US20040219905A1 - Authentication of mobile devices via proxy device - Google Patents

Authentication of mobile devices via proxy device Download PDF

Info

Publication number
US20040219905A1
US20040219905A1 US10/836,056 US83605604A US2004219905A1 US 20040219905 A1 US20040219905 A1 US 20040219905A1 US 83605604 A US83605604 A US 83605604A US 2004219905 A1 US2004219905 A1 US 2004219905A1
Authority
US
United States
Prior art keywords
network
cellular
authentication
mobile terminal
mobile device
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
US10/836,056
Other versions
US7203482B2 (en
Inventor
Steven Blumenthal
Oliver Ibe
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Cisco Technology Inc
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to US10/836,056 priority Critical patent/US7203482B2/en
Publication of US20040219905A1 publication Critical patent/US20040219905A1/en
Assigned to BLUMENTHAL, STEVEN reassignment BLUMENTHAL, STEVEN ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: IBE, OLIVER C.
Application granted granted Critical
Publication of US7203482B2 publication Critical patent/US7203482B2/en
Assigned to KRAASTEN BROS. FUND B.V. LLC reassignment KRAASTEN BROS. FUND B.V. LLC ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: BLUMENTHAL, STEVEN, IBE, OLIVER C.
Assigned to OL SECURITY LIMITED LIABILITY COMPANY reassignment OL SECURITY LIMITED LIABILITY COMPANY MERGER (SEE DOCUMENT FOR DETAILS). Assignors: KRAASTEN BROS. FUND B.V. LLC
Assigned to INTELLECTUAL VENTURES ASSETS 9 LLC reassignment INTELLECTUAL VENTURES ASSETS 9 LLC ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: OL SECURITY LIMITED LIABILITY COMPANY
Assigned to CISCO TECHNOLOGY, INC. reassignment CISCO TECHNOLOGY, INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: CISCO SYSTEMS, INC.
Assigned to CISCO SYSTEMS, INC. reassignment CISCO SYSTEMS, INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: INTELLECTUAL VENTURES ASSETS 9 LLC
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W12/00—Security arrangements; Authentication; Protecting privacy or anonymity
    • H04W12/06—Authentication
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L63/00—Network architectures or network communication protocols for network security
    • H04L63/08—Network architectures or network communication protocols for network security for authentication of entities
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L63/00—Network architectures or network communication protocols for network security
    • H04L63/08—Network architectures or network communication protocols for network security for authentication of entities
    • H04L63/0884—Network architectures or network communication protocols for network security for authentication of entities by delegation of authentication, e.g. a proxy authenticates an entity to be authenticated on behalf of this entity vis-à-vis an authentication entity
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W12/00—Security arrangements; Authentication; Protecting privacy or anonymity
    • H04W12/03—Protecting confidentiality, e.g. by encryption
    • H04W12/033—Protecting confidentiality, e.g. by encryption of the user plane, e.g. user's traffic
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W80/00—Wireless network protocols or protocol adaptations to wireless operation
    • H04W80/04—Network layer protocols, e.g. mobile IP [Internet Protocol]
    • H04W80/045—Network layer protocols, e.g. mobile IP [Internet Protocol] involving different protocol versions, e.g. MIPv4 and MIPv6
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W84/00—Network topologies
    • H04W84/02—Hierarchically pre-organised networks, e.g. paging networks, cellular networks, WLAN [Wireless Local Area Network] or WLL [Wireless Local Loop]
    • H04W84/04—Large scale networks; Deep hierarchical networks
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W84/00—Network topologies
    • H04W84/02—Hierarchically pre-organised networks, e.g. paging networks, cellular networks, WLAN [Wireless Local Area Network] or WLL [Wireless Local Loop]
    • H04W84/10—Small scale networks; Flat hierarchical networks
    • H04W84/12—WLAN [Wireless Local Area Networks]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
    • H04W88/02—Terminal devices
    • H04W88/06—Terminal devices adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Definitions

