Title: Subscriber wireless access system
Abstract: A subscriber wireless access system equipped with customer stations wirelessly connected to base stations and accommodating communication terminal devices in the customer stations. The system is provided with at least one exchange for connecting the base stations with a virtual dedicated line network for enabling customer stations wirelessly connected to different base stations to be interconnected via a virtual dedicated line network. The exchange includes table information assigned to the customer stations with virtual network connection information allocated for connected the customer stations, means responsive to receipt of data from a customer station via a subordinate base station for, with reference to the table, sending the data through the virtual network to another base station, and means responsive to receipt of data through the virtual network for, with reference to the table, converting the data to customer station identification information and sending the data to a subordinate base station.
Patent Number: 6,947,739 Issued on 09/20/2005 to Yokoyama
| Inventors:
|
Yokoyama; Naoki (Tokyo, JP)
|
| Assignee:
|
Hitachi Kokusai Electric Inc. (Tokyo, JP)
|
| Appl. No.:
|
026544 |
| Filed:
|
December 27, 2001 |
Foreign Application Priority Data
| Dec 28, 2000[JP] | 2000-400119 |
| Current U.S. Class: |
455/426.2; 370/310.2; 370/338; 370/353; 370/355; 370/356; 370/395.31; 370/399; 370/466; 455/554.2; 455/560; 455/561 |
| Intern'l Class: |
H04Q 007/20; H04M 001/00; H04L 012/66; H04L 012/28 |
| Field of Search: |
455/445,560,517,518,519,426.2,554.2,426.1,561
370/389,392,397,399,395.2,395.3,395.31,328,329,338,352,353,354,355,356,401,410,466,310.1,310.2
709/238,243,244,250
|
References Cited [Referenced By]
U.S. Patent Documents
| 5809501 | Sep., 1998 | Noven.
| |
| 5875185 | Feb., 1999 | Wang et al.
| |
| 5940371 | Aug., 1999 | Mitts et al.
| |
| 5958018 | Sep., 1999 | Eng et al.
| |
| 5974036 | Oct., 1999 | Acharya et al.
| |
| 6041358 | Mar., 2000 | Huang et al.
| |
| 6373834 | Apr., 2002 | Lundh et al.
| |
| 6473411 | Oct., 2002 | Kumaki et al.
| |
| 6606310 | Aug., 2003 | Vialen et al.
| |
| 6738812 | May., 2004 | Hara et al.
| |
| 6768724 | Jul., 2004 | Olkkonen.
| |
| 2002/0034962 | Mar., 2002 | Yokoyama.
| |
| 2002/0086705 | Jul., 2002 | Yokoyama.
| |
| 2002/0191562 | Dec., 2002 | Kumaki et al.
| |
| Foreign Patent Documents |
| 2003-78548 | Mar., 2003 | JP.
| |
| 2003/-333635 | Nov., 2003 | JP.
| |
Primary Examiner: Perez-Gutierrez; Rafael
Attorney, Agent or Firm: Wenderoth, Lind & Ponack, L.L.P.
Claims
1. A subscriber wireless access system equipped with customer stations which
are wirelessly connected to base stations and for accommodating communication terminal
devices in the customers stations, said subscribers wireless access system comprising:
exchanges for connecting the base stations with a virtual dedicated line network
so as to enable customer stations which are wirelessly connected to different base
stations to be interconnected via a virtual dedicated line network;
wherein each of said exchanges include:
a table for correlating identification information assigned to the customer stations
with virtual dedicated line network connection information allocated for connecting
the customer stations;
means for receiving data from a customer station via a subordinate base station,
and, with reference to the table, sending the received data through the virtual
dedicated line network to another base station; and
means for receiving data through the virtual dedicated line network, and, with
reference to the table, converting the received data to customer station identification
information of a customer station and sending the converted data to a subordinate
base station,
wherein at least one of said exchanges is provided in each of the base stations;
wherein said table of each of said exchanges contains identical virtual dedicated
line network connection information for the customer stations connected through
the virtual dedicated line network;
wherein each customer station is assigned station-specific identification information
for identifying the individual customer station and group identification information
for identifying the individual customer station as a member of a customer station
group, and each customer station group is assigned unique group identification
information;
wherein each base station has a first table for correlating the virtual dedicated
line network connection information with the group identification information of
each customer station group and a second table for correlating the station-specific
identifier information and the group identification information of each customer
station group, and said first and second tables of each of the base stations contain
the same group identification information for customer stations belonging to the
same customer station group; and
wherein said first and second tables of the base stations are management information
bases and, by utilizing a simple network management protocol system, the group
identification information is written to the management information bases by using
information sent from a management unit connected via the virtual dedicated line
network.
