The present invention particularly relates to a technique for high-speed switching among a plurality of wireless communication systems including a wireless communication system using an in-home ADSL, FTTH, etc. for a wired line of a network side and a technique for system switching between a macrocell and a femtocell.
In a conventional wireless system, as represented by a third-generation mobile phone or others, a wireless communication provider has installed a base station, a gateway, and a core network, and the wireless communication provider has also installed and operated a wired cable between the base station and the gateway.
Also, in response to the recent increase in the needs for speed-up of wireless communication and for diversification of communication applications, it has been difficult to cover a wide area by one base station and support the communication of all the users positioned in the wide area. Therefore, for example, a method of utilizing a plurality of systems by combining different wireless communication systems of WiMAX, wireless LAN, and others exist in the wide area in addition to a cellular and installation of a base station covering a smaller area in the same wireless system as represented by a femtocell have been studied.
An example of a conventional system configuration representing such a circumstance is shown in
If the wireless communication methods of the access point #1 and the access point #2 are different from each other, the system configuration shown in
If the wireless communication methods of the access point #1 and the access point #2 are the same as each other, the system configuration shown in
Here,
In any case, when a terminal (105) moves within these areas, inter-system handover or handover between macrocell and femtocell occurs so as to enable a higher-speed (or more QoS-ensured) communication for the terminal. On a network, in order to achieve these handovers, a control node (106) is connected via both the access points and wired cables (109 and 110). In a destination of the control node, communication counterpart or a connection-destination server (108) exists via a network (107).
Also, if the gateway which integrates and controls the plurality of access points (base stations) exists such as the cellular, gateways (201 and 202) of respective systems are installed between the access points (101 and 103) and the control node (106) as shown in
Here, the access points and the gateways are mutually connected by wired cables (203 and 204), respectively, and these wired cables have been installed and operated by the wireless communication provider as described above. Also, each band of the wired cables has been designed so as to ensure a communication at the maximum communication speed of a wireless line in accordance with the ability of the contained access point or base station or the number of base stations contained in the gateway. For example, when the cellular (EVDO) Rev.0 is taken as an example, the downlink of the wireless communication method of Rev.0 is maximally 2.4 Mb/s regardless of the number of contained users (in other words, 2.4 Mb/s are shared by a plurality of users), and therefore, the band required for the downlink for one base station (101) is 2.4 Mb/s. If the gateway (201) contains 10 base stations, the band minimally required for the downlink is 2.4 M×10=24 Mb/s, and therefore, a wired cable (205) between the control node and the gateway is designed to enable communication of 24 Mb/s or higher, and a cable between the gateway and each access point is designed to enable communication of 2.4 Mb/s or higher. In this manner, the bands of wired lines are designed so that the wireless lines can be always contained from a viewpoint of the installation and operation by the wireless communication provider.
On an assumption that the wired side can always contain the wireless lines, several band controlling methods for achieving the QoS of the user have been studied.
For example, in Patent Document 1, a required band depending on a content requested by a user terminal is ensured for each of a wired line and a wireless line. A wireless terminal (1 of FIG. 1 of Patent Document 1) transmits a content transmission request (S1) to a server (7 of FIG. 1 of Patent Document 1) via a wireless base station (3 of FIG. 1 of Patent Document 1). The server selects the wired band information corresponding to the content requested by the wireless terminal from wired band information 10 retained so as to correspond to each content, and determines a wired band used when the corresponding content is transmitted from the server to the wireless base station. Also, the wireless base station generates wireless band information used when the corresponding content is transmitted from the wireless base station to the wireless terminal based on the wired band information of which the server notifies, determines a band in a wireless zone to be used when the corresponding content is transmitted from the wireless base station to the wireless terminal, and sets the wireless zone (see paragraph 0019 of Patent Document 1 or others).
On the other hand, in Patent Document 2, on a basis of a state that a cognitive base station (20 of Patent Document 2) recognizes a state of the wireless band enabling a communication with a cognitive terminal (40 of Patent Document 2), it compares with the band required for the communication, and allocates the communication band.
When the communication occurs, a cognitive gateway (10 of Patent Document 2) first transmits an allocation request of the wireless band to the cognitive base station. The cognitive base station determines the information of the band which can be allocated between the cognitive base station and the cognitive terminal based on the information of the usage state of radiowaves recognized through the communication or others with the cognitive terminal, and notifies the cognitive gateway of this information. The cognitive gateway compares the information of the allocatable band of which the cognitive base station notifies with the band required for the communication, and notifies the cognitive base station of the information of the band to be actually allocated to the wireless zone (see paragraph 0084 of Patent Document 2 or others).