  • a mobile communication network generally uses strong digital cryptographic mechanisms to authenticate a mobile station (MS) (handset device, laptop computer, or personal digital assistant (PDA)) before it can be permitted to operate in the network. It may also require the MS to encrypt voice and data traffic sent over the radio interface.
  • MS mobile station
  • PDA personal digital assistant
  • Mechanisms such as Subscriber Identity Modules (SIM) cards and cellular authentication and voice encryption (CAVE) algorithm are used for GSM, CDMA or IDEN cell phones and other devices that operate in these networks. These mechanisms can also be used to authenticate these devices on private networks.
  • SIM Subscriber Identity Modules
  • CAVE cellular authentication and voice encryption
  • Cryptographic methods are used to authenticate a MS to the service provider's network and to encrypt voice and data traffic.
  • ANSI-41 standards which are used in IS-136 and IS-95 networks, use shared secret keys where the key is loaded into the mobile station and also kept at the authentication center associated with the home location register (HLR) of the mobile user's billing service provider.
  • HLR home location register
  • VLR visitor location register
  • the VLR can be associated with the user's service provider or it can be owned by another service provider. Communication between the HLR and VLR usually occurs over packet switched Signaling System 7 (SS7) networks via the roaming arrangements between the carriers, if the home network and the visited network belong to different carriers. Otherwise, it occurs over the carrier's private internal data network.
  • SS7 packet switched Signaling System 7
  • the ANSI-41 mechanism to register a MS with a service provider uses the cellular authentication and voice encryption (CAVE) algorithm to produce an authentication result (AUTHR) to be sent to the authentication system of its HLR.
  • the CAVE algorithm uses as inputs the equipment serial number (ESN) installed in the phone by the manufacturer, the mobile identification number (MIN) (in North America MIN is usually the phone number) installed at the time the device is sold and first brought into service on the service provider's network, the shared secret data (SSD) that are installed in the MS and also kept at the service provider's authentication center (AC) associated with the HLR, and a random number provided to the MS by the service provider.
  • the AUTHR is received by the authentication center and if it matches the AUTHR that it computed using the CAVE algorithm with the same set of input parameters, the user is allowed to register with the service provider's network and use their mobile device.
  • the MS also uses the MIN, ESN, SSD and a random number from the carrier network to produce a voice privacy mask (VPMASK) and a signaling message encryption key (SMEKEY).
  • VPMASK voice privacy mask
  • SMEKEY signaling message encryption key
  • the VPMASK and SMEKEY are also computed by the authentication center associated with the HLR and the results are compared with those of the MS.
  • the VPMASK is used to encrypt voice over the radio channel between the MS and the nearest service provider system.
  • the SMEKEY is used to encrypt certain fields of signaling messages between the MS and the nearest service provider system.
  • the authentication mechanism for GSM systems is similar to that of ANSI-41 systems except that GSM stores the secret key and the authentication algorithm in a subscriber identity module (SIM) smart card.
  • SIM subscriber identity module
  • the SIM is designed to be tamper-proof and contains data and algorithms that cannot be easily read out by a user.
  • the MS and HLR perform similar calculations using the same algorithm A 3 and encryption variables K i and a random number from the service provider's network to produce a signed result (SRES).
  • SRESs are compared and if they match, the MS is authenticated and admitted into the network. This comparison is typically performed by the serving Mobile Switching Center (MSC), though other devices along the path can also do this comparison.
  • MSC serving Mobile Switching Center
  • One of the outputs of another authentication algorithm A 8 is an encryption key K c that is fed into an encrypter and decrypter using algorithm A 5 to encode the voice or data stream.
  • K i , A 3 , A 5 , and A 8 are variables that are all contained in the SIM smart card.
  • a new class of devices that operate on public or private cellular networks using GSM, CDMA, or IDEN in one mode of operation and on public or private IEEE 802.11 wireless local area networks (LANs) in another mode of operation is being introduced.
  • the invention features a mechanism to permit the cryptographic authentication of the mobile device in the cellular carrier's network when the device is present in the 802.11 network, wireless LAN, served by a Cellular Controller and not connected directly to the cellular carrier's network via a radio link.
  • the Cellular Controller acts as a proxy for the mobile device when the device is in a building served by an 802.11 wireless LAN
  • the invention features separation of a mobile device's radio function from its ANSI-41 authentication mechanism to permit the proxy function to work and to not have to duplicate the ANSI-41 authentication data and CAVE algorithm.
  • the invention features separation of a mobile device's radio function from its GSM SIM module to permit the proxy function to work and to not have to duplicate the SIM module.
  • UDP user datagram protocol
  • TCP transmission control protocol
  • FIG. 1 is a block diagram showing of an architecture of an exemplary network, according to the present invention.
  • FIG. 2 is a message flow diagram illustrating authentication of a mobile station (MS) on a cellular according to the present invention.
  • FIG. 3 is a message flow diagram illustrating authentication of a mobile station (MS) on a cellular according to another embodiment of the present invention.
  • the Cellular Controller permits mobile devices (also known as mobile terminals, mobile stations) to operate inside a building or some other defined area that has 802.11 wireless local area network coverage in the 802.11 wireless mode and to be present on the cellular carrier's network via a radio proxy for the that mobile device.
  • the radio proxy of the device that exists in the Cellular Controller behaves to the cellular carrier's network exactly as the device would behave if the real one was connected to the carrier's network. That is, the Cellular Controller emulates the mobile device
  • FIG. 1 An architecture of an exemplary network is shown in FIG. 1.
  • a subscriber cell phone, PDA, laptop
  • the device's default operation is the 802.11 mode and therefore the cellular radio of the mobile device is turned off.
  • the Cellular Controller creates a proxy for the user's mobile device in the cellular carrier's network (cellular WANs). This proxy authenticates the user on the cellular carrier's network and then sends and receives calls and data messages to and from the cellular carrier's network on behalf of the user.
  • the Cellular Controller works with the Control Server in the enterprise's LAN to locate the user in the building and to determine which 802.11 Access Point is serving the user.
