat ion path between this base stat ion
device and the MEC server 200 is determined to be blocked. In the
present example embodiment , the second service has a higher pr iori ty level
than the first service. In addi t ion, the number of t imes at which the
second service is provided by the base stat ion device 204 is a
15 predetermined counted value or more. On the other hand, the number of
t imes at which the second service is provided by the base stat ion device
203 is less than the predetermined counted value. Therefore, the control
device 206 determines to block the communicat ion path between the base
stat ion device 204 and the MEC server 200.
20 [0038]
Then, the control device 206 controls the swi tch 202 whereby the
swi tch 202 blocks the communicat ion path between the MEC server 200
and the base stat ion device 204. Then, the swi tch 202 blocks the
communicat ion path between the MEC server 200 and the base stat ion
25 device 204 (Step S13). As a resul t , the base stat ion device 204 stops
provision of the first service. On the other hand, communicat ion between
the MEC server 201 and the base stat ion device 204 is cont inued.
Therefore, the base stat ion device 204 can cont inue providing the second
service. That is, the communicat ion terminal 208 can cont inue receiving
12
the second service via the base stat ion device 204.
[0039]
Here, the communicat ion terminal 207 is assumed to be a
communicat ion terminal having received the fi rst service via the base
stat ion device 204 prior to Step S13. However, since 5 the communicat ion
path between the base stat ion device 204 and the MEC server 200 is
blocked, the communicat ion terminal 207 is not provided wi th the first
service via the base stat ion device 204. In view of this, the control
device 206 refers to informat ion on the servers wi th which the base stat ion
10 devices 203 and 204 can communicate and posi t ion informat ion of the
communicat ion terminal 207. Then, the control device 206 ext racts the
base stat ion device that can provide the first service to the communicat ion
terminal 207.
[0040]
15 In the present example embodiment , the base stat ion device 203 can
communicate wi th the MEC server 200 that provides the first service. In
addi t ion, the number of t imes at which the MCS, being the second service,
is provided by the base stat ion device 203 is less than the predetermined
counted value. Furthermore, the communicat ion terminal 207 is located
20 wi thin the range of the coverage of cel l 209 of the base stat ion device 203.
Therefore, the control device 206 determines that the base stat ion device
203 can provide the fi rst service to the communicat ion terminal 207.
[0041]
In this case, the control device 206 per forms handover control
25 whereby the communicat ion terminal 207 is handed over to the base stat ion
device 203 from the base stat ion device 204 (Step S14). That is, the
control device 206 requests that the base stat ion device 204 should hand
over the communicat ion terminal 207 from the base stat ion device 204 to
the base stat ion device 203. Then, the base stat ion device 204 hands over
13
the communicat ion terminal 207 from the base stat ion device 204 to the
base stat ion device 203. Accordingly, the communicat ion terminal 207
can receive the fi rst service via the base stat ion device 203. Note that
informat ion on which service the communicat ion terminal 207 is receiving
may be grasped by the control device 206 using a system 5 that manages
informat ion on a subscriber and charging, such as a system of O&M, for
example.
[0042]
As described above, the present example embodiment can isolate
10 the base stat ion device 204 from the MEC server 200 detected to be
abnormal . Therefore, the abnormal i ty caused in the MEC server 200 can
be prevented from damaging the base stat ion device 204 that is providing
the MCS, and provision of the MCS can be cont inued. Therefore, even
when the communicat ion terminal 207 receives an unauthorized access
15 because of being a poorly secured terminal , the unauthor ized access wi l l be
prevented from adversely affect ing the MCS.
[0043]
Furthermore, in the present example embodiment , such control is
per formed whereby the communicat ion terminal having received the first
20 service via the base stat ion device 204 is handed over to the base stat ion
device 203. According to this control , the communicat ion terminal 207
can cont inue receiving the first service. Here, the base stat ion device 203
only provides the MCS the number of t imes less than the predetermined
counted value. Therefore, i f by any chance the abnormal i ty caused in the
25 MEC server 200 affects the base stat ion device 203, the abnormal i ty is
unl ikely to adversely affect the MCS. In part icular, the base stat ion to
which the base stat ion device 203 does not provide any MCS wi l l never
affect an MCS.
