The present invention relates to a third-generation mobile-communication/wireless-LAN integration system and a third-generation mobile-communication/wireless-LAN integration method, which integrate a third-generation mobile communication system with a wireless LAN.
Conventionally, various studies have been made for integration of the 3rd generations cellular telecommunication system (hereinafter, “3G cellular system”) and a wireless LAN (hereinafter, WLAN), since high-speed data communications in the WLAN and wide coverage of the 3G cellular system supplement each other. Conventionally, one example of a concept and a realizing method has been proposed in the IEEE (the Institute of Electrical and Electronics Engineers).
In
The tight model proposed by the IEEE is a model in which an operator of the 3G cellular system also serves as an operator of the WLAN system, and the 3G cellular system and the WLAN system are both controlled by the GPRS core network standard, which is the 3G cellular system standard. Therefore, a mechanism for authentication and position registration in the 3G cellular system can be used as it is (see Nonpatent Literature 1).
Nonpatent Literature 1
IEEE Wireless Communications, vol. 9, no. 5, October 2002, pp. 112-124 WLAN-GPRS Integration for Next-Generation Mobile Networks Apostolis K. Salkintzis, Chad Fors and Rajesh Pazhyannur
In the tight model having the configuration described above, the WLAN system is regarded as the RAN of the 3G cellular system. However, there are following problems.
That is, in the current WLAN standard (for example, IEEE 802.11b), the mobile terminal 1 determines own movement at all times. Accordingly, position registration is also always performed based on the mobile terminal 1. As a result, there is an unsolved problem that switching from the WLAN system to the 3G cellular system cannot be controlled by determination of the 3G cellular system.
Furthermore, at the time of confirming switching from the 3G cellular system to the WLAN system on the 3G cellular system side, the size of servicing area of the WLAN system and that of the 3G cellular system are not always the same. Therefore, there are unsolved problems that it cannot be confirmed whether the WLAN system can be used at the current position of the mobile terminal 1, even if it is in the servicing area of the 3G cellular system, and at the current position of the mobile terminal 1, measurement with respect to the WLAN system (detection of a cell and an access point station) is performed, even if there is no cell of the WLAN system.
In the measurement with respect to the WLAN system, there are unsolved problems that the mobile terminal 1 performs measurement with respect to all detectable WLAN access point stations, and, even when a measurement result not required is included in the measurement results, all measurement results are transmitted to the network by a measurement information notification.
Furthermore, it is necessary to perform MAC frame transfer in conformity with IEEE 802.11 to perform communications via the WLAN system. For this purpose, a mechanism that can mutually exchange an MAC address of the WLAN interface of the mobile terminal 1 and an MAC address of the RNC interface, which is an MAC frame termination point on the network side, is required.
In the normal IP packet communication, the problem of IP address and MAC address is solved by ARP processing. However, in the tight model, since an IP address is not added to each entity, there is an unsolved problem that an ARP function does not function accurately.
Furthermore, there is an unsolved problem that, in the WLAN system, since there is no paging function in the 3G cellular system, power is consumed excessively.
The present invention has been achieved to solve these problems, and an object of the present invention is to provide a third-generation mobile-communication/wireless-LAN integration system and a third-generation mobile-communication/wireless-LAN integration method that can solve the problems mentioned above, not by connecting the WLAN system to the 3G cellular system as one network, but by making the WLAN system usable as one high-speed channel in the 3G cellular system.
A third-generation mobile-communication/wireless-LAN integration system according to one aspect of the present invention is a system in which a third-generation mobile communication system and a wireless LAN system are integrated. The third-generation mobile communication system includes an access network unit that controls the wireless LAN system by regarding the wireless LAN system as a packet communication channel. According to the present invention, the integration with the wireless LAN system as a packet communication channel in the third-generation mobile communication system can be easily performed at a low cost.