  • the Cellular Controller When the Cellular Controller receives a call from the cellular carrier network that is destined for a mobile device it is proxying for, it uses the Session Initiation Protocol (SIP)-based voice over IP (VoIP) to forward the call via the corporate LAN to the mobile device.
  • SIP Session Initiation Protocol
  • VoIP voice over IP
  • voice and data messages that originate at the mobile device operating in 802.11 WLAN mode use SIP to set up a call to the Cellular Controller, if it is intended to be transmitted out of the building over the cellular carrier's network.
  • the device uses VoIP over WLAN to transmit the voice packets over the wireless LAN infrastructure where it is received by the Access Point and forwarded to the Cellular Controller over the wired LAN infrastructure.
  • the Cellular Controller converts the packet into the appropriate format for transmission over the cellular network.
  • a dual-mode mobile device When a dual-mode mobile device is turned on in the 802.11 mode inside the building served by the Cellular Controller, it goes through an enterprise registration process with the Control Server to determine if it is allowed to use the 802.11 wireless LAN. If it is an allowed device then the Control Server instructs the Cellular Controller to set up a cell phone proxy for this dual-mode mobile device in the CDMA network for which the user is a subscriber.
  • the Cellular Controller requests that the cellular carrier network send it a Random (RAND) number to initiate the authentication process.
  • the Cellular Controller opens a TCP connection to the mobile device over the enterprise's wired and wireless LAN and transmits RAND to the mobile using TCP/IP.
  • the mobile device receives the RAND and uses it along with its SSD, MIN and ESN to run the CAVE algorithm. It then sends the authentication result (AUTHR) back to the Cellular Controller over the wired and wireless LAN using TCP/IP.
  • the Cellular Controller strips off the TCP/IP headers and transmits the AUTHR back to the cellular carrier network on behalf of the mobile device for which it is proxying. If the AUTHR matches the calculation made by the authentication center inside the cellular carrier's network, the user is authenticated and the proxy is allowed to send and receive calls on the cellular carrier network on behalf of the mobile device that is operating in the 802.11 network.
  • Authentication of a mobile station (MS) with an ANSI-41 (CDMA or IDEN) cellular network involves additional steps.
  • To authenticate a mobile station operating on an 802.11 wireless local area network on an ANSI-41 wide area cellular network using a cellular proxy server such as the Cellular Controller there is a separation of the over-the-air radio portion of the mobile station from its authentication mechanism.
  • the Cellular Controller sends and receives authentication messages on behalf of the mobile station and then passes them onto to the mobile station using TCP/IP protocols over the internal wired and wireless local area networks.
  • the mobile station receives these TCP/IP encapsulated messages, strips off the TCP/IP headers and then passes the message content to the CAVE authentication mechanism in the mobile station.
  • FIG. 2 is a message flow diagram that summarizes the above procedure. The messages in the figure represent actions taken rather than the exact messages exchanged.
  • a dual-mode mobile device When a dual-mode mobile device is turned on in the 802.11 mode inside the building served by the Cellular Controller, it goes through an enterprise registration process with the Cellular Controller to determine if it is allowed to use the 802.11 wireless LAN. If it is an allowed device then the Cellular Controller sets up a cell phone proxy for this dual mode mobile device on the GSM network in which the user is a subscriber using the user's personal identification number (PIN) that is registered with the Cellular Controller during the mobile device's registration in the WLAN. The Cellular Controller requests that the cellular carrier network initiate the authentication process. The Cellular Controller opens a TCP connection to the mobile device over the enterprise's wired and wireless LAN and transmits the RAND to the mobile device using TCP/IP.
  • PIN personal identification number
  • the mobile device receives the RAND and uses it along with its secret key K i to run the A 3 algorithm through its SIM module. It then sends the signed result (SRES) back to the Cellular Controller over the wired and wireless LAN via a TCP connection.
  • the Cellular Controller strips off the TCP/IP headers and transmits the SRES back to the cellular carrier network on behalf of the mobile device for which it is proxying. If the SRES matches the calculation made by the authentication center inside the cellular carrier's network, the user is authenticated and the proxy is allowed to send and receive calls on the cellular carrier network on behalf mobile device that is operating in the 802.11 network.
  • the RAND received by the mobile device over the 802.11 wireless LAN is passed to the A 8 algorithm associated with the SIM module and used to compute K c , an encryption key used to encrypt voice and data messages sent over the cellular carrier's network.
  • the mobile device generates encrypted data, which is then packetized and transmitted over the wireless and wired LAN using UDP/IP for the voice traffic and TCP/IP for the data messages to the Cellular Controller.
  • the Cellular Controller strips off the UDP/IP and TCP/IP headers and sends the encrypted bits over the GSM channel to the cellular carrier's network.
  • a similar reverse process receives encrypted voice and data from the cellular carrier network at the Cellular Controller, packetize the data, and then encapsulates it in either UDP/IP or TCP/IP for transmission to the mobile device over the enterprise's wired and wireless LAN infrastructure.
  • the over-the-air radio portion of the mobile station is separately handled from its authentication mechanism.
  • the Cellular Controller sends and receives authentication messages on behalf of the mobile station and then passes them onto to the mobile station using TCP/IP protocols over the internal wired and wireless local area networks.
  • the mobile station receives these TCP/IP encapsulated messages, strips off the TCP/IP headers and then passes the message content to the SIM module authentication mechanism in the mobile station.
  • the results are sent back to the Cellular Controller over the internal wireless and wired local area networks using TCP/IP protocols.
  • the Cellular Controller strips off the TCP/IP headers and using its radio passes the messages back over-the-air to the GSM cellular network. To the GSM cellular network, this exchange looks like its normal authentication exchange with a mobile station.
  • FIG. 3 is a message flow diagram that summarizes the above procedure. The messages in the figure represent actions taken rather than the exact messages exchanged.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Security & Cryptography (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Computer Hardware Design (AREA)
  • Computing Systems (AREA)
  • General Engineering & Computer Science (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

