TWI279150B - Authentication in a hybrid communications network - Google Patents

Abstract

A method of authenticating a mobile station from a first base station in a first cellular communications system controlled by a first mobile switching control station to a second base station in a second, different cellular system controlled by a second mobile switching control station is described. The method comprises generating at the second cellular communication system an authentication code as the result of applying an algorithm to a private key assigned to the mobile station for the second cellular communications system and a random number-generated by the second cellular communications system. An authentication code is also generated at the first cellular communication system as the result of applying an algorithm to the private key and the random number. The authentication code generated at the first cellular communication system is then transmitted to a mobile station in a data packet, and, from there, the authentication code is transmitted to the second cellular communication system. The authentication code generated at the first cellular communications system is then compared with the authentication code generated at the second cellular communications system.

Description

127915〇•. (1) Enemy, inventions _ (Technical field, prior art, content, implementation, and drawings in which the invention pertains) Brief Description of the Invention 1. Technical Field The present invention relates broadly to Identification methods and devices in different cell communication systems. Prior Art The so-called code division multiple access (CDMA) modulation technique is just one of several techniques for facilitating communication for a large number of system users. Other techniques may be used (eg, time division multiple access (TDMA), frequency division multiple access (FDMA), such as amplitude versus sideband (ACSSB). The AM modulation principle such as modulation, but the advantages of CDMA are obviously superior to other modulation techniques. The following U.S. patents have been published in the use of CDMA technology in a multi-directional proximity communication system: U.S. Patent No. 4,901,307 entitled "Spread Spectrum Multiple Access Communication System Using Satellite Or Terrestrial Repeaters", which has been assigned to this transfer. A multi-directional proximity technique is disclosed in U.S. Patent No. 4,901,307, in which a large number of mobile telephone system users (each having a transceiver) use code division multi-directional proximity (code) Division multiple access ; CDMA) spread spectrum communication signal to pass through a satellite repeater or ground communication base station (also known as a cell base station or a cell-site). When the spectrum is reused many times, it can be increased

1279150 (2) System user capacity. The spectral efficiency achieved by the use of CDMA technology is higher than with other multi-directional proximity technologies. In conventional mobile telephone systems, the available frequency bands are divided into channels (the bandwidth is typically 30 KHz) while using FM modulation techniques. The system service area is geographically divided into cells of different sizes. The available frequency channels are divided into arrays, each group usually containing an equal number of channels. frequency

Groups are assigned to the unit to minimize the possibility of co-channel interference. For example, consider a system with seven sets of frequency groups and cells of equal size hexagons. A set of frequencies used in a unit is not used in the six nearest or surrounding cells. In addition, the set of frequency groups used in a unit is not used in the twelve nearest neighbors.

In conventional cellular communication systems, the effect of the handover is to continue the call or other type of connection (i.e., the data link) when the mobile station traverses the cell boundary. When the unit or station that handles the call or connection informs that the signal strength received from the mobile station drops below a predetermined limit, it is initiated from one unit to another. A low signal strength indicator means that the mobile station must be near the cell boundary. When the signal level drops below a predetermined limit, the base station asks the system controller to determine whether the signal strength of the mobile station signal received by the adjacent base station is stronger than the signal strength received by the current base station. The system controller transmits the message with the handover request to the neighboring base station in response to the current base station inquiry. A base station adjacent to the current base station uses a special scanning receiver for finding a letter of the mobile station on a designated channel

1279150 (7). In the unlikely event that the neighboring base station returns sufficient signal levels to the system controller, an attempt is made to hand over. Next, when an idle channel is selected from the channel set used in the new base station, the handover is initiated. A control message is transmitted to the mobile station to command the mobile station to switch from the current channel to the new channel. At the same time, the system controller switches the call from the first base station to the second base station. In traditional systems, if the handover to the new base station fails, the call is dropped. There are many reasons why delivery fails. If there are no idle channels available for call communication in the adjacent unit, a delivery failure will occur. If another base station reports that it is in the discussion of the mobile station in the discussion, in fact, the base station actually uses the same channel in a completely different unit and receives the different mobile stations. The delivery failed. This reported error can cause the call to be switched to the wrong unit, usually a unit with insufficient signal strength to maintain communication. In addition, if the mobile station cannot receive the channel switching command, the handover failure will occur. Practical operational experience points out that frequent handover failures question system reliability. Another common problem in traditional telephone systems occurs when the mobile station is at the boundary between two units. In this case, the signal level tends to fluctuate at both base stations. This level of signal fluctuations leads to a "ping-ponging" situation in which repeated requests are made to process calls back and forth between the two base stations. The non-essential delivery requirements for such amounts will increase. The possibility that the mobile station incorrectly receives the channel switching command, or the command cannot be received. In addition, if the call is inadvertently transferred to the unit where all channels are currently in use and cannot be handed over, the soldier ball The situation will trigger 1279150 (4)

