Method for transferring the context of a mobile terminal in a wireless telecommunication network

FIELD OF THE INVENTION The present invention relates to a method for transmitting mobile terminal context in a wireless telecommunication network, wherein the network includes a plurality of base stations, and these base stations communicate with each other through the telecommunication network. link.

BACKGROUND A mobile telecommunications network provides telecommunications services for mobile terminals roaming within an area containing multiple radio cells. Generally speaking, the mobile telecommunications network provides mobile telecommunications operators with grants of related resources. The means to verify that the mobile terminal has the right to access its network before.

A mobile telecommunication network usually contains many base stations, which are connected to multiple base station controllers, and these base station controllers themselves are connected to a small number of VLRs (visitor location registers), and these VLRs are connected to at least one public HLR (home location register).

In this type of network, information related to authorized mobile terminals is stored in the mobile terminal and HLR. This information is the so-called mobile terminal context. _oBy comparing the information stored in the mobile terminal with the information stored in the HLR, the mobile terminal can be authenticated (authenticate) _oAccording to this information, the mobile telecommunication network permits or does not permit mobile terminal access. During the verification process, this centralized verification will generate a certain latency (latency).

In order to reduce the waiting time, the concept of VLR is introduced to minimize access to the HLR, which processes a large number of mobile terminals, and usually does not encounter all mobile terminals in the entire network. Large signail ing required to perform access permissions _o The VLR can be considered as fulfilling the HLR function delegation. More specifically, the VLR handles the HLR function for all mobile terminals within its range of influence. For this purpose, the VLR and the HLR will complete the delegation of competence, so that sometimes the VLR can autonomously determine the access permission.

In the verification process, since the base station must relay the verification request from the mobile terminal to the VLR, and the VLR must process requests from many mobile terminals in parallel, this layered architecture still generates a certain waiting time.

In order to reduce the waiting time, we can delegate the verification process to the base station. However, because

200680043191.3 This solution is not compatible with the concept of fast mobility, so this solution is unacceptable. When the mobile terminal moves from one cell of the base station to the cell of another base station every time, the access permission should be renegotiated between the mobile terminal and the other base station. Another base station that does not know the context of the mobile terminal will ask the HLR for such information, and this will significantly increase the signal transmission processed by the HLR. In the sense that the mobile terminal can move to another cell controlled by another base station before the mobile terminal context is received, the signal transmission time for exchanging the mobile terminal context will be too long to allow in practice Effectively realize the cell reselection function for fast-moving mobile terminals.

For the above reasons, we can see that in the current technology, the effective cell reselection process is limited to the inside of a cell controlled by one VLR. When traversing areas served by different VLRs, the mobility is not enough. satisfying.

For wireless local area network access points, such as the access points disclosed in the standard IEEE802.11, these access points include certain access control mechanisms. In these access control mechanisms, the Radius server can be located at the access point. Within itself. However, this type of wireless local area network does not propose any solution that can maintain fast access permission and fast and effective cell reselection between adjacent wireless local area networks.

New-generation mobile telecommunication networks (such as third-generation cellular networks) provide high data rate transmission, but do not improve the latency in the verification process.

In addition, the new mobile telecommunications network proposes numerous services with different service qualities. Each time a handover is performed, the new serving base station must set the communication parameters to be used by the radio interface and the fixed network interface in order to transmit the communication context. These communication parameters can be diverse, such as code number, frequency, time slot, data format, communication port, and so on. And these communication parameters are obtained by the base station from high level parameters (such as quality of service) of the communication context. For this purpose, in the handover process, the new serving base station must obtain the high-level parameters of the communication context from the mobile terminal or the old serving base station, and then the new serving base station obtains the communication parameters from this information. This transmission of information related to mobile terminals will slow down the handover process. In addition, the process of obtaining communication parameters from the high-level parameters of the communication context is very slow, and may include additional signal transmission processes. In addition, the overall time for exchanging mobile terminal information and obtaining communication parameters will be too long. Therefore, it is possible for the slave mobile terminal to move to another base station before the mobile terminal related information is received or before the communication parameters are obtained. In the sense of another cell, in practice, it will not be possible to allow fast-moving mobile terminals to effectively implement the handover function.

200680043191.3 Summary of the Invention Therefore, the purpose of the present invention is to provide a method and device that can reduce the waiting time in mobility processing such as cell reselection processing or handover processing.

To this end, the present invention relates to a method for obtaining the context of a mobile terminal, wherein the mobile terminal is expected to be served by a first base station of a wireless telecommunication network, the network comprising a plurality of links linked together through a telecommunication network A base station, characterized in that the method includes the following steps performed by the first base station expected to provide services for the mobile terminal:

-Receiving a first message from a mobile terminal via a wireless interface, where the message contains at least the identifier of the mobile terminal and at least the identifier of the second base station,

-Transmitting a second message via a telecommunications network, where the second message contains at least one identifier contained in the received message,

-Receive the mobile terminal context through the telecommunications network.

The present invention also relates to a device for obtaining the context of a mobile terminal, wherein the mobile terminal is expected to be served by a first base station of a wireless telecommunication network, the network comprising a plurality of base stations connected together by a telecommunication network, characterized in that the The equipment is contained in the first base station expected to provide services for the mobile terminal, and includes:

-A device for receiving a first message from a mobile terminal via a wireless interface, wherein the message contains at least one identifier of the mobile terminal and at least one identifier of the second base station,

-A device for transmitting a second message via a telecommunication network, wherein the second message contains at least one identifier contained in the received message,

-A device for receiving a third message from a second base station via a telecommunication network, wherein the third message contains the context of the mobile terminal.

As a result, the waiting time for mobility processing such as cell reselection processing or handover processing can be shortened.

If a mobile terminal in idle mode moves from one cell of the base station to another base station cell, the other base stations can obtain the mobile terminal context for the authentication process without performing operations as disclosed in the prior art. The HLR and VLR processes used for verification are not always required, and other base stations can also perform the verification process independently, thereby realizing fast cell reselection processing.

As a result, HLR and VLR can handle a reduced number of messages, and their complexity will be reduced.

200680043191.3 No. If the mobile terminal in the communication mode moves from one cell of the base station to another cell of the base station, the handover process will also be shortened.

According to a specific feature, the second base station is a base station that is serving the mobile terminal.

Therefore, when a cell reselection process occurs in a neighboring base station, the context will be transmitted in a short range at this time. Doing so can shorten the waiting time for performing cell reselection or performing handover procedures.

According to the first implementation mode of the present invention, the second message is transmitted to the second base station and includes at least the identifier of the second base station, the identifier of the mobile terminal and the context of the mobile terminal are received in the third message.

As a result, the waiting time for performing cell selection or performing handover procedures will be shortened.

According to a specific feature, the first message includes a certificate, where the certificate contains the identifier of the mobile terminal, the identifier of the second base station, the signature obtained by encoding these identifiers using the private key of the second base station, and/or by using the mobile The terminal private key encodes the signature obtained by these identifiers. Before transmitting the second message, it is expected that the first base station serving the mobile terminal will check whether the certificate is compromised.

Thus, the first base station can identify the second base station currently serving the mobile terminal, and send a request to the second base station in order to obtain the context of the identified mobile terminal.