A mechanism to permit the cryptographic authentication of a mobile device in the cellular carrier's network when the device is present in the 802.11 network, wireless LAN, served by a Cellular Controller and not connected directly to the cellular carrier's network via a radio link is disclosed. The Cellular Controller acts as a proxy for the mobile device when the device is in a building served by an 802.11 wireless LAN. The solutions features the separation of a mobile device's radio function from its ANSI-41 authentication mechanism to permit the proxy function to work and to not have to duplicate the ANSI-41 authentication data and CAVE algorithm.

Description

    RELATED APPLICATIONS
  • This application is claims the benefit of the filing date of Provisional Appl. Nos. 60/467,822 and 60/467,430, filed on May, 5, 2003, under 35 U.S.C. 119(e), both of which applications are incorporated herein by this reference in their entirety. [0001]
  • This application relates to U.S. patent application Ser. No. ______ filed concurrently herewith, by the same inventors, entitled Data Handoff Method Between Wireless Local Area Network and Wireless Wide Area Network, which is incorporated herein in its entirety by this reference.[0002]
    • BACKGROUND OF THE INVENTION
  • A mobile communication network generally uses strong digital cryptographic mechanisms to authenticate a mobile station (MS) (handset device, laptop computer, or personal digital assistant (PDA)) before it can be permitted to operate in the network. It may also require the MS to encrypt voice and data traffic sent over the radio interface. Mechanisms such as Subscriber Identity Modules (SIM) cards and cellular authentication and voice encryption (CAVE) algorithm are used for GSM, CDMA or IDEN cell phones and other devices that operate in these networks. These mechanisms can also be used to authenticate these devices on private networks. [0003]
  • Cryptographic methods are used to authenticate a MS to the service provider's network and to encrypt voice and data traffic. ANSI-41 standards, which are used in IS-136 and IS-95 networks, use shared secret keys where the key is loaded into the mobile station and also kept at the authentication center associated with the home location register (HLR) of the mobile user's billing service provider. There are also mechanisms that allow these secret keys to be shared with the visitor location register (VLR) of a visited network. The VLR can be associated with the user's service provider or it can be owned by another service provider. Communication between the HLR and VLR usually occurs over packet switched Signaling System 7 (SS7) networks via the roaming arrangements between the carriers, if the home network and the visited network belong to different carriers. Otherwise, it occurs over the carrier's private internal data network. [0004]
  • The ANSI-41 mechanism to register a MS with a service provider uses the cellular authentication and voice encryption (CAVE) algorithm to produce an authentication result (AUTHR) to be sent to the authentication system of its HLR. The CAVE algorithm uses as inputs the equipment serial number (ESN) installed in the phone by the manufacturer, the mobile identification number (MIN) (in North America MIN is usually the phone number) installed at the time the device is sold and first brought into service on the service provider's network, the shared secret data (SSD) that are installed in the MS and also kept at the service provider's authentication center (AC) associated with the HLR, and a random number provided to the MS by the service provider. The AUTHR is received by the authentication center and if it matches the AUTHR that it computed using the CAVE algorithm with the same set of input parameters, the user is allowed to register with the service provider's network and use their mobile device. [0005]
  • There is also a mechanism to encrypt voice and data transmissions over the wireless channel. In this case in addition to using the CAVE algorithm to produce the AUTHR, the MS also uses the MIN, ESN, SSD and a random number from the carrier network to produce a voice privacy mask (VPMASK) and a signaling message encryption key (SMEKEY). The VPMASK and SMEKEY are also computed by the authentication center associated with the HLR and the results are compared with those of the MS. The VPMASK is used to encrypt voice over the radio channel between the MS and the nearest service provider system. The SMEKEY is used to encrypt certain fields of signaling messages between the MS and the nearest service provider system. [0006]
  • The authentication mechanism for GSM systems is similar to that of ANSI-41 systems except that GSM stores the secret key and the authentication algorithm in a subscriber identity module (SIM) smart card. The SIM is designed to be tamper-proof and contains data and algorithms that cannot be easily read out by a user. [0007]
  • To authenticate a user, the MS and HLR perform similar calculations using the same algorithm A[0008] 3 and encryption variables Ki and a random number from the service provider's network to produce a signed result (SRES). The SRESs are compared and if they match, the MS is authenticated and admitted into the network. This comparison is typically performed by the serving Mobile Switching Center (MSC), though other devices along the path can also do this comparison. One of the outputs of another authentication algorithm A8 is an encryption key Kc that is fed into an encrypter and decrypter using algorithm A5 to encode the voice or data stream. Ki, A3, A5, and A8 are variables that are all contained in the SIM smart card.
  • A new class of devices that operate on public or private cellular networks using GSM, CDMA, or IDEN in one mode of operation and on public or private IEEE 802.11 wireless local area networks (LANs) in another mode of operation is being introduced. [0009]
    • SUMMARY OF THE INVENTION
  • In a general aspect, the invention features a mechanism to permit the cryptographic authentication of the mobile device in the cellular carrier's network when the device is present in the 802.11 network, wireless LAN, served by a Cellular Controller and not connected directly to the cellular carrier's network via a radio link. The Cellular Controller acts as a proxy for the mobile device when the device is in a building served by an 802.11 wireless LAN [0010]
  • In another aspect, the invention features separation of a mobile device's radio function from its ANSI-41 authentication mechanism to permit the proxy function to work and to not have to duplicate the ANSI-41 authentication data and CAVE algorithm. [0011]
  • In another aspect, the invention features separation of a mobile device's radio function from its GSM SIM module to permit the proxy function to work and to not have to duplicate the SIM module. [0012]
  • Communication between the Cellular Controller, which contains the radio function and acts as a proxy for the mobile device on the cellular carriers while the device is operating on the 802.11 wireless LAN, and the mobile device in the wireless LAN can use user datagram protocol (UDP) to carry encrypted voice and data messages and transmission control protocol (TCP) to carry authentication messages. [0013]
  • The above and other features of the invention including various novel details of construction and combinations of parts, and other advantages, will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular method and device embodying the invention are shown by way of illustration and not as a limitation of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention.[0014]
    • BRIEF DESCRIPTION OF THE DRAWINGS
  • In the accompanying drawings, reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale; emphasis has instead been placed upon illustrating the principles of the invention. Of the drawings: [0015]
  • FIG. 1 is a block diagram showing of an architecture of an exemplary network, according to the present invention; [0016]
  • FIG. 2 is a message flow diagram illustrating authentication of a mobile station (MS) on a cellular according to the present invention; and [0017]
  • FIG. 3 is a message flow diagram illustrating authentication of a mobile station (MS) on a cellular according to another embodiment of the present invention.[0018]
    • DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
  • Provisional patent application serial No. 60/419,674 titled “Method of Seamless Roaming Between Wi-Fi Network and Cellular Network” and U.S. patent application Ser. No. 10/668,608, filed Oct. 17, 2003, entitled “Method of Seamless Roaming Between Wireless Local Area Networks and Cellular Carrier Networks”, which are incorporated herein in their entirely by this reference, describe a Cellular Controller device that connects the 802.11 wireless local area network to the cellular carrier's network. [0019]