The possibility of a call interruption. The following US patents have been published during the delivery period to provide communication methods and systems through the mobile station: The US patent titled "Method And System For Providing Communications In A CDMA Cellular Telephone has been assigned to the assignee, the content of which is In the context of citation, communication within the final S-communication system of the base station of the unit that is to be accessed by the mobile station from the unit corresponding to the mobile station is not interrupted. In the communication between unit bases (where two or more base stations transmit the mobile station), this type of handover is considered 'soft'. Now using such 'soft' handover can be substantially reduced in one The incidence of table tennis conditions required for repeated delivery. An improved handover technique 5,267,261, entitled "Mobile Station Assisted CDMA Cellular Communications System", the assignee of which is incorporated herein by reference. The way to change is to measure the strength of each base station signal in the mobile station. These preamble strength measurements are soft-assisted in a way that facilitates the implementation of the improved base-delivery technique for soft-delivery, and the monitoring of the signal strength. When the measured signal strength exceeds the base station via the base station that is communicating with the mobile station, it will be transmitted to the system controller. From the system controller to the new one or more units for the case number 5,101,501, A Soft Handoff In System", the patent is included in this article. In this ring of the base station to the relative I, the cell platform and the mobile station or base station The sectors are delivered in the same way. It is confirmed that the pair is sent to the base station: the US Patent Case No. Soft Handoff In A patent has been transferred to Benliang Soft Handover Technology for the transmission of the "preamble · · handover processing program: candidates Identification. From the *limit value of the adjacent base station, a signal strength message is transmitted to the base station and passed to the line 1279150 (5)

The command message of the mobile station establishes simultaneous communication through the new base station and the current base station. When the mobile station detects that the strength of the preamble signal corresponding to at least one of the base stations communicating with the mobile station has dropped below a predetermined level, the mobile station passes the base station that is communicating with the mobile station to the system controller Report the measured signal strength indication corresponding to the base station. The command message transmitted from the system controller to the identified base station and transmitted to the mobile station terminates communication through the corresponding base station, and the communication is read through other base stations.

While the foregoing techniques are well suited for call forwarding between units of the same cellular communication system, more difficult situations arise when the mobile station moves to a unit served by a base station of another cellular communication system. A complicating factor in such "system-to-system" handover is that adjacent cellular communication systems often have distinct characteristics. For example, adjacent cellular communication systems typically operate at different frequencies and maintain base station output power or preamble strength at different levels. These differences actually prevent the mobile station from performing a comparison of the leading signal strengths and are considered in the context of existing mobile-assisted soft handover techniques.

When resources are not available to handle inter-system soft handoff, if the non-disruptive service is to be maintained, the handoff timing of calls or connections between systems becomes critical. That is to say, the execution timing of inter-system handover must be likely to result in a successful transfer of calls or connections between systems. In this handover (referred to herein as hard handover), communication between the mobile station and a system must be terminated before communication between the mobile station and other systems can begin. For example, an attempt can only be made to hand over if: (i) an intervening channel is available in the new unit; -10·

1279150 (6) (ii) The mobile station is actually within the range of the new unit base station, but before losing contact with the current unit base station; and (iii) the location of the mobile station is confident that the channel switching command was received. Ideally, the handling of hard handover between each such system is,

Minimize the possibility of '’table tennis’’ delivery requirements between base stations in different systems. However, because the existing handover procedures cannot determine when and through which base stations, it is extremely difficult to provide new frequency and channel information to the mobile station and to direct the transfer of existing calls or connections. These and other shortcomings of existing intersystem handover techniques can degrade the quality of cellular communications and are expected to further degrade performance levels due to the inability to simultaneously receive cellular communication systems. Thus, there is a need for an intersystem handover technique that reliably directs the handover of calls or connections between base stations of different cellular communication systems.

A method and system for inter-system handover between base station communication between first and second cellular communication systems has been published in the following U.S. Patent: U.S. Patent No. 5,697,055 entitled "Mobile Station Assisted Soft Handoff" In A CDMA Cellular Communications System, which has been assigned to the assignee, the contents of which are incorporated herein by reference. In the mobile station, measuring the measurable signals transmitted by the second base station of the second system Parameter: When the measured measurable parameter value passes the first predetermined level, the mobile station transmits a signal quality message to the first mobile switching console via the first base station of the first system. A request message is communicated from the first mobile switching console to a second mobile switching console within the second system. On the second base station, -π - 1279150 (7)

The measurable parameters of the signals received from the mobile station are also measured. The second base station establishes communication with the mobile station when the measured measurable parameter values are typically predetermined. Alternatively, the signal strength of the first preamble transmitted by the first base station is measured on the mobile station. Then, when the measured signal strength of the first preamble signal is lower than the second predetermined level, a handover request message is transmitted to the second base station to establish base station communication. The provision of a voice link between the mobile switching consoles allows for the transfer of existing connections between the first and second cellular communication systems and promotes the effectiveness of soft handoff between systems.

