KR100695216B1 - System and Method for Minimizing of Handoff Interruption Time By Simplifying Authorization Procedure for Handoff for use in High-Speed Portable Internet Network - Google Patents

Abstract

The present invention relates to a system and method for minimizing delay time due to handoff through simplification of an authentication procedure according to handoff in a portable Internet network.

The present invention provides a handoff notification in which a serving BS includes a security context as a target BS in a portable Internet network including a mobile subscriber station (MSS), a serving base station (BS), and a target base station (HO-Pre). If the MSS 100 transmits a RNG_REQ (Ranging Request) message to the target BS 220, the target BS 220 determines the authentication by HMAC Digest of the received RNG_REQ message, and determines the result. As a result, a delay time due to a handoff through the creation of a RNG_RSP (Ranging Response) message including authentication required information and a simple handoff of an authentication procedure according to the handoff of performing an authentication procedure by sending an RNG_RSP message to an MSS. Provide a system and method of minimization.

According to the present invention, the burden on the CPU of the target BS processing the authentication is reduced, and the time required for the authentication procedure performed after the handoff is reduced, thereby minimizing the delay time due to the handoff.

Mobile Internet, WiBro, HPi, Handoff, Authentication Process, HMAC Tuple, Handoff Delay

Description

System and Method for Minimizing of Handoff Interruption Time By Simplifying Authorization Procedure for Handoff for use in High-Speed Portable Internet Network}

1 is a configuration diagram schematically illustrating a portable internet system;

2 is a view for explaining the authentication procedure after the handoff in the conventional portable Internet system,

3 is a view for explaining a delay time minimization system due to handoff and call processing by simplifying an authentication procedure according to a handoff in a portable Internet network according to a preferred embodiment of the present invention;

4 is a flowchart illustrating a method for minimizing delay time due to handoff through simplification of an authentication procedure according to handoff in a portable Internet network according to a preferred embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

100: MSS 110: BS

120: ACR 130: HA

140: AAA 150: IP network                 

160: Internet 210: Serving BS

220: target BS

The present invention relates to a system and method for minimizing delay time due to handoff through simplification of an authentication procedure according to handoff in a portable Internet network. More specifically, the BS is attached by attaching a Key-Hashing Message Authentication Code (HMAC) Tuple to a ranging request (hereinafter, referred to as 'RNG_REQ') message transmitted by a mobile subscriber station (MSS) to a base station (BS). Relates to a method and apparatus for authenticating an MSS.

As computer, electronic, and communication technologies have made rapid progress, various wireless communication services using wireless networks have been provided. The most basic wireless communication service is a wireless voice call service that provides a voice call to a mobile terminal user wirelessly, which can provide a service regardless of time and place. In addition, while providing a text message service to complement the voice call service, a wireless Internet service has recently emerged to provide an Internet communication service to a user of a mobile communication terminal through a wireless communication network.

As a result of the development of mobile communication technology, a service provided by a code division multiple access (CDMA) mobile communication system transmits data such as circuit data, packet data, etc., as well as a voice service. It is developing into a multimedia communication service.

In recent years, with the development of information and communication, IMT-2000 (International Mobile Telecommunication 2000), a third generation mobile communication system that has been standardized by ITU-R (for example, CDMA2000 1X, 3X, EV-DO, WCDMA (WideBand CDMA)) Etc.) are commercially available. IMT-2000 is CDMA 2000 1X, 3X, EV-DO, WCDMA (WideBand CDMA), etc .. It is a service that can provide wireless Internet at a transmission speed of up to 144 Kbps, much faster than the supportable data transfer rate of 14.4 Kbps or 56 Kbps. In particular, by using IMT-2000 service, it is possible to provide various multimedia services (AOD, VOD, etc.) at higher speed as well as improving existing voice and WBS service quality.