  • The Cellular Controller permits mobile devices (also known as mobile terminals, mobile stations) to operate inside a building or some other defined area that has 802.11 wireless local area network coverage in the 802.11 wireless mode and to be present on the cellular carrier's network via a radio proxy for the that mobile device. The radio proxy of the device that exists in the Cellular Controller behaves to the cellular carrier's network exactly as the device would behave if the real one was connected to the carrier's network. That is, the Cellular Controller emulates the mobile device [0020]
  • An architecture of an exemplary network is shown in FIG. 1. When a subscriber (cell phone, PDA, laptop) with a dual mode mobile device is in the building (corporate LAN) controlled by the Cellular Controller, the device's default operation is the 802.11 mode and therefore the cellular radio of the mobile device is turned off. The Cellular Controller creates a proxy for the user's mobile device in the cellular carrier's network (cellular WANs). This proxy authenticates the user on the cellular carrier's network and then sends and receives calls and data messages to and from the cellular carrier's network on behalf of the user. The Cellular Controller works with the Control Server in the enterprise's LAN to locate the user in the building and to determine which 802.11 Access Point is serving the user. [0021]
  • When the Cellular Controller receives a call from the cellular carrier network that is destined for a mobile device it is proxying for, it uses the Session Initiation Protocol (SIP)-based voice over IP (VoIP) to forward the call via the corporate LAN to the mobile device. Similarly, voice and data messages that originate at the mobile device operating in 802.11 WLAN mode use SIP to set up a call to the Cellular Controller, if it is intended to be transmitted out of the building over the cellular carrier's network. The device then uses VoIP over WLAN to transmit the voice packets over the wireless LAN infrastructure where it is received by the Access Point and forwarded to the Cellular Controller over the wired LAN infrastructure. The Cellular Controller converts the packet into the appropriate format for transmission over the cellular network. [0022]
  • When a dual-mode mobile device is turned on in the 802.11 mode inside the building served by the Cellular Controller, it goes through an enterprise registration process with the Control Server to determine if it is allowed to use the 802.11 wireless LAN. If it is an allowed device then the Control Server instructs the Cellular Controller to set up a cell phone proxy for this dual-mode mobile device in the CDMA network for which the user is a subscriber. The Cellular Controller requests that the cellular carrier network send it a Random (RAND) number to initiate the authentication process. The Cellular Controller opens a TCP connection to the mobile device over the enterprise's wired and wireless LAN and transmits RAND to the mobile using TCP/IP. The mobile device receives the RAND and uses it along with its SSD, MIN and ESN to run the CAVE algorithm. It then sends the authentication result (AUTHR) back to the Cellular Controller over the wired and wireless LAN using TCP/IP. The Cellular Controller strips off the TCP/IP headers and transmits the AUTHR back to the cellular carrier network on behalf of the mobile device for which it is proxying. If the AUTHR matches the calculation made by the authentication center inside the cellular carrier's network, the user is authenticated and the proxy is allowed to send and receive calls on the cellular carrier network on behalf of the mobile device that is operating in the 802.11 network. [0023]
  • Authentication of a mobile station (MS) with an ANSI-41 (CDMA or IDEN) cellular network involves additional steps. To authenticate a mobile station operating on an 802.11 wireless local area network on an ANSI-41 wide area cellular network using a cellular proxy server such as the Cellular Controller, there is a separation of the over-the-air radio portion of the mobile station from its authentication mechanism. The Cellular Controller sends and receives authentication messages on behalf of the mobile station and then passes them onto to the mobile station using TCP/IP protocols over the internal wired and wireless local area networks. The mobile station receives these TCP/IP encapsulated messages, strips off the TCP/IP headers and then passes the message content to the CAVE authentication mechanism in the mobile station. The results are sent back to the Cellular Controller over the internal wireless and wired local area networks using TCP/IP protocols. The Cellular Controller strips off the TCP/IP headers and, using its radio, passes the messages back over-the-air to the ANSI-41 cellular network. To the ANSI-41 cellular network, this exchange looks like its normal authentication exchange with a mobile station. FIG. 2 is a message flow diagram that summarizes the above procedure. The messages in the figure represent actions taken rather than the exact messages exchanged. [0024]
  • Authentication on a GSM network involves additional steps. [0025]
  • When a dual-mode mobile device is turned on in the 802.11 mode inside the building served by the Cellular Controller, it goes through an enterprise registration process with the Cellular Controller to determine if it is allowed to use the 802.11 wireless LAN. If it is an allowed device then the Cellular Controller sets up a cell phone proxy for this dual mode mobile device on the GSM network in which the user is a subscriber using the user's personal identification number (PIN) that is registered with the Cellular Controller during the mobile device's registration in the WLAN. The Cellular Controller requests that the cellular carrier network initiate the authentication process. The Cellular Controller opens a TCP connection to the mobile device over the enterprise's wired and wireless LAN and transmits the RAND to the mobile device using TCP/IP. The mobile device receives the RAND and uses it along with its secret key K[0026] i to run the A3 algorithm through its SIM module. It then sends the signed result (SRES) back to the Cellular Controller over the wired and wireless LAN via a TCP connection. The Cellular Controller strips off the TCP/IP headers and transmits the SRES back to the cellular carrier network on behalf of the mobile device for which it is proxying. If the SRES matches the calculation made by the authentication center inside the cellular carrier's network, the user is authenticated and the proxy is allowed to send and receive calls on the cellular carrier network on behalf mobile device that is operating in the 802.11 network.
  • If voice and signaling encryption is used in the cellular carrier's network, then the RAND received by the mobile device over the 802.11 wireless LAN is passed to the A[0027] 8 algorithm associated with the SIM module and used to compute Kc, an encryption key used to encrypt voice and data messages sent over the cellular carrier's network. In this case, the mobile device generates encrypted data, which is then packetized and transmitted over the wireless and wired LAN using UDP/IP for the voice traffic and TCP/IP for the data messages to the Cellular Controller. The Cellular Controller strips off the UDP/IP and TCP/IP headers and sends the encrypted bits over the GSM channel to the cellular carrier's network. A similar reverse process receives encrypted voice and data from the cellular carrier network at the Cellular Controller, packetize the data, and then encapsulates it in either UDP/IP or TCP/IP for transmission to the mobile device over the enterprise's wired and wireless LAN infrastructure.
  • To authenticate a mobile station operating on an 802.11 wireless local area network on an GSM wide area cellular network using a cellular proxy server such as the Cellular Controller, the over-the-air radio portion of the mobile station is separately handled from its authentication mechanism. The Cellular Controller sends and receives authentication messages on behalf of the mobile station and then passes them onto to the mobile station using TCP/IP protocols over the internal wired and wireless local area networks. The mobile station receives these TCP/IP encapsulated messages, strips off the TCP/IP headers and then passes the message content to the SIM module authentication mechanism in the mobile station. The results are sent back to the Cellular Controller over the internal wireless and wired local area networks using TCP/IP protocols. The Cellular Controller strips off the TCP/IP headers and using its radio passes the messages back over-the-air to the GSM cellular network. To the GSM cellular network, this exchange looks like its normal authentication exchange with a mobile station. [0028]
  • FIG. 3 is a message flow diagram that summarizes the above procedure. The messages in the figure represent actions taken rather than the exact messages exchanged. [0029]
  • While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims. [0030]