While this configuration is well suited for situations where both systems are CDMA architectures and therefore capable of performing soft handoffs, there are still issues with how to handle intersystem transfers where one or more systems in the system are unable to perform this handover. For example, the so-called G S Μ standard does not have a soft handover mechanism. Therefore, there is a problem in the call handover process using the air interface from the CDMA network to the GSM network. In addition, since the CDMA 2000 mechanism cannot forward the data required to perform GS Μ authentication, G S Μ authentication cannot be completed. Encryption in G S is different from encryption in CDMA 2000. One way to solve this problem is to modify the G S to enable handover to a non-GSM system, such as a CDMA system. However, GSM has been in existence for many years, and relatively speaking, the industry is not willing to spend large sums of money to modify existing equipment to accept adjacent incompatible systems. If a new message is added to the spatial interface of the Supported Dual Mode Mobile, it must be modified to support these new messages. Obviously, this is not the desired form in terms of the position of the employed. Another problem between the CDMA system and the GSM system is that -12 -

1279150 (8) CDMA and GSM authentication use two different methods and keys. The authentication method of GSM and CDMA IX is basically the same, but the keys have different sizes. CDMA IX has additional procedures, such as the unique challenge and count method, which are used to prevent channel interception and replay attacks, respectively. SUMMARY OF THE INVENTION The present invention solves the problems set forth above.

According to one aspect of the present invention, a method for authenticating a mobile station is disclosed, wherein the mobile station moves from a first base station controlled by a first mobile switching console in a first cellular navigation system to a second base station controlled by a second mobile switching console in a second, different cellular communication system, the method comprising: generating an authentication code in the second cellular communication system, wherein the authentication is generated The code is a result of applying an algorithm to a private unit assigned to the mobile station of the first cellular communication system and a random number generated by the second cellular communication system; generating in the first cellular communication system An authentication code, wherein the identification code generated is a result of applying an algorithm to the private key and the random number; in a data packet, the identification code generated in the first cellular communication system Transmitting to a mobile station; transmitting the authentication code generated by the first cellular communication system from the mobile station to the second cellular communication system; and generating the same in the first cellular communication system The code recognition codes to authenticate the second communication system type cell than those produced. The foregoing and further features and advantages of the present invention will become more apparent from the following detailed description of exemplary embodiments of the invention, which are illustrated in the accompanying drawings. . In the drawing: a brief description of the schema

Figure 1 shows a schematic representation of a cellular communication system; Figure 2 shows a schematic representation of the boundary between two cellular communication systems; Figure 3 shows a schematic of a dual mode mobile station;

Figure 4 shows a schematic representation of the data exchange in the G S Μ system; and Figure 5 shows a schematic diagram of the single mode mobile station. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION Figure 1 shows a schematic diagram of an exemplary mobile telephone system. The system shown in the figure can utilize any multi-directional proximity modulation technique to facilitate communication between a large number of system mobile stations or mobile phones and base stations. Such multi-directional proximity communication system technologies include: time division multiple access (TDMA), frequency division multi-directional proximity (frequenCy division)

Multiple access (FDMA), code division multiple access (CDMA) and AM modulation principle such as amplitude versus signal side frequency band (ampiitucje companded single sideband modulation). For example, the aforementioned The advantages of the CDMA spread spectrum modulation technique disclosed in U.S. Patent No. 4,901,307 are obviously superior to other multi-directional proximity communication systems, and thus are preferred modulation techniques. In a typical CDMA system, each base The station will transmit a unique preamble k 'which contains the preamble carrier transmitted on the corresponding preamble channel. The leading k number is a non-declining, direct sequence, spread spectrum signal, and each-14-Restaurant 1279150 (10) The base station will transmit the preamble signal at any time using a general pseudorandom noise (PN) spreading code. In addition to providing coherent demodulation phase reference and reference for signal strength measurement used in handover decision In addition, the preamble also allows the base station to acquire the initial system synchronization (ie, timing). The preamble transmitted by each base station may typically be the same PN extension. , But with a different code phase offset.

In the system shown in Figure 1, the system controller and switch 10 (also known as the Mobile Switching Center (MSC)) typically includes video and processing circuitry (not shown) for providing a plurality of base stations 1 2 , 1 4 and 16 system control. Controller 10 also controls the path selection from the Public Switched Telephone Network (PSTN) to the appropriate base station for transmission to the appropriate mobile station. Controller 10 also controls the path selection from the mobile station via at least one base station to the PSTN. The controller 10 can be used to route calls between mobile users via appropriate base stations, since such mobile stations typically cannot communicate directly with each other.