In the case of Patent Document 1, for example, the wireless terminal transmits a request for reception of streaming, the server side determines to carry out the streaming at a rate of 300 kb/s, and the wireless band information is generated so as to ensure a band of 300 kb/s on the wired side between the server and the wireless base station and also ensure 300 kb/s on the wireless side between the wireless base station and the wireless terminal, so that the wireless zone is set.
In this case, when the content transmission request is provided to the server side from the wireless terminal, the wired band and the wireless band are determined in accordance with only the wired band information and the wireless band information used in the transmission of the corresponding content, and the wired band and the wireless band used in the transmission of the corresponding content are not determined in consideration of the state of the wired line between the server and the wireless base station and the state of the wireless band between the wireless base station and the wireless terminal. Also, these flows are operated for each user content, and, if a plurality of users (wireless terminals) during communication with one certain wireless base station transmit the content transmission request, it is required to control the setting of the band in the wireless zone between the wireless base station and the wireless terminals since an available band in the wireless zone between the wireless base station and the wireless terminals is limited. However, it is not described how the generation of the wireless band information is operated. As described above, in Patent Document 1, the band allocation in accordance with the available wired band and wireless band cannot be achieved.
Also, in Patent Document 2, for example, when the streaming communication at 300 kb/s or higher occurs, the cognitive gateway makes an inquiry to the cognitive base station about the state of the wireless zone. The cognitive base station recognizes the usage of radiowaves or others, and replies to the cognitive gateway that 400 kb/s can be allocated in the wireless zone. In the cognitive gateway, since the hand required for the corresponding streaming communication is 300 kb/s, 300 kb/s which is the band required for the streaming communication is compared with the information of 400 kb/s which is replied as the allocatable band from the cognitive base station. As a result, the band allocation information is transmitted to the cognitive base station side so as to allocate 300 kb/s to the wireless zone.
In this case, the band required for the streaming communication is compared with the allocatable band to the wireless zone to determine the band in the wireless zone, and the state of the wired band is not a target of the comparison. As described above, in Patent Document 2, the used bands of the wired line and the wireless line cannot be allocated in accordance with the available wired band and wireless band.
In both of these Patent Documents, the wireless communication provider has installed the base station, the gateway, and the core networks, and has also installed and operated the wired cable between the base station and the gateway. Therefore, the system has been built by the wireless communication provider so as to exactly ensure the band of the wired line among the base station, the gateway, and the control node. Therefore, when the wireless band between the wireless base station and the wireless terminal is allocated, there has not been a problem that the band of the wired line among the base station, the gateway, and the control node is narrower than the wireless band between the wireless base station and the wireless terminal, and therefore, it is required to control the wireless band in consideration of the band of the wired line because of the narrowness.
However, the wired cable between the wireless base station and the gateway which has been installed and operated in the past by the wireless communication provider is expensive since it is a cable laid only for the operation. When a wireless base station is newly installed or additionally installed in order to respond to the needs in recent years for the high-speed wireless communication and the diversification of communication applications, a system configuration has been changed in order to reduce a cost such that the wireless communication provider lays the wired cable connecting between the wireless base station and the gateway so as to be replaced by a low-price narrow-band cable, or such that the wireless communication provider does not lay a dedicated line and borrows a wired network of an ADSL provider for the operation.
The state that the wireless communication provider lays the wired cable connecting between the wireless base station and the gateway so as to be replaced by the low-price narrow-band cable in order to reduce the cost corresponds to a case that the wired cable (204) connecting between the gateway and the wireless base station in
In this case, the wireless communication system cannot ensure the communication with the wireless terminal. For example, with taking the cellular (EVDO) Rev.0 as the example, when it is assumed that the cable (204) has a narrow band and can carry out the communication at 1 Mb/s, the band required for the downlink at one base station (103) is 2.4 Mb/s, and therefore, only a volume of 1 Mb/s of 2.4 Mb/s to be originally transmitted by the wired cable can be transmitted. As a result, a problem arises that all the data does not reach the wireless terminal (105), and the communication cannot be carried out. That is, in a case that the handover from the cell 102 to the cell 104 is carried out by the wireless terminal 105, if the handover to the base station 103 is carried out in consideration of only the wireless band information in the wireless zone as a conventional technique, the band of the wired line between the gateway #2 (202) and the base station #2 (103) is narrow, and the wireless terminal 105 during the communication cannot maintain the communication in some cases. Also, in a case that the wireless communication is started when the wireless terminal 105 is located at a position of both the cell 102 and the cell 104, it is controlled either the base station #1 (101) or the base station #2 (103) is used to carry out the wireless communication in consideration of only the wireless band information of the wireless zone in a conventional technique. However, when the wired band between the gateway and the base station cannot be sufficiently ensured for the communication band requested by the wireless terminal, the wired line is a bottleneck, and the communication cannot be carried out.
