Abstract:
A public telephone and Internet access system that comprises Personal Digital Assistants (PDA) that are connected to an ethernet or other Local Area Network by a network cradle, and a number of ethernet telephones connected to the same Local Area Network. The PDAs store encrypted information about their owners, including the owner&#39;s name, their phone forwarding preferences, access permissions to the network, and charging/billing information. When a PDA is attached to a network cradle, this information is automatically transferred to the gatekeeper, which is a server that performs management tasks for the ethernet phone network. These tasks include deciding whether or not a user is allowed to sign up and use a public ethernet phone, maintaining billing and charging information, and forwarding incoming calls for a given user to the ethernet phone at the user&#39;s current location. This invention provides a secure method for the PDA and the gatekeeper to exchange authentication information.

Description:
RELATED APPLICATIONS 
     The present application is a continuation in part of U.S. patent application Ser. No. 09/181,431, METHOD, APPARATUS AND COMMUNICATIONS SYSTEM FOR COMPANION INFORMATION AND NETWORK APPLIANCES, Wang, Peter Si-Sheng, Dalgic, Ismail, filed Oct. 30, 1998 U.S. Pat. No. 6,161,134, and incorporated herein by reference for all purposes. The following U.S. patent application Ser. No. 08/866,819, METHOD AND APPARATUS FOR PROVIDING SECURITY IN A STAR OR HUB NETWORK CONNECTION, Jain, Nesset, Sherer, filed May 30, 1997, and U.S. patent application Ser. No. 08/955,869, METHOD AND APPARATUS FOR PROVIDING SECURITY IN A STAR NETWORK CONNECTION USING PUBLIC KEY CRYPTOGRAPHY, Jain, Nessett, Sherer, filed Oct. 28, 1997 are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to improvements in networked computer environments and has particular applications to the transmission of information between digital devices over a communications medium. More specifically, the present invention relates to the combination of a portable computer with a communications device to form a compound network apparatus used to provide secure and authenticated access to public or private telephone and internet systems. 
     2. Related Art 
     Recent advances in the manufacture and design of integrated circuits have enabled technology producers to provide portable instruments including palm-sized computers [or personal digital assistants (PDAs)], such as the Palm VII from Palm Computing, Inc., Santa Clara, Calif. Accessories are available that allow a portable computer to become part of a telecommunications device. One such accessory is described in U.S. Pat. No. 5,606,594, granted to Register et al. on Feb. 25, 1997, entitled “Communication Accessory and Method of Telecommunicating for a PDA”. Similarly, U.S. Pat. No. 5,497,339, granted to Bernard et al. on Mar. 5, 1996 provides for PDA that mounts within a communications device. A prior system describes an information appliance (PDA) and a network appliance (or telephone) that function independently as well as with each other as companion appliances. 
     In prior art, a communications appliance (digital telephone or ethernet telephone) is connected directly to the Local Area Network (LAN), and the information appliance (computer or PDA) is connected directly to the communications appliance. That is, the communications appliance is always connected between the LAN and the information appliance (they are connected in series). Both system security means as well as types and methods of data transmission are limited by the capabilities of the communications appliance (telephone). This topology limits the application to systems requiring ethernet telephones or other specially adapted telephones. Thus prior art excludes applications which could possibly incorporate an existing public switched telephone network (PSTN). 
     Prior attempts to solve PDA-based number portability and mobility problems, as well as problems of authentication, accounting and billing support for LAN telephones has been based on the use of calling cards, some of which require the user to recall a Personal Identification Number (PIN). 
     SUMMARY OF THE INVENTION 
     Accordingly, what is needed is a more generally applicable system that can be used in business or industry without the requirement of special telephones. In the present invention, both the information appliance (computer or PDA) and the communications appliance (an ethernet telephone) are connected directly to the LAN. A non-ethernet telephone can be connected directly to the LAN by connecting a Voice Over IP Gateway between the telephone and the LAN. This topology obviates the need for specialized telephones and in addition allows the application of any of the various security schemes disclosed in the above cited U.S. patent application Ser. No. 08/866,819, and Ser. No. 08/866,819. Furthermore, the types and means of data transmission are limited by the information appliance (a computer or PDA) rather than by the telephone. 
     What is needed yet is a method and system that is economically feasible for use in either private or commercial LAN or internet systems, whether connected by coaxial cable, by twisted pair wire commonly known as CAT5, by fiber optic cable, by wireless means or by some combination thereof. 