The controller 10 can be coupled to the base station by various methods (e.g., using a telephone line, fiber optic link, or by the microwave communication link shown in Figure 1), three such exemplary bases are shown in FIG. Stations 12, 14 and 16 and an exemplary mobile station 18 (which includes a mobile phone). Arrows 20a and 2Bb define a possible communication link between base station 12 and mobile station 18. Arrows 2 2 a and 2 2 b define a possible communication link between base station 14 and mobile station 18. Arrows 2 4 a and 2 4 b define possible communication links between base station i 6 and mobile station 18. The geographic shape of the base station service area or cell is designed such that the mobile station is usually closest to a base station. When the mobile station is in standby (i.e., there is no ongoing call), the mobile station continuously monitors the transmission of the preamble from each base station near -15 - 1279150 (ii). As shown in Figure 1, base stations 12, 14 and 16 transmit preamble signals to mobile station 18 over communication links 20b, 22b and 24b, respectively. The mobile station then determines which cell it is located by comparing the strength of the preamble transmitted from these particular base stations. In the example shown in Figure 1, the mobile station 18 is considered to be closest to the base station 16. When the mobile station is in a call, the control message is transmitted to the nearest base station, here the base station 16. After receiving the call request message, the base station 16 sends a signal to the system controller 10 and forwards the call number. Next, the system controller 10 passes the PSTN to connect the call to the intended recipient. In the event that a call is initiated within the PSTN, the controller 10 will transmit the call information to all base stations in the area. The base station then transmits a paging message to the intended recipient mobile station. When the mobile station receives the paging message, it will respond with a control message transmitted to the nearest base station. The control message signals the system controller that the particular base station is communicating with the station. The controller 10 then routes the call to the mobile station through the closest base station. When the mobile station 18 moves outside the coverage of the originating base station (i.e., the base station 16), the call is attempted to continue the call by transmitting the call through the other base station. In the handover handler - there are different ways to initiate a call handover or to place a call through another base station. In the base station initial handover method, the starting base station (base station 16) notices that the signal transmitted by the mobile station 18 has dropped to a certain limited level. Next, the base station 16 transmits a handover request to the system controller 10 for relaying the-16-1279150 (12), and the purchase request is relayed to all adjacent base stations of the base station 1 2, 1 4 . The controller transmission type requirements include channel related information, including the PN code sequence used by the mobile station 18. The base stations 1 2 and 14 adjust the receiver to the channel used by the mobile station and measure the signal strength (usually using digital technology). If one of the base station's 12 and 14 receivers returns a signal strength that is higher than the signal strength of the starting base station, it will be handed over to the base station.

Alternatively, the mobile station itself may initiate a so-called mobile station assisted handover. The base station transmits the preamble, which is used to identify the base station, among other things. The mobile station is equipped with a search receiver that is used to scan the preamble signal transmissions of adjacent base stations 12 and 14 in addition to performing other functions. If it is confirmed that the strength of the preamble signal of one of the adjacent base stations 1 2 and 14 is higher than the predetermined limit value, the mobile station 18 transmits the message of the result to the base station 1 60.

Next, an interactive process between the mobile station and the base station allows the mobile station to communicate through one or more of the base stations 1 2, 14 and 16. During this process, the mobile station identifies and measures the signal strength of the received preamble. This information is communicated to M S C via a base station that is communicating with the mobile station. After receiving this information, M S C immediately starts or terminates the connection between the mobile station and the base station, thereby enabling the mobile station to assist the delivery. - The aforementioned processing procedure is also known as "soft" handover because the mobile station communicates through more than one base station at the same time. During soft handover, M S C may combine or select signals received from each base station, where these base station mobile stations are communicating with the mobile station during movement between different units. At •17-

1279150 (13) In a similar manner, M S C can relay signals from the PSTN to each base station that is communicating with the mobile station. If the mobile station is located within the coverage of two or more base stations that are not part of the same cellular communication system (i.e., 'not controlled by the same M S C'), the mobile station assisted handover tends to be more complicated. An example of performing handover between base stations belonging to different systems will now be described with reference to Figure 2, which shows a schematic diagram of a cellular communication network 30 containing CDMA cell types controlled by the CDMA Mobile Switching Center MSCc. Communication system (eg, IS-95 1X)., and GSM cellular communication system controlled by GS Μ mobile switching center MSCg. In FIG. 2, five exemplary base stations B 1 A to B 5 A are depicted in units C 1 A to C 5 A of the CDMA system, respectively, and five exemplary base stations b 1 B to B 5 B are respectively Located in units C 1 B to C 5 B of the GS Μ system. Although the cells C1A to C5A and C1B to C5B are depicted as being circular in the drawing based on the convenience of illustration, it should be understood that the cells are generally designed in other shapes, and the actual shape depends on the topography and terrain in the area in which they are located. Units C 1 Α to C3A and C1B to C3B may hereinafter be referred to as "boundary" units because these units are close to the boundary between the first and second cellular communication systems. This naming allows the remaining units within each system to be referred to as "internal" units. The following description relates to a mobile station capable of receiving and responding to signals from base stations in CDMA and GSM cell-based communication systems. However, it is expected that any type of .63⁄4 communication system can be used, for example, CDMA One, CDMA2000, CDMA 2000 lx, CDMA 2000 3x, High Data Rate Principles (HDR), CDMA lxEV, CDMA UEVDO, TDMA, TDSCDMA , W-CDMA, GPRS and other communication systems