Also, the state that the wireless communication provider does not lay the wired cable connecting between the base station and the gateway by its own company in order to reduce the cost and uses the network of the ADSL provider for the connection corresponds to a system configuration shown in
Since the wireless communication provider lays only a cable (308) from the gateway (202) to the network of the ADSL provider, the cost can be reduced. However, the ADSL provider controls the line of the ADSL network (301) including, for example, in-house installed. ADSL modems (306 and 307), by a controller (302) and therefore, the band between the base station (103) and the gateway (202) changes depending on the states of other ADSL line users. Here, the bands (304 and 305) of the wired lines are controlled by the controller (302).
In this case, the wireless communication system cannot ensure the communication with the wireless terminal. For example, when the cellular (EVDO) Rev.0 is taken as an example, the band required for the downlink at one base station (103) is 2.4 Mb/c, and therefore, the band originally to be transmitted by the cable (304) is 2.4 Mb/s. Even if the cable (303) containing the base station (103) and the ADSL modems (306 and 307) in the ADSL network (301) is a wideband line of, for example, 20 Mb/s, in a case that the ADSL modems (306 and 307) are during the large-volume streaming communication or others and use 19 Mb/s thereof, only 1 Mb/s is allocated to the wired cable (304) connected to the base station, and only the volume of 1 Mb/s of 2.4 Mb/s to be originally transmitted by the cable can be transmitted. As a result, as the conventional technique, the problem arises that the communication cannot be carried out due to the inter-base-station handover based on only the information of the wireless band or due to the state that, when the base station is selected upon the communication start, all of data does not reach the wireless terminal (105).
Further, in a case that a base station covering a relatively small area such as a femtocell is provided and this base station uses the laid in-house ADSL wired line or others as the connection to the core network side, the link between the base station and the gateway is disconnected due to powering off of the base station, or the band of the wired line is temporally varied since the line (303) is shared by the other users (306 and 307) as the communication line as shown in the example of
As a result, even if a wireless condition is good so that a high-speed band of total 20 Mb/s combining the uplink and the downlink can be allocated to the wireless line, only total 1.5 Mb/s combining the uplink and the downlink can be ensured for the wired line between the femtocell base station and the gateway. Even if the data is transmitted by using the band which has been allocated to the wireless zone in, for example, the uplink when viewed from a user, all of the data cannot be transmitted by the wired line. As a result, there is a problem that data loss occurs and the communication cannot be correctly carried out.
Also, even if the wireless condition is good so that the high-speed band of 20 Mb/s can be allocated and the band of 20 Mb/s is actually allocated to the wireless line, if only 1.5 Mb/s can be ensured for the wired line between the femtocell base station and the gateway, a wireless band of more than required is used at the femtocell base station, there is a problem that this interferes with adjacent macrocell base station, and therefore, there is a problem that the high-speed communication cannot be carried out as a whole system.
Further, the in-house installed femto base station is not in the power-on state for 24 hours 365 days, and therefore, when a user connected to the macrocell is desired to switch to a move-destination femtocell base station, a state that the power of the femtocell base station is off so as not to be switched occurs. However, in the conventional technique, the state of the band of the wired line between the base station and the gateway cannot be recognized, and the switching to the base station whose power is off is carried out, and therefore, there is a problem that the communication is interrupted.
Accordingly, a preferred aim of the invention of the present application is to enable a wireless terminal to communicate even when a total band of a wired cable between a base station and a gateway is a narrower band than a total band of a wireless line.
Also, another preferred aim of the invention of the present application is to enable a wireless communication terminal to communicate even when a wired cable between a base station and a gateway is shared by other network of an ADSL provider or others.