2. A subscriber wireless access system according to claim 1, wherein when different
customer stations under to the base stations are formed into closed customer station
groups, communication terminal devices under each customer station group are virtually
connected to each other.
3. A subscriber wireless access system according to claim 1, wherein the group
identification information assigned to the customer stations are included in wireless
frames of the base stations and the customer stations.
4. A subscriber wireless access system equipped with customer stations which
are wirelessly connected to base stations and for accommodating communication terminal
devices in the customer stations, said subscriber wireless access system comprising:
at least one exchange for connecting the base stations with a virtual dedicated
line network so as to enable customer stations which are wirelessly connected to
different base stations to be interconnected via a virtual dedicated line network;
wherein said at least one exchange includes:
a table for correlating identification information assigned to the customer stations
with virtual dedicated line network connection information allocated for connecting
the customer stations;
means for receiving data from a customer station via a subordinate base station,
and with reference to said table, sending the received data through the virtual
dedicated line network to another base station; and
means for receiving data through the virtual dedicated line network, and with
reference to said table, converting the received data to customer station identification
information of a customer station and sending the converted data to a subordinate
base station,
wherein each customer station is assigned station-specific identification information
for identifying the individual customer station and group identification information
for identifying the individual customer station as a member of a customer station
group, and each customer station group is assigned unique group identification
information; and
wherein each base station has a first table for correlating the virtual dedicated
line network connection information with the group identification information of
each customer station group and a second table for correlating the station-specific
identifier information and the group identification information of each customer
station group, and said first and second tables of each of the base stations contain
the same group identification information for customer stations belonging to the
same customer station group; and
wherein said first and second tables of each of the base stations are management
information bases and, by utilizing a simple network management protocol system,
the group identification information is written to the management information bases
by using information sent from a management unit connected via the virtual dedicated
line network.
5. A subscriber wireless access system according to claim 4, wherein when different
customer stations under to the base stations are formed into closed customer station
groups, communication terminal devices under each customer station group are virtually
connected to each other.
6. A subscriber wireless access system according to claim 4, wherein the group
identification information assigned to the customer stations are included in wireless
frames of the base stations and the customer stations.
7. A subscriber wireless access system equipped with customer stations which
are wirelessly connected to base stations and for accommodating communication terminal
devices in the customer stations, said subscriber wireless access system comprising:
exchanges for connecting the base stations with a virtual dedicated line network
so as to enable customer stations which are wirelessly connected to different base
stations to be interconnected via a virtual dedicated line network;
wherein each of said exchanges includes:
a table for correlating identification information assigned to the customer stations
with virtual dedicated line network connection information allocated for connecting
the customer stations;
means for receiving data from a customer station via a subordinate base station,
and with reference to the table, sending the received data through the virtual
dedicated line network to another base station; and
means for receiving data through the virtual dedicated line network, and, with
reference to the table, converting the received data to customer station identification
information of a customer station and sending the converted data to a subordinate
base station;
wherein an exchange is provided in each of the base stations;
wherein said table of each of said exchanges contains identical virtual dedicated
line network connection information for the customer stations connected through
the virtual dedicated line network;
wherein each customer station is assigned station-specific identification information
for identifying the individual customer station and group identification information
for identifying the individual customer station as a member of a customer station
group, and each customer station group is assigned unique group identification
information; and
wherein each base station has a first table for correlating the virtual dedicated
line network connection information with the group identification information of
each customer station group and a second table for correlating the station-specific
identifier information and the group identification information of each customer
station group, and said first and second tables of each of the base station contain
the same group identification information for customer stations belonging to the
same customer station group.