Furthermore, the access network unit includes a radio network controller connected to a base transceiver station capable of performing a wireless communication with a mobile terminal in the wireless LAN system, and electrically connected to an access point station of the wireless LAN system. Therefore, network control in the third-generation mobile communication system can be operated directly on the channel with a small improvement, and channel switching control lead by the third-generation mobile communication system can be easily achieved.
Moreover, the radio network controller forms a signaling channel of the third-generation mobile communication system with the mobile terminal via the base transceiver station, and forms a data channel with the mobile terminal via the access point station. The channel setting control of the wireless LAN between the third-generation mobile communication system and the wireless LAN lead by the third-generation mobile communication system can be performed.
A third-generation mobile-communication/wireless-local-area-network integration method according to another aspect of the present invention is for integrating a third-generation mobile communication system and a wireless local-area-network system. The third-generation mobile-communication/wireless-local-area-network integration method includes connecting the wireless local-area-network system to an access network unit of the third-generation mobile communication system; and controlling the wireless local-area-network system by regarding the wireless local-area-network system as a packet communication channel. According to the present invention, channel switching control lead by the third-generation mobile communication system can be easily achieved.
Exemplary embodiments of a third-generation mobile-communication/wireless-LAN integration system according to the present invention will be explained below in detail with reference to the accompanying drawings. Note that the present invention is not limited to the embodiments.
The UTRAN 2 has a radio network controller 8, a base transceiver station 9 connected to the radio network controller 8, and a plurality of WLAN access point stations 10 and 11, as in the conventional configuration.
The mobile terminal 1 in the WLAN system can perform wireless communications with the base transceiver station 9 and the WLAN access point stations 10 and 11. The UTRAN 2 is connected to the SGSN 4 in the GPRS core network of the 3G cellular system. The SGSN 4 is connected to the GGSN 5 and the HLR 6.
According to the present embodiment, the radio network controller 8 is connected to the base transceiver station 9 to control the base transceiver station 9, and is also connected to the WLAN access point stations 10 and 11 to control the WLAN access point stations 10 and 11, as in the conventional configuration. Thus, the WLAN access point stations 10 and 11 of the WLAN system are included in the UTRAN 2, and the radio network controller 8 controls the WLAN access point station 10 as one high-speed packet channel of the 3G cellular system.
The operation is explained next. According to the present embodiment, the WLAN system is simply recognized as one radio data channel. The mobile terminal 1 is controlled via a signaling channel 20 using an existing channel of the 3G cellular system. The radio network controller 8 performs signaling according to the RAN standard of the 3G cellular system such as NBAP (3GPP TS25.433) with respect to the base transceiver station 9 and RRC (3GPP TS25.331) with respect to the mobile terminal 1, and controls the mobile terminal 1 by the standard itself of the 3G cellular system. As shown in
When the data channel 21 is switched from the one of the WLAN system to the one of the 3G cellular system, or from the one of the 3G cellular system to the one of the WLAN system, the radio network controller 8 executes the switching in a channel switching framework in the RAN standard of the 3G cellular system.
Thus, in the 3G cellular/WLAN according to the present embodiment, since the 3G cellular system has the access network unit that performs control, assuming that the WLAN system is the packet communication channel, integration of the 3G cellular system and the WLAN system can be easily performed at a low cost.
Furthermore, the UTRAN 2 as the access network unit has the radio network controller 8 connected to the base transceiver station 9 which can perform wireless communications with the mobile terminal 1 in the WLAN system and also electrically connected with the WLAN access point stations 10 and 11 of the WLAN system. Accordingly, network control in the 3G cellular system can be operated directly on the channel with a small improvement, and channel switching control lead by the 3G cellular system can be easily achieved.
Furthermore, the radio network controller 8 forms the signaling channel 20 of the 3G cellular system between the mobile terminal 1 and the radio network controller 8 via the base transceiver station 9, and forms the data channel 21 between the mobile terminal 1 and the radio network controller 8 via the access point station 10. Accordingly, WLAN channel setup control between the 3G cellular system and the wireless LAN lead by the 3G cellular system can be performed.