Further, still another preferred aim of the invention of the present application is to reduce interference in a wireless line and achieve a high-speed communication as a whole system when a total band of a wired cable between a base station and a gateway is a narrower band than a total band of a wireless line.
Still further, still another preferred aim of the invention of the present application is to enable a communication to continue without interruption even when a power of a base station is of so that switching (handover) to that base station cannot be carried out.
In a wireless communication system including: a wireless communication base station device; a gateway; and a wireless communication terminal contained in the wireless communication base station device, the gateway controls a wireless band between the wireless communication base station device and the wireless communication terminal based on a band which is available for a wired line between the wireless communication base station device and the gateway and a wireless band which is available between the wireless communication base station device and the wireless communication terminal.
Even when the link between the base station and the gateway is disconnected due to the power off of the base station or even when the total band of the wired line is varied, the wired band and the wireless band can be allocated in accordance with variation in the wired band which is available among the control node, the gateway, and the base station and the wireless band which is available for the base station. Further, the system can be switched in accordance with variation in the wired band which is available among the control node, the gateway, and the base station and the wireless band which is available for the base station.
A first embodiment according to the present invention is explained.
A system configuration in a first embodiment is the same as a conventional system configuration shown in
A block diagram of a control node and a base station corresponding to
A control node (401) includes: a switch controlling unit (402) for switching between an access point #1 (406) and an access point #2 (406); a wired-band information database (403) for retaining the information of a wired cable between the control node (401) and each base station or others as a database; a band measuring function (404) for measuring a bandwidth of a wired cable between the control node (401) and each base station; and a wireless-band instructing function (405) for instructing a bandwidth of a wireless line used by the base station (406) based on its measurement result.
Also, the base station (406) includes: a band measuring function (407) for measuring a wired bandwidth between the control node (401) and the base station in cooperation with the control node (401); a wireless-band controlling function (408) for controlling a bandwidth of a wireless line and a used band thereof in accordance with instruction from the control node; and a wireless-band information notifying function (409) for notifying a peripheral base station of the information of an unoccupied (idler) frequency band based on the band information of the wireless line set by the (408).
Accordingly, first, “base-station/control-node band information request” is transmitted (501) from the control node (401) to the base station (while the base station is sometimes called “access point” depending on the system, the base station and the access point are synonymous with each other in this explanation). The base station which has received this request responds the required information (502) in order to recognize the wired bandwidth between the base station and the control node. For example, if “ping” is transmitted as the (501) from the control node, the base station transmits a response for “ping” as the (502) to the control node. Alternatively, a message requesting the information of the bandwidth is transmitted as the (501) from the control node, and the base station may contain the information of the bandwidth of the wired line recognized in the link establishment of the wired line between the base station and the control node in the message and, transmit the message to the control node.
Based on such these responses from the base station, the control node recognizes the information of the wired bandwidth transmitted from the base station. For example, when a command response such as the “ping” is used in the (502), it recognizes the bandwidth of the wired line (503) by using a calculating formula such as “the bandwidth of the wired line”=(the number of transmitted bytes/(“ping response received time”−“ping transmitted time”)). Alternatively, when the information of the bandwidth of the wired line is contained in the message and is transmitted from the base station to the control node, the information of the bandwidth of the wired line is extracted from the message. Note that, if there is no response, it is judged that “the band of the corresponding wired line=0”.
The control node having received the information updates a corresponding data (504) as a database as shown in
Here,
Here, the explanation is returned to
When the communication actually occurs (509), it is judged whether the switching is carried out or not (510) based on this updated database in consideration of not only the state (601) of the wireless line but also the information (603) of the total band of the currently available wireless lines of the base station and the state (602) of the wired line. Here, the information (603) of the total band of the wireless lines may be the information of the bandwidth (for example, 10 MHz or others) set in the wireless line or the maximum band (for example, 40 Mb/s) enabling the communication as a result of the setting.
A judgment flow carried out in the switch controlling unit (402) of the control node in the inter-base-station judgement (501) is shown in
Incidentally, a rest of the control flow of
A detail of a control flow carried out in the wireless-band instructing function (405) of the control node (401) in this case is shown in
Here, the process is returned to the flow of
This state is shown in
Also, the peripheral base station is notified (508) of the information of the frequency band corresponding to unused 18.5 Mb/s (information of the (904) in
By the control described above, it can be controlled not to use the same frequency band at the adjacent base stations, and therefore, the scheduling can be achieved so as to avoid the interference between the adjacent base stations, so that, in the communication with terminals, the average throughput is improved or the communication with good communication efficiency can be achieved so that the probability of satisfying the QoS is increased.