[0044]
14
Note that , in the present example embodiment , provision of the first
service by the base stat ion device 203 is assumed to be cont inued after an
abnormal i ty is detected in the MEC server 200. However, the present
invent ion is not l imi ted to this ar rangement . That is, i t is also possible to
stop the communicat ion of the MEC server 200 and stop 5 provision of the
fi rst service in al l the base stat ion devices, depending on the analysis
resul t of the abnormal i ty detect ed in the MEC server 200.
[0045]
Further, in the present example embodiment , the control device 206
10 controls the handover of the communicat ion terminal 207 from the base
stat ion device 204 to the base stat ion device 203. However, the present
invent ion is not l imi ted to this ar rangement . That is, i t is also possible to
arrange so that the base stat ion device 203 and the base stat ion device 204
per forms handover control using an inter face between base stat ion devices,
15 such as X2 in the long term evolut ion (LTE). In this case, the base
stat ion device 204 obtains ident i ficat ion informat ion of the MEC server
wi th which an adjacent base stat ion device can communicate, informat ion
on the types of services provided by the adjacent base stat ion device, and
the l ike, from the adjacent base stat ion device, via the interface between
20 the base stat ion devices. Then, the base stat ion device 204 may
determine to hand over the communicat ion terminal 207 to the base stat ion
device 203, based on the obtained informat ion.
[0046]
In addi t ion, in the present example embodiment , the MEC server is
25 used as a server to provide the first service and the second service.
However, the present invent ion is not l imi ted to this arrangement . That is,
any server that provides a servic e by communicat ing wi th the base stat ion
device via an inter face such as an appl icat ion programming inter face (API )
can be used.
15
[0047]
In addi t ion, in the present example embodiment , the priori ty level
of a service is determined based on the requi red level of rel iabi l i ty.
However, the present invent ion is not l imi ted to this arrangement . That is,
the priori ty level of a service may be determined based 5 on another index
such as a required level of real -t ime per formance.
[0048]
In addi t ion, in the present example embodiment , the processing in
Step S14 is per formed after the processing in Step S13. However, the
10 present invent ion is not l imi ted to this ar rangement . That is, the
processing in Step S14 may be per formed pr ior to the processing in Step
S13.
[0049]
In addi t ion, in the present example embodiment , when the MEC
15 server 201 that provides an MCS is detected to be abnormal , i t is also
possible to not i fy the system of O&M that the abnormal i ty has been
detected, instead of blocking the communicat ion path between the MEC
server 201 and the base stat ion device 204.
[0050]
20 [Third example embodiment ]
Next , a third example embodiment of the present invent ion is
descr ibed below. The communicat ion system 30 according to the present
example embodiment has a configurat ion simi lar to that of the
communicat ion system 20 according to the second example embodiment as
25 i l lustrated in Fig. 3. The fol lowing describes a di fference in operat ion of
the communicat ion system 30 according to the present example
embodiment wi th respect to the communicat ion system 20 according to the
second example embodiment . The operat ion of the communicat ion
system 30 according to the present example embodiment is described below
16
wi th reference to Fig. 5. Note that Steps S11 to S14 are simi lar to thei r
counterparts in the second example embodiment .
[0051]
Simi larly to the second example embodiment , the communicat ion
system 30 according to the present example embodiment 5 hands over the
communicat ion terminal 207 from the base stat ion device 204 to the base
stat ion device 203, in Step S14. Here, when the communicat ion terminal
207 stays in the coverage of cel l 210 of the base stat ion device 204, a
so-cal led ping pong phenomenon l ikely occur s, in which the
10 communicat ion terminal 207 is handed over from the base stat ion device
203 to the base stat ion device 204 again.
[0052]
In view of the above, the communicat ion system according to the
present example embodiment per forms control to prevent the
15 communicat ion terminal 207 from being handed over from the base stat ion
device 203 to the base stat ion device 204, after Step S14 (Step S15).