1279150 (14) System. For this purpose, the configured mobile station is equipped with a dual band transceiver with a receive chain tunable to different operating frequencies belonging to the two cellular communication systems. Figure 3 of the accompanying drawings shows the schematic of this mobile station. As shown, the mobile station 40 includes an antenna 42 that is coupled to the CDMA transmission and reception chain 46 and the GSM transmission and reception chain 48 via a duplexer 44. The transmission/reception chains 46, 48 are conventional transmission/reception chains of the respective CDMA and GSM systems. The transmission/reception chain outputs the appropriately demodulated and converted data to the conventional baseband circuit 50, and receives the data transmitted from the baseband circuit 4'. The transmit/receive chains 46, 48 are controlled by the controller 52, one of which functions to switch between the two transmit/receive chains in response to the L-number from the CDMA or GSM system. Therefore, in this embodiment, the two transmission/reception chains are not in an active state at the same time. In another embodiment, the two transmit/receive chains can be in an active state at the same time. In another embodiment, the configured mobile station is equipped with a single transceiver having a receive button tunable to one of two cellular communication systems.

Figure 5 of the accompanying drawings shows a schematic diagram of this mobile station. As shown, the mobile station 53 includes an antenna 54. The duplexer 55 is connected to (::1;) 1^8 transmission and reception chain 36 (if the station is a CDMA handset) ^ Otherwise, the mobile station 53 It is connected to the GSM transmission and reception chain 57. Transmission/reception chains %, 57 are the traditional transmission/reception chains of the respective CDMA and GSM systems. The transmission/reception chain outputs the appropriately demodulated and converted data to a conventional baseband circuit and receives the data transmitted from the baseband circuit 58. The transmit/receive chain (56 is controlled by controller 59. See Figure 2' CDMA Mobile Switching Center (MSCc# from Public Switching-19).

1279150 (15) The telephone network (PSTN) to the appropriate base station B 1 A to B 5 A telephone beer routing path for transmission to the designated mobile station. The CDMA Mobile Switching Center MSCc also controls the routing of calls from at least one base station to the PSTN from the mobile station located within the coverage of the cellular/cellular communication system. The GSM Mobile Switching Center MSCg operates in a similar manner to manage the operation of base ports B' to 358 and to place calls between cellular communication systems. Control messages and the like are communicated between the MSCc and the MSCg through the inter-system data link 34. When the mobile station is located in the internal unit of the (10) eight system, the mobile station is usually programmed to view each of the nearby (ie, , internal and/or boundary) base station transmit signal transmission. Next, the trigger station determines which internal unit it is located by comparing the strength of the preamble transmitted by the station. For example, when the mobile station approaches the internal unit boundary, the mobile station assisted handover will be initiated by the method described in the aforementioned U.S. Patent No. 5,267,26. When the mobile station is located in the boundary unit <:1 eight to (:3 or eight) or (:18 to <::36), there are different situations. For example, considering that the ordering station is located in the unit Within C2A, but is approaching unit C2B. In this case, the mobile station will start receiving the available signal level from base station B 2 B. Then report to the base station B2B and any other base station that the mobile station is communicating. Determine the mobile station by measuring one or more measurable parameters of the received signal (eg, signal strength, noise ratio, frame erasure rate, bit error rate, and/or relative time delay) Or the base station receives the time of the signal level. This mechanism is similar to the US-specific ##&-20- mentioned above.

1279150 (16) Mechanisms published in 5,697,055. If both systems are CDMA systems, the handover between C2 A and C2B can be implemented using the handover mechanism published in U.S. Patent No. 5,697,055. However, there is a problem because there is currently no call handover mechanism for using the air interface from the CDMA network to the GS network. Since the CDMA mechanism cannot forward the data required to perform GSM authentication, GSM authentication cannot be completed. Encryption in GSM is different from encryption in CDMA. If you add a new message to the spatial interface that supports the Dual Modem, you must modify it to support these new messages. This is an undesired situation. The solution to this problem is to use a generic message containing instructions that can forward the mobile station from the CDMA network to the G S M network. Generic messages must be able to carry the information needed to perform G S Μ authentication and encryption. Preferably, the generic message should also support the addition function in G S Μ. In other words, the established GS Μ communication protocol must remain unchanged so that changes to existing GS Μ systems are minimized, and part of the handover operation includes the establishment of user identification and must be maintained once delivery has been implemented. Entity connection messaging and data confidentiality (encryption). The definition and operational requirements for user identification and authentication are provided in GSM 02.09. The authentication procedure is also used to set the encryption key. Therefore, the authentication procedure is performed after the network has established user identification and before the channel is encrypted. Two network functions are required to achieve this, namely, the authentication process itself, and the management of the system and the authentication key and encryption key. Keep in mind that the ideal situation is to use the ready-to-use tunnel channel (during handover and non-delivery situations) and may be one-way or