These states are described in more detail with reference to
Meanwhile, in the base station #2, a wireless frequency to be used in the wireless zone of the base station #2 is determined (507) based on the information (508) of the unoccupied frequency band having transmitted by the base station #1 and the information (506) of limiting the band of the wireless line in accordance with the state of the wired line between the base station #2 and the control node as following the control method shown in
A second embodiment according to the present invention is explained.
A system configuration according to the second embodiment is the same as the conventional system configuration shown in
A block diagram of a control node 1103, base stations 1108, and gateways 1104 according to the present embodiment is shown in
As shown in
The gateway (1104) includes: a band measuring function (1105) for measuring the band of the wired line between the base station and the gateway, which corresponds to the CN/AP band measuring function 404 provided in the control node in the first embodiment; a band notifying function (1106) for notifying the control node of the measured information of the wired line; and a wireless-band instructing function (1107) for transmitting an instruction for controlling the bandwidth of the wireless line based on the measured information of the wired line, which is a function corresponding to the wireless-band instructing function 405 provided in the control node in the first embodiment. The band measuring function (1105) and the wireless-band instructing function (1107) are the same as the (404) and the (405) of
The base station (1108) includes: a band measuring function (1109) for measuring the band of the wired line between the gateway and the base station in cooperation with the gateway; a wireless-band controlling function (1110) for controlling the band of the wireless line in accordance with the instruction from the gateway; and a wireless-band information notifying function (1111) for notifying the peripheral base station of the information of the unoccupied frequency band based on the information of the band of the wireless line set by the (1110). Here, the band measuring function (1109), the wireless-band controlling function (1110), and the wireless-band information notifying function (1111) are the same as the (407), the (408), and the (409) of
A control flow according to the second embodiment is shown in
On the wired network side configuring the wireless communication system, conventionally, the wireless communication provider has installed and operated the wired line to ensure the band sufficient for containing the wireless line. However, in the present embodiment, it is required to recognize how large bandwidth is available for the wired line.
Accordingly, first, the GW/AP band measuring function 1105 of the gateway transmits (1201) a “base-station/gateway hand information request” from the gateway to the base station. The GW/AP band measuring function 1109 of the base station which has received this request responds (1202) the required information for recognizing the wired bandwidth between the base station and the gateway. A specific example for achieving the (1201) and the (1202) have been already described in the first embodiment and is not different from that in the present embodiment, either, and therefore, is not explained here.
Based on the response (1202) from the base station, the gateway recognizes the information of the wired bandwidth having transmitted from the base station. The method of recognizing the information of the wired bandwidth has been already described in the first embodiment and is not different from this also in the present embodiment, and therefore, is not explained here.
The GW/AP band notifying function 1106 of the gateway having recognized the band information of the wired line between the base station and the gateway notifies (1204) the control node of this information. The control node receives this information, and updates (1209) the corresponding data as the database 1103 as shown in
The judgment flows in the case that the communication actually occurs and in the case of the switching judgment are the same as those of the first embodiment, and therefore, are not explained here.
At a stage when the gateway recognizes the state of the wired band between the base station and the gateway, the communication at the wired band which is available between the base station and the gateway or at higher cannot be used in the wireless zone between the terminal and the base station, and therefore, the gateway generates (1205) a control signal for limiting the band of the wireless zone, and transmits (1206) it to the base station. The content of the process at the base station is the same as that described in the first embodiment, and therefore, is omitted here.
Note that, in the second embodiment, the gateway is as a master (upper-level) station for controlling the plurality of base stations, and therefore, the base station may directly notify the adjacent base station of the information of the unoccupied frequency band as the (1208) of
A third embodiment according to the present invention is explained.
In the third embodiment, a case that the base station is a femtocell base station is considered. For a femtocell, a relatively small cover area is assumed such that the femtocell is installed in a house or an office, and a base station is installed in the house or office. Therefore, there is a high possibility that the power of the wired line is turned off or that the band variation is caused due to the sharing of the ADSL line (303) with other users, and the femtocell is one of candidates to which the present invention is applied.
