KR100716409B1 - Method for selecting network in overlap area of heterogeneous network and mobile station for the same - Google Patents

Abstract

The present invention relates to a network selection method for performing initial access or handoff in a heterogeneous network overlapping area and a mobile station for the same.

A network selection method in a heterogeneous network overlapping area according to the present invention comprises the steps of: receiving agent advertisement messages from each network in a region where the heterogeneous network overlaps; Calculating throughput for the agent advertisement message; And registering the mobile IP by accessing the network having the highest throughput.

In addition, the mobile station according to the present invention includes a connection interface module having interface drivers corresponding to at least two kinds of heterogeneous networks; A message receiver configured to receive an agent advertisement message from each network in an area where the heterogeneous networks overlap; A throughput calculator configured to calculate a throughput for the agent advertisement message; And an access processing unit that registers a mobile IP by accessing the network having the highest throughput.

According to the present invention, there is an advantage of providing a communication service quality that a user can actually feel by selecting the best communication network in an area where heterogeneous networks overlap.

Heterogeneous Network, Mobile Station, Handoff, Throughput, MIP

Description

Method for selecting network in overlap area of heterogeneous network and mobile station for the same}

The following drawings attached to this specification are illustrative of preferred embodiments of the present invention, and together with the detailed description of the invention to serve to further understand the technical spirit of the present invention, the present invention is a matter described in such drawings It should not be construed as limited to

1 is a diagram showing an example of a general system configuration for providing a unified communication service between heterogeneous networks.

2 is a flowchart illustrating a process of performing a network selection method according to a preferred embodiment of the present invention.

3 is a block diagram showing the configuration of a mobile station according to a preferred embodiment of the present invention;

4 is a procedure diagram showing a process in which a heterogeneous handoff process is performed by a mobile station of FIG.

<Description of main reference numerals in the drawings>

Mobile station 101 ... Connection interface module

102 ... message transmitter 103 ... message receiver

104 ... throughput calculation section 105 ... connection processing section

The present invention relates to a network selection method in a heterogeneous network overlapping area and a mobile station therefor, and more particularly, to a method for selecting any one communication network capable of providing the best communication quality in a service right where heterogeneous mobile communication networks overlap. And a mobile station for this purpose.

Recently, as interoperability between various mobile communication services is required and the number of users per mobile carrier reaches a saturation state, mobile communication services between different types of mobile communication networks (hereinafter, 'heterogeneous networks') are integrated. There is a growing interest in providing heterogeneous integrated services that can be provided.

Examples of integrated services between heterogeneous networks realized so far include a communication service for interworking between code division multiple access (CDMA), wireless LAN (WLAN), wideband CDMA (WCDMA) and WLAN. As an example, FIG. 1 illustrates a system for integrating a WLAN 10 of the Wi-Fi (802.11b) standard and an EV-DO CDMA network 11 to select and use a communication network in the mobile station 12. have.

In the case of integrated services between heterogeneous networks, handoff processing is important in areas where service rights overlap. Conventionally, a manual method of giving a user a choice of a communication network is used, or a pilot of a predetermined communication network is used. It has been widely used to automatically connect to other networks when the signal strength falls below the threshold.

For example, in the WLAN-CDMA heterogeneous network where handoff processing is performed based on the pilot signal strength of the WLAN, when the WLAN signal strength drops below a certain value in a region where the WLAN and the CDMA network overlap, the CDMA is automatically A network connection was used.

As another example, Korean Patent Laid-Open No. 2001-56283 (Hard Handoff Method from Asynchronous Code Division Multiple Access System to Synchronous Code Division Multiple Access System) performs a handoff by additionally transmitting an asynchronous CDMA pilot channel from a synchronous CDMA base station. In synchronization with the timing, the mobile station measures the signal strength of the asynchronous CDMA pilot channel and transmits it to the asynchronous CDMA base station, and performs handoff at the mobile station after information for handoff is exchanged between the base stations according to the measurement result. A treatment method is disclosed.

However, in the heterogeneous network, since the data transmission characteristics are very different for each communication network, when the handoff is performed uniformly based on the strength of the pilot signal, communication service quality may be degraded. For example, if the pilot signal strength of the WLAN is used as a handoff criterion, even though the detected signal strength of the WLAN is smaller than the reference value, the throughput may be higher than that of the CDMA network. There is a risk of falling.