If the certificate is compromised, the first base station can refuse to send a request to the second base station to obtain the context of the identified mobile terminal. Only those mobile terminals whose access rights are guaranteed by the second base station can handover with the first base station to implement cell reselection. Doing so can prevent unintended wireless cellular network signal transmission from flowing through base stations associated with malicious mobile stations without access rights.

In addition, the time for verifying the access right of the mobile terminal to access the network via the first base station will be shortened.

According to a specific feature, once the third message is received, the first base station expected to provide services for the mobile terminal will start to provide services for the mobile terminal and transmit at least the first base station identifier and the mobile terminal identifier to the mobile terminal.

Thus, the mobile terminal can store the identifier of the first base station, and if another cell reselection or handover process occurs, the mobile terminal will prepare to send it to the third base station. In this way, the waiting time of the verification process will be shortened.

According to a specific feature, when the first base station expected to serve the mobile terminal starts to provide service for the mobile terminal, the first base station will receive the fourth message from the third base station through the telecommunications network.

200680043191.3 The first message, the message contains at least the base station identifier and the mobile terminal identifier that provide services for the mobile terminal. In addition, the first base station also transmits a fifth message to the third base station through the telecommunication network, where the fifth message contains The mobile terminal context, and the first base station will stop providing services to the mobile terminal.

Thus, before sending the context to the third base station, the first base station can identify the context associated with the mobile terminal.

Then, the mobile terminal context will be transmitted to the third base station expected to serve the mobile terminal.

According to a specific feature, the fourth message contains a certificate, wherein the certificate contains the mobile terminal identifier, the first base station identifier, and the signature obtained by encoding these identifiers using the private key of the first base station, and/or by using the mobile terminal The private key encodes the signature obtained by these identifiers.

Thus, the first base station can trust the context of the mobile terminal it is processing.

Thus, the first base station can believe that the third base station did not try to delete its context for inappropriate reasons (for example, by reusing the old certificate previously issued by the fourth base station).

According to the second implementation mode of the present invention, the first message at least contains another identifier of the third base station selected by the mobile terminal.

Thus, the path used by the mobile terminal to move between the first and second base stations can be determined.

According to the specific feature of the second mode of realization, the second message is transmitted to the third base station selected by the mobile terminal, and the second message contains at least the identifier received in the first message.

Thus, even if the first and second base stations are not connected, the first base station still knows the third base station that is easily connected to the second base station.

According to a specific feature of the second mode of implementation, the base station identifier is transmitted in a list sorted according to the order in which the mobile terminal selects the base station.

Thus, the path history used by the mobile terminal to move from the first base station to the second base station can be accurately determined.

According to the specific feature of the second mode of implementation, the first message contains multiple identifiers of the third base station, and the first base station determines to which third base station the second message must be transmitted, and transmits the second message to The determined third base station.

As a result, the waiting time can be shortened.

According to the specific features of the second implementation mode, the first base station determines that the second message must be transmitted

200680043191.3 The third base station is determined according to the sequence of base station identifiers in the list.

According to the specific feature of the second mode of implementation, the first message contains a certificate that contains a mobile terminal identifier, a base station identifier, and a signature obtained by encoding these identifiers using the private key of the second base station, and/or by using The private key of the mobile terminal encodes the signature obtained by these identifiers. Before transmitting the second message, it is expected that the first base station serving the mobile terminal will check whether the certificate is damaged.

Thus, if the certificate is compromised, the first base station can reject the request context.

According to a specific feature of the second mode of implementation, the second message contains a certificate, where the certificate includes a mobile terminal identifier, a base station identifier, and a signature obtained by encoding these identifiers using the private key of the second base station, and/or by using The mobile terminal private key encodes the signature obtained by these identifiers.

Thus, if the certificate is compromised, the second base station can refuse to send the context.

According to the specific feature of the second mode of implementation, once the context is received in the third message, the first base station will start to serve the mobile terminal and at least transmit the identifier of the first base station and the mobile terminal to the mobile terminal.

According to the specific feature of the second mode of implementation, once the first base station expected to serve the mobile terminal starts to serve the mobile terminal, the first base station will receive a fourth message from the fourth base station through the telecommunication network, where the message at least contains The identifier of the first base station serving the mobile terminal and the identifier of the mobile terminal. In addition, a fifth message containing the context of the mobile terminal will be transmitted to the fifth base station through the telecommunication network, and the first base station will stop serving the mobile terminal .

According to the specific feature of the second mode of implementation, the fourth message contains multiple identifiers of the fifth base station. The first base station determines to which fifth base station the message must be transmitted, and transmits the fifth message to the determined fifth base station. Base station.

According to the specific feature of the second implementation mode, the fifth base station to which the second message must be transmitted is determined according to the order of the base station identifiers in the list.

The present invention also relates to a method for requesting a base station to provide a service for a mobile terminal, wherein the base station is a base station of a wireless telecommunication network, and the mobile terminal is served by another base station in the wireless telecommunication network, characterized in that the method includes The mobile terminal requesting the service provided by the base station performs the following steps:

-Receiving a first message from the base station currently serving the mobile terminal, the first message at least containing the identifier of the base station currently serving the mobile terminal and the identifier of the mobile terminal,

200680043191.3 No.

-Transmit a second message to the base station requesting the mobile terminal to provide the service, wherein the second message includes at least the identifier of the base station currently serving the mobile terminal and the identifier of the mobile terminal.

The present invention also relates to a device for requesting a base station to serve a mobile terminal. The base station is a base station in a wireless telecommunication network, and the mobile terminal is served by another base station in the wireless telecommunication network, characterized in that the device is included in the request Among the mobile terminals served by the base station, and include:

-A device for receiving at least the identifier of the base station currently serving the mobile terminal and the mobile terminal identifier from the base station currently serving the mobile terminal,

-A device for transmitting a message to a base station requesting a service for a mobile terminal, wherein the message at least contains the identifier of the base station currently serving the mobile terminal and the identifier of the mobile terminal.

Thus, the base station requested by the mobile terminal for service can send a request to the base station currently serving the mobile terminal, so as to obtain the information necessary for the base station requested by the mobile terminal to serve the mobile terminal. The base station requested by the mobile terminal for service does not need to send such a request to the server, thereby reducing the delay in providing services to the mobile terminal.

According to a specific feature, the first message includes a certificate, where the certificate contains a mobile terminal identifier, a base station identifier, and a signature obtained by encoding these identifiers using the private key of the base station currently serving the mobile terminal.

Thus, by checking the integrity of the certificate, the base station requested to serve the mobile terminal can independently verify that the mobile terminal has the access right to the service provided by it. The compromised certificate can be discarded, thereby saving the capacity of the wireless cellular network.

According to a specific feature, the second message contains a certificate, where the certificate includes a mobile terminal identifier, a base station identifier, and a signature obtained by encoding these identifiers using the private key of other base stations and/or encoding these identifiers by using the private key of the mobile terminal The signature obtained by the character.

Thus, by checking the integrity of the certificate, the base station currently serving the mobile terminal can independently verify that the base station requested by the mobile terminal has the right to process the context of the mobile terminal. The compromised certificate can be discarded, thereby saving the capacity of the cellular mobile network.

According to a specific feature of the second implementation mode, the mobile terminal selects a third base station, stores the identifier of the selected base station, and the second message contains the base station identifiers sorted according to the order in which the mobile terminal selects the base stations.