In other words, integration of the WLAN system with the 3G cellular system can be easily achieved based on the RAN standard of the current 3G cellular system. Further, a higher-speed access can be provided at a lower cost, as compared to building a system using HSDPA (High Speed Downlink Packet Access) or DSCH (Downlink Shared Channel) proposed as a high-speed packet channel of the 3G cellular system. Since the RAN control of the 3G cellular system is run as it is, channel switching between the WLAN and the 3G cellular system lead by the network can be achieved with a small improvement.
To recognize the channel of the WLAN system as a channel usable without depending on the cell space of the 3G cellular system, the radio network controller 8 must be able to determine whether the mobile terminal 1 can use the WLAN channel at the current position with respect to a cell to which the mobile terminal 1 is going to camp. According to the present embodiment, therefore, the radio network controller 8 extends the measurement information notification in the RAN standard of the 3G cellular system, to achieve a determination unit that determines whether the mobile terminal 1 can use the WLAN channel, and includes the measurement result of the WLAN in the measurement information notification.
At a timing 42, the mobile terminal 1 moves to the position 32. Since the position 32 is in the coverage of both the 3G cellular system cell 30 and the WLAN system cell 31, the mobile terminal 1 sends a measurement information notification 43 in which measurement results of the 3G cellular system cell 30 and the WLAN system cell 31 are set to the radio network controller 8 as the measurement result. At this time, the measurement result of the WLAN system cell 31 includes signal strength from the WLAN access point station 10.
Since the measurement result of the 3G cellular system cell 30 and the measurement result of the WLAN system cell 31 are set in the measurement information notification 43, the radio network controller 8 having received the measurement information notification 43 can recognize that the current position of the mobile terminal 1 is in the coverage of both the 3G cellular system cell 30 and the WLAN system. Accordingly, at this point in time, when a data channel is set to the mobile terminal 1, the radio network controller 8 can determine that the data channel can be set not only to the 3G cellular system but also to the WLAN system.
Thus, in the 3G cellular/WLAN according to the present embodiment, the mobile terminal 1 performs measurement of the 3G cellular system and measurement of the WLAN system, and sends the measurement results to the radio network controller 8. Accordingly, channel setup control of the 3G cellular/WLAN lead by the 3G cellular system can be performed.
According to the present embodiment, the mobile terminal 1 uses the individual channel of the 3G cellular system as the signaling channel. However, the mobile terminal 1 can use a common channel of the 3G cellular system as the signaling channel. Similarly to the above, it suffices that the mobile terminal 1 notifies the measurement information of the WLAN access point station in the measurement information notification.
In the second embodiment, the measurement of the WLAN system is performed regardless of the current position of the mobile terminal 1, whereas according to the present embodiment, a system information notification of the 3G cellular system instructs as to whether the measurement of the WLAN system is necessary at the current position of the mobile terminal 1.
According to such a positional relationship, since a position 51 is within the coverage of the 3G cellular system cell 50, the mobile terminal 1 is connectable to the 3G cellular system. However, it is not connectable to the WLAN system. On the other hand, since there is no WLAN system cell in the coverage of the 3G cellular system cell 50, the measurement of the WLAN system is not required.
At a timing 63, the mobile terminal 1 moves to the position 32. Since there is a WLAN system cell in the coverage of the 3G cellular system cell 30, the measurement of the WLAN system is performed to determine whether the WLAN system can be used. Therefore, in a system information notification 64 from the base transceiver station 9, “measurement required” is set relating to whether to measure the WLAN system. The mobile terminal 1 having received the system information notification 64 performs the measurement of the WLAN system by referring to “measurement required”, and sets the measurement result of the WLAN system in a measurement information notification 65.