That is, the control device 206 controls the communicat ion terminal 207
not to be handed over to the base stat ion device 204 again, after the
communicat ion terminal 207 is handed over from the base stat ion device
20 204 to the base stat ion device 203.
[0053]
The fol lowing is a speci fic method to control the communicat ion
terminal 207 not to be handed over to the base stat ion device 204. For
example, the communicat ion terminal 207 may be control led not to
25 transmi t a measurement report concerning the cel l of the base stat ion
device 204. Al ternat ively, i t is also possible to remove the cel l of the
base stat ion device 204, from a l ist of neighboring cel ls of the base stat ion
device 203, which is managed by ei ther the control device 206 or the base
stat ion device 203. Al ternat ively, i t is possible to post a flag indicat ing
17
“NO HANDOVER” on the cel l of the base stat ion device 204, in the l ist of
neighboring cel ls . Al ternat ively, i t is possible to add informat ion
concerning services provided by each base stat ion device, to the
neighboring cel l informat ion of the base stat ion device 203, the
neighboring cel l informat ion being managed by ei ther 5 the control device
206 or the base stat ion device 203. Then, delet ing the first service from
the provided service informat ion corresponding to the cel l of the base
stat ion device 204 may also be used for prevent ion of the handover of the
communicat ion terminal 207 to the base stat ion device 204.
10 [0054]
As descr ibed above, in the present example embodiment , after
being handed over from the base stat ion device 204 to the base stat ion
device 203, the communicat ion terminal 207 is control led not to be handed
over to the base stat ion device 204 again. Wi th this, a ping pong
15 phenomenon between the base stat ion device 203 and the base stat ion
device 204 can be prevented. Here, the base stat ion device 204 has
stopped providing the first service, whi le the base stat ion device 203
cont inues providing the fi rst service. Therefore, by not being handed
over to the base stat ion device 204, the communicat ion terminal 207 can
20 cont inuously receive the first service.
[0055]
[Fourth example embodiment ]
Next , a fourth example embodiment of the present invent ion is
descr ibed below. Fig. 6 i l lustrates a configurat ion of a communicat ion
25 system 40 according to the present example embodiment . The
communicat ion system 40 has a configurat ion simi lar to the configurat ion
of the communicat ion system 20 according to the second example
embodiment ; however, the communicat ion system 40 is di fferent from the
communicat ion system 20 in point of locat ions of the communicat ion
18
terminal 207. That is, in the second example embodiment , the
communicat ion terminal 207 is located in a posi t ion at which the coverage
of cel l 209 of the base stat ion device 203 overlaps wi th the coverage of cel l
210 of the base stat ion device 204; whereas in the present example
embodiment , the communicat ion terminal 207 is 5 located inside the
coverage of cel l 210 of the base stat ion device 204 and outside the
coverage of cel l 209 of the base stat ion device 203. In this case, the
communicat ion terminal 207 cannot per form handover from the base
stat ion device 204 to the base stat ion device 203.
10 [0056]
In view of this, i t is assumed that the communicat ion system 40
according to the present example embodiment changes the coverage of cel l
of the base stat ion device 203. An operat ion of the communicat ion
system 40 according to the present examp le embodiment is described below
15 wi th reference to Fig. 7. Note that , since being simi lar to their
counterpart in the second example embodiment , the descript ion of Steps
S11 to S13 wi l l be left out .
[0057]
When the communicat ion terminal 207 is not located inside the
20 coverage of cel l 209 of the base stat ion device 203, and when the
communicat ion path between the MEC server 200 and the base stat ion
device 204 is blocked, the control device 206 per forms coverage change
control over the coverage of cel l of the base stat ion device 203 whereby
the coverage of cel l 209 of the base stat ion device 203 covers the
25 communicat ion terminal 207 (Step S16). A speci fic method for the
coverage change control is to change the transmission power, the antenna
t i l t , or the azimuth angle of a beam, into a direct ion where the
communicat ion terminal 207 is located. When there are a plural i ty of
communicat ion terminal s unable to obtain the fi rst service, besides the
19
communicat ion terminal 207, the posi t ions of the plural i ty of
communicat ion terminal s may be stat ist ical ly processed, and the
transmission power, the antenna t i l t , or the azimuth angle of a beam may be
changed into a direct ion where the communicat ion terminal s are
concentrated the most . For the posi t ion of the communicat 5 ion terminal
207, informat ion of a posi t ioning funct ion such as a global posi t ioning
system (GPS) incorporated in the terminal may be used. Al ternat ively, i t
is possible to est imate the posi t ion of the terminal and the azimuth angle of
the terminal wi th respect to the base stat ion device 203, using a method
10 such as t ri laterat ion based on the intensi ty informat ion of the radio wave
received by the communicat ion terminal 207 from the surrounding base
stat ion device and the posi t ional informat ion of the sur rounding base
stat ion device.