Claims (8)

What is claimed is:
1. A method comprising:
emulating a mobile terminal, or a group of mobile terminals on a wide area wireless network using a fixed radio terminal; and
establishing a communication path passing from the wide area wireless network through the fixed radio terminal over a local network to the mobile terminal or group of mobile terminals.
2. The method of claim 1 wherein the step of emulating the mobile terminal includes passing authentication data between the wide area wireless network and the mobile terminal over the local network.
3. The method of claim 1 further comprising hosting functions of an ANSI-41 authentication mechanism at the mobile terminal.
4. The method of claim 1 further comprising hosting functions of a GSM authentication mechanism at the mobile terminal.
5. The method of claim 1 further comprising passing voice or data communication between the mobile terminal and the wide area wireless network over the established communication path.
6. The method of claim 1 further comprising hosting voice or data encryption functions at the mobile terminal for processing the voice communication.
7. The method of claim 6 wherein the step of hosting the voice or data encryption functions at the mobile terminal includes hosting a CAVE algorithm.
8. The method of claim 6 wherein step of hosting the voice or data encryption functions at the mobile terminal includes hosting a GSM algorithm.
US10/836,056 2003-05-02 2004-04-30 Authentication of mobile devices via proxy device Expired - Lifetime US7203482B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US10/836,056 US7203482B2 (en) 2003-05-02 2004-04-30 Authentication of mobile devices via proxy device

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US46782203P 2003-05-02 2003-05-02
US46743003P 2003-05-02 2003-05-02
US10/836,056 US7203482B2 (en) 2003-05-02 2004-04-30 Authentication of mobile devices via proxy device

Publications (2)

Publication Number Publication Date
US20040219905A1 true US20040219905A1 (en) 2004-11-04
US7203482B2 US7203482B2 (en) 2007-04-10

Family

ID=33314275

Family Applications (1)

Application Number Title Priority Date Filing Date
US10/836,056 Expired - Lifetime US7203482B2 (en) 2003-05-02 2004-04-30 Authentication of mobile devices via proxy device

Country Status (1)

Country Link
US (1) US7203482B2 (en)

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050099981A1 (en) * 2003-09-26 2005-05-12 Welmin Liu HRPD network access authentication method based on CAVE algorithm
US20060046693A1 (en) * 2004-08-31 2006-03-02 Hung Tran Wireless local area network (WLAN) authentication method, WLAN client and WLAN service node (WSN)
US20060092872A1 (en) * 2004-11-04 2006-05-04 Samsung Electronics Co., Ltd. Communication method and apparatus using heterogeneous neighbor base station information in a broadband wireless access communication system
JP2006197536A (en) * 2004-12-15 2006-07-27 Matsushita Electric Ind Co Ltd Radio network control device, radio lan relay device, radio communication system, and communication method for radio communication system
US20070058788A1 (en) * 2005-08-22 2007-03-15 Nortel Networks Limited Multimedia subsystem service control for circuit-switched subsystem calls
WO2008127877A1 (en) * 2007-04-11 2008-10-23 Cisco Technology, Inc. Gw coupled sip proxy
US20090046703A1 (en) * 2007-08-13 2009-02-19 Cisco Technology, Inc. Using an ip registration to automate sip registration
US20090104891A1 (en) * 2006-06-24 2009-04-23 Guiming Shu Access method of network terminals, access system and gateway
US20090172802A1 (en) * 2007-12-31 2009-07-02 Sandisk Corporation Local proxy system and method
US20090207843A1 (en) * 2008-02-15 2009-08-20 Andreasen Flemming S System and method for providing network address translation control in a network environment
US20100150003A1 (en) * 2008-12-12 2010-06-17 Cisco Technology, Inc. System and Method for Provisioning Charging and Policy Control in a Network Environment
US20100290390A1 (en) * 2009-05-15 2010-11-18 Novatel Wireless Inc. Systems and methods for controlling device network access through a wireless router
US20100290442A1 (en) * 2009-05-15 2010-11-18 Novatel Wireless Inc. Systems and methods for automatic connection with a wireless network
US20110107248A1 (en) * 2008-04-04 2011-05-05 Zumtobel Lighting Gmbh Computer-aided System for Managing and/or Controlling a Building Management System
US8180338B1 (en) 2006-06-14 2012-05-15 Genband Us Llc Selective call anchoring in a multimedia subsystem
US8195778B1 (en) 2009-12-19 2012-06-05 Cisco Technology, Inc. System and method for providing mobility across access technologies in a network environment
US20130007869A1 (en) * 2011-06-29 2013-01-03 Renjit Tom Thomas Method and system for automatic recovery from lost security token on embedded device
US8600006B2 (en) 2006-12-27 2013-12-03 Genband Us Llc Voice continuity among user terminals
US8644298B1 (en) 2007-09-12 2014-02-04 Genband Us Llc Adding a service control channel after session establishment
US8811954B1 (en) 2005-10-31 2014-08-19 Genband Us Llc Network domain selection
US9008005B2 (en) 2009-04-27 2015-04-14 Cisco Technology, Inc. System and method for providing intelligent gateway selection in a network environment
US9215588B2 (en) 2010-04-30 2015-12-15 Cisco Technology, Inc. System and method for providing selective bearer security in a network environment
US11197165B2 (en) 2019-12-16 2021-12-07 Cisco Technology, Inc. Automated neighbor frequency provisioning in private 3GPP networks

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8140845B2 (en) * 2001-09-13 2012-03-20 Alcatel Lucent Scheme for authentication and dynamic key exchange
US7835751B2 (en) * 2002-10-18 2010-11-16 Ibe Oliver C Method of seamless roaming between wireless local area networks and cellular carrier networks
FR2872376A1 (en) * 2004-06-24 2005-12-30 France Telecom METHOD AND DEVICE FOR CONTROLLING WIRELESS ACCESS TO TELEMATIC AND VOICE SERVICES
KR100666943B1 (en) * 2005-01-11 2007-01-11 삼성전자주식회사 Method and apparatus for reducing power consumption of composite wireless terminal
SG152087A1 (en) * 2007-10-22 2009-05-29 Roam Over Ip Pte Ltd Method, system and apparatus for providing a carrier- independent international telecommunications roaming service