However, the existing mobile communication system has a limitation in providing high-speed wireless Internet due to high base station construction cost and high usage rate of the wireless Internet, and a small screen size of the mobile communication terminal, thus limiting the available contents. Wireless Local Area Network (WLAN) technology has limitations in providing public services due to problems such as radio wave interference and narrow coverage. Accordingly, a high-speed portable internet system (hereinafter referred to as 'HPi') has emerged, which guarantees portability and mobility and can use a high-speed wireless internet service at a low price.

HPi system is a service that enables users to access various information and contents by using the various types of portable terminals such as laptop, PDA, handheld PC, etc. . In addition, it provides mobility of 60 km / h per hour, and has a downlink transmission rate of 24.8 Mbps but an uplink transmission rate of 5.2 Mbps, which is an IP (Internet Protocol) based wireless data system having up-down asymmetric transmission characteristics.

The HPi system uses a 2.3 GHz frequency band and uses Time Division Duplex (TDD) for Duplex and Orthogonal Frequency Division for Multiple Access for OFDM to effectively use the allocated frequency spectrum. Multiple Access (TDMA) / Time Division Multiple Access (TDMA) is used. In this case, OFDMA / TDMA is a multiple access scheme similar to TDMA, in which all subcarriers spread over the entire bandwidth are allocated to one user for a predetermined time and to another user for the next predetermined time.

1 is a schematic view showing an HPi system.

As shown in FIG. 1, the HPi system includes an MSS 100, a BS 110, an access control router (ACR) 120, a home agent (HA) 130, and an authentication, authorization, and accounting (AAA) 140. ), The IP network 150, the Internet 160, and the like.

Here, the MSS 100 refers to a mobile communication terminal using an ultra high-speed wireless Internet service by accessing an HPi system, and a low power RF (RF) / IF (Intermediate Frequency) module and controller function, service characteristics, and MAC according to a radio wave environment. Media Access Control) It has frame variable control function, handover function, authentication and encryption function.

BS 110 is a base station of the Hpi system to wirelessly transmit data received from the ACR 120 to the MSS 100, low-power RF / IF module and controller functions, OFDMA / TDD packet scheduling and channel multiplexing functions, services MAC frame variable control, 50 Mbps high-speed traffic real-time control, handover function, etc. according to characteristics and propagation environment. In addition, the MSS 100 and BS 110 have a 50 Mbps packet transmission modulation and demodulation function, a high speed packet channel coding function, a real time modem control function, and the like for data transmission.

The ACR 120 is a packet access router that accommodates a plurality of BSs 110 and connects the BSs 110. The ACR 120 is a handover control function between the BSs 110, a handover function between the ACRs 120, a packet routing function, and the Internet. It has a connection function and so on and is connected to an IP network.

The HA 130 performs routing for transmitting a packet transmitted from the outside when using Mobile IP such as the Internet 160, and the AAA 140 works with the BS 110 to transmit packet data used by the MSS 100. Charge for and authenticate the connection from the MSS 100.

The IP network 150 connects the BS 110, the HA 130, and the AAA 150, and receives the packet data from an external packet data service such as the Internet 170 and transmits the packet data to the BS 110.

2 is a view for explaining an authentication procedure after handoff in a conventional HPi system.

The HPi system moves between the MSS 100 and the target BS 220 when the moving MSS 100 leaves the area of the serving BS 210 and enters the area of the target BS 220. The off procedure is performed to provide continuous service to the MSS 100. According to the current standard, after this handoff procedure is terminated, the BS providing the service is changed so that the subscriber authentication procedure is performed again.

As shown in FIG. 2, the serving BS 210 notifies the target BS 220 through the HO-Pre-Notification message that the MSS 100 intends to handoff. The handoff notification message serves to inform the target BS 220 that the MSS 100 is to perform a handoff.

When the MSS 100 sends an RNG_REQ message with the ID information of the serving BS 210 to the target BS 220 to attempt a handoff, the target BS 220 may provide the MSS 110 in response to the RNG_REQ. A ranging response message, which has SLP (Service Level Prediction) information representing a degree of service that can be expressed as a value, is transmitted to the MSS 100.

Again, the MSS 100 transmits an Authentication Request message with certificate information to be authenticated, and the target BS 220 determines whether to authenticate through a certificate including a received MAC address, and determines an authentication response ( Authorization Response) sends a message to the MSS (100) to notify whether the authentication.