[0058]
15 Then, when the communicat ion terminal 207 is located inside the
coverage of cel l 209 of the base stat ion device 203 by changing the
coverage of cel l of the base stat ion device 203, the control device 206
hands over the communicat ion terminal 207 to the base stat ion device 203
(Step S17).
20 [0059]
Here, simi larly to the third example embodiment , the cont rol device
206 may control not to hand over the communicat ion terminal 207 to the
base stat ion device 204 again (Step S18). In addi t ion, the processing in
Step S13 may be per formed after the processing in Step S18.
25 [0060]
On the other hand, cases may occur in which, even by changing the
coverage of cel l of the base stat ion device 203, the communicat ion
terminal 207 cannot be included in the coverage of cel l 209 of the base
stat ion device 203. In view of this, prior to execut ing Step S16, the
20
control device 206 may extract the base stat ion device that can provide the
fi rst service as wel l as can communicate wi th the communicat ion terminal
207 by changing the coverage.
[0061]
For example, as i l lustrated in Fig. 8, the communicat 5 ion system 40
according to the present example embodiment is assumed to further include
a base stat ion device 300 that can communicate wi th the MEC server 200.
An operat ion of the communicat ion system 40 in this case is described
below wi th reference to Fig. 9. Since being simi lar to their counterpart in
10 the second example embodiment , the descript ion of Steps S11 to S13 wi l l
be left out . When the communicat ion path between the base stat ion
device 204 and the MEC server 200 is blocked, the control device 206
selects a base stat ion device over which coverage change control is to be
per formed, from among the base stat ion devices 203 and 300 that can
15 communicate wi th the MEC server 200 (Step S19) . In the present
example embodiment , the base stat ion device 300 that is most adjacent to
the communicat ion terminal 207 is assumed to be selected. Then, the
control device 206 controls to change the coverage of cel l of the selected
base stat ion device 300 (Step S20) . When the communicat ion terminal
20 207 is located inside the coverage of cel l 301 of the base stat ion device 300
by changing the coverage of cel l of the base stat ion device 300, the control
device 206 cont rols to hand over the communicat ion terminal 207 from the
base stat ion device 204 to the base stat ion device 300 (Step S21).
Furthermore, the control device 206 may also control the communicat ion
25 terminal 207 not to be handed over to the base stat ion device 204 again
(Step S22). Note that the processing in Step S13 may be per formed after
the processing in Step S22.
[0062]
As described above, in the present example embodiment , coverage
21
change control is per formed over the cel l of the base stat ion device
whereby the communicat ion terminal 207 enters the cel l of the base stat ion
device that can provide the first service. Wi th this, the communicat ion
terminal 207 can cont inue receiving the first service.
5 [0063]
Each i tem of processing of the above-described example
embodiment may be executed by software. That is, a computer program
for per forming each i tem of processing may be read in and executed by a
CPU included in an informat ion processing apparatus. Even when a
10 program is used to per form each i tem of processing, the processing in
content that is simi lar to the processing of the above-descr ibed example
embodiment can be real ized. The ment ioned program may be stored in a
non-t ransi tory medium such as a semiconductor storage device such as a
read only memory (ROM) , a random access memory (RAM) , and a flash
15 memory, an opt ical disk, a magnet ic disk, and a magnetoopt ical disk.
[0064]
The whole or part of the example embodiments disclosed above can
be described as, but not l imi ted to, the fol lowing supplementary notes.