As described above, in the 3G cellular/WLAN according to the present embodiment, the radio network controller 8 sends a measurement condition relating to the wireless LAN system together with the information of each cell to the mobile terminal 1 in the system information notification, and the mobile terminal 1 performs measurement according to the measurement condition relating to the wireless LAN system. Since the system information, which instructs whether to perform the measurement of the WLAN system at the current position of the mobile terminal 1, is sent to the mobile terminal 1, a measurement load of the mobile terminal 1 can be reduced.
In the third embodiment, it is instructed whether the measurement of the WLAN system is required at the current position of the mobile terminal 1 by notifying the system information of the 3G cellular system to the mobile terminal 1, whereas according to the present embodiment, an ESSID (Extended Service Set Identifier) of the WLAN access point station to be measured is instructed to the mobile terminal 1 by notifying the system information of the 3G cellular system to the mobile terminal 1, to narrow down the measurement condition of the WLAN system.
A case that, at a timing 83, the radio quality of the WLAN system cell 70 is improved and user connection is allowed to the WLAN system cell 70 is explained next. At this time, “ANY” is set as the ESSID in a system information notification 84. The “ANY” indicates that all ESSIDs are set as the measuring objects. Therefore, the mobile terminal 1 having received the system information notification 84 refers to the set value “ANY” of the ESSID, to measure the WLAN system without putting any limitation on the ESSID. The mobile terminal 1 present at the position 71 sets the measurement results of not only the 3G cellular system cell 30 and the WLAN system cell 31 but also the WLAN system cell 70 in a measurement information notification 85, and sends the notification to the radio network controller 8.
Thus, the measurement load on the mobile terminal can be reduced by instructing the ESSID of the WLAN system to be measured by the system information notification of the 3G cellular system, and measurement information not required is removed from the measurement information notification 85, thereby reducing the load on the network. That is, in the 3G cellular/WLAN according to the present embodiment, the radio network controller 8 notifies the measurement condition relating to the wireless LAN system to the mobile terminal 1 together with the information of each cell in the system information notification, and the mobile terminal 1 performs measurement according to the measurement condition relating to the wireless LAN system.
According to the present embodiment, the “ANY” is set as the ESSID information in the system information notification 84. However, a plurality of ESSIDs can be specified in a list format, such as both “A” and “B”.
According to the present embodiment, BSSID (Basic Service Set Identifier) information of the WLAN access point station is added to WLAN system measurement result information in the measurement information notification transmitted from the mobile terminal 1. When the channel of the WLAN system can be used, the radio network controller 8 refers to the measurement information notification transmitted from the mobile terminal, to select one WLAN access point station based on the BSSID. Information of the selected WLAN access point station is transmitted to an MS through a WLAN channel setup procedure of the 3G cellular system, thereby setting a WLAN channel.
The present embodiment is explained with reference to
At a timing 104, the mobile terminal 1 having received the WLAN system channel setup request 103 recognizes the WLAN access point station 10 as a connection destination, and performs an association setup 105 to set the channel of the WLAN system, to connect to the WLAN access point station 10.
Thus, in the 3G cellular/WLAN according to the present embodiment, the radio network controller 8 selects an access point station to be connected to the mobile terminal 1 based on the measurement information from the mobile terminal 1, the selection result is transmitted to the mobile terminal 1, and the mobile terminal 1 accesses the access point station based on the selection result. Therefore, when a channel is set to the WLAN system, the WLAN access point station, which is the connection destination of the mobile terminal, can be determined, lead by the network.
In the above example, when the WLAN access point station is selected at the timing 102, only the measurement information notification 101 from the mobile terminal 1 is used, but measurement information such as a load status of the traffic can be obtained from the network side such as the WLAN access point station, and can be used as a condition of selecting the WLAN access point station.
In the fifth embodiment, the selection of the WLAN access point station is performed by the radio network controller 8, whereas according to the present embodiment, selection of the WLAN access point station is performed by a wireless LAN probe procedure of the mobile terminal, and the radio network controller 8 determines whether to use the WLAN system channel.