1279150 (17) Two-way. One of the tunneling mechanisms is the so-called ADDS (Application Data Delivery Service) message and short data burst message, which are used to pass GSM parameters in the CDMA system. These parameters are usually not It will be checked by the GSM base controller BSC, but is a parameter required for the dual mode mobile station. Using ADDS messages and data bursts together allows for the transfer of general packet bearers between the network's mobile services switching center (M S C) or other network elements (eg, SMS, azimuth location servers, OTASP). The system uses this approach to deliver GSM information end-to-end between the network and the mobile station without any changes to the CDMA BSCc or BTSc. In the network configuration shown in Figure 2, the ADDS message is used to transport G S Μ handover data (e.g., timing information and authentication data) from the MSCc to the mobile station via the BSCc. The mobile station then uses the so-called MAP (Mobile Application Protocol) message to transport the delivery data to the MSCg in the GSM network. This only requires a slight change in MSCg' which is able to interpret the data in the M A P message and control the mobile station accordingly. Of course, other data transfer alternatives are also available. When the mobile station is located at the boundary between the CDMA and GSM systems (eg, 'in cell C?A and is approaching cell C2B), the mobile station starts the parent hand handler by returning the message to MSCc. The MSCc notified that the mobile station should be handed over to the status of the multi-GS system. A unit library (not shown) can be used as part of the handover process. The database is used to provide basic information about the G S network to the mobile station, enabling the mobile station to perform CDMA MSC and GS 视 as needed.

Handover of 1279150 (18). In the G S Μ system, there are two types of handover available, namely synchronous and asynchronous. For ease of implementation, it is best to use asynchronous delivery. Therefore, the mobile station will be notified that it will be delivered to G S 非 in a non-synchronous manner. After the mobile station receives the handover command, the mobile station first transmits a little access burst to the GS Μ base station controller BSCg until the mobile station receives the MAP handover message sent back to the CDMA MSCc to promote Generate GS Μ authentication information and provide it to the mobile station. GS Μ has a non-synchronous handover procedure, in which data bursts can assist BSCg to obtain the timing of the mobile station. Therefore, ADDS contains an 'action time• message to specify when the handover will occur. The mobile station will only start the general transmission after it has received this information. Another problem with the handover between CDMA and GSM is that CDMA and GS authentication use two different methods and keys. G S Μ is basically the same as CDMA 1X, but the keys have different sizes. CDMA IX has additional procedures, such as the Unique Challenge and Count method, which are used to prevent channel interception and replay attacks, respectively. For the CDMA physical layer used in the GSM system, without the need to modify the GSM MSC'g ^ extensively, the 〇 S Μ authentication method should be reused on the CDM A physical layer. The advantage of this approach is that the system does not need to support two different types of authentication centers, two types of S Μ Μ 。 cards, and so on. Jian; fortune t sequence is composed of ^ lian exchange between Letong and the mobilization station. The system transmits the unpredictable number RAND to the mobile station. Next, the mobile station uses the algorithm for the A3 algorithm to calculate the result (also known as the signature of the RAND number). A3 algorithm uses raND and individual users -23 -

1279150 (19) Individual Subscriber Authentication Key Ki to calculate its SRES. The user authentication key Ki is configured when the customer first subscribes to the service, and is stored in the S[M (subscriber identity module) card and the system's home location register (HLR). ) w. K i is a private transmission in the encryption method and therefore will not be transmitted over the network. Finally, the mobile station transmits the signature SRES to the system, which is tested for its effectiveness.