Also, in the femtocell, it is assumed that the femtocell is installed in the house or office and contains a wireless terminal within an area of the femtocell, and therefore, a distance between the femtocell base station and the wireless terminal is several meters to several tens of meters, which is a relatively short distance. As a result, it is required to install many femtocell base stations to cover a wide area where the user move, and therefore, the interference reduction to the adjacent base station is one of the achievement points. The interference reduction can be achieved by limiting the band used for the wireless zone and mutually sharing the information of the unused frequency band as shown from
A fourth embodiment according to the present invention is explained.
In the fourth embodiment, it is assumed that, when a terminal moves from an outside of a building to an inside thereof, the base station of the connection destination is switched from a macrocell supporting the outside of the building to a femtocell supporting the inside thereof. In a system configuration according to the present embodiment, the gateway #1 and the base station #1101 on the left side of the configuration of
In each of
In
Next, as shown in
On the other hand, if the RSSI of the femtocell base station is larger than the RSSI of the macrocell, their wired line states such as their bands (BW of 1502) available for the wired line, their delay time, or their stability is compared (1603) with each other. Here, if the wired band which is available between the femto base station and the gateway is larger than the wired line band which is available between the macrocell and the gateway, the base station is switched to the femtocell.
On the other hand, if the wired band available between the femto base station and the gateway is equal to or smaller than the wired line band available between the macrocell and the gateway, the process proceeds to 1604. In the 1604, if the band of the wired line which is available between the femto base station and the gateway is larger than the band required for the application communication in which the wireless terminal 105 is currently during the communication in the macrocell, the base station is switched to the femto base station. On the other hand, if the band of the wired line available between the femto base station and the gateway is equal to or lower than the band required for the application communication in which the wireless terminal 105 is currently during the communication in the macrocell, the communication is continued in the macrocell without switching to the femtocell. If the bandwidths of the wired lines in the macrocell and the femtocell are equal to each other, the base station is switched to a base station connected to a wired line which is more stable, that is, whose bandwidth variation is small in consideration of its stability. Further, if no difference is observed in their values of the stability or if their values of the stability cannot be compared with each other, their information of their delay time are compared with each other. If the delay time of the femtocell is smaller than the delay time of the macrocell, the base station is switched to the femtocell.
If the switching is carried out from the communication in the macrocell to the femtocell base station, when the database is in the state of
A fifth embodiment according to the present invention is explained.
In the present embodiment, with assuming that the base station is installed in the house or office, a flow of a case that the power of the device is turned on is described. When the wireless communication provider has installed and operated the wired line or others, it has been assumed that the wired line is operated for 24 hours 365 days, and therefore, it is a situation which has not been assumed before.
A control flow is shown in
First, when the power of the base station is turned on (1701), a link is established (1702) between the base station and the gateway. Subsequently, a “base-station/gateway band information request” is transmitted (1703) from the gateway to the base station. The base station, which has received the request, responds (1704) information of the wired band. In this manner, the control node receives a notification of the wired band available between the base station and the gateway from the gateway, and can update the database (1502), and therefore, the communication using the corresponding base station and the switching to the base station can be achieved.
The control flow for limiting the band of the wireless line in accordance with the band of the wired line is in accordance with the flow described in the first or second embodiment.
A sixth embodiment according to the present invention is explained.
In the present embodiment, with assuming that the base station is installed in the house or office, a flow of the case when the power of the device is turned on is described. When the wireless communication provider has been installed and operated the wired line or others, it has been assumed that the wired line is operated for 24 hours 365 days, and therefore, it is a situation which has not been assumed before.
A flow after the link establishment is different from that of the fifth embodiment.
In the present embodiment, as shown in
A seventh embodiment according to the present invention is explained.
In the present embodiment, with assuming that the base station is installed in the house or office, a flow of the case that the power of the device is turned off is described. When the wireless communication provider has installed and operated the wired line or others, it has been assumed that the wired line is operated for 24 hours 365 days, and therefore, it is a situation which has not been assumed before. When the power of the base station is turned off, even if this base station is selected as the connection destination, the band of the wired line is not ensured, and therefore, there is a problem that the communication cannot be carried out, and it is required to avoid this situation.
As shown in,
An eighth embodiment according to the present invention is explained.
In the present embodiment, with assuming that the base station is installed in the house or office, a flow of a case that the power of the device is turned off is described. When the wireless communication provider has installed and operated the wired line or others, it has been assumed that the wired line is operated for 24 hours 365 days, and therefore, it is a situation which has not been assumed before.