The present embodiment is explained with reference to
The radio network controller 8 having received the measurement information notification 121 can recognize the signal level of the WLAN system cell 31 and the WLAN system cell 70. If a determination reference is set that when the signal level is 60 or higher, the WLAN system channel can be selected, at a timing 122, the radio network controller 8 determines to use the WLAN system channel.
At the timing 122, the radio network controller 8 having determined to use the WLAN system channel sets “NULL” as the BSSID in a WLAN system channel setup request 123 with respect to the mobile terminal 1 and transmits the WLAN system channel setup request 123 to the mobile terminal 1. Since the BSSID=“NULL” means that a particular WLAN access point station is not specified, at a timing 124, the mobile terminal 1 having received the WLAN system channel setup request 123 performs wireless LAN probe 125 to probe for a WLAN access point station to be connected.
At a timing 126, the mobile terminal 1 selects the WLAN access point station 10 to be connected according to the procedure of the wireless LAN probe 125, and performs association setup 126 to set the channel of the WLAN system.
In the 3G cellular/WLAN according to the present embodiment, the radio network controller 8 notifies the mobile terminal 1 that a system to be connected with the mobile terminal 1 is the wireless LAN system based on the measurement information from the mobile terminal 1, and the mobile terminal 1 probes for the access point station to be connected according to the wireless LAN probe procedure and connects thereto. Accordingly, when a channel is set to the WLAN system, it can be determined under control lead by the network whether to connect to the WLAN system.
According to the present embodiment, MAC frame transfer is achieved by signaling of the 3G cellular system so that the mobile terminal 1 and the radio network controller 8 exchange MAC address information. The 3G cellular system cell is controlled by one radio network controller. Therefore, the MAC address of the radio network controller 8 is notified to the mobile terminal 1 and the MAC address of the mobile terminal 1 is notified to the radio network controller 8 by an RRC Connection setup procedure. Accordingly, the MAC addresses are mutually exchanged between the mobile terminal 1 and the radio network controller 8.
The operation is explained with reference to
Thereafter, when the mobile terminal 1 sets signaling connection of the 3G cellular system, the mobile terminal 1 performs the RRC Connection setup procedure. First, the mobile terminal 1 transmits a RRC Connection Setup Request 132 to the radio network controller 8. The MAC address of the mobile terminal 1 is set in the RRC connection setup request 132.
The radio network controller 8 having received the RRC Connection Setup Request 132 learns the MAC address of the mobile terminal 1 at a timing 133. Thereafter, the RRC Connection setup procedure is complete in order of an RRC Connection setup 134 and an RRC Connection Setup Complete 135. According to this procedure, the MAC addresses can be exchanged between the mobile terminal 1 and the radio network controller 8, and MAC frame transfer in conformity with IEEE 802.11 becomes possible between the mobile terminal 1 and the radio network controller 8 without performing the ARP processing.
Thus, in the 3G cellular/WLAN according to the present embodiment, the mobile terminal 1 and the radio network controller 8 exchange the MAC address information by the signaling channel. By exchanging the MAC addresses by the signaling of the 3G cellular system, communication connection can be established.
In the seventh embodiment, the MAC addresses are exchanged by the signaling of the 3G cellular system, whereas according to the present embodiment, the MAC address is notified on the WLAN channel, to exchange the MAC addresses between the mobile terminal 1 and the radio network controller 8.
The operation is explained with reference to
Thereafter, when a WLAN system channel setup request procedure is performed at a timing 142, an association setup procedure 143 is executed between the mobile terminal 1 and the WLAN access point station 10.
Thereafter, the MAC address of the mobile terminal 1 is notified by an AP Update 144, which is a specific message. This message is transmitted to the radio network controller 8 via the WLAN access point station 10, with which the mobile terminal 1 sets an association. Accordingly, an L2 switch entity (including an L2 interface of the radio network controller 8) relating to the communication from the WLAN access point station 10 to the radio network controller 8 can learn correspondence between the MAC address of the mobile terminal 1 and an interface directed to the MAC address of the mobile terminal 1.