Note that the encryption key and the authentication procedure specified for use are not related to the handover handler. Figure 4 of the accompanying drawings shows how authentication is performed in the GSM MSC. The authentication key in GSM is called K i and its length is 1 2 8 bits. The network generates a random number (RAND), which is also 128 bits in length. RAND and Ki are input to the A3 algorithm to calculate a 32-bit result (SRES) from the input data $. The RAND random number will also be transmitted to the mobile station by air message. In the GSM system, each mobile station contains a smart card, a so-called SIM (subscriber identity module) card. The S I Μ authentication command specified in GSM 11· 1 1 . These commands can only be executed if the command does not interfere with the correct operation of the g S Μ application. As defined in GSM 1 1.1, if the S IΜ is removed during a mobile station call, the call is terminated immediately. S[M in the mobile station also calculates SRES by applying the A3 algorithm to the received RAND random number and the Ki copy stored locally. The result of the calculation is again SRES and should be the same as the calculation result of the system. Therefore, the mobile station transmits the resulting SRES to the network, which is calculated by the network compared to the SRES value calculated for the network. If the SRES values are the same, the mobile station is true. In the system shown in Figure 2, the ADDS message is used to transmit the RAND random number on the air interface and the result SRES is returned. -twenty four-

1279150 The method of A8 is also used to calculate the encryption key Kc using SRES. The Kc key generated by the SIM in the mobile station by the GSM authentication and encryption algorithm is provided to the CDMA entity layer instead of the private long code mask (usually generated by the CDMA CAVE algorithm). . The 64-bit Kc key is uniquely mapped to a 42-bit private long code and serves as the basis for the "private long code mask" to provide voice privacy. The entire CDMA message will pass and interpret the private long code mask, and is the same as the private long code mask generated by the CAVE algorithm. In a hybrid CDMA/GSM network, this voice privacy practice allows the system to maintain a unique authentication center and a unique S IM type 0 G S to perform encryption at the frame level. The frame will be encrypted using the frame number and the 64-bit Kc key, where the key is derived from the discussion with reference to Figure 4. The frame number and K c mask are applied to all frames. In a CDMA IX system, a 42-bit private long code is used to perform encryption. In the hybrid system shown in Fig. 2, a corresponding algorithm correspondence method between the Kc gold input and the meta-private long code is used to derive a 42-bit private long code using Kc gold. This correspondence method is implemented in MSCc to directly inform B S C of the private long code to be used. ADDS operations allow for the unobstructed delivery of services between terrestrial communication network components (eg, 'MSC, SMS, PDC) and mobile stations. The system uses this job to pass the authentication information RAND to the MS, and to pass the SRES back to the MSC. The ADDS messaging job is moved from the MSCc to the BSCc and the paging channel is allowed to pass the data to the mobile station. The ADDS Transfer (Transfer) job is moved from the BSCc to the MSCc, and it is allowed to pass the pick-up frequency to the beak -25

1279150 (21) Transfer from the mobile station to the network. ADDS delivery (Deliver) job moved from MSCc to

BSCc, or move from BSCc to MSCc, and allows traffic channels to be transmitted between the mobile station and the network. The ADDS parameter has been defined as the "ADDS User Part", which contains the 6-bit "Data Burst Type" used to indicate the format of the application data message. The ADDS operation utilizes the "ADDS User Part" parameter to incorporate service-specific information. The authentication operation utilizes the "ADDS User Part" to carry the identification information. The illustrated system uses a new "material burst type", called ''GSM-MAP Authentication'', and the central mobile station interprets accordingly.

Please note that exemplary embodiments may be implemented whenever the receiving end has a repository for storing information related to the authentication handler, or when the receiving end has access to the database. The processor of the exemplary embodiment can be used to implement an encryption mechanism with one party, and another encryption mechanism with the other party. The basic implementation of the exemplary embodiments can be implemented without the need for an physical connection of intermediate resources, as communication between the parties is performed over the wireless medium. Those skilled in the art should understand that the various illustrative logic blocks, modules, circuits, and algorithm steps described in connection with the specific embodiments disclosed herein can be implemented as electronic hardware, computer software, or combinations thereof. The various illustrated components, blocks, modules, circuits, and steps have been described in terms of their function. The functionality is implemented as hardware or software, depending on the particular application and the design constraints that affect the overall system. Those skilled in the art should understand that it is possible to exchange hardware or software based on these conditions and how to best implement the instructions for each particular application. For example, you can use a dedicated integrated circuit (ASIC), a programmable -26 - 1279150, a follow-up page (22) planning logic, discrete gate or transistor logic, discrete firewall components (for example, Memory and FIFO), a processor that executes a set of firmware instructions, any traditional programmable programming software module and microprocessor, field programmable gate array (FPGA) or other programmable logic device (PLD), Or any combination of these to implement or perform the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the specific embodiments disclosed herein. The processor may be a microcontroller, but in the alternative, the processor may be any conventional processor, controller, microcontroller or state machine. The software module can reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPR0M memory, hard disk drive, removable disk, CD-ROM, DVD-ROM, scratchpad Or any other magnetic or optical storage medium. Those skilled in the art will further appreciate that the instructions, commands, information, signals, bits, symbols, and wafers referred to in the preceding specification facilitate the use of electricity, current, electromagnetic waves, magnetic fields, or particles, light fields, or particles. , or any group thereof will be represented. The present invention has been described with reference to the preferred embodiments thereof, but it is understood that the specific embodiments disclosed are only exemplary embodiments, and that various changes and modifications can be made without The spirit or scope of the present invention as defined in the accompanying claims is hereby incorporated. - Schematic representation of symbols 10 System controllers and switches 12,14,16,BlAtoB5A,BlBtoB5B Base station 1 8,40,53 Mobile station 1279150 (23) 20a,22a,24a,20b,22b,24b 30 MSCc MSCg