     What is described is a public telephone and Internet access system that comprises Personal Digital Assistants (PDA) that are connected to an ethernet Local Area Network (LAN) by a network cradle, and a number of ethernet telephones connected to the same LAN. Even though we describe the process in terms of ethernet LANs, the mechanisms apply to other 802 LANs as well. the PDAs store encrypted information about their owners, including the owner&#39;s name, their phone forwarding preferences, access permissions to the network, and charging/billing information. When a PDA is attached to a network cradle, this information is automatically transferred to the gate keeper, which is a server that performs management tasks for the ethernet phone network. These tasks include deciding whether or not a user is allowed to sign up and use a public ethernet phone, maintaining billing and charging information, and forwarding incoming calls for a given user to the ethernet phone at the user&#39;s current location. 
     The present invention provides these advantages and others not specifically mentioned above but described in the sections to follow. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a generalized topology for a typical LAN. 
         FIG. 2  is a generalized topology to illustrate one possible embodiment of this invention and is included for clarity of discussion. It will be apparent to those of skill in the art that this invention has applications with many different topologies and therefore should not be seen as limited by this topology. 
         FIG. 3  is a state diagram illustrating steps of the authentication process in accordannce with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the following detailed description of the present invention, a method and system to provide secure user access to public or private telephone systems and the internet, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be obvious to one skilled in the art that the present invention may be practiced without these specific details. In other instances well known methods, procedures, components, and circuits have not been described in detail so as not to unnecessarily obscure aspects of the present invention. 
     Networking Devices and Standards 
     This specification assumes familiarity with the general concepts, protocols and devices currently used in Local Area Networks (LANs) and Wide Area Networks (WANs) such as the IEEE 802.x and ISO 8802 protocol suites and other series of documents released by the Internet Engineering Task Force that are publicly available. For discussion purposes, a generalized topology for a typical LAN ( 40 ) is given in  FIG. 1 . LAN topology refers to the manner in which the hardware elements comprising the network are interconnected. Common topologies for LANs are bus, tree, ring and star. LANs may also have a hybrid topology made up of a combination of these. Overall, the LAN in  FIG. 1  has a tree topology, but also incorporated is  72   d  having a bus topology and  70   d  having a star topology. The present invention may be used with any of the above mentioned topologies including a ring topology. 
     The LAN in  FIG. 1  represents an arrangement of various hardware and software elements that operate together to allow a number of digital devices to exchange data within the LAN, and also may include internet connections to external WANs such as WAN  82  and  84 . Connection to a Public Switched Telephone Network (PSTN) can be provided by a Voice over IP Gateway that might be included in WAN 2 . The typical LAN is comprised of one or more LAN Intermediate Systems (ISs) such as ISs  60 – 62  and  67  that are responsible for data transmission throughout the LAN and a number of End Systems (ESs) such as ESs  50   a–f ,  51   a–c , and  52   a–g , that represent end user equipment. The ESs may be familiar end-user data processing equipment, such as personal computers, Personal Digital Assistants (PDAs), workstations, printers and additionally other digital devices such as digital telephones or real-time video displays. Different types of ESs can operate together on the same LAN. In the LAN topology of  FIG. 1 , ISs  60  and  61  are referred to as bridges, WAN ISs  64  and  66  are referred to as routers, and IS  67  is referred to as a repeater. The LAN network topology in  FIG. 1  is of a general nature for discussion purposes, and this invention is not limited in application to this topology. 
     A segment is generally a single interconnected medium such as a coaxial cable, a contiguous wire(s), optical fiber or a particular frequency band. The LAN in  FIG. 1  has segments  70   a–g ,  71   a–e ,  72   a–e  and  73   a . A segment may connect just two devices, such as segment  70   a  (also referred to as a point-to-point or star connection). A segment such as  72   d  may connect a number of devices using a Carrier Sense Multiple Access/Collision Detection (CSMA/CD) protocol or other multiple access protocol such as a token bus or token ring. Signals transmitted on a single segment such as  72   d  are simultaneously heard by all of the ESs and ISs connected to that segment. 