Thus, in the 3G cellular/WLAN according to the present embodiment, when the mobile terminal 1 transmits the MAC address information to the radio network controller 8, the mobile terminal 1 performs communications using own specific message. Therefore, when the mobile terminal selects the WLAN access point station, the mobile terminal has a function of transmitting the selection information of the WLAN access point station to the radio network controller, thereby enabling establishment of the communication connection.
According to the present embodiment, the WLAN system channel is established by an RB Setup procedure, which is the signaling of the 3G cellular system.
The operation is explained with reference to
With regard to the RB Setup request 152, there are cases that the WLAN access point station to be connected is explicitly specified and not explicitly specified. According to the present embodiment, a case that the WLAN access point station to be connected is not explicitly specified is explained.
The mobile terminal 1 having received the RB Setup request 152 determines that a setup of a WLAN system channel is requested, probes for a WLAN access point station at a timing 153 to select a WLAN access point station, and, at a timing 154, sets an association with the WLAN access point station 10. When the mobile terminal 1 has not yet notified the radio network controller 8 of the own MAC address, the mobile terminal 1 notifies the radio network controller 8 of the own MAC address according to procedures 155 and 156. Upon establishment of communication connection to the WLAN system, the mobile terminal 1 transmits an RB Setup Response 157 to the radio network controller 8, to notify that a WLAN system channel has been set up.
Thus, in the 3G cellular/WLAN according to the present embodiment, after notifying the security parameter of the 3G cellular system and the security parameter of the WLAN system to the radio network controller 8, the mobile terminal 1 uses the wireless bearer setup procedure of the 3G cellular system, to form the WLAN system channel. Thus, the WLAN system channel can be established by the RB Setup procedure of the 3G cellular system.
Since the 3G cellular system cell and the WLAN system cell are independent of each other, the timing of a handover operation in the 3G cellular system and the timing of the WLAN handover operation is basically independent of each other. The handover operation in the 3G cellular system conforms to the specification of 3GPP. According to the present embodiment, handover control of the WLAN system channel lead by the 3G cellular system is explained.
At a position 163, since it is in the coverage of the WLAN system cell 160, the WLAN system channel should be set via the WLAN access point station 11.
At a timing 171, since the mobile terminal 1 moves to the position 162, the signal strength becomes stronger in the WLAN system cell 160 covered by the WLAN access point station 11 than in the WLAN system cell 31 covered by the WLAN access point station 10. The mobile terminal 1 transmits this result to the radio network controller 8 in a measurement information notification 173.
The radio network controller 8 having received the measurement information notification 173 selects, at a timing 174, the WLAN access point station 11 as a connection destination of the mobile terminal 1. The radio network controller 8 transmits a hard handover request 175 specifying the WLAN access point station 11 as a handover destination to the mobile terminal 1.
Upon reception of the hard handover request 175, the mobile terminal 1 recognizes the WLAN access point station 11 as the connection destination, and after performing a release association 177 with the WLAN access point station 10, executes a reassociation setup 178 with the WLAN access point station 11.
Upon establishment of a reassociation with the WLAN access point station 11, the mobile terminal 1 transmits a hard handover response 179 to the radio network controller 8, to notify the completion of the hard handover request 175. Thereafter, the mobile terminal 1 communicates via the WLAN access point station 11.
Thus, in the 3G cellular/WLAN according to the present embodiment, the mobile terminal 1 transmits the measurement information of an adjacent access point station to the radio network controller 8, and the radio network controller 8 switches the access point station based on the information. In other words, when switching of the access point station is performed lead by the network of the 3G cellular system, the mobile terminal transmits the measurement information of the adjacent access point station to the radio network controller, and the WLAN access point station is changed over according to the determination of the radio network controller, to perform hard handover. In this case, seamless WLAN access point station switching can be achieved based on the determination of the radio network controller, which is the network side in the 3G cellular system.