According to the specific feature of the second mode of implementation, the mobile terminal is configured in the first state, in which state, when the mobile terminal is configured in a state where the signal transmission is interrupted, the signal transmission is

200680043191.3 is interrupted and the third base station is selected.

As a result, the power resources of the mobile terminal will be saved.

According to the specific feature of the second mode of implementation, the mobile terminal determines the number of selected third base stations, and configures the mobile terminal in a second state, in which state, if the determined number is equal to a predetermined value, signal transmission is possible .

As a result, the power resources of the mobile terminal will be saved.

According to a specific feature of the second mode of implementation, once the mobile terminal is configured in the second state, the second message is transmitted.

The present invention also relates to a message transmitted in a wireless cellular network, wherein the network includes a plurality of base stations connected to each other through a telecommunication network, and one of the base stations is currently serving a mobile terminal, characterized in that the message is at least Including the mobile terminal identifier and the identifier of the base station currently serving the mobile terminal.

According to a specific feature, the message also includes an ordered list of base station identifiers selected by the mobile terminal.

According to a specific feature, the message is transmitted between the mobile terminal and another base station that is expected to provide services for the mobile terminal.

According to a specific feature, the first message includes a certificate that contains the mobile terminal identifier, the identifier of the base station currently serving the mobile terminal, and the identifier obtained by encoding these identifiers using the private key of the base station currently serving the mobile terminal Signatures and/or signatures obtained by encoding these identifiers using the mobile terminals private key.

Since the features and advantages associated with these messages are the same as those described above in connection with the method and device according to the present invention, they will not be repeated here.

According to another aspect, the present invention relates to a computer program that can be directly loaded into a programmable device, including instructions or code portions that implement the steps of the method according to the present invention when the computer program is executed on the programmable device.

Since the features and advantages associated with these computer programs are the same as those explained above in connection with the method and device according to the present invention, they will not be repeated here.

BRIEF DESCRIPTION OF THE DRAWINGS By reading the following description of exemplary embodiments, the characteristics of the present invention will become clearer

200680043191.3 The first place appears, where the description is generated with reference to the drawings, and in which: Figure 1a is the first diagram describing the mobile telecommunications network architecture according to the present invention; Figure 1b is the first diagram describing the mobile telecommunications network architecture according to the present invention Figure 2 is a block diagram of a base station according to the present invention; Figure 3 is a block diagram of a mobile terminal according to the present invention; Figure 4a is an algorithm executed by the mobile terminal according to the first implementation mode of the present invention; Figure 4b is The algorithm executed by the mobile terminal according to the second mode of implementation of the present invention; Figure 5a is the algorithm executed by the base station according to the first mode of implementation of the present invention; Figures 5b and 5c disclose the algorithm executed by the base station according to the second mode of implementation of the present invention Algorithm.

DETAILED DESCRIPTION Figure 1a is a first diagram describing a mobile telecommunication network architecture according to the present invention. In a mobile telecommunication network, the server 20 is connected to a plurality of base stations 10a and 10b through the telecommunication network 50. The telecommunication network 50 is a dedicated wired network, a public network similar to a public switching network, an IP-based network, a wireless network, an asynchronous transfer mode network, or a combination of the foregoing networks.

According to the present invention, the telecommunications network 50 connects the base stations 10 together, and can transmit messages and information between the base stations 10 or between the base stations 10 and the server 20.

The server 20 stores information related to each mobile terminal 30 of the mobile telecommunication network. When the base station 10 requests the context about the unknown mobile terminal 30, the server 20 will create the context from the stored information related to the mobile terminal 30, and The context of the mobile terminal 30 is transferred to the base station 10 through the telecommunication network 50.

Each base station 10 can transmit and/or receive data through the wireless area 15. Hereinafter, such a wireless area will be referred to as a cell 15.

Only one server 20 is shown in FIG. 1a, but we can understand that a larger number of servers 20 can be used in the present invention. Similarly, only two base stations 10a, 10b and their corresponding cells 15a, 15b are shown here, but we can understand that a larger number of base stations 10 and cells 15 can be used in the present invention.

The mobile terminal 30 is shown in FIG. 1a. The mobile terminal 30 is served by the base station 10a, and moves from the cell 15a of the base station 10a to the cell 15b of the base station 10b.

If the mobile terminal 30 can establish, receive, or continue communication through the base station 10, the mobile terminal 30 is served by the base station 10, or the base station 10 provides services for the mobile terminal 30.

200680043191.3 First, when the mobile terminal 30 is in idle mode and moves from a cell to a neighboring cell, for example, when it moves from a cell 15a to a cell 15b, a cell reselection process will occur at this time. When the mobile terminal 30 is not communicating with another telecommunication device, but there is a context in the base station 10 serving the mobile terminal 30, the mobile terminal 30 is in an idle mode. When the mobile terminal 30 is in idle mode, if communication must be established, it must continuously reselect the best base station 15. This process is the cell reselection process.

For example, in the cell reselection process, the context of the mobile terminal 30 is data used to verify the mobile terminal 30 and check its access rights, such as an encryption key (encryption key) and the like in the subsequent contact with the mobile terminal 30. The data used when establishing communication, and the details about the service access contract of the mobile terminal 30 (detail). The base station 10 uses the context of the mobile terminal 30 to register the mobile terminal 30 as a mobile terminal 30 in its cell 15 and a terminal served by the base station 10.

When the mobile terminal 30 communicates with another telecommunication device through the designated cell 15 of the designated base station 10 and moves to the neighboring cell 15 of the base station 10, a handover process will occur at this time. During the handover process, the designated base station 10 must stop serving the mobile terminal 30, and the neighboring base station 10 must start serving the mobile terminal 30 in order to be able to continue communication. During the soft handover process, the neighboring base station 10 must start serving the mobile terminal 30, and the designated base station 10 will remain serving the mobile terminal 30, which will enable macro-diversity (macro-diversity), that is, at the same time. Continue to communicate on each cell.

During the handover process, the target base station 10 needs to use the context of the mobile terminal 30 to configure its wireless interface and its network interface, so as to connect the mobile terminal 30 to the telecommunication network 50 and provide information flow relay during the handover process.

More specifically, for example, the context of the mobile terminal 30 included in the handover process includes: the public (lublic) key of the mobile terminal 30 in the asymmetric encryption/authentication system, and the secret (secret) in the symmetric stream encryption system. ) Encryption/decryption key, which defines the quality of service information of the communication flow according to the average and peak data rates, granularity, time/waiting time constraints of the communication context of the mobile terminal 30, and restrictions on travel to and from the mobile terminal 30 The input port reference of the network interface required for the communication with the telecommunications network 50 to perform routing.

This information is used to establish wireless interfaces and network interfaces. Once established, the wireless interface will be ready to synchronize with the mobile terminal 30. Once the mobile terminal 30 that knows the wireless interface configuration completes the synchronization on the wireless interface, the handover process is complete.

200680043191.3 The base station 10 must establish a wireless interface and a network interface at the same time. For example, the base station 10 determines on which frequency/slot/code it should perform operations in order to provide it to the mobile terminal, which greatly depends on the quality of service parameters such as the average peak rate. In addition, the base station 10 also checks the availability of software and hardware resources on the wireless and network interfaces, and establishes a connection between the software and hardware resources.