     A LAN may also contain a number of repeaters, such as repeater  67 . A repeater generally physically repeats out of each of its ports all data received on any one port, such that the network behavior perceived by ESs  50   a–c  and the port of IS  60  connected to  67  is identical to the behavior these ports would perceive if they were all connected on the same segment such as  52   d–g  and the corresponding port of  62 . Repeaters configured in a star topology such as  67  are also referred to as hub repeaters. The terms hub or star are used in networking to indicate either a switch/bridge layer  2  device, or a repeater layer  1  device. In the  FIG. 1  LAN, bridges  61 ,  62 , and  63  have a star or hub configuration as does repeater  67 . 
     Drivers and Adapters 
     Each of the ISs and ESs in  FIG. 1  includes one or more adapters and hardware or software instructions sometimes referred to as drivers. An adapter generally includes circuitry and connectors for communication over a segment and translates data from the digital form used by the computer circuitry in the IS or ES into a form such as electrical or optical signals, or radio waves that may be transmitted over the segment. An ES such as  50   b  will generally have one adapter for connecting to its single segment. A LAN IS such as  61  will have five adapters, one for each segment to which it is connected. A driver is a set of instructions resident on a device that allows the device to accomplish various tasks as defined by different network protocols. Drivers are generally software programs stored on the ISs or ESs in a manner that allows the drivers to be modified without modifying the IS or ES hardware. 
     Network ISs: Routers. Bridges. Repeaters 
     The LAN in  FIG. 1  includes bridges  60 – 63 . A bridge is understood in the art to be a type of computer optimized for very fast data communication between two or more segments. A bridge according to the prior art generally makes no changes to the data packets it receives on one segment before transmitting them on another segment. 
     A LAN may also contain a number of repeaters, which is one possible configuration for device  67 . A repeater generally repeats out of each of its ports all data received on any one port, such that the network behavior perceived by ESs such as  50   a–c  is generally identical to the behavior they would perceive if they were connected on the same segment such as  52   d–g.    
     It is intended that this invention be applicable in such instances as private businesses, educational institutions, government organizations as well as in configurations available to the general public. One possible embodiment of this invention is illustrated by the topology in  FIG. 2 . The LAN network ( 100 ) is a generalized representation as discussed previously within which are various hardware and software elements that operate together to allow a number of digital devices to exchange data within the LAN, and also to exchange data with external devices such as ESs, routers or WANs. Numerous different topologies within the LAN are appropriate for this invention and thus the segments between hardware elements within the LAN are omitted. One embodiment utilizes telephones connected to an Ethernet LAN. Other embodiments are realized by means of other 802 LANs. 
     A method and system are disclosed that will allow access to a LAN for the purpose of local communication within the LAN, for local or long distance telephone communication by connection to a Public Switched Telephone Network (PSTN), or for communication by connection to the internet. System security is incorporated since user access to the LAN is granted only after a requesting user and any connected equipment are identified and authenticated. Once any request is authenticated and user access is allowed to the LAN, any disruption to the connection between that equipment and the LAN will be recognized by the LAN, and such equipment will immediately be denied access to the LAN. Furthermore, the present invention provides additional system security by incorporating a method to detect and immediately disconnect from previously authenticated equipment that exhibits any operational variation(s) unfamiliar to the LAN. An embodiment of this invention consists of a LAN, with a dedicated server called a Gatekeeper ( 110 ), a Router ( 120 ) to connect the LAN to the Internet, a gateway ( 130 ) used to connect the LAN to a Public Switched Telephone Network (PSTN) ( 131 ), and one or more telephone booths (PBs) ( 140 ,  150 ) each of which contains a telephone and a PDA cradle. The PDA cradle is the device used to connect the PDA to the LAN. Each PB connects to the LAN by means of a hub/switch (Bridge/Switch) ( 1 S). PBs  140 ,  150 ,  160  and  170  are connected directly to IS- 1  ( 141 ), IS- 2 ( 151 ), IS- 3 ( 161 ) and IS- 4 ( 171 ) respectively. 
     Phone booths  140  and  150  each contain an Ethernet phone, which is identical to a regular telephone in appearance and basic functionality, but has a connector for ethernet as opposed to an analog or digital phone line. Both ethernet phones are connected directly to the LAN. Phone booth  140  also contains a PDA cradle that has an ethernet interface, but phone booth  150  contains a serial cradle to accommodate a PDA having a serial interface such as RS-232. The cradle in phone booth  140  is connected directly to the LAN, while the cradle in phone booth  150  connects directly to the LAN by means of the serial-to-network converter. It is also possible to use other non-ethernet interfaces such as parallel or Universal Serial Bus (USB), or infrared. 