[0065]
20 (Supplementary Note 1)
A communicat ion system comprising:
a first server that provides a first service;
a second server that provides a second service; and
a first base stat ion device that communicates wi th the first se rver
25 and the second server, wherein
when the second service has a higher prior i ty level than the first
service, and when an abnormal i ty is detected in the first server, a
communicat ion path between the first base stat ion device and the fi rst
server is blocked.
22
[0066]
(Supplementary Note 2)
The communicat ion system according to Supplementary Note 1,
comprising:
a swi tch that per forms swi tching between the 5 communicat ion path
between the first base stat ion device and the first server and a
communicat ion path between the second server and the fi rst base stat ion
device, wherein
when the abnormal i ty is detected, the swi tch blocks the
10 communicat ion path between the first base stat ion device and the fi rst
server.
[0067]
(Supplementary Note 3)
The communicat ion system according to Supplementary Note 2,
15 further compr ising:
a control device that controls the swi tching by the swi tch.
[0068]
(Supplementary Note 4)
The communicat ion system according to any one of Supplementary
20 Notes 1 to 3, further comprising:
a moni toring device that detects an abnormal i ty in the fi rst server,
wherein
the moni toring device detects the abnormal i ty based on an amount
of traffic between the fi rst server and the fi rst base stat ion device.
25 [0069]
(Supplementary Note 5)
The communicat ion system according to any one of Supplementary
Notes 1 to 4, wherein
the pr iori ty level is determined based on a level of rel iabi l i ty
23
requi red for each service.
[0070]
(Supplementary Note 6)
The communicat ion system according to any one of Supplementary
Notes 5 1 to 5, wherein
the first base stat ion device has a counted value for the number of
t imes at which the first base stat ion device has provided the second service
to a communicat ion terminal located inside a cel l of the fi rst base stat ion
device, the counted value being a predetermined value or more.
10 [0071]
(Supplementary Note 7)
The communicat ion system according to Supplementary Note 6,
wherein
the counted value is counted wi thin a predetermined period of t ime.
15 [0072]
(Supplementary Note 8)
The communicat ion system according to any one of Supplementary
Notes 1 to 7, further comprising:
a second base stat ion device that communicates wi th the first
20 server; and
a communicat ion terminal that subscr ibes to the first service, and
receives the fi rst service via the fi rst base stat ion device, wherein
when the communicat ion terminal is located inside coverage of a
cel l of the second base stat ion device, and when the communicat ion path
25 between the first base stat ion device and the first server is blocked, the
communicat ion system performs handover control whereby the
communicat ion terminal is handed over from the fi rst base stat ion device
to the second base stat ion device.
[0073]
24
(Supplementary Note 9)
The communicat ion system according to Supplementary Note 8,
wherein
the handover control further includes control whereby the
communicat ion terminal having been handed over is prevented 5 from being
handed over to the first base stat ion device.
[0074]
(Supplementary Note 10)
The communicat ion system according to Supplementary Note 8 or 9
10 further compr ising:
a cont rol device that manages informat ion on a type of a server wi th
which each of the first base stat ion device and the second base stat ion
device can communicate, wherein
the cont rol device per forms the handover cont rol over the fi rst base
15 stat ion device based on the informat ion.
[0075]
(Supplementary Note 11)
The communicat ion system according to Supplementary Note 8 or 9,
wherein
20 the first base stat ion device, via an X2 inter face, obtains
informat ion on a type of a server wi th which the second base stat ion device
can communicate, and the fi rst base stat ion device per forms the handover
control based on the informat ion.
[0076]
25 (Supplementary Note 12)
The communicat ion system according to any one of Su pplementary
Notes 8 to 11, wherein
when the communicat ion terminal is not located inside the coverage
of the cel l of the second base stat ion device, and when the communicat ion
25
path between the first base stat ion device and the fi rst server is blocked,
the communicat ion system per forms coverage change control over the cel l
of the second base stat ion device.
[0077]
(Supplementary 5 Note 13)
The communicat ion system according to any one of Supplementary
Notes 1 to 12, wherein
the fi rst server and the second s erver provide a service whi le
communicat ing wi th the fi rst base stat ion device or the second base stat ion
10 device via an appl icat ion programming inter face (API ).