According to the present invention, each mobile terminal 30 served by the base station 10 receives the identifier of the base station 10 from the base station 10. When a cell reselection process or a handover process occurs, the mobile terminal 30 will transmit the identifier of the base station 10 currently serving it to the base station 10 expected to serve it. The base station 10 expected to serve the mobile terminal 30 obtains the context of the mobile terminal 30 from the base station 10 currently serving the mobile terminal 30.

In FIG. 1a, only one mobile terminal 30 is shown, but we can understand that the wireless network manages a large number of mobile terminals 30.

FIG. 1b is a second diagram describing the architecture of a mobile telecommunication network according to the present invention.

In a mobile telecommunication network, the server 120 is connected to a plurality of base stations 110a-110e through the telecommunication network 150. The telecommunication network 150 is a dedicated wired network, a public network similar to a public switching network, an IP-based network, a wireless network, an asynchronous transfer mode network, or a combination of the foregoing networks.

The telecommunications network 150 connects certain base stations 110 together through connections, and can transmit messages and information between the connected base stations 110 or between the base stations 110 and the server 120.

As an illustration and not a limitation, the connection 151ab is established between the base station 110a and the base station 110b, the connection 151ac is established between the base station 110a and the base station 110c, the connection 151bc is established between the base station 110b and the base station 110c, and the connection 151bc is established between the base station 110b and the base station 110b. A connection 151bd is established between 110c, a connection 151cd is established between the base station 110c and the base station 110d, and a connection 151de is established between the base station 110d and the base station 110e.

The server 120 is the same as the server 20 and will not be described here.

Every base station 110 can transmit and/or receive data through the wireless zone 115. Hereinafter, this wireless area is referred to as a cell 115.

In FIG. 1b, only one server 120 is shown, but we can understand that a larger number of servers 120 can be used in the present invention. Similarly, only five base stations 110a-110e and their corresponding cells 115a-115b are shown here, but we can understand that a larger number of base stations 110 and cells 115 can be used in the present invention.

The mobile terminal 130 is shown in FIG. 1b. The mobile terminal 130 is provided by the base station 110a

200680043191.3 serves and moves from the cell 115a of the base station 110a to the cell 115e of the base station 110e via the cell 115b of the base station 110b, the cell 115c of the base station 110c, and the cell 115d of the base station 110d_oIn FIG. 1b, the displacement is depicted by arrow 131.

If the mobile terminal 130 can establish, receive, or continue communication through the base station 110, the mobile terminal 130 is served by the base station 110, or the base station 110 provides services for the mobile terminal 130.

When the base station 110 provides services for the mobile terminal 130, the base station 110 will maintain the context associated with the mobile terminal 1030. For example, the base station 110a is providing services for the mobile terminal 130.

When the mobile terminal 130 is in an active mode, communication can be established with the mobile terminal 130 at this time, and data can be transmitted and/or received with (and/or to) the base station 110.

When the mobile terminal 130 is in the active mode, and when no data is being transmitted in the established communication, the mobile terminal 130 can switch to a dormant state, in which the mobile terminal 130 stops radio transmission in order to save Its electrical energy. In the standby state, the mobile terminal 130 continues to measure the received signal level, selects a new base station 110, and stores the identifier of the selected base station, but does not trigger signal transmission (s ignal1ing) with these base stations 110.

For example, when the mobile terminal 130 moves through the cells 115b-115d, if the mobile terminal 30 is in a standby state, the base stations 110b-110d will not serve it. The base stations 110b-110d do not have the context of the mobile terminal 130. And the mobile terminal 130 will store the identifiers of the base stations 110b-110d.

As disclosed for the mobile terminal 30 with reference to FIG. 1a, the mobile terminal 130 can perform cell reselection processing or handover.

The context of the mobile terminal 130 is the same as the context disclosed for the mobile terminal 30 with reference to FIG. 1a.

The base station 110 uses the context of the mobile terminal 130 in the same manner as disclosed for the base station 10 with reference to FIG. 1a.

Fig. 2 is a block diagram of a base station according to the present invention.

For example, the base station 10 has an architecture based on components connected together by a bus 201 and a processor 200 controlled by the program disclosed in FIG. 5a.

200680043191.3 The first bus 201 links the processor 200 to a read-only memory ROM202, a random access memory RAM203, a network interface 204, and a wireless interface 206.

The memory 203 contains registers that are used to receive variables, identifiers of certain base stations 10, the content of messages transmitted by mobile terminals 30, other base stations 10 or servers, the context of mobile terminals 30 served by base stations 10, and The program instructions related to the algorithm disclosed in Figure 5a.

The processor 200 controls the operations of the network interface 204 and the wireless interface 206.

The read-only memory 202 contains program instructions related to the algorithm disclosed in FIG. 5a, where the program instructions are transmitted when the base station 10 powers on the random access memory 203.

The base station 10 is connected to the telecommunication network 50 through the network interface 204. For example, the network interface 204 is a DSL (Digital Subscriber Line) modem, or ISDN (Integrated Services Digital Network) interface and so on. Through this interface, the base station 10 exchanges information with the server 20 and other base stations 10 in the wireless cellular telecommunication network. For the mobile terminal 30 included in the cell 15 of the base station 10, communications established or received by the mobile terminal will pass through the network interface 204 and the wireless interface 206.

Through the wireless interface 206, the base station 10 receives at least the identifier of the base station 10 currently serving the mobile terminal 30 from the mobile terminal 30 expected to be served by the base station 10.

The base station 110 is the same as the base station 10. For example, each base station 110 has an architecture based on components connected together by a bus 301 and a processor 300 controlled by the programs disclosed in FIGS. 5b and 5c.

Fig. 3 is a block diagram of a mobile terminal according to the present invention.

For example, the mobile terminal 30 has an architecture based on components connected together by a bus 301 and a processor 300 controlled by the program disclosed in FIG. 4a.

The bus 301 links the processor 300 to the read only memory R0302, the random access memory RAM303, and the wireless interface 306.

The memory 303 contains registers that can be used to receive variables, the identifier of the base station 10 currently serving the mobile terminal 30, the content of the message received from the base station 10 currently serving the mobile terminal 30, and the contents of the message disclosed in FIG. 4a. Program instructions related to the algorithm.

The processor 300 controls the operations of the network interface 304 and the wireless interface 306.

The read-only memory 302 contains program instructions related to the algorithm disclosed in FIG. 4, where the program instructions are transmitted when the base station 10 supplies power to the random access memory 303.

200680043191.3 Through the wireless interface 306, the mobile terminal 30 establishes or receives certain communications with other telecommunication equipment via the base station 10 it serves, measures the signal power intensity transmitted by the base station 10 nearby, and receives signals from the base station 10 serving it. Or send a message to the base station 10 expected to serve the mobile terminal 30.

The mobile terminal 130 is the same as the mobile terminal 30. For example, the mobile terminal 130 has an architecture based on components connected together by a bus 301 and a processor 300 controlled by the program disclosed in FIG. 4b.

Figure 4a is an algorithm executed by a mobile terminal according to the first mode of implementation of the present invention.

Once the mobile terminal 30 transmits the cell update message to the base station 10, the algorithm will be executed by each mobile terminal 30, more specifically, executed by the processor 300 of the mobile terminal 30.