In addition, when multiple heterogeneous networks such as CDMA, WCDMA, WLAN, and wireless broadband (WiBro) are mixed in the future, the data service rate of each communication network is different from each other. There is a weak vulnerability.

On the other hand, when a mobile station initially attempts to connect to a communication network in an area where service rights of heterogeneous networks overlap, it is conventionally a manual method in which a user manually selects a communication network, or automatically, according to a prioritized priority. Generally, the network selection method has been used. In the case of the network selection method, since the initial connection is completed, handoff should be performed to the network with the largest pilot signal strength, which has a disadvantage in that the processing is complicated and the connection speed may be delayed. .

The present invention has been made in consideration of the above-described matters, and provides a network selection method for performing initial access or handoff based on the result of measuring throughput for each communication network in a heterogeneous network overlapping area, and a mobile station for the same. The purpose is to.

In order to achieve the above object, a network selection method in a heterogeneous network overlapping area according to the present invention includes: (a) receiving agent advertisement messages from each network in a region where the heterogeneous network overlaps; (b) calculating throughput for the agent advertisement message; And (c) registering a mobile IP by accessing a network having the highest throughput.

Additionally, before step (a), the method may further include broadcasting an agent request message for inducing transmission of the agent advertisement message.

The throughput calculation process of step (b) is preferably performed according to the following equation.

(P: throughput, S _s : agent request message size, S _a : agent advertisement message size, T _s : agent request message transmission time, R _a : agent advertisement message reception time)

The heterogeneous network may correspond to two or more selected from CDMA, WCDMA, WLAN, and Wibro.

According to another aspect of the present invention, a connection interface module having interface drivers corresponding to at least two kinds of heterogeneous networks; A message receiver configured to receive an agent advertisement message from each network in an area where the heterogeneous networks overlap; A throughput calculator configured to calculate a throughput for the agent advertisement message; And a connection processing unit for accessing a network having the highest throughput and registering a mobile IP.

In addition, the present invention may further include a message transmitter for broadcasting an agent request message for inducing transmission of the agent advertisement message.

Preferably, the throughput calculator is configured to calculate throughput according to the following equation.

(P: throughput, S _s : agent request message size, S _a : agent advertisement message size, T _s : agent request message transmission time, R _a : agent advertisement message reception time)

The access interface module preferably includes interfaces corresponding to two or more communication networks selected from CDMA, WCDMA, WLAN, and Wibro.

According to another aspect of the present invention, in a recording medium loaded on a mobile station, a procedure for receiving agent advertisement messages from each network in a region where heterogeneous networks overlap, and a procedure for calculating throughput for the agent advertisement message And a computer readable recording medium having recorded thereon a program capable of executing a procedure for registering a mobile IP by accessing a network having the highest throughput.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and claims should not be construed as having a conventional or dictionary meaning, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

2 illustrates a process of performing a network selection method according to a preferred embodiment of the present invention.

Referring to FIG. 2, first, an agent solicitation message is broadcast by a mobile station located in an area where a heterogeneous network overlaps, and then an agent transmitted from each communication network in correspondence to the agent solicitation message. Processing for receiving an Agent Advertisement Message is performed (steps S10 and S20).

Here, heterogeneous networks are two or more types of mobile communication networks accessible by the mobile station, and may include a CDMA network, a WCDMA network, a WLAN, or a Wibro network.

A mobile station is a terminal device equipped with at least two kinds of mobile communication interfaces to be connected to the heterogeneous network. For example, a mobile station may be a notebook, a personal digital assistant, or a mobile phone. have.

The agent request message and the agent advertisement message, which are typically used for registration of mobile IP (MIP) for any mobile communication network, are broadcast messages using Internet Control Message Protocol (ICMP) packets. It is preferred, but not limited to these examples, various modifications are of course possible. In this case, the procedure of step S10 may be omitted when it is not necessary to broadcast the agent request message separately, for example, when the period of the agent advertisement message transmitted from the heterogeneous networks is short.