Although not shown in
In the tenth embodiment, hard handover control of the WLAN system channel lead by the network of the 3G cellular system is shown, whereas according to the present embodiment, the hard handover control of the WLAN system channel lead by the mobile terminal is shown.
The operation is explained with reference to
At a timing 182, since the mobile terminal 1 moves to the position 163, the mobile terminal 1 is away from the coverage of the WAN system cell 31 covered by the WLAN access point station 10, and the association with the WLAN access point station 10 is released at a release 183. Accordingly, the mobile terminal 1 performs a WLAN probe 184.
Since the mobile terminal 1 is present at the position 163, which is in the coverage of the WLAN system cell 160, and the mobile terminal 1 can find the WLAN access point station 11. Therefore, the mobile terminal 1 performs an association setup 185 with the WLAN access point station 11. The mobile terminal 1 also transmits the MAC address of the mobile terminal 1 to the radio network controller 8 by an access point station update 186, and the radio network controller 8 learns the MAC address of the mobile terminal 1, thereby establishing communication connection. Accordingly, the mobile terminal 1 communicates via the WLAN access point station 11 at a timing 188.
Thus, in the 3G cellular/WLAN according to the present embodiment, the mobile terminal 1 switches the access point station according to the own determination, and transmits the switching information to the radio network controller 8. In the case of access point station switching lead by the mobile terminal, the radio network controller 8 relearns a packet transmission address with respect to the mobile terminal 1, thereby enabling achievement of hard handover lead by the mobile terminal.
According to the present embodiment, when a user moves from an area where the user cannot catch the WLAN system channel to an area where the WLAN system channel is available, switching from the 3G cellular system to the WLAN system is achieved based on a Channel Switching procedure of the 3G cellular system.
The operation is explained with reference to
The mobile terminal 1 moves from the position 164 to the position 161. A measurement 192 at the position 161 is performed with respect to not only the 3G cellular system cell 30 but also the WLAN system cell 31 covered by the WLAN access point station 10. The mobile terminal 1 transmits a measurement result of the measurement 192 to the radio network controller 8 in a measurement information notification 193.
Upon reception of the measurement information notification 193, the radio network controller 8 selects channel switching to the WLAN access point station 10 at a timing 194. The radio network controller 8 transmits to the mobile terminal 1 a Physical Channel Reconfiguration 195 instructing the WLAN access point station 10 as a channel switching destination. Upon reception of the Physical Channel Reconfiguration 195, the mobile terminal 1 recognizes the WLAN access point station 10 as the channel switching destination, and executes an association setup 197 with the WLAN access point station 10. After establishing the association, the mobile terminal 1 transmits Physical Channel Reconfiguration Complete 198 to the radio network controller 8, to notify completion of channel switching. Thereafter, the mobile terminal 1 communicates via the WLAN access point station 10. Upon reception of the Physical Channel Reconfiguration Complete 198, the radio network controller 8 releases the resources of the base transceiver station 9 at a timing 200.
Thus, in the 3G cellular/WLAN according to the present embodiment, the radio network controller 8 performs switching from the channel of the 3G cellular system to the channel of the WLAN system by the signaling of the 3G cellular system. Thus, switching from the channel of the 3G cellular system to the channel of the WLAN system can be achieved based on the Channel Switching procedure of the 3G cellular system.
According to the present embodiment, when the user moves from an area where the WLAN system channel is available to an area where the user cannot catch the WLAN system channel, switching from the WLAN system to the 3G cellular system is achieved based on the Channel Switching procedure of the 3G cellular system.