In step S400, the processor 300 detects the reception of a message transmitted by the base station 10 serving it through the wireless interface 306. As shown by the arrow in FIG. 1a, the mobile terminal 30 is moving from the cell 15a to the cell 15b. The base station 10a is providing services for the mobile terminal 30, and the base station 10b is expected to provide services for the mobile terminal 30.

The message contains at least the identifier of the base station 10 and the unique identifier of the mobile terminal 30, where the identifier of the base station 10 can at least enable other base stations 10 near the base station 10 currently serving the mobile terminal 30 to uniquely identify the current mobile terminal 30. Serving base station 10. Preferably, the message also contains a certificate.

The certificate contains at least the unique identifier of the mobile terminal 30, the identifier of the base station 10 currently serving the mobile terminal 30, and is obtained by encoding these identifiers using the private key of the base station 10 currently serving the mobile terminal 30 Signature. The public key of the base station 10 associated with the private key can be used together with the certificate content to ensure the integrity of the certificate content and to verify the base station 10 currently serving the mobile terminal 30. For example, the characteristics of the used private key and public key, signature generation processing, integrity detection, and source verification scheme may follow the RSA verification algorithm.

In the next step S401, the processor 300 stores the content of the received message in the RAM memory 303.

In the next step S402, the processor 300 generates a command message to the wireless interface 306 to start measuring the power intensity of the pilot signal transmitted by the nearby base station 10. According to FIG. 1a showing two base stations 10a and 10b, the wireless interface 306 measures the power strength of the pilot signals transmitted in the cells 15a and 15b of the base stations 10a and 10b.

200680043191.3 At the next step S403, the processor 300 determines whether the cell 15 must be changed. According to our example, if the power strength of the pilot signal transmitted in the cell 15b of the base station 10b is greater than the specified threshold, or greater than the specified power strength of the pilot signal transmitted in the cell 15a of the base station 10a currently serving the mobile terminal 30 Then the processor 300 determines to change the cell 15, that is, it is expected to be served by the base station 10 that controls the cell 15b. In this case, the processor 300 moves to step S404.

If the power strength of the pilot signal transmitted in the cell of the other base station 10 is lower than the specified threshold or lower than the specified ratio of the power strength of the pilot signal transmitted in the cell 15 of the base station 10 currently serving the mobile terminal 30 , Then the processor 300 will return to step S402 that has been described.

In step S404, the processor 300 forms a message including the message content stored in step S401.

According to an embodiment variant of the present invention, the processor 300 will form a certificate, which contains at least the unique identifier of the mobile terminal 30, the public key of the mobile terminal 30, the identifier of the base station 10 currently serving the mobile terminal 30, The signature of the base station obtained by encoding these identifiers using the private key of the base station 10 currently serving the mobile terminal 30, and the signature of the mobile terminal 30 obtained by encoding these identifiers using the private key of the mobile terminal 30 .

It should be pointed out here that the signature of the base station 10 currently serving the mobile terminal 30 may not be included in the formed message.

According to another embodiment variant, the formed message is encrypted with the public key of the base station 10 expected to serve the mobile terminal 30.

In the next step S405, the processor 300 transmits the formed message to the base station 10 expected to serve it.

It should be noted here that each base station 10 in the wireless telecommunication network broadcasts information enabling the mobile terminal 30 to send messages to it. The mobile terminal 30 then uses this information to transmit a message to the base station 10 that it is expected to serve.

Then, the processor 300 will return to step S400 that has been described.

Figure 4b is an algorithm executed by the mobile terminal according to the second mode of implementation of the present invention.

This algorithm is executed by each mobile terminal 130. More specifically, this algorithm is executed by the processor 300 of each mobile terminal 130.

In step S450, the processor 300 detects the base station serving it through the wireless interface 306

200680043191.3 No.

110 Receipt of transmitted messages. According to the example of FIG. 1b, the mobile terminal 130 is served by the base station 110a. The message contains at least the identifier of the base station 110a, which enables other base stations 110 connected to the base station 110a to uniquely identify the base station 110a currently serving the mobile terminal 130. In addition, the message also includes the unique identifier of the mobile terminal 130. Preferably, the message contains a certificate disclosed with reference to Figure 4a.

In the next step S451, the processor 300 stores the content of the received message in the RAM memory 303.

In the next step S452, the processor 300 commands the change of the state of the mobile terminal 130. The mobile terminal 130 changes from the active state to the inactive state, that is, commands to cut off the transmission part of the wireless interface 306.

In the next step S453, the processor 300 instructs the wireless interface 306 to proceed to measure the power strength of the pilot signal transmitted by the nearby base station 110. According to FIG. 1b, the wireless interface 306 measures the power strength of the pilot signals transmitted in the cells 115a and 115b of the base stations 110a and 110b.

In the next step S454, the processor 300 determines whether the cell 115 must be changed. According to the example of FIG. 1b, the power strength of the pilot signal transmitted in the cell 115b of the base station 110b is greater than a specified threshold, or greater than the specified power strength of the pilot signal transmitted in the cell 115a of the base station 110a currently serving the mobile terminal 130 Then the processor 300 decides to change the cell 115. In this case, the processor 300 will move to step S455.

Otherwise, the processor 300 will return to the already described step S453.

In step S455, the processor 300 receives a message from the base station 110b. The message contains at least the identifier of the base station 110b, which enables other base stations 110 connected to the base station 110b to uniquely identify the base station 110b.

In the next step S456, the processor 300 stores the identifier of the base station 110b in the RAM memory 303. More specifically, the processor 300 updates an ordered list, where the list contains the identifier of the base station 110b, followed by the identifier of the base station 110a.

In step S457, the processor 300 checks whether the mobile terminal 130 must change from the standby state to the active state. This situation will occur if the following situation occurs: the mobile terminal 130 is in a standby state for a predetermined period of time such as a few seconds, the mobile terminal selects a predetermined number of cells 115, or the mobile terminal receives such a message, the The message indicates that data is to be sent to the mobile terminal 130 or that communication needs to be established with another mobile terminal 130 or a remote wire device not shown in FIG. 1b.

If the mobile terminal 130 changes from the standby state to the active state, then the processor 300 will

200680043191.3 moves to step S458. Otherwise, the processor 300 will return to step S453.

For example, the mobile terminal 130 remains in a standby state.

In step S453, the processor 300 generates a command signal to the wireless interface 306 to proceed to measure the power strength of the pilot signal transmitted by the nearby base station 110.

In the next step S454, the processor 300 determines whether the cell 115 must be changed. According to the example of FIG. 1b, the processor 300 determines to change the cell 115. In this case, the processor 300 moves to step S455.

In step S455, the processor 300 receives a message from the base station 110c. The message contains at least the identifier of the base station 110c, which enables other base stations 110 connected to the base station 110c to uniquely identify the base station 110c.

In the next step S456, the processor 300 stores the identifier of the base station 110c in its RAM memory 303. More specifically, the processor 300 updates the ordered list, where the list contains the identifier of the base station 110c, followed by the identifier of the base station 110b and the identifier of the base station 110a.

In the next step S457, the processor 300 checks whether the mobile terminal 300 must change from the standby state to the active state.

For example, the mobile terminal 130 remains in a standby state.