8. A subscriber wireless access system according to claim 7, wherein when different
customer stations under to the base stations are formed into closed customer station
groups, communication terminal devices under each customer station group are virtually
connected to each other.
9. A subscriber wireless access system according to claim 7, wherein the group
identification information assigned to the customer stations are included in wireless
frames of the base stations and the customer stations.
10. A subscriber wireless access system equipped with customer stations which
are wirelessly connected to base stations and for accommodating communication terminal
devices in the customer stations, said subscriber wireless access system comprising:
at least one exchange for connecting the base stations with a virtual dedicated
line network so as to enable customer stations which are wirelessly connected to
different base stations to be interconnected via virtual dedicated line network;
wherein said at least one exchange includes:
a table for correlating identification information assigned to the customer stations
with virtual dedicated line network connection information allocated for connecting
the customer stations;
means for receiving data from a customer station via a subordinate base station
and, with reference to said table, sending the received data through the virtual
dedicated line network to another base station; and
means for receiving data through the virtual dedicated line network, and, with
reference to said table, converting the received data to customer station identification
information of a customer station and sending the converted data to a subordinate
base station;
wherein each customer station is assigned station-specific identification information
for identifying the individual customer station and group identification information
for identifying the individual customer station as a member of a customer station
group, and each customer station group is assigned unique group identification
information; and
wherein each base station has a first table for correlating the virtual dedicated
line network connection information with the group identification information of
each customer station group and a second table for correlating the station-specific
identifier information and the group identification information of each customer
station group, and said first and second tables of each of the base station contain
the same group identification information for customer stations belonging to the
same customer station group.
11. A subscriber wireless access system according to claim 10, wherein when different
customer stations subordinate to the base stations are formed into closed customer
station groups, communication terminal devices under each customer station group
are virtually connected to each other.
12. A subscriber wireless access system according to claim 10, wherein the group
identification information assigned to the customer stations are included in wireless
frames of the base stations and the customer stations.
13. A base station for connecting to a virtual dedicated line network so as to
enable customer stations which are wirelessly connected with different base stations
to be interconnected via the virtual dedicated line network,
wherein each customer station is assigned station-specific identification information
for identifying the individual customer station and group identification information
for identifying the individual customer station as a member of a customer station
group, and each customer station group is assigned unique group identification
information; and
wherein said base station comprises:
a first table for correlating virtual dedicated line network connection information
allocated for connecting the customer stations with the group identification information
of each customer station group;
a second table for correlating the station-specific identifier information and
the group identification information of each customer station group,
wherein said first and second tables of said base station contain the same group
identification information for customer stations belonging to the same customer
station group, and said first and second tables are thereby operable to correlate
the station-specific identification information assigned to the customer stations
with the virtual dedicated line network connection information;
means for receiving data from a customer station via a subordinate base station
and, with reference to said tables, sending the received data through the virtual
dedicated line network to another base station; and
means for, with reference to said tables, receiving data through the virtual
dedicated line network, converting the received data to customer station identification
information and sending the converted data to a subordinate base station.
14. A base station according to claim 13, wherein when different customer stations
under to said base stations are formed into closed customer station groups, communication
terminal devices under each customer station group are virtually connected to each other.
15. An exchange for connecting base stations to a virtual dedicated line network
so as to enable customer stations which are wirelessly connected with different
base stations to be interconnected via the virtual dedicated line network, said
exchange comprising:
a table for correlating identification information assigned to the customer stations
with virtual dedicated line network connection information allocated for connecting
the customer stations;
means for, with reference to the table, sending data received from a customer
station via a subordinate base station through the virtual dedicated line network
to another base station; and
means for, with reference to the table, converting data received through the
virtual dedicated line network to customer station identification information and
sending the converted data to a subordinate base station;
wherein each customer station is assigned station-specific identification information
for identifying the individual customer station and group identification information
for identifying the individual customer station as a member of a customer station
group, and each customer station group is assigned unique group identification
information; and
wherein each base station has a first table for correlating the virtual dedicated
line network connection information with the group identification information of
each customer station group and a second table for correlating the station-specific
identifier information and the group identification information of each customer
station group, and said first and second tables of each the base stations contain
the same group identification information for customer stations belonging to the
same customer station group.