[0078]
(Supplementary Note 14)
The communicat ion system according to any one of Supplementary
Notes 1 to 13, wherein
15 communicat ion of the fi rst server is stopped depending on an
analysis resul t of the abnormal i ty detected in the first server.
[0079]
(Supplementary Note 15)
A base stat ion device in a communicat ion system, comprising:
20 a means that communicates wi th a first server that provides a first
service;
a means that communicates wi th a second server that provides a
second service; and
a means that stops communicat ion wi th the first server, when an
25 abnormal i ty is detected in the fi rst serve r in cases where the second service
has a higher pr ior i ty level than the first service.
[0080]
(Supplementary Note 16)
The base stat ion device according to Supplementary Note 15,
26
wherein
the pr iori ty level is determined based on a level of rel iabi l i ty
requi red for each service.
[0081]
(Supplementary 5 Note 17)
The base stat ion device according to Supplementary Note 15 or 16,
wherein
the base stat ion device has a counted value for the number of t imes
at which the base stat ion device has provided the second service to a
10 communicat ion terminal located inside a cel l of the base stat ion device, the
counted value being a predetermined value or more.
(Supplementary Note 18)
The base stat ion device according to Supplementary Note 17,
wherein
15 the counted value is counted wi thin a predetermined period of t ime.
[0082]
(Supplementary Note 19)
The base stat ion device according to any one of Supplementary
Notes 15 to 18, wherein
20 when a communicat ion terminal that receives the fi rst service via
the base stat ion device is located inside coverage of a cel l of another base
stat ion device that communicates wi th the first server, and when a
communicat ion path between the fi rst server and the base stat ion device is
blocked, the base stat ion device per forms handover control whereby the
25 communicat ion terminal is handed over from the base stat ion device to the
other base stat ion device.
[0083]
(Supplementary Note 20)
The base stat ion device according to Supplementary Note 19,
27
wherein
the handover control includes control whereby the communicat ion
terminal having been handed over is prevented from being handed over
from the other base stat ion device to the base stat ion device.
5 [0084]
(Supplementary Note 21)
The base stat ion device according to Supplementary Note 19 or 20,
wherein
the base stat ion device, via an X2 inter face, obtains informat ion on
10 a type of a server wi th which the other base stat ion device can
communicate, and the base stat ion device per forms the handover control
based on the informat ion.
[0085]
(Supplementary Note 22)
15 The base stat ion device according to any one of Supplementary
Notes 15 to 21, wherein
the fi rst server and the second server provide a service whi le
communicat ing wi th the fi rst base stat ion device or the second base stat ion
device via an appl icat ion programming inter face (API ).
20 [0086]
(Supplementary Note 22)
A control device in a communicat ion system, wherein
the communicat ion system includes:
a first server that provides a first service;
25 a second server that provides a second service; and
a first base stat ion device that communicates wi th the first server
and the second server, and
when the second service has a higher prior i ty level than the first
service, and when an abnormal i ty is detected in the first server, the control
28
device controls whereby a communicat ion path between the fi rst base
stat ion device and the fi rst server is blocked.
[0087]
(Supplementary Note 23)
The control device according to Supplementary 5 Note 22, wherein
the communicat ion system includes a swi tch that per forms
swi tching between the communicat ion path between the first base stat ion
device and the fi rst server and a communicat ion path between the second
server and the first base stat ion device, and
10 the control device blocks the communicat ion path by cont rol l ing th e
swi tching per formed by the swi tch.
[0088]
(Supplementary Note 24)
The control device according to Supplementary Note 22 or 23,
15 wherein
the pr iori ty level is determined based on a level of rel iabi l i ty
requi red for each service.
[0089]
(Supplementary Note 25)
20 The cont rol device according to any one of Supplementary Notes 22
to 24, wherein
the communicat ion system further includes:
a second base stat ion device that communicates wi th the first
server; and
25 a communicat ion terminal that subscr ibes to the first service, and
receives the fi rst service via the fi rst base stat ion device, wherein
when the communicat ion terminal is located inside coverage of a
cel l of the second base stat ion device, and when the communicat ion path
between the first server and the first base stat ion device is blocked, the
29
control device performs handover control whereby the communicat ion
terminal is handed over from the first base stat ion device to the second
base stat ion device.