     Phone booth  160  contains a non-ethernet telephone which is connected to Bridge/Switch IS- 3  by means of a Voice Over IP Gateway, while the ethernet cradle is connected directly to Bridge/Switch IS- 3 . Phone booth  170  also contains a non-ethernet telephone which is connected to Bridge/Switch IS- 4  by means of a Voice Over IP Gateway, and the serial cradle is connected to Bridge/Switch IS- 4  by means of a Serial-to-Network Converter. 
     If the user in the phone booth does not have a PDA with the appropriate software, the system allows only toll-free calls including calling card access numbers and emergency  911  calls. In order to make full use of the system, the user must have a PDA that fits in the cradle, and that has the phone management software. When the user drops his/her PDA in the network cradle and activates the phone management software, the network cradle receives the user&#39;s authentication and billing information from the PDA software and sends a message to the hub/switch to which it is connected. The hub/switch then communicates with the gatekeeper ( 110 ) to check the user&#39;s credentials, and if they are satisfactory, allows network connectivity for the network cradle and permits the phone to make toll calls. If the booth includes a serial cradle, then the serial cradle and serial-to-network converter performs the same function as the network cradle to exchange authentication information with the hub/switch. 
       FIG. 3  provides a state diagram illustrating the authentication process in accordance with an embodiment of the present invention. Authentication is initiated by the hub/switch when it detects a connection on a port (detection of a linkbeat or observance of a message)(step  200 ). Alternatively, the network cradle, serial-to-network converter, or serial cradle indicates to the hub/switch to initiate authentication when a device is plugged in. This indication can be a physical signal (turning the linkbeat off momentarily) or a message to this effect. The hub/switch uses a backend AAA infrastructure through the gatekeeper to authenticate the connecting user as described in previously cited patent application Ser. No. 08/866,819, and Ser. No. 08/955,869. More specifically, the hub/switch will request certain user data such as user identification (ID) and password (PW) (step  201 ) from the PDA. At this point (step  202 ), the PDA provides information to the hub/switch. 
     The information supplied by the PDA is then forwarded by the hub/switch to the gatekeeper for user identification and authentication (step  203 ). If the user is authenticated successfully (step  204 ) and the user has a dedicated link to the hub/switch port (via a network cradle for example) (step  200 ), the hub/switch port is opened (step  205 ) and a success message is sent to the network cradle (step  206 ). The network cradle now allows the user to make phone calls. If the switch port is shared (via a serial-to-network converter supporting multiple serial ports for example), a message is sent by the hub/switch to the cradle/converter to open up the corresponding serial port. If the user authentication fails ( 204 ), the hub/switch port is blocked (dedicated port) ( 205 ) or a failure message is sent to the cradle/converter ( 206 ) to block the corresponding serial port. A failure message is displayed to the user on the PDA ( 206 ). 
     The above process can be extended to shared switch ports via network cradles as well (multiple network cradles connected to a switch port via a repeater). In this case, the authenticator (hub/switch) indicates to the authenticating network cradle to open/block the network port based on the results of authentication. The authenticator can also install filters to allow/disallow traffic from the corresponding MAC addresses. 
     Advantages of the present invention include portability of numbers. An authenticated user can simply drop the PDA into a cradle and begin making toll phone calls at the push of a button. A phone number stored in the PDA address book can be dialed automatically by the PDA. The graphical user interface on the PDA can display information such as callee&#39;s phone number and name, duration and cost of an ongoing call and a history of calls made. The phone booth can be extended into a virtual office since the PDA can communicate the user&#39;s phone number to the gatekeeper, and set up automatic call forwarding such that the calls made to the user&#39;s office number are forwarded to the ethernet phone at the phone booth. 
     Furthermore, the PDA can be used to access the internet, allowing applications such as World Wide Web and e-mail to be executed on the PDA. A user can be given the option to carry a voice conversation over the public internet, thereby reducing the toll costs. Moreover, in this case, the long distance charges can be directly paid to the organization providing the toll booths, which may include places such as airport, restaurant or hotel installations. Such organizations are thereby offered an economic benefit. 
     The preferred embodiment of the present invention, a method and system to provide secure user access to public or private telephone systems and the internet, is thus described. While the present invention has been described in particular embodiments, it should be appreciated that the present invention should not be construed as limited by such embodiments, but rather construed according to the below claims.