Then, the processor 300 returns to step S453, selects the cell 115d in step S454, and receives a message from the base station 110d in step S455. The message contains at least the identifier of the base station 110d, which enables other base stations 110 connected to the base station 110d. The base station 110d is uniquely identified.

In step S456, the processor 300 stores the identifier of the base station 110d in the RAM memory 303. More specifically, the processor 300 updates the ordered list, where the list contains the identifier of the base station 110d, followed by the identifier of the base station 110c, the identifier of the base station 110b, and the identifier of the base station 110a.

In step S457, the processor 300 checks whether the mobile terminal 130 must change from the standby state to the active state.

For example, the mobile terminal 300 remains in a standby state.

Then, the processor 300 returns to step S453, selects the cell 115e in step S454, and receives a message from the base station 110e in step S455, where the message at least contains the identifier of the base station 110e, which enables other base stations connected to the base station 110e 110 uniquely identifies the base station 110e.

200680043191.3 At step S456, the processor 300 stores the identifier of the base station 110e in the RAM memory 303. More precisely, the processor 300 will update the ordered list, where the list contains the identifier of the base station 110e, followed by the identifier of the base station 110d, the identifier of the base station 110c, the identifier of the base station 110b, and The identifier of the base station 110a.

In the next step S457, the processor 300 checks whether the mobile terminal 130 needs to change from the standby state to the active state.

For example, the mobile terminal 130 must change from a standby state to an active state.

In step S458, the processor 300 reads the list containing the stored identifiers of the base stations 110.

The list is ordered and contains the identifiers of the base stations 110 that manage the movement of the mobile terminal through the cell 115. The first identifier of the list is the identifier of the base station 110e, the second identifier of the list is the identifier of the base station 110d, the third identifier of the list is the identifier of the base station 110c, and the fourth identifier of the list is The identifier of the base station 110b, and the last identifier of the list is the identifier of the base station 110a.

In the next step S459, the processor 300 will form a message, where the message contains the list read in step S459 and the identifier of the mobile terminal 130.

According to an embodiment variant of the present invention, the processor 300 forms a certificate, wherein the certificate contains at least the unique identifier of the mobile terminal 130, the public key of the mobile terminal 130, the read list, and the signature of the base station 110 serving the mobile terminal 130. The certificate is obtained by using the private key of the base station 110a currently serving the mobile terminal 130 and the signature of the mobile terminal 130 to encode the identifier of the mobile terminal 130 and the identifier of the base station 110a serving the mobile terminal 130. The signature of the terminal 130 is obtained by using the private key of the mobile terminal 130 to encode these identifiers.

It should be pointed out here that the formed message may not include the signature of the base station 110a currently serving the mobile terminal 130.

According to another embodiment variant, the formed message is encrypted with the public key of the base station 110 expected to serve the mobile terminal 130, that is, the base station 110e.

In the next step S460, the processor 300 transmits the formed message to the base station 110e expected to serve it._o It should be pointed out here that each base station 110 in the wireless telecommunication network will broadcast a signal that enables the mobile terminal 130 to send messages to it. The mobile terminal 130 uses this information to transmit a message to the base station 110 for which it is expected to provide services.

200680043191.3 Then, the processor 300 moves to step S460, and checks whether an acknowledgement (acknowledge) message ACK is received from the base station 110e expected to serve it.

If the response message is not received in the predetermined period of time, the processor 300 returns to step S460.

If the response message is received, the processor 300 will move to step S461 and reset the base station identifier list stored in steps S451 and S456.

Then, the processor 300 returns to step S450 that has been described._o Figure 5a is an algorithm executed by a base station according to the first mode of implementation of the present invention.

This algorithm is executed by each base station 10 in the wireless network, and more precisely, executed by the processor 200 of each base station 10.

In step S500, the processor 200 receives the message.

In the next step S501, the processor 200 checks whether that message is sent from the base station 10 or the mobile terminal 30. If a message is sent from the base station 10, the message is received through the network interface 204. Then, the processor 200 moves to step S513. Otherwise, the message will be received through the wireless interface 206, and the processor 200 moves to step S502_o In step S502, the processor 200 checks whether the received message contains the identifier of the base station 10. The identifier of the base station 10 is the identifier of the base station 10 currently serving the mobile terminal 30.

If the message does not contain the identifier of the base station 10, it means that the mobile terminal 30 is not served by the base station 10. For example, the mobile terminal 30 is connected in the cell 15 of the base station 10 receiving the message, and the context of the mobile terminal 30 does not exist in the wireless telecommunication network.

If the message contains the identifier of the base station 10, the processor 200 will move to step S506. If the message does not contain the identifier of the base station 10, the processor 200 will move to step S503.

In step S503, the processor 200 obtains the context of the mobile terminal 30 that sent the message from the server 20. To this end, the processor 200 will use the identifier of the mobile terminal 30 contained in the message received in step S500.

In the next step S504, the processor 200 forms a message. The message contains at least the identifier of its base station 10. Preferably, the message contains a certificate.

The certificate contains at least the unique identifier of the mobile terminal 30, the identifier of the base station 10 that received the message, and these identifiers are compiled by using the private key of the base station 10 that received the message.

200680043191.3 The signature obtained by the first code, where the base station is the base station that was once expected to provide services for the mobile terminal 30 and is now providing services for the mobile terminal 30.

In the next step S505, the processor 200 transmits the message via the wireless interface 206 to the mobile terminal 30 that sent the message received in step S500. Then, the processor 200 returns to step S500 and waits for a new message.

If the message received in step S500 contains the identifier of the base station 10, the processor 200 will move from step S502 to step S506.

In step S506, the processor 200 uses the base station identifier contained in the received message to determine the base station 10 currently serving the mobile terminal 30 that has sent the message.

In the next step S507a, the processor 200 processes the received message. The processing includes storing the content of the received message in the RAM memory 203, or, before storing the message, if the message contains at least one signature, checking the integrity of the message content in step S507b.

If the message contains the signature of the base station 10, the processor 200 will use the public key of the base station 10 with the identifier contained in the message to decode the signature, and determine whether the information obtained by the decoding is the same as that contained in the certificate. If the information is different, the certificate has been destroyed, the processor 200 will stop processing and return to step S500.

It should be pointed out here that for the base station 10 whose identifier is included in the message, its public key is received from the server 20 or from another base station 10 in the setup base station 10.

If the message contains the signature of the mobile terminal 30, the processor 200 will use the public key of the mobile terminal 30 obtained from the server 20 or the mobile terminal 30 itself to decode the signature, and determine whether the information obtained by the decoding is the same as that contained in the certificate. The information is the same. If the information is different, the certificate is damaged, and the processor 200 will stop processing and return to step S500_o What needs to be pointed out here is that when the received message contains two signatures, both of the above checks are performed.

By checking the integrity of the message, malicious attacks can be avoided.

Once step S507a or step S507a and step S507b are executed correctly, the processor 200 moves to step S508.

At this step, the processor 200 transmits a message to the determined base station 10, which contains the identifier of the base station 10 currently serving the mobile terminal 30, the identifier of the mobile terminal 30, and the identifier of its base station 10 (ie, expected The identity of the base station 10 serving the mobile terminal 30

200680043191.3) and the signature of the base station 10 and/or the mobile terminal 30 (if the message received in step S500 contains one or more signatures).