ClAtoCSA

ClBtoC5B 42.54 44.55 46.56 48.57 40,50 52,59 34 Communication Key Cellular Communication Network Coded Multi-Directional Proximity (CDMA) Action Center GS Μ Mobile Switching Center CDMA System Unit GSM System Unit Antenna Duplexer CDMA Transmission and Receive Chain GSM Transmission and reception chain baseband circuit controller intersystem data link

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Claims (1)

1279150 ... Patent Application No. 091135435|Hyun Or;· ί y JW - Patent Application Replacement (September 95: 'Picking, Patent Application Range: 1. A method for identifying a mobile station, where the mobile station Passing from a first base station controlled by a first mobile switching console in the first cellular communication system to a second base controlled by a second mobile switching console in a second, different cellular communication system Taiwan, the method includes: Generating an authentication code in the second cellular communication system, wherein the authentication code is generated by applying an algorithm to a private key assigned to the mobile station of the second cellular communication system and by the second The cellular communication system produces a random number result; the first cellular communication system generates an identification code, wherein the identification code generated is a result of applying an algorithm to the private key and the random number; Transmitting the authentication code generated by the first cellular communication system to a mobile station by using a data packet; Transmitting the authentication code generated in the first cellular communication system from the mobile station to the second cellular communication system; and comparing the authentication code generated in the first cellular communication system to the first The identification code generated by the two-cell communication system. 2. The method of claim 1, wherein: the first cellular communication system comprises a coded multi-directional proximity (CDMA) system; and the data packet comprises an ADDS message. 3. The method of claim 1, wherein: Year, > 1. The data packet includes an instruction to instruct the mobile station to remove the authentication code from the data packet; and the method further includes removing the authentication from the data packet at the mobile station code. 4. The method of claim 3, wherein the authentication code is transmitted to the second cellular communication system in a different data package. 5. The method of claim 4, wherein the second cellular communication system comprises a G S Μ system. 6. The method of claim 1, wherein the first cellular communication system comprises a first base station controlled by a first mobile switching console, and the second cellular communication system comprises a first cellular communication system a second base station controlled by the mobile switching console, the method comprising: measuring, at the mobile station, a parameter of a signal transmitted by the first base station; measuring, at the mobile station, transmitting by the second base station a parameter of the signal; when the parameter reaches a predetermined condition, transmitting a signal quality message from the mobile station to the first mobile switching console via the first base station; generating the Information of a channel request message of one of the second mobile switching consoles; communicating the information from the first mobile switching console to the mobile station; on the mobile station, from the first mobile switching console Information generates a channel request message for the second mobile switching console; and communicates the channel request message from the mobile station to the second mobile switching console. 7. The method of claim 6, further comprising generating channel information at the second mobile switching console for identifying a channel of the mobile station in the second mobile switching console. 8. The method of claim 7, further comprising establishing communication between the mobile station and the second base station in the identification channel. 9. The method of claim 8, further comprising cutting off communication between the mobile station and the second base station. 10. The method of claim 6, wherein the parameter corresponds to a signal strength. 11. A device in a system having a mobile station connected from a first base station controlled by a first mobile switching console in a first cellular communication system to a second a second base station controlled by a second mobile switching console in a different cellular communication system, the apparatus comprising: an authentication code generating component for generating an authentication code in the second cellular communication system, wherein the generating The authentication code is a result of applying an algorithm to a private key of the mobile station assigned to the second cellular communication system and a random number generated by the second cellular communication system; the authentication code generating component For generating an authentication code in the *cell type communication system, wherein the identification code generated is an algorithm applied a result of the private key and the random number; a transmission component for transmitting the authentication code generated in the first cellular communication system to a mobile station in a data packet; a transmission component for The identification code generated by the first cellular communication system is transmitted from the mobile station to the second cellular communication system; and a comparison component for comparing the identification code generated in the first cellular communication system The authentication code generated in the second cellular communication system. 12. The device of claim 11, wherein: the first cellular communication system comprises a CDMA system; and the data packet comprises an ADDS message. 13. The device of claim 11, wherein: the data packet includes an instruction to instruct the mobile station to remove the authentication code from the data packet; and the device further includes a removal component for The authentication code is removed from the data packet at the mobile station. 14. The apparatus of claim 13 wherein the authentication code is transmitted to the second cellular communication system in a different data package. 15. The device of claim 14, wherein the second cellular communication system comprises a G S system.