However, in such a conventional authentication method, an asymmetric cryptographic algorithm such as Rivest-Shamir-Adelman (RSA), which is an encryption algorithm for processing subscriber authentication, is computationally complex to allow MSS 100 or target BS 220 to handle authentication. In order to increase the burden on the CPU and to perform the authentication procedure, the message sent and received between the MSS 100 and the target BS 220 increases the service delay time due to handoff. Accordingly, in recent years, there is a demand for a method of minimizing a delay time due to handoff in an Hpi system.

In order to solve the above problems, the present invention attaches the entire authentication procedure by attaching the HMAC Digest calculated using Security Context information such as AK received and stored from the serving BS to the RNG_REQ message transmitted by the MSS to the target BS. Do not go through. It is an object of the present invention to provide a method and apparatus for authenticating an MSS by determining whether the HMAC Digest calculated from the Security Context received from the serving BS is identical to the HMAC Digest received from the MSS.

In order to achieve the above object, the present invention provides an authentication procedure in a high-speed portable internet (HPi) network that minimizes the handoff interruption time by simplifying the authentication procedure performed immediately after the handoff. A mobile subscriber station (MSS) for transmitting and receiving a ranging message to perform a procedure; A target BS (Target Base Station) for receiving an RNG_REQ message from the MSS to determine whether to authenticate and transmitting an RNG_RSP message to the MSS; And a serving base station (BS) for transmitting a handoff notification backbone (HO pre-notification backbone) message to the target BS. Minimize latency caused by the system.

According to a second object of the present invention, there is provided a MSS for transmitting and receiving a ranging message, a target BS for transmitting and receiving a ranging message with the BS, determining whether to authenticate, and a serving BS for transmitting a handoff notification backbone message to the target BS. CLAIMS 1. A method for minimizing handoff downtime by simplifying an authentication procedure in a system comprising: (a) receiving the handoff notification backbone message from the serving BS; (b) receiving an RNG_REQ message from the MSS; (c) determining whether to authenticate by matching the HMAC Digest included in the RNG_REQ message received from the MSS with the HMAC Digest calculated using security information of the handoff notification backbone message received from the serving BS; And (d) generating authentication need information as a result of the determination of step (c) and attaching it to the RNG_RSP message and transmitting it to the MSS. It provides a method for minimizing the delay time due to handoff through.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used as much as possible even if displayed on different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

3 is a diagram illustrating a system for minimizing delay time due to handoff and call processing by simplifying an authentication procedure according to handoff in a portable Internet network in an HPi network according to a preferred embodiment of the present invention.

4 is a flowchart illustrating a method for minimizing delay time due to handoff by simplifying an authentication procedure according to handoff in a portable Internet network in an HPi system according to a preferred embodiment of the present invention.

If the MSS 100 receiving the service leaves the area of the serving BS 210, the serving BS 210 notifies the target BS 220 of the handoff that the MSS 100 is about to handoff (HO-Pre). Notify). The handoff notification message serves to notify the target BS 220 that the MSS 100 will perform a handoff. The serving BS 210 includes the security context information (hereinafter referred to as 'Security Context') in the handoff notification message and sends it to the target BS 220 (S410).

The MSS 100 not only provides the ID of the serving BS 210 to the target BS 220 but also a key hash message authentication code digest (HMAC Digest). ) And transmits an RNG_REQ message including S).

The target BS 220 extracts an AK (Authorization Key) from the received Security Context attached to the handoff notification backbone message received from the serving BS, calculates an HMAC Digest from the extracted AK, and calculates the calculated HMAC Digest. And the HMAC Digest included in the RNG_REQ message received from the MSS, if the two HMAC Digest is determined to be the same, it is determined that the authentication is valid, and if the two MAC-Digest is not the same, it is determined that the authentication is not valid (S430 ).