After the agent advertisement message is received by the mobile station from each communication network, processing for calculating the throughput for each advertisement message is performed (step S30). Calculation processing of the throughput, the size of the agent solicitation message (S _s), the size of the agent advertisement message (S _a), sending time of the agent solicitation message (T _s), reception of an agent advertisement message time (R _a), such as the factor It can be performed in a variety of ways using. Preferably, the throughput calculation process is performed by a calculation algorithm represented by the following equation (1).

Here, the 'size' of the agent request message and the agent advertisement message is a physical quantity representing a data capacity, and has a unit of byte, for example. Further, the sending time of the agent solicitation message (T _s) and the reception of an agent advertisement message time (R _a) is, for example, has units of milliseconds (ms).

Referring to Equation 1, it can be seen that the throughput, which is the amount of data processed for a unit time, can be calculated by calculating the total capacity of data transmitted / received during a time interval in which a message flows between a mobile station and a corresponding communication network. For example, during a 10 millisecond (ms) time interval, if an Agent Advertisement message of 700 bytes has been received after a 500-byte Agent Request message has been sent, the network will be 10 milliseconds (ms). Since it is a network capable of processing 1200 bytes of data, it provides 960kbps throughput.

After calculating the throughput for the agent advertisement message of each communication network, the calculation result is analyzed to determine the communication network with the highest throughput, and the process of accessing the determined communication network and registering the MIP is performed (step S40). To this end, as is known between the mobile station and the communication network to which the mobile station is connected, a MIP registration request message is transmitted, authentication, generation / update of a mobility binding list, and a MIP registration response message. Reply Message) A series of registration processing such as reception is performed.

The network selection procedure in the heterogeneous network overlapping area as described above is performed at the initial connection when the mobile station first selects the data communication network from the stationary state, or at the handoff when the mobile station moves to the channel of the new communication network.

3 shows a configuration of a mobile station according to a preferred embodiment of the present invention.

Referring to FIG. 3, a mobile station 100 according to a preferred embodiment of the present invention includes a connection interface module 101 that provides a physical connection function for at least two or more heterogeneous networks, and an agent advertisement message received from the heterogeneous network. A message receiving unit 103, a throughput calculating unit 104 for calculating throughput for the received agent advertisement message, and a connection processing unit 105 for selecting a communication network having the highest throughput and performing MIP registration processing are provided.

Although a heterogeneous network including a WLAN 200, a CDMA network 300, and a Wibro network 400 is shown in the figure, a communication network to which the mobile station 100 can be connected is not limited to this example. Various communication networks such as Bluetooth implemented on the platform may be applicable.

The access interface module 101 includes interface drivers corresponding to the WLAN 200, the CDMA network 300, and the Wibro network 400, respectively. Here, since each interface driver itself for physical connection with the corresponding communication network may employ the same known technical means, a detailed description thereof will be omitted.

The message receiver 103 receives an agent advertisement message transmitted from a corresponding agent of each communication network.

Preferably, the mobile station 100 of the present invention further includes a message transmitter 102 for broadcasting an agent request message capable of inducing transmission of the agent advertisement message for each communication network.

The agent request message and the agent advertisement message respectively processed by the message transmitter 102 and the message receiver 103 are preferably broadcast messages using an Internet Control Message Protocol (ICMP) packet. Of course, it is not limited.

The throughput calculator 104 calculates throughput for each agent advertisement message received and processed by the message receiver 103. To this end, the throughput calculation unit 104 may determine the size (S _s ) and the transmission time (T _s ) of the agent request message processed by the message transmitter 102, and the size of the agent advertisement message processed by the message receiver 103 ( S _a) and the reception time (R _a) is preferably configured to calculate the throughput according to the algorithm of equation (1) described above using the parameters and the like. Here, the throughput calculation unit 104 may be configured to use another algorithm as long as it can calculate the throughput for the agent advertisement message of each communication network.

The connection processing unit 105 analyzes the calculation result of the throughput calculating unit 104 to select a communication network having the highest throughput, and accesses the communication network to perform MIP registration processing. That is, the connection processing unit 105 transmits a MIP registration request message to a communication network having the highest throughput, and processes such as authentication and generation / update of a mobility binding list. Receives a MIP Registration Reply message transmitted from the network after completion.