16. An exchange according to claim 15, wherein when different customer stations
under to the base stations are formed into closed customer station groups, communication
terminal devices under each customer station group are virtually connected to each other.
Description
FIELD OF THE INVENTION
The present invention relates to a subscriber wireless access system for accommodating,
in a customer station which is wirelessly connected to a base station, personal
computers and other such communications terminal devices, or a LAN connected to
such communication terminal devices. (A subscriber wireless access system of this
type is also called, for example, a fixed wireless access (FWA) system.) More particularly,
the present invention relates to a technology for controlling communications through
a virtual dedicated line network which is implemented by an ATM (asynchronous transfer
mode) network or the like.
DESCRIPTION OF THE PRIOR ART
Personal computers, mobile tools, mobile telephones and various other kinds
of communication terminal equipment have recently become common items of everyday
use. Wireless LANs for wirelessly interconnecting such communications terminal
devices have been developed and put into operation.
Subscriber wireless access systems which accommodate customer station
communication terminal devices, or a LAN or the like that is connected to communication
terminal devices, and which wirelessly connect the customer station with a base
station have been developed and implemented.
The wireless communication capability such a subscriber wireless access system
provides between the base station and the customer stations makes it possible to
interconnect the communications network on the base station side and the communication
terminal devices on the customer station side. Moreover, by allowing the base station
to function as a bridge, such a system can provide an interconnection among the
communication terminal devices of multiple customer stations accommodated by one
and the same base station.
The use of a subscriber wireless access system therefore makes it possible, by
simply setting up a base station and a customer station, to connect communication
terminal devices, or their LANs, to a communications network without the need to
install communication lines.
The use of a subscriber wireless access system also makes it possible to group
a number of customer stations which are served by the same base station. For example,
a subscriber's LANs can be divided up and each connected to a different customer
station within the same group. A company (subscriber) with several buildings can
connect the LANs that are installed in the individual buildings to different customer
stations within the same group and thus enjoy such benefits as company wide LAN integration.
The rising importance of and need for telecommunications are producing a strong
demand for the constant interconnection between communication terminal devices.
The demand for a constant connection is also strong from users of subscriber wireless
systems, who are seeking to use an ATM network and other virtual dedicated line
network services which are offered by communications companies so as to maintain
a constant connection among the communication terminal devices under their customer stations.
The subscriber wireless access system, which uses a virtual dedicated line network
so as to interconnect different base stations, enables the communication terminal
devices which are served by the different customer stations wirelessly connected
to these different base stations to maintain a constant connection via the virtual
dedicated line network.
In the subscriber wireless access system, however, since the base stations accommodate
multiple customer stations belonging to different entities, the mere connection
of base stations by a virtual dedicated line network results in a constant connection
between customer stations that should not be constantly connected (i.e., between
their communication terminal devices).
Consider, for example, the case where company A's head office in Tokyo
has a customer station which is served by a base station in Tokyo and its branch
office in Osaka has a customer station which is served by a base station in Osaka.
If the LAN of the Tokyo head office customer station and the LAN of the Osaka branch
office customer station are constantly connected, the LAN of company B's customer
station, which is accommodated by the same base station as company A's Tokyo head
office customer station, will also be constantly connected with company A's Osaka
branch office. This is undesirable from a secrecy protection stand point.
The present invention was accomplished in light of these circumstances and has
as an object to provide a subscriber wireless access system which enables a trouble-free
constant connection through a virtual dedicated line network.
Other objects of the present invention will become more apparent from the following description.