The operation is explained with reference to
At a timing 202, the mobile terminal 1 moves from the position 161 to a position 165. It is assumed that in a measurement 203 at the position 165, although the measurement of the WLAN system cell 31 covered by the WLAN access point station 10 is possible, the measurement result is not good. The mobile terminal 1 transmits a result of the measurement 203 to the radio network controller 8 in a measurement information notification 204. Upon reception of the measurement information notification 204, the radio network controller 8 selects channel switching to the 3G cellular system cell 30 covered by the base transceiver station 9 at a timing 205. The radio network controller 8 ensures the resources 206 of the base transceiver station 9 by an NBAP procedure. The radio network controller 8 then transmits Physical Channel Reconfiguration 207, to the mobile terminal 1, specifying the cell 30 covered by the base transceiver station 9 as the channel switching destination. Upon reception of Physical Channel Reconfiguration 207, the mobile terminal 1 executes channel switching to the 3G cellular system cell 30 covered by the base transceiver station 9 and transmits Physical Channel Reconfiguration Complete 208 to the radio network controller 8. Further, the mobile terminal 1 performs a release association 209 with the WLAN access point station 10, and can communicate via the base transceiver station 9.
Thus, in the 3G cellular/WLAN according to the present embodiment, the radio network controller 8 performs switching from the channel of the WLAN system to the channel of the 3G cellular system by the signaling of the 3G cellular system. Therefore, switching from the channel of the WLAN system to the channel of the 3G cellular system can be achieved based on the Channel Switching procedure of the 3G cellular system.
According to the present embodiment, paging of the 3G cellular system is used for supplying power to the WLAN system only when it is required, to reduce the power consumption of the WLAN system.
The operation is explained with reference to
In the 3G cellular/WLAN according to the present embodiment, the mobile terminal 1 stands by in the waiting mode of the 3G cellular system, and when the mobile terminal 1 is going to use the channel of the WLAN system, the mobile terminal 1 uses signaling of the 3G cellular system.
Thus, since the paging function of the 3G cellular system is used for calling the mobile terminal 1, power is supplied to the WLAN system only when it is necessary, thereby enabling reduction of the power consumption in the WLAN system.
According to the present embodiment, the operation sequence at the time of call-in has been explained. However, at the time of call-out from the mobile terminal 1 in the waiting mode of the 3G cellular system, by supplying the power to the WLAN system at the timing when the procedure of WLAN system channel setup request is started, power consumption in the WLAN system can be reduced likewise.
In the first embodiment described above, the radio network controller is connected to the WLAN access point station so that the WLAN system is used as one high-speed packet channel of the 3G cellular system, by connecting the radio network controller to the WLAN access point station and controlling the connection. Whereas according to the present embodiment, the radio network controller is connected to the WLAN access point station, and the radio network controller and the base transceiver station control the WLAN access point station, so that the WLAN system can be used as one high-speed packet channel of the 3G cellular system.
The operation is explained with reference to
In the first embodiment described above, the radio network controller is connected to the WLAN access point station so that the WLAN system is used as one high-speed packet channel of the 3G cellular system. Whereas according to the present embodiment, an interworking box (IWB) is connected between the radio network controller and the base transceiver station, and between the radio network controller and the WLAN access point station, so that the radio network controller and the interworking box control the WLAN access point station, and the WLAN system is used as one high-speed packet channel of the 3G cellular system.
The operation is explained with reference to
Thus, in the 3G cellular/WLAN according to the present embodiment, the radio network controller 8 is connected to the base transceiver station 9 via the IWB 12, in addition to the configuration of the fifteenth embodiment. Accordingly, the WLAN system can be used as one high-speed packet channel of the 3G cellular system by improving the radio network controller and adding the IWB, without giving any impact on the existing base transceiver station and the WLAN access point stations.
The present invention is a mobile communication system of a new form, which integrates a third-generation mobile communication system having a wide coverage and the wireless LAN capable of performing high-speed data communications, and is preferable as a mobile communication system in the near future.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP04/07282 | 5/21/2004 | WO | 11/16/2006 |