The target BS 220 generates an RNG_RSP message including authentication required information (Authorization Required) as a determination result (S440). Here, the RNG_RSP message includes authentication required information as well as service level prediction (SLP) information expressing a degree of a service that can be provided to the MSS 110 as a value.

The authentication necessity information indicates whether the authentication is valid or not, and when the target BS 220 does not receive the Security Context from the serving BS 210, the result determined by HMAC Digest is not valid. Alternatively, when the Hpi network operator enforces the policy, it plays a role of indicating that the MSS 100 performs a full authorization procedure.

If the target BS 220 does not receive the Security Contest from the serving BS 210, the target BS 220 can find the serving BS 210 using the BS ID sent by the MSS 100 in the RNG_REQ. Therefore, it can request the security BS to the serving BS (200).

The target BS 220 transmits the RNG_RSP message to the MSS 100 in response to the RNG_REQ message (S450). If the authentication necessity information included in the received RNG_RSP message indicates that the authentication is valid, the MSS 100 indicates that the authentication is completed, and if the target BS does not receive the Security Context from the serving BS, if the target BS does not receive the Security Context from the serving BS, If the result is not valid or if the HPi network operator enforces the policy, the full authorization procedure is performed.

HMAC is a mechanism that authenticates a message using an encrypted hash function. HMAC is combined with a Secret Shared Key and used with an iterative cryptographic hash function such as MD5 or SHA-1. The degree of encryption in HMAC depends on the nature of the underlying hash function.

Security Context is composed by type as shown in Table 1.

Here, AK Related is AK related information used for authentication, and TEK Related is TEK related information used for data encryption.

Table 2 shows the RNG_REQ message encoding, and Table 3 shows the RNG_RSP message encoding.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

As described above, according to the present invention, two message transmission and reception procedures between the MSS 100 and the target BS 220 are omitted and ranging to reduce the burden on the CPU of the target BS processing authentication and to perform the authentication procedure. (RNG_REQ and RNG_RSP) By completing the authentication process only by exchanging messages, the time required for the authentication process is reduced, thus minimizing service delay time due to handoff.

Claims (15)