SUMMARY OF THE INVENTION
The present invention provides a subscriber wireless access system which is equipped
with customer stations that are wirelessly connected to base stations and accommodating
communication terminal devices in the customer stations directly or through a network
such as a LAN. The subscriber wireless access system according to the present invention
comprises: at least one exchange for connecting base stations with a virtual dedicated
line network for enabling customer stations which are wirelessly connected to different
base stations to be interconnected via a virtual dedicated line network, where
the at least one exchange includes a table correlating identification information
that is assigned to the customer stations with virtual dedicated line network connection
information allocated for connecting the customer stations; means responsive to
the receipts of data from a customer station via a subordinate base station for,
with reference to the table, sending the data through the virtual dedicated line
network to another base station, and means responsive to the receipt of data through
the virtual dedicated line network for, with reference to the table, converting
the data to customer station identification information of a customer station and
sending the data to a subordinate base station.
For example, in a specific configuration, the exchange stores in the table station-specific
IDs (CPE-IDs: consumer premises equipment identifiers) which are assigned to the
individual customer stations or tags (VLAN-Tags: virtual local area network tags)
for customer station identification which are set in Ethernet frames in conformity
with IEEE 802.1Q in association with virtual dedicated line network connection
information (VPI/VCI: virtual path identifier/virtual channel identifier), response
to the receipt of data form a customer station via a subordinate base station by,
with reference to the table, converting identification information of the sending
customer station that is attached to the data (CPE-ID or VLAN-Tag) to virtual dedicated
line network connection information (VPI/VCI) and sending the data to another base
station through the virtual dedicated line network, and responds to the receipt
of data through the virtual dedicated line network by, with reference to the table,
converting the virtual dedicated line network connection information (VPI/VCI)
of the data to customer station identification information (CPI-ID or VLAN-Tag)
and sending the converted data to a subordinate base station (i.e., a customer station).
A constant connection between customer stations (namely, their subordinate communication
terminal devices) can therefore be realized. Moreover, since the subscriber wireless
access system can establish a constant connection between specific subscribers,
the distribution of information from a pay TV station to subscribers and other
similar services is made possible.
In the subscriber wireless access system according to the present invention,
an
exchange is preferably connected to each of the base stations or incorporated in
each of the base stations so as to control the communications between the base
station and the virtual dedicated line network. Preferably, the tables of the exchanges
store identical virtual dedicated line network connection information (VPI/VCI)
for customer stations which are connected through the virtual dedicated line network.
For instance, the connection information which is associated with the identification
information of customer station A stored in one exchange table and the connection
information which is associated with the identification information of a customer
B stored in another exchange connected to the same virtual dedicated line network
are identical. Thus, for example, the customer station of a company's Tokyo head
office and the customer station of the same company's Osaka branch office can maintain
a constant connection in a closed environment, and as a result, the communication
terminal devices which are served by the two customer stations can stay in constant
connection while maintaining communication privacy.
In the subscriber wireless access system of the present invention, each customer
station is preferably assigned station-specific identification information for
identifying the individual customer station and group identification information
for identifying the customer station as a member of a customer station group. Further,
each base station has tables correlating the station-specific identifier information
and the group identification information and stores the same group identification
information (VLAN-Tag) for customer stations belonging to the same group.
For example, in a specific configuration, the station-specific identifier information
of each customer station is a CPE-ID and the group identification information is
a VLAN-Tag, the base stations correlate and manage the CPE-IDs and the VLAN-Tags
by using the tables, and the same VLAN-Tag is stored for customer stations belonging
to the same group. For instance, in a case where five customer stations whose CPE-IDs
are A to E are installed under a certain base station and the two customer stations
whose CPE-IDs are B and D are to be grouped, these two customer stations are managed
by assigning them the same VLAN-Tag in the table.
Therefore, since the group identification information (VLAN-Tags) of the
base stations and the customer stations are included in the wireless frames and
since the base stations conduct communications control by using the VLAN-Tags,
different customer stations under the base stations can be formed into closed groups,
and the communication terminal devices under each group of customers stations can
be virtually connected as if connected to the same LAN.
Further, if the VLAN-Tags constituting the identification information of
the customer stations are managed by associating them with the virtual dedicated
line network connection information (VPI/VCI) which is also in the exchange table,
customer station groups under different base stations can also be constantly connected
through the virtual dedicated line network.