4 illustrates a heterogeneous handoff procedure performed by a mobile station according to a preferred embodiment of the present invention.

Referring to FIG. 4, first, a mobile station 100 located in an overlapping area of a heterogeneous network such as WLAN 200, CDMA 300, and Wibro 400 drives its message transmitter 102 to external agents of respective communication networks. In order to grasp the information on the FA, the agent request message is broadcasted (step S100), and correspondingly, an agent advertisement message transmitted from each communication network is received (step S101).

When the agent advertisement message of each communication network is received by the message receiving unit 103 of the mobile station 100, the throughput calculating unit 104 uses factors such as the size and transmission time of the agent request message, the size and reception time of the agent advertisement message, and the like. To calculate the throughput (step S102).

When the calculation of the throughput is completed, the connection processing unit 105 of the mobile station 100 analyzes the calculation result to determine the communication network having the highest throughput, for example, the CDMA network 300, and accesses the CDMA network 300 to request MIP registration. The message is transmitted (step S103).

Accordingly, the CDMA network 300 performs an authentication procedure with respect to the mobile station 100, and upon successful authentication, performs a process such as generation / update of a mobility binding list and then the mobile station 100 again. In step S104, a MIP registration reply message is transmitted.

As such, when the MIP registration is completed by selecting a communication network having the highest throughput in the heterogeneous network overlapping area, a handoff process is performed to switch the communication channel of the mobile station 100 to the newly selected communication network.

Although the present invention has been described above by means of limited embodiments and drawings, the present invention is not limited thereto and will be described below by the person skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of the claims.

According to the present invention, since the communication network for initial connection or handoff is determined on the basis of the throughput in the heterogeneous network overlapping area, a reliable network selection process can be performed, and the user can select the best communication network that the user can actually feel. There is this.

Claims (11)

A method for selecting a network during initial connection or handoff, performed by a mobile station having a connection interface corresponding to at least two kinds of heterogeneous networks, Broadcasting an agent request message for inducing transmission of an agent advertisement message; Receiving agent advertisement messages from each network in an area where the heterogeneous networks overlap; Calculating throughput for the agent advertisement message; And Registering a mobile IP by accessing a network having the highest throughput; and selecting a network in a heterogeneous network overlapping area. delete The method of claim 1,

(P: throughput, S _s : agent request message size, S _a : agent advertisement message size, T _s : agent request message transmission time, R _a : agent advertisement message reception time) The network selection method in a heterogeneous network overlap region, characterized in that for calculating the throughput according to the formula expressed by. The method according to claim 1 or 3, The heterogeneous network is a network selection method in a heterogeneous network overlap region, characterized in that at least two selected from CDMA, WCDMA, WLAN and Wibro. In a mobile station of a mobile communication system, A connection interface module having interface drivers corresponding to at least two kinds of heterogeneous networks; A message transmitter for broadcasting an agent request message for inducing transmission of an agent advertisement message; A message receiver configured to receive an agent advertisement message from each network in an area where the heterogeneous networks overlap; A throughput calculator configured to calculate a throughput for the agent advertisement message; And And a connection processing unit which registers a mobile IP by connecting to a network having the highest throughput. delete The method of claim 5, wherein the throughput calculation unit,

(P: throughput, S _s : agent request message size, S _a : agent advertisement message size, T _s : agent request message transmission time, R _a : agent advertisement message reception time) And calculates the throughput according to the equation represented by. The method according to claim 5 or 7, The access interface module is characterized in that the mobile station having interfaces corresponding to two or more communication networks selected from among CDMA, WCDMA, WLAN and Wibro. A recording medium mounted on a mobile station for reading, A procedure for broadcasting an agent request message for inducing transmission of an agent advertisement message; Receiving agent advertisement messages from each network in an area where heterogeneous networks overlap; Calculating a throughput for the agent advertisement message; A computer-readable recording medium that records a program that can execute a procedure for registering a mobile IP by accessing a network with the highest throughput. delete The method of claim 9,

(P: throughput, S _s : agent request message size, S _a : agent advertisement message size, T _s : agent request message transmission time, R _a : agent advertisement message reception time) A computer-readable recording medium having recorded thereon a program capable of executing the procedure for calculating the throughput according to a formula represented by.

Images