[0090]
(Supplementary 5 Note 26)
The control device according to Supplementary Note 25, wherein
the handover control further includes control whereby the
communicat ion terminal having been handed over is prevented from being
handed over to the first base stat ion device.
10 [0091]
(Supplementary Note 27)
The control device according to Supplementary Note 25 or 26,
wherein
the control device manages informat ion on a type of a server wi th
15 which each of the first base stat ion device and the second base stat ion
device can communicate, and
the cont rol device per forms the handover cont rol over the fi rst base
stat ion device based on the informat ion.
[0092]
20 (Supplementary Note 28)
The cont rol device according to any one of Supplementary Notes 25
to 27, wherein
when the communicat ion terminal is not located inside the coverage
of the cel l of the second base stat ion device, and when the communicat ion
25 path between the first server and the first base stat ion device is blocked,
the cont rol device per forms coverage change control over the cel l of the
second base stat ion device.
[0093]
(Supplementary Note 29)
30
The cont rol device according to any one of Supplementary Notes 2 2
to 28, wherein
the fi rst server and the second server provide a service whi le
communicat ing wi th the fi rst base stat ion device or the second base stat ion
device via an appl icat ion programming 5 inter face (API ).
[0094]
(Supplementary Note 30)
The cont rol device according to any one of Supplementary Notes 22
to 29, wherein
10 communicat ion of the fi rst server is stopped depending on an
analysis resul t of the abnormal i ty detected in the first server.
[0095]
(Supplementary Note 31)
A communicat ion method in a communicat ion system, wherein
15 the communicat ion system includes:
a first server that provides a first service;
a second server that provides a second service; and
a first base stat ion device that communicates wi th the first server
and the second server, the communicat ion method comprising:
20 blocking a communicat ion path between the first base stat ion
device and the first server, when an abnormal i ty i s detected in the fi rst
server in cases where the second service has a higher prior i ty level than the
fi rst service.
[0096]
25 (Supplementary Note 32)
The communicat ion method according to Supplementary Note 31,
comprising:
detect ing the abnormal i ty based on an amount of traffic between the
fi rst server and the first base stat ion device.
31
[0097]
(Supplementary Note 33)
The communicat ion method according to Supplementary Note 31 or
32, wherein
the pr iori ty level is determined based on a level 5 of rel iabi l i ty
requi red for each service.
[0098]
(Supplementary Note 34)
The communicat ion method according to any one of Supplementary
10 Notes 31 to 33, wherein
the communicat ion system further includes:
a second base stat ion device that communicates wi th the first
server; and
a communicat ion terminal that subscr ibes to the first service, and
15 receives the fi rst service via the fi rst base stat ion device,
the communicat ion method compr ising:
per forming handover control whereby the communicat ion terminal
is handed over from the fi rst base stat ion device to the second base stat ion
device, when the communicat ion path between the fi rst base stat ion device
20 and the first server in cases where the communicat ion terminal is located
inside coverage of a cel l of the second base stat ion device.
[0099]
(Supplementary Note 35)
The communicat ion method according to Supplementary Note 34,
25 wherein
the handover control further includes control whereby the
communicat ion terminal having been handed over is prevented from being
handed over to the first base stat ion device.
[0100]
32
(Supplementary Note 36)
The communicat ion method according to any one of Supplementary
Notes 31 to 35, comprising:
per forming coverage change control over a cel l of the second base
stat ion device when the communicat ion path between the 5 first base stat ion
device and the first server is blocked in cases where the communicat ion
terminal is not located inside coverage of the cel l of the second base
stat ion device.
[0101]
10 (Supplementary Note 37)
The communicat ion method according to any one of Supplementary
Notes 31 to 36, wherein
the fi rst server and the second server provide a service whi le
communicat ing wi th the fi rst base stat ion device or the second base stat ion
15 device via an appl icat ion programming inter face (API ).