The subscriber wireless access system can be configured as a single network management
protocol (SNMP) system, the tables of the base stations can be configured as management
information bases (MIBs), and the group identification information (VLAN-Tags)
can be written to the management information bases by using information that is
sent from a management unit (SNMP manager) which is connected via the virtual dedicated
line network.
This makes it possible, for example, for an administration (operation) center
that has received a subscriber request for the formation of a group to establish
the desired group by remote operations with respect to the base stations. Groups
of customer stations which are constantly connected through the virtual dedicated
line network can therefore be easily established without the need for workers to
visit and conduct an on-site setup at the individual base stations.
In the subscriber wireless access system according to the present invention,
the
group identification information (VLAN-Tags) which are assigned to the customer
stations are preferably included in the wireless frames of the base stations and
the customer stations and, therefore, as explained above, the communication terminal
devices under multiple customer stations can be virtually connected as if connected
to the same LAN. In addition, the subordinate customer stations can be notified
of the group identification information (VLAN-Tags) that is written in the base
station tables.
The present invention also provides an exchanges for connecting base stations
to a virtual dedicated line network so as to enable customer stations which are
wirelessly connected with different base stations to be interconnected via the
virtual dedicated line network. This exchange according to the present invention
comprises: a table correlating identification information which is assigned to
the customer stations (VLAN-tags, CPE-IDs or the like) with virtual dedicated line
network connections information that is allocated for connecting the customer stations
(VPI/VCI or the like); means for, with reference to the table, sending data that
is received from a customer station via a subordinate base station through the
virtual dedicated line network to another base station; and means for, with reference
to the table, converting data that is received through the virtual dedicated line
network to customer station identification information and sending the converted
data to a subordinate base station.
The present invention also provides a base station which is capable of connecting
to a virtual dedicated line network for enabling customer stations which are wirelessly
connected with different base stations to be interconnected via the virtual dedicated
line network. The base station according to the present invention comprises: a
table correlating identification information which is assigned to the customer
stations (VLAN-tags, CPE-IDs or the like) with virtual dedicated line network connection
information that is allocated for connecting the customer stations (VPI/VCI or
the like); means for, with reference to the table, sending data that is received
from a customer station via a subordinate base station through the virtual dedicated
line network to another base station; and means for, with reference to the table,
converting data that is received through the virtual dedicated line network to
customer station identification information and sending the converted data to a
subordinate base station.
BRIEF EXPLANATION OF THE DRAWINGS
FIG. 1 is a block diagram of a subscriber wireless access system according to
an embodiment of the present invention.
FIG. 2 is a conceptual diagram for explaining the contents of tables of a subscriber
wireless access system according to an embodiment of the present invention.
FIG. 3 is a conceptual diagram for explaining an Ethernet frame according to
an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be explained in detail with respect to the case
where the communication protocol between the base station and the customer stations
utilizes Ethernet frames tagged with VLAN-Tags conforming with IEEE 802.1Q.
FIG. 1 is a block diagram of the subscriber wireless access system according
to the present embodiment. FIG. 2 is a diagram showing the contents of correlation
tables of the exchanges and base stations.
As shown in FIG. 1, multiple base stations are connected by SNMP via an ATM trunk
network N, which is a virtual dedicated line network. Each base station accommodates
a number of customer stations which are wirelessly connected by Ethernet frames.
Each customer station is connected through a router R with a local area network
L accommodating a large number of communication terminal devices (PCs; not shown).
The ATM trunk network N is connected with various servers of Internet service
providers (ISP-A, ISP-B) and the like. The ATM trunk network N is also connected
with a SNMP manager server M which is installed at an operation center that manages
the subscriber wireless access system according to the present invention.
In the ensuring explanation, the two base stations are designated base stations
#
1 and base station #
2, the four customer stations which are accommodated
by the base station #
1 are designated CPE#
1-CPE#
4, and the
four customer stations which are accommodated by the base station #
2 are
designated CPE#
5-CPE#
8.