In the next step S509, the processor 200 receives the context of the mobile terminal 30 from the base station 10 currently serving the mobile terminal 30.

In the next step S510, the processor 200 applies the received context of the mobile terminal 30 so that it can be served by its base station 10.

In the next step S511, the processor 200 forms a message.

This message contains at least the identifier of its base station 10, that is, the identifier of the base station 10 currently serving the mobile terminal 30. In addition, it also includes the unique identifier of the mobile terminal 30 that sent the message received in step S500. Preferably, the message contains a certificate.

The certificate includes at least the unique identifier of the mobile terminal 30, the identifier of the base station 10 currently serving the mobile terminal 30, and a signature obtained by encoding these identifiers using the private key of the base station 10.

In the next step S512, the processor 200 transmits the previously formed message through the wireless interface 206. In the memory 303 of the mobile terminal 30, the content of the message will replace the content of the message previously received from the previous base station 10 that provides the service.

Then, the processor 200 returns to step S500 and waits for a new message to be processed.

If it is specified in step S501 that the message received in step S500 is a message transmitted by the base station 10, the processor 200 moves to step S513a.

In the next step S513a, the processor 200 processes the received message. This processing includes storing the received message content in the RAM memory 203, or checking the integrity of the message content in step S513b before storing the message content.

The processor 200 checks whether the identifier of the base station 10 currently serving the mobile terminal 30 is the same as the identifier of its base station, and checks whether the identifier of the mobile terminal 30 is an identifier of the mobile terminal 30 currently served by the base station 10. If one of the checks fails, the processor 200 will stop message processing and return to step S500.

If the message contains the signature of the base station 10, the processor 200 will use its public key to decode the signature and determine whether the information obtained by the decoding is the same as the information contained in the certificate. If the information is different, the certificate is damaged, and the processor 200 stops message processing and returns to step S500_o If the message contains the signature of the mobile terminal 30, the processor 200 will use the public key of the mobile terminal 30 obtained from the server 20 or the mobile terminal 30 itself to decode the signature,

200680043191.3 First and determine whether the information obtained by decoding is the same as the information contained in the certificate. If the information is different, the certificate is damaged, the processor 200 will stop processing and return to step S500_o Once step S507a and steps S513a, S513b are correctly executed, the processor 200 will move to step S514 and read from the RAM memory 203 the context of the mobile terminal 30 with the identifier contained in the message.

In the next step S515, the processor 200 transmits the context of the mobile terminal 30 to the base station 10 expected to serve the mobile terminal 30 through the network interface 204.

The base station 10 stops serving the mobile terminal 30, the processor 200 deletes the associated context from the RAM memory, and then returns to step S500 and waits for a message to be received.

It should be pointed out here that when the base station 10 starts or stops providing services for the mobile terminal 30, it will notify the server 20.

Figures 5b and 5c disclose an algorithm executed by a base station according to the second mode of implementation of the present invention.

This algorithm is executed by each base station 110 in the wireless network, more precisely, it is executed by the processor 200 of each base station 110.

In step S530, the processor 200 detects the reception of the message.

In the next step S531, the processor 200 checks whether a message is sent from the base station 110 or the mobile terminal 130. If a message is sent from the base station 110, the message is received through the network interface 204, and then the processor 200 moves to step S550. Otherwise, the message is received through the wireless interface 206, and the processor 200 moves to step S532.

In step S532, the processor 200 checks whether the received message contains a list of identifiers of the base station 110.

If the message contains the list of identifiers of the base station 110, the processor 200 moves to step S536. If the message does not contain the identifier list of the base station 110, the processor 200 moves to step S533.

Steps S533-S535 are the same as steps S503-S505 in FIG. 5a, and they will not be described here. Once step S535 is executed, the processor 200 will return to step S530 and wait for a new message.

If the message received in step S530 contains the list of identifiers of the base station 110, the processor 200 moves from step S532 to step S536.

The message is the same as the message transmitted in step S460 of FIG. 4b, and is received by the base station 110e.

200680043191.3 According to the example disclosed with reference to FIG. 4b, the base station identifier list is ordered and contains the identifier of the base station 110. The identifier of the base station 110 manages the cell 115 that the mobile terminal 130 moves through. The first identifier of the list is the identifier of the base station 110e, the second identifier of the list is the identifier of the base station 110d, the third identifier of the list is the identifier of the base station 110c, and the fourth identifier of the list is The identifier of the base station 110b, and the last identifier in the list is the identifier of the base station 110a.

In step S536, the processor 200 checks whether they are multiple connections connected to the base station 10, wherein the identifier of the base station is included in the base station identifier list, and the identifier has a lower identifier in the list than the identifier of the base station 110e. The grade.

If they are multiple connections, the processor 200 will move to step S538 and select the identifier of the base station 110 with the lowest rank in the list of base station identifiers from the identifiers of the connected base stations 110.

If a single connection is established with a base station 110 having an identifier included in the base station identifier list, the processor 200 will move to step S539.

According to the example of FIG. 1b, the base station 110e is only connected to the base station 110d. Then, the processor 200 moves to step S539, and selects the identifier of the base station 110d.

In the next step S540, the processor 200 processes the received message. This processing includes storing the content of the received message in the RAM memory 203, or, before storing the content, if the message contains at least one signature, checking the integrity of the message content in step S541.

If the message contains the signature of the base station 110a, the processor 200 uses the public key of the base station 110a having the identifier included in the message to decode the signature, and determines whether the information obtained by the decoding is the same as the information contained in the certificate. If the information is different, the certificate is damaged, and the processor 200 will stop processing and return to step S530.

If the message contains the signature of the mobile terminal 130, the processor 200 will use the public key of the mobile terminal 130 obtained from the server 120 or the mobile terminal 130 itself to decode the signature, and determine whether the signature obtained by decoding is consistent with that contained in the certificate. The signatures are the same. If the information is different, the certificate is damaged, and the processor 200 will stop processing and return to step S530.

It should be pointed out here that when the received message contains two signatures, both of the above checks will be performed.

Then, by checking the integrity of the message, malicious attacks can be avoided.

200680043191.3 Once steps S540 or S540 and S541 are correctly executed, the processor 200 will move to step S542.

In this step, the processor 200 will transmit a message to the determined base station 110 (ie the base station 110d), where the message contains a list of base station identifiers and the identifier of the mobile terminal 130. If the message received in step S530 contains a Or multiple signatures, then the message preferably includes the signatures of the base station 110a and/or the mobile terminal 130.

After that, the processor 200 returns to step S530.

If the message received in step S530 is sent from the base station 110, the processor 200 moves to step S550 and checks whether the message contains the context of the mobile terminal 130.

If the message contains the context of the mobile terminal 130, the processor 200 moves to step S551. If the message does not contain the context of the mobile terminal 130, the processor 200 moves to step S558.

According to this example, the base station 110d receives the message, and the processor 200 of the base station 110d moves to step S558.

In step S558, the processor 200 of the base station 110d checks whether the identifier of the base station 110d is the last identifier in the list of base station identifiers. If the identifier of the base station 110d is the last identifier in the list of base station identifiers, the processor 200 moves to step S559, otherwise the processor 200 moves to step S554.