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020191635A1 (en) * 2001-06-14 2002-12-19 Chow Albert T. Broadband network with enterprise wireless communication method for residential and business environment
US20030134638A1 (en) * 2002-01-02 2003-07-17 Rangamani Sundar Method, system and apparatus for providing mobility management of a mobile station in WLAN and WWAN environments
US20030202486A1 (en) * 2002-04-29 2003-10-30 Hereuare Communications, Inc. Method and system for simulating multiple independent client devices in a wired or wireless network
US20040072593A1 (en) * 2002-10-10 2004-04-15 Robbins Barry R. Extension of a local area phone system to a wide area network
US20040105434A1 (en) * 2002-08-19 2004-06-03 Allan Baw EtherCell
US20040203800A1 (en) * 2002-10-24 2004-10-14 John Myhre System and method for content delivery using alternate data paths in a wireless network
US20050031124A1 (en) * 2003-04-02 2005-02-10 Nikhil Jain Ciphering between a CDMA network and a GSM network

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020191635A1 (en) * 2001-06-14 2002-12-19 Chow Albert T. Broadband network with enterprise wireless communication method for residential and business environment
US20030134638A1 (en) * 2002-01-02 2003-07-17 Rangamani Sundar Method, system and apparatus for providing mobility management of a mobile station in WLAN and WWAN environments
US20030202486A1 (en) * 2002-04-29 2003-10-30 Hereuare Communications, Inc. Method and system for simulating multiple independent client devices in a wired or wireless network
US20040105434A1 (en) * 2002-08-19 2004-06-03 Allan Baw EtherCell
US20040072593A1 (en) * 2002-10-10 2004-04-15 Robbins Barry R. Extension of a local area phone system to a wide area network
US20040203800A1 (en) * 2002-10-24 2004-10-14 John Myhre System and method for content delivery using alternate data paths in a wireless network
US20050031124A1 (en) * 2003-04-02 2005-02-10 Nikhil Jain Ciphering between a CDMA network and a GSM network

Cited By (47)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090190562A1 (en) * 2003-09-26 2009-07-30 Samsung Electronics Co., Ltd. Hrpd network access authentication method based on cave algorithm
US7630345B2 (en) * 2003-09-26 2009-12-08 Samsung Electronics Co., Ltd HRPD network access authentication method based on CAVE algorithm
US20050099981A1 (en) * 2003-09-26 2005-05-12 Welmin Liu HRPD network access authentication method based on CAVE algorithm
US7990930B2 (en) 2003-09-26 2011-08-02 Samsung Electronics Co., Ltd. HRPD network access authentication method based on cave algorithm
US20060046693A1 (en) * 2004-08-31 2006-03-02 Hung Tran Wireless local area network (WLAN) authentication method, WLAN client and WLAN service node (WSN)
US20060092872A1 (en) * 2004-11-04 2006-05-04 Samsung Electronics Co., Ltd. Communication method and apparatus using heterogeneous neighbor base station information in a broadband wireless access communication system
JP2006197536A (en) * 2004-12-15 2006-07-27 Matsushita Electric Ind Co Ltd Radio network control device, radio lan relay device, radio communication system, and communication method for radio communication system
US20070058788A1 (en) * 2005-08-22 2007-03-15 Nortel Networks Limited Multimedia subsystem service control for circuit-switched subsystem calls
US8208442B2 (en) 2005-08-22 2012-06-26 Genband Us Llc Multimedia subsystem service control for circuit-switched subsystem calls
US8811954B1 (en) 2005-10-31 2014-08-19 Genband Us Llc Network domain selection
US10582061B2 (en) 2005-10-31 2020-03-03 Genband Us Llc Network domain selection
US9692903B2 (en) 2005-10-31 2017-06-27 Genband Us Llc Network domain selection
US8180338B1 (en) 2006-06-14 2012-05-15 Genband Us Llc Selective call anchoring in a multimedia subsystem
US20090104891A1 (en) * 2006-06-24 2009-04-23 Guiming Shu Access method of network terminals, access system and gateway
EP2026533A4 (en) * 2006-06-24 2010-08-25 Huawei Tech Co Ltd METHOD FOR ACCESSING TERMINAL NETWORK, NETWORK ACCESS SYSTEM, AND GATEWAY EQUIPMENT
US8543092B2 (en) 2006-06-24 2013-09-24 Huawei Technologies Co., Ltd. Access method of network terminals, access system and gateway
US8600006B2 (en) 2006-12-27 2013-12-03 Genband Us Llc Voice continuity among user terminals
WO2008127877A1 (en) * 2007-04-11 2008-10-23 Cisco Technology, Inc. Gw coupled sip proxy
US7764963B2 (en) 2007-04-11 2010-07-27 Cisco Technology, Inc. GW coupled SIP proxy
US20090046703A1 (en) * 2007-08-13 2009-02-19 Cisco Technology, Inc. Using an ip registration to automate sip registration
US8233401B2 (en) 2007-08-13 2012-07-31 Cisco Technology, Inc. Using an IP registration to automate SIP registration
US8644298B1 (en) 2007-09-12 2014-02-04 Genband Us Llc Adding a service control channel after session establishment
US8839403B2 (en) * 2007-12-31 2014-09-16 Sandisk Il Ltd. Local proxy system and method
US9137249B2 (en) 2007-12-31 2015-09-15 Sandisk Il Ltd. Local proxy system and method
US20090172802A1 (en) * 2007-12-31 2009-07-02 Sandisk Corporation Local proxy system and method
US20110103266A1 (en) * 2008-02-15 2011-05-05 Cisco Technology, Inc., A California Corporation System and method for providing location and access network information support in a network environment
US8942112B2 (en) 2008-02-15 2015-01-27 Cisco Technology, Inc. System and method for providing selective mobility invocation in a network environment
US20090207843A1 (en) * 2008-02-15 2009-08-20 Andreasen Flemming S System and method for providing network address translation control in a network environment
US7899039B2 (en) 2008-02-15 2011-03-01 Cisco Technology, Inc. System and method for providing location and access network information support in a network environment
US20090207759A1 (en) * 2008-02-15 2009-08-20 Andreasen Flemming S System and method for providing a converged wireline and wireless network environment
US20090207823A1 (en) * 2008-02-15 2009-08-20 Andreasen Flemming S System and method for providing selective mobility invocation in a network environment
US8711847B2 (en) 2008-02-15 2014-04-29 Cisco Technology, Inc. System and method for providing location and access network information support in a network environment
US20090207757A1 (en) * 2008-02-15 2009-08-20 Andreasen Flemming S System and method for providing location and access network information support in a network environment
US20110107248A1 (en) * 2008-04-04 2011-05-05 Zumtobel Lighting Gmbh Computer-aided System for Managing and/or Controlling a Building Management System
US7957314B2 (en) 2008-12-12 2011-06-07 Cisco Technology, Inc. System and method for provisioning charging and policy control in a network environment
US20100150003A1 (en) * 2008-12-12 2010-06-17 Cisco Technology, Inc. System and Method for Provisioning Charging and Policy Control in a Network Environment
US9008005B2 (en) 2009-04-27 2015-04-14 Cisco Technology, Inc. System and method for providing intelligent gateway selection in a network environment
US20100290442A1 (en) * 2009-05-15 2010-11-18 Novatel Wireless Inc. Systems and methods for automatic connection with a wireless network
US20150050918A1 (en) * 2009-05-15 2015-02-19 Novatel Wireless, Inc. Systems and methods for controlling device network access through a wireless router
US9055606B2 (en) 2009-05-15 2015-06-09 Novatel Wireless, Inc. Systems and methods for automatic connection with a wireless network
US20100290390A1 (en) * 2009-05-15 2010-11-18 Novatel Wireless Inc. Systems and methods for controlling device network access through a wireless router
US9282460B2 (en) * 2009-05-15 2016-03-08 Novatel Wireless, Inc. Systems and methods for controlling device network access through a wireless router
US8195778B1 (en) 2009-12-19 2012-06-05 Cisco Technology, Inc. System and method for providing mobility across access technologies in a network environment
US9215588B2 (en) 2010-04-30 2015-12-15 Cisco Technology, Inc. System and method for providing selective bearer security in a network environment
US8918853B2 (en) * 2011-06-29 2014-12-23 Sharp Laboratories Of America, Inc. Method and system for automatic recovery from lost security token on embedded device
US20130007869A1 (en) * 2011-06-29 2013-01-03 Renjit Tom Thomas Method and system for automatic recovery from lost security token on embedded device
US11197165B2 (en) 2019-12-16 2021-12-07 Cisco Technology, Inc. Automated neighbor frequency provisioning in private 3GPP networks