In this embodiment, an exchange is incorporated in the ATM trunk network interface
unit of each base station. The exchange section of each base station, which mainly
handles communications control of the virtual dedicated line network, is designated
ATM-SW, and the base station section of each base station, which mainly handles
wireless communications control of the customer stations, is designated BSE.
In each of the base station #
1 and the base station #
2, the ATM-SW
is provided with a MIB table T
1, and the BSE is provided with a MIB table
T
2. The contents of the MIB tables can be defined by the SNMP server through
the ATM trunk network N.
In this embodiment, the MIB tables T
1 and T
2 are defined to store
contents like those shown in FIG.
2.
In the table T
2 which is provided in the BSE of the base station #
1,
the station-specific identifier CPE-IDs of the of the subordinate CPEs #
1-#
4
are entered in association with the group identifiers VLAN-Tag of the same CPEs.
VLAN-Tag:
1 is associated with CPE#
1 assigned CPE-ID:
1, VLAN-Tag:
2 is associated with CPE#
2 assigned CPE:
2, and VLAN-Tag:
3 is associated with both CPE#
3 assigned CPE:
3 and CPE#
4
assigned CPE:
4. In other words, the CPE#
3 and CPE#
4 are defined
as belonging to the same group.
In the table T
2 which is provided in the BSE of base station #
2,
the station-specific identifier CPE-IDs of the subordinate CPEs #
5-#
8
are written in association with the group identifiers VLAN-Tag of the same CPEs.
VLAN-Tag:
1 is associated with CPE#
5 assigned CPE-ID:
5, VLAN-Tag:
2 is associated with both CPE#
6 assigned CPE:
6 and CPE#
7
assigned CPE:
7, and VLAN-Tag:
3 is associated with CPE#
8
assigned CPE:
8. In other words, the CPE#
6 and CPE#
7 are defined
as belonging to the same group.
In the embodiment shown in FIG. 1, the CPE#
3 and CPE#
4 are two
customer
stations at user A's Tokyo head office, and the CPE#
6 and CPE#
7 are
customer stations of the same user A's Nagoya branch office. This embodiment conducts
communications control between user A's Tokyo and Nagoya customer stations, and
conducts communications control with the Tokyo and Nagoya customer stations, which
are kept in constant connection.
The BSEs of the base stations #
1 and #
2 are provided with communications
control capability for controlling wireless communications with the customer stations
using the Ethernet frame shown in FIG.
3. The BSEs conduct communications
control by using the MAC address which is included in the frame as the address
of a specific communication terminal device, control communications within customer
station groups according to the VLAN-Tag that is included in the frame, and control
the handling of transmission data that is included in the IP frame.
The ATM-SW and BSE of the base station #
1 are connected by VLAN-Tag logical
channels. In the table T
1 provided in the ATM-SW of the base station #
1,
the VLAN-Tags are entered in association with information VPI/VCI specifying a
connection with a path of the ATM trunk network N. For example, VPI/VCI:
2/
1
is associated with VLAN-Tag:
3. In other words, communication by VLAN-Tag:
3 is conducted in a constantly connected state through the connection which
is specified by VPI/VCI:
2/
1 of the ATM trunk network N.
The ATM-SW and BSE of the base station #
2 are connected by VLAN-Tag logical
channels. In the table T
1 provided in the ATM-SW of the base station #
2,
the VLAN-Tags are entered in association with information VPI/VCI specifying a
connection with a path of the ATM trunk network N. For example, VPI/VCI:
2/
1
is associated with VLAN-Tag:
2. In other words, communication by VLAN-Tag:
2 is conducted in a constantly connected state through the connection which
is specified by VPI/VCI:
2/
1 of the ATM trunk network N.
The ATM-SW of each of the base stations #
1 and #
2 is provided with
conversion/control capability for use the contents of its table T
1 to convert
VPI/CVI to VLAN-Tag and thereby pass data that is received from the ATM trunk network
N through the VLAN logical channels to the BSE, and also to use the content of
its table T
1 to convert VLAN-Tag to VPI/VCI and thereby send the data that
is received from the BSE through the VLAN logical channel out on the ATM trunk
network N.