[0102]
(Supplementary Note 38)
The communicat ion method according to any one of Supplementary
Notes 31 to 37, comprising:
20 stopping communicat ion of the first server depending on an
analysis resul t of the abnormal i ty detected in the first server.
[0103]
(Supplementary Note 39)
A program for use in a communicat ion system, wherein
25 the communicat ion system includes:
a first server that provides a first service;
a second server that provides a second service; and
a first base stat ion device that communicates wi th the first s erver
and the second server,
33
the program causing a computer to execute:
blocking a communicat ion path between the first base stat ion
device and the first server, when an abnormal i ty is detected in the fi rst
server in cases where the second service has a higher prior i ty level than the
first service.

CLAIMS
[Claim 1]
A communicat ion system comprising:
a first server that provides a first service;
a second server that provides a second 5 service; and
a first base stat ion device that communicates wi th the first server
and the second server, wherein
when the second service has a higher prior i ty level than the first
service, and when an abnormal i ty is detected in the fir st server, a
10 communicat ion path between the first base stat ion device and the fi rst
server is blocked.
[Claim 2]
The communicat ion system according to Claim 1, wherein
the pr iori ty level is determined based on a level of rel iabi l i ty
15 requi red for each service.
[Claim 3]
The communicat ion system according to Claim 1 or 2, wherein
the first base stat ion device has a counted value for the number of
t imes at which the first base stat ion device has provided the second service
20 to a communicat ion terminal located inside a cel l of the fi rst base stat ion
device, the counted value being a predetermined value or more.
[Claim 4]
The communicat ion system according to any one of Claims 1 to 3,
further compr ising:
25 a second base stat ion device that communicates wi th the first
server; and
a communicat ion terminal that subscr ibes to the first service, and
receives the fi rst service via the fi rst base stat ion device, wherein
when the communicat ion terminal is located inside coverage of a
36
cel l of the second base stat ion device, and when the communicat ion path
between the first base stat ion device and the first server is blocked, the
communicat ion system performs handover control whereby the
communicat ion terminal is handed over from the fi rst base stat ion device
to the second base 5 stat ion device.
[Claim 5]
The communicat ion system according to Claim 4, wherein
the handover control further includes control whereby the
communicat ion terminal having been handed over is prevented from being
10 handed over to the first base stat ion device.
[Claim 6]
The communicat ion system according to Claim 4 or 5, wherein
when the communicat ion terminal is not located inside the coverage
of the cel l of the second base stat ion device, and when the communicat ion
15 path between the first base stat ion device and the fi rst server is blocked,
the communicat ion system per forms coverage change control over the cel l
of the second base stat ion device.
[Claim 7]
The communicat ion system according to any one of Claims 1 to 6,
20 wherein
the fi rst server and the second server provide a service whi le
communicat ing wi th the first base stat ion device via an appl icat ion
programming inter face (API) .
[Claim 8]
25 A base stat ion device in a communicat ion system, comprising:
a means that communicates wi th a first server that provides a first
service;
a means that communicates wi th a second server that provides a
second service; and
37
a means that stops communicat ion wi th the first server, when an
abnormal i ty is detected in the fi rst server in cases where the second service
has a higher pr ior i ty level than the first service.
[Claim 9]
A control device in a communicat 5 ion system, wherein
the communicat ion system includes:
a first server that provides a first service;
a second server that provides a second service; and
a first base stat ion device that communicates wi th the first server
10 and the second server, and
when the second service has a higher prior i ty level than the first
service, and when an abnormal i ty is detected in the first server, the contro l
device controls whereby a communicat ion path between the fi rst base
stat ion device and the fi rst server is blocked.
15 [Claim 10]
A communicat ion method in a communicat ion system, wherein
the communicat ion system includes:
a first server that provides a first service;
a second server that provides a second service; and
20 a first base stat ion device that communicates wi th the first server
and the second server, the communicat ion method comprising:
blocking a communicat ion path between the first base stat ion
device and the first server, when an abnormal i ty is detected in the fi rst
server in cases where the second service has a higher prior i ty level than the
25 fi rst service.