In
In this embodiment, the gateway side can recognize the state at the timing of the power off, and therefore, the recognition of the state of the base station and the database update can be achieved earlier than those of the seventh embodiment, and the unnecessary switching to the base station whose communication with the wireless terminal is disconnected can be avoided, so that the communication can be continued.
Also, the invention of the present application has a feature in the following point.
In a wireless communication system which includes: a wireless communication base station device; a gateway; and a wireless communication terminal contained in the wireless communication base station device, the gateway controls a wireless band between the wireless communication base station device and the wireless communication terminal based on a band which is available for a wired line between the wireless communication base station device and the gateway and a wireless band which is available between the wireless communication base station device and the wireless communication terminal, and the wireless communication base station device notifies another wireless communication base station device of a wireless frequency band used for the communication between the wireless communication base station device and the corresponding wireless communication terminal in the corresponding wireless communication base station device.
In a wireless communication base station device which is connected to a gateway and which contains a wireless communication terminal, a used band between the wireless communication base station device and the wireless communication terminal is controlled based on a band which is available for a wired line between the wireless communication base station device and the gateway and a wireless band which is available between the wireless communication base station device and the wireless communication terminal, the gateway is connected to a plurality of another wireless communication base station devices or another node via a wired line, and the wired line between the wireless communication base station device and the control node is variable depending on a usage state of a wired band between the gateway and the plurality of another wireless communication base station devices or the another node.
In the wireless communication base station device described above, the plurality of wireless communication base station devices are connected via the gateway, the wireless communication base station device notifies the another wireless communication base station device of a wireless frequency band not used for the communication between the corresponding wireless communication base station device and the wireless communication terminal in the corresponding wireless communication base station device.
In the wireless communication base station device described above, the wireless communication base station device notifies the another wireless communication base station device of a wireless frequency band used for the communication between the corresponding wireless communication base station device and the wireless communication terminal in the corresponding wireless communication base station device.
In the wireless communication base station device described above, the wireless communication base station device does not transmit radiowaves having a frequency band except for the selected wireless frequency band.
In the wireless communication base station device described above, when the another wireless communication base station device is notified of wireless frequency band information used for the communication between the wireless communication base station device and the wireless communication terminal of which the wireless communication base station device notifies, a used wireless frequency band is determined so as to avoid the corresponding notified wireless frequency band.
Also, in a wireless communication system which includes: a wireless communication base station device; a control node; and a wireless communication terminal contained in the wireless communication base station device, a used band between the wireless communication base station device and the wireless communication terminal is determined based on a band which is available for a wired line between the wireless communication base station device and the control node and a wireless band which is available between the wireless communication base station device and the wireless communication terminal.
In the wireless communication system described above, the control node is connected to a plurality of another wireless communication base station devices or another node via a wired line, the wired line between the wireless communication base station device and the control node is variable depending on a usage state of the wired band between the control node and the plurality of another wireless communication base station devices or the another node.
In the wireless communication system described above, the wireless communication system includes the plurality of wireless communication base station devices, and the control node switches the wireless communication base station device to which the wireless communication terminal is connected, based on a band which is available for the wired line between the wireless communication base station device and the control node and a wireless band which is available between the wireless communication base station device and the wireless communication terminal.
In a control node connected to a plurality of wireless communication base station devices which contains a wireless communication terminal, the control node switches the wireless communication base station device to which the wireless communication terminal is connected, based on a band which is available for a wired line between the wireless communication base station device and the control node and a wireless band which is available between the wireless communication base station device and the wireless communication terminal, and, when a wired band satisfying a band required for data communication during communication by the wireless communication terminal is available between another wireless communication base station device and the control node, the communication of the wireless communication terminal with the wireless communication base station device is switched into the communication with the another wireless communication base station device.
Also, in a gateway connected to a wireless communication base station device which contains a wireless communication terminal, band information of a wired line with the wireless communication base station device is measured, and the wireless communication base station device is notified of the information.
In the gateway described above, it is further connected to a control node for switching a plurality of wireless communication systems, and the control node is notified of the measured band information of the wired line with the wireless communication base station device.
The present invention can be particularly used for a technique for high-speed switching between a plurality of wireless communication systems including a wireless communication system in which in-home ADSL, FTTH, or others is used for a wired line on a network side, and a technique for system switching between a macrocell and a femtocell.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2009/059462 | 5/22/2009 | WO | 00 | 12/14/2011 |