Owing to the conversion/control capability of ATM-SW, therefore the group on
the base station #
1 side including CPE#
3 and CPE#
4 assigned
VLAN-Tag:
3 and the group on the base station #
2 side including CPE#
6
and CPE#
7 assigned VLAN-Tag:
2 are constantly connected through the
connection of the ATM trunk network N which is specified by VPI/VCI:
2/
1.
The customer stations installed at user A's Tokyo head office (i.e., the communication
terminal devices under them) and the customer stations installed at user A's Nagoya
branch office (i.e., the communication terminal devices under them) are constantly connected.
In the subscriber wireless access system of the foregoing configuration, if for
example, a subscriber (user A) wants to group the CPE#
6 and CPE#
7
and sends a request to this effect to the operating center, the operating center
SNMP manager M rewrites the MIB Table 2 that is provided in the BSE of the base
station #
2 in line with the sent request. Specifically, the SNMP manager
server M connects with the base station #
2 through an ATM trunk network
N setting connection VPI/VCI:
1/
1, uses a setting VLAN-Tag:
500
to access the BSE of the base station #
2, and sets the same VLAN-Tag:
2
for the CPE#
6 and CPE#
7 in the MIB table
2.
Since, as shown in FIG. 3, the wireless frames of the BSE and CPE include
VLAN-Tags, the CPE is notified of the VLAN-Tag that is set in the MIB table 2 of
the BSE in this way by wireless communication between the BSE and the CPE.
If, for example, a subscriber (user A) wants to establish a constant connection
between the group which is composed of the CPE#
3 and CPE#
4 of the
base station #
1, which have already been grouped by setting the same VLAN-Tag:
3 and a customer station group which is composed of the CPE#
6 and
CPE#
7 of the base station #
2, and sends a request to this effect
to the operating center, the operating center SNMP manager server M rewrites the
MID table 1 that is provided in the ATM-SW of the base station #
1 in line
with the sent request.
Specifically, the SNMP manager server M connects with the base station
#
1 via the setting connection VPI/VCI:
1/
1 of the ATM trunk
network N, accesses ATM-SW, and, in the MIB table T
1, sets in association
with VLA-Tag:
3 of the CPE#
3 and CPE#
4 of the base station
#
1 the same VPI/VCI:
2/
1 as set for the CPE#
6 and CPE#
7
of the base station #
2.
The present invention thus enables the setting of CPE groups and the establishment
of a constant connection between CPEs through the ATM trunk network N by a remote
operation from the SNMP manager server M.
When the foregoing table setting is in effect and data are, for instance, transmitted
from a communication terminal device under the CPE#
3 to a communication
terminal device under the CPE#
4, the VLAN-Tag that is included in the transmission
frame which is sent from the CPE#
3 to the BSE of the base station #
1
transfers the data to the CPE#
4 which is associated with the same VLAN-Tag.
Even under the same base station, therefore, communication terminal devices
that are accommodated under different customer stations (CPEs) can communicate
with each other just as if they were connected by the same LAN.
When data is sent from a communication terminal device under the CPE#
3
to a communication terminal device under a CPE of the same user that is accommodated
by another base station (base station #
2), the data is handed over to the
ATM-SW in the base station #
1 and, based on the MIB table T
1, is
sent to the base station #
2 through the constant VPI/VCI:
2/
1
connection which is established in the ATM trunk network N. The base station #
2,
based on the VPI/VCI:
2 and its own MIB table
1, converts the received
data to the associated VLAN-Tag:
2 and sends the converted data to the CPE#
6
and CPE#
7 which are accommodated by the base station #
2.
Customer stations (communication terminal devices) which are accommodated
by different base stations can therefore be constantly connected based on settings.
As explained above, the present invention provides a subscriber wireless access
system that enables a trouble-free constant connection between customer stations
which are accommodated by different base stations through a virtual dedicated line
network without difficulty and enables the simple formation of customers station
groups. In addition, the present invention enables the operations for making and
modifying the settings for establishing such constant connections and customer
station groups to be centralized and performed remotely.
*