In the system for minimizing the delay time due to handoff by simplifying the authentication procedure according to the handoff in the portable Internet network, A mobile subscriber station (MSS) for transmitting and receiving a ranging message to perform an authentication procedure; A target base station (BS) for receiving a RNG_REQ message from the MSS to determine whether to authenticate and to send a RNG_RSP (Ranging Response) message to the MSS; And A serving base station (BS) for transmitting a handoff notification backbone (HO Pre Notification Backbone) message to the target BS; A system for minimizing delay time due to handoff through simplification of an authentication procedure according to handoff in a portable Internet network, including The method of claim 1, The MSS sends the RNG_REQ message encoded with a serving BS ID and an HMAC Digest to the target BS to perform an authentication procedure after handing off to the target BS, and from the target BS, a service level prediction (SLP). And receiving the RNG_RSP message encoded with authentication required information indicating whether the MSS should perform an authentication procedure, and receiving authentication from the target BS. System for minimizing delay due to handoff through simplified procedure. The method of claim 2, The HMAC Digest is calculated and generated by HMAC_KEY_U extracted from the AK received from the serving BS when the service is received from the serving BS. Latency Minimization System. The method of claim 1, The target BS extracts an AK (Authorization Key) from the received Security Context attached to the handoff notification backbone message received from the serving BS, calculates an HMAC Digest from the extracted AK, and calculates the calculated HMAC Digest. And comparing the HMAC Digest included in the RNG_REQ message received from the MSS, if the two HMAC-Digest is determined to be the same, it is determined that the authentication is valid, and if the two MAC-Digest is not the same, it is determined that the authentication is not valid, A system for minimizing delay time due to handoff through simplification of an authentication procedure according to a handoff in a portable internet network, characterized in that authentication information is generated and encoded in the RNG_RSP message. The method according to claim 4, The authentication necessity information indicates whether the MSS should perform an authentication procedure, when the target BS does not receive the Security Context from the serving BS, the result determined by HMAC Digest is not valid or HPi If the network operator enforces a policy, the MSS indicates to perform a full authorization procedure, thereby minimizing the delay time due to the handoff by simplifying the authentication procedure according to the handoff in the mobile Internet network. system. The method of claim 1, The handoff notification backbone message is a message in which the serving BS notifies the target BS of a handoff attempt of the BS, and asks whether the target BS can provide a service by receiving a handoff request of the MSS. A system for minimizing delay time due to handoff by simplifying an authentication procedure according to handoff in a portable Internet network, wherein the message is a message. The method of claim 1, The serving BS attaches and transmits a Security Context, which is information about encryption or authentication of data transmitted and received by the serving BS, to the handoff notification backbone message transmitted to the target BS. A system for minimizing delay due to handoff through the simplification of the authentication procedure according to the present invention. The method of claim 1, The MSS includes a personal digital assistant (PDA), a cellular phone, a personal communication service (PCS) phone, a hand-held PC (GPS), a global system for mobile (GSM) phone, a wideband CDMA (W-CDMA) phone, and CDMA. -Minimization of delay time due to handoff through simplification of the authentication procedure according to the handoff in the mobile Internet network, characterized in that at least one of -2000 phone and Mobile Broadband System (MBS) phone. A mobile subscriber station (MSS) for transmitting and receiving a ranging message, a target base station (BS) transmitting and receiving the MSS and the ranging message, and determining whether to authenticate, and a handoff notification backbone to the target BS ( In a system comprising a serving base station (BS) for transmitting a HO Pre Notification Backbone (HO) message in a method for minimizing the delay time due to handoff through the simplification of the authentication procedure according to the handoff in the portable Internet network , (a) receiving the handoff announcement backbone message from the serving BS; (b) receiving an RNG_REQ message from the MSS; (c) determining whether to authenticate using the HMAC Digest included in the RNG_REQ message received from the MSS and the handoff notification backbone message received from the serving BS; And (d) generating authentication necessity information according to the determination result of step (c) and attaching it to the RNG_RSP message and transmitting it to the MSS; A method of minimizing delay time due to handoff through simplification of an authentication procedure according to handoff in a portable Internet network, comprising: a. The method of claim 9, wherein step (a) is Wherein the serving BS informs the target BS of a handoff attempt by the BS, and the target BS transmits the handoff notification backbone message, which is a message used to notify a handoff attempt of the MSS. A method of minimizing delay time due to handoff by simplifying an authentication procedure according to handoff in a portable Internet network. The method of claim 9, wherein step (b) And receiving the RNG_REQ message encoded by the serving BS ID and the HMAC Digest from the MSS. The method of claim 11, The HMAC Digest is generated by calculating the HMAC_KEY_U extracted from the AK received from the serving BS when the MSS is being serviced by the serving BS. How to minimize latency due to off. The method of claim 9, wherein step (c) is The AK (Authorization Key) is extracted from the received Security Context attached to the handoff notification backbone message received from the serving BS, and HMAC Digest is calculated again from the extracted AK, and the calculated HMAC Digest and MSS are calculated. Comparing the HMAC Digest included in the received RNG_REQ message, if it is determined that the two HMAC-Digest is the same, it is determined that the authentication is valid, and if the two HMAC-Digest is not the same, it characterized in that the authentication is not valid A method of minimizing delay time due to handoff by simplifying an authentication procedure according to handoff in an internet network. The method of claim 13, The Security Context simplifies the authentication procedure according to handoff in the portable Internet network, characterized in that the serving BS stores information providing the HPi service to the MSS and AK related information for authentication and TEK related information for data encryption. How to minimize delay due to handoff via. The method of claim 11, wherein step (d) If the determination result of step (c) is not valid or invalid and the target BS does not receive the Security Context from the serving BS, the result determined by HMAC Digest is not valid or the HPi network operator In the case of forced enforcement, the authentication procedure according to the handoff in the mobile Internet network is generated as authentication information indicating whether to perform a full authorization procedure and attached to the RNG_RSP message and transmitted to the MSS. A method for minimizing delay due to handoff through simplification.

Images