Also Published As

Publication number Publication date
US7203482B2 (en) 2007-04-10

Similar Documents

Publication Publication Date Title
US7203482B2 (en) Authentication of mobile devices via proxy device
AU2005236981B2 (en) Improved subscriber authentication for unlicensed mobile access signaling
US6584310B1 (en) Method and apparatus for performing authentication in communication systems
EP1878285B1 (en) Fast user plane establishment in a telecommunications network
FI111208B (en) Arrangement of data encryption in a wireless telecommunication system
US8265049B2 (en) Method and apparatus for implementing generic access network functionality in a wireless communication device
MXPA04012155A (en) Wlan as a logical support node (sgsn) for interworking between the wlan and a mobile communications system.
KR100927321B1 (en) Radio access communication systems and devices, and methods and protocols for use therein
US20080200147A1 (en) Authentication of Mobile Communication Networks
CN100435518C (en) Authentication method of communication system
US20050031124A1 (en) Ciphering between a CDMA network and a GSM network
EP1856928A1 (en) Wireless communication systems and apparatus and methods and protocols for use therein
US20080031214A1 (en) GSM access point realization using a UMA proxy
JP2002152190A (en) Method for distributing cipher key through overlay data network
Kumar et al. Seamless and Secure Communication for 5G Subscribers in 5G-WLAN Heterogeneous Networks
US20090235072A1 (en) System, terminal, method, and software for communicating messages
Doukas Security Technologies for Mobile Radio Systems
Omollo et al. Data and voice signal intelligence interception over the GSM Um Interface
Kalibjian The Impact Of Wireless Security Protocols on Post Processed Telemetry Data Transfer
KR20070030201A (en) Certification of Mobile Communication Networks

Legal Events

Date Code Title Description
AS Assignment

Owner name: BLUMENTHAL, STEVEN, MASSACHUSETTS

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:IBE, OLIVER C.;REEL/FRAME:018521/0901

Effective date: 20060816

STCF Information on status: patent grant

Free format text: PATENTED CASE

AS Assignment

Owner name: KRAASTEN BROS. FUND B.V. LLC, DELAWARE

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:BLUMENTHAL, STEVEN;IBE, OLIVER C.;REEL/FRAME:021679/0958

Effective date: 20080809

FEPP Fee payment procedure

Free format text: PAT HOLDER NO LONGER CLAIMS SMALL ENTITY STATUS, ENTITY STATUS SET TO UNDISCOUNTED (ORIGINAL EVENT CODE: STOL); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

FPAY Fee payment

Year of fee payment: 4

FEPP Fee payment procedure

Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

FPAY Fee payment

Year of fee payment: 8

AS Assignment

Owner name: OL SECURITY LIMITED LIABILITY COMPANY, DELAWARE

Free format text: MERGER;ASSIGNOR:KRAASTEN BROS. FUND B.V. LLC;REEL/FRAME:036672/0611

Effective date: 20150826

Owner name: INTELLECTUAL VENTURES ASSETS 9 LLC, DELAWARE

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:OL SECURITY LIMITED LIABILITY COMPANY;REEL/FRAME:036673/0297

Effective date: 20150925

AS Assignment

Owner name: CISCO TECHNOLOGY, INC., CALIFORNIA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:CISCO SYSTEMS, INC.;REEL/FRAME:037780/0450

Effective date: 20160219

AS Assignment

Owner name: CISCO SYSTEMS, INC., CALIFORNIA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:INTELLECTUAL VENTURES ASSETS 9 LLC;REEL/FRAME:037888/0275

Effective date: 20151105

MAFP Maintenance fee payment

Free format text: PAYMENT OF MAINTENANCE FEE, 12TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1553); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

Year of fee payment: 12

OSZAR »