According to this example, the identifier of the base station 110d is not the last identifier in the list of base station identifiers, and the processor 200 moves to step S554.

In step S554, the processor 200 checks whether they are multiple connections to the base station 110, where the base station 110 has an identifier included in the base station identifier list, and the identifier in the list has an identifier greater than that of the base station 110d. Lower level.

If they are multiple connections, the processor 200 moves to step S556, if there is a single connection with the base station 110 (the base station 110 has an identifier included in the list and its rank in the list is lower than the identifier of the base station 110d Level), then the processor 200 will move to step S555 to select the identifier, and move to step S557.

According to the example of FIG. 1b, the base station 110d is connected to the base stations 110c and 110b. Then, the processor 200 moves to step S556, and selects the identifier of the base station 110 having the lowest rank in the base station identifier list from the identifiers of the connected base stations 110, that is, the identifier of the base station 110b.

In the next step S557, the processor 200 sends the determined base station (that is, the base station

200680043191.3 No.

110b) Transmit a message, where the message contains a list of base station identifiers and a list of mobile terminals 130. In addition, if the message received in step 530 contains one or more signatures, then the message preferably includes base station 110a and/or mobile terminal 130 Signature.

After that, the processor 200 returns to step S530.

The base station 110b receives the message, performs steps S530, S531, S550, S558, and S554-S557, and transmits a message to the base station 110a, where the message contains a list of base station identifiers and the identifier of the mobile terminal 130. If the message contains one or more signatures, then the message preferably also includes the signatures of the base station 110a and/or the mobile terminal 130.

The base station 110a receives the message and executes steps S530, S531, and S550. The processor 200 of the base station 110a determines in step S558 that the identifier of the base station 110a is the last identifier in the list of base station identifiers. Then, the processor 200 moves to step S559.

In the next step S559, the processor 200 processes the received message. This processing includes storing the content of the received message in the RAM memory 203, or checking the integrity of the message content in step S560 before storing the message.

Step S560 is the same as step S507b in FIG. 5a.

Once step S559 or steps S559 and S560 are executed correctly, the processor 200 moves to step S561_O In step S561, the processor 200 checks whether they are multiple connections with the base station 110, where the base station 110 has an identifier included in the base station identifier list, and the identifier in the list has a greater number than the identifier of the base station 110a. High grade.

If they are multiple connections, the processor 200 moves to step S562. If a single connection is established with a base station 110, the base station 110 has the identifier included in the base station identifier list and the identifier of the base station 110 is in the list With a higher level than the identifier of the base station 110a, then the processor 200 will move to step S561, and select the identifier and move to step S563.

According to the example of FIG. 1b, the base station 110a is connected to the base stations 110b and 110c. Then, the processor 200 moves to step S562, and selects the identifier of the base station 110c having the highest rank in the base station identifier list among the identifiers of the base stations 110d and 110c.

In the next step S563, the processor 200 reads the context of the mobile terminal 130 having the identifier included in the message from the RAM memory 203.

In the next step S564, the processor 200 transmits the context of the mobile terminal 130 to the base station 110c through the network interface 204 and in combination with the base station identifier list.

200680043191.3 The base station 110a stops serving the mobile terminal 130, and the processor 200 deletes the relevant context from the RAM memory 203, and then returns to step S530 and waits for the message to be received.

It should be pointed out here that when the base station 110 starts or stops serving the mobile terminal 130, it will notify the server 120.

The base station 110c receives the message, executes steps S530 and S531, and determines in step S550 that the message contains the context of the mobile terminal 130. Then, the processor of the base station 110c moves to step S551_O In step S551, the processor 200 of the base station 110c checks whether the identifier of the base station 110c is the first in the list of base station identifiers. If the identifier is the first one, the processor 200 moves to step S570, otherwise the processor 200 moves to step S554.

In step S554, the processor 200 checks whether they are multiple connections connected to the base station 110, wherein the identifier of the base station is included in the base station identifier list, and its rank is higher than the identifier of the base station 110c.

If they are multiple connections, the processor 200 moves to step S556, and selects the identifier of the base station 110 having the highest rank in the list of base station identifiers among the identifiers of the connected base stations 110.

If there is a single connection with the base station 110, and the identifier of the base station is included in the base station identifier list and has a higher level in the list than the identifier of the base station 110c, the processor 200 moves to step S555.

According to the example of FIG. 1b, the base station 110c is connected to the base station 110d, wherein the identifier of the base station 110d is included in the base station identifier list, and has a higher rank than the identifier of the base station 110c in the base station identifier list. Then, the processor 200 moves to step S555, and selects the identifier of the base station 110d.

In the next step S557, the processor 220 transmits a message to the determined base station (ie, base station 110d), where the message includes a list of base station identifiers, the identifier of the mobile terminal 130, and the context of the mobile terminal 130.

After that, the processor 200 returns to step S530.

The base station 110d receives the message, performs steps S530, S531, S550, S551, and S554-S557, and transmits a message to the base station 110e, where the message includes a list of base station identifiers, the identifier of the mobile terminal 130, and the context of the mobile terminal 130.

The base station 110e receives the message, the processor 200 of the base station 110e executes steps S530, S531, and S550, and determines in step S551 that the identifier of the base station 110e is a base station identifier column

200680043191.3 The first one in the table.

Then, the processor 200 of the base station 110e moves to step S570.

In step S570, the processor 200 reads the context of the mobile terminal 130 in the received message.

In step S571, the processor 200 applies those contexts received for the mobile terminal 130 to enable them to be served by the base station 110e.

In the next step S572, the processor 200 commands the transmission of a response message to the mobile terminal 130.

In the next step S573, the processor 200 forms a message. The message at least contains the identifier of its base station 110 (that is, the identifier of the base station 110e that currently serves the mobile terminal 130) and the unique identifier of the mobile terminal 130. Preferably, the message contains a certificate.

The certificate contains at least the unique identifier of the mobile terminal 130, the certificate of the base station 110e currently serving the mobile terminal 130, and the signature obtained by encoding these identifiers using the private key of the base station 110e.

In the next step S574, the processor 200 transmits the previously formed message through the wireless interface 206. In the memory of the mobile terminal 130, the content of the message will replace the content of the message previously received from the former base station 110a serving it.

Then, the processor 200 returns to step S530, and waits for a new message to be processed.

It should be pointed out here that in any of the first and second implementation manners of the present invention, the identifier of the base station is the identifier of the base station or the identifiers of one or more cells managed by the base station 110.

It should be pointed out here that the base station identifier list is arranged in the order from the most recently selected base station 110 to the earliest selected base station 110. However, the base station identifier list can also be arranged in the order from the earliest selected base station 110 to the most recently selected base station. The base stations 110 are arranged in order. In this case, instead of determining one or more identifiers with a lower level, the processor 200 will determine one or more identifiers with a higher level. Likewise, unlike determining one or more identifiers with a higher level, the processor 200 will determine one or more identifiers with a lower level. In addition, different from determining whether the base station identifier is the last one in the list, the processor 200 will determine whether the base station identifier is the first one in the list, and determine whether the base station identifier is the first identifier in the list. Differently, the processor 200 will determine whether the base station identifier is the last identifier in the list.

Of course, without departing from the scope of the present invention, the numerous embodiments of the present invention

200680043191.3 The first amendment is feasible.

200680043191.3