Abstract: A system and method for authenticating a client having a privilege server, a head end server, and a web adapter performs the steps of negotiating an authentication scheme between the server proxy and the privilege server. User information is presented to the web adapter. The user information is provided to the head end server and in turn presents the information to the web adapter. The user is validated in accordance with the authentication scheme. When the user is validated a ticket is generated for the user. The ticket is presented to the client privilege server proxy that decrypts the ticket. A token is formed from the ticket and the client user identification. The token from the client is provided to the privilege server. A packet is formed having a sequence number and session key encrypted with the ticket. The packet is provided to the head end server which in turn authenticates the user.

Abstract: An embodiment of the present invention is a site controller that comprises a microcomputer with a RAM for main memory and an EPROM for program memory, an interface for accepting RS-485 data and voice communication on respective differential wire pairs from a daisy chain of student response keypad terminals, a public telephone data access arrangement with hybrid for sending and receiving voice over a dial-up line, a universal asynchronous receiver-transmitter for data communication by modem with a remote host site via an X.25 PAD and an audio processor for half-duplex communication between an instructor and a student that has voltage controlled amplifiers and side chain devices that reduce audio amplifier gain during periods of silence in order to eliminate feedback howl and adjustable delay and threshold devices for gating the respective channels through in the half-duplex mode.

Abstract: A daisy chain voice-data terminal for communicating data and voice signals between remote locations, comprising, according to an embodiment of the present invention, a microcomputer with a RAM for main memory and an EPROM for program memory, a membrane keypad connected to an input port of the microcomputer, a liquid crystal display adjacent to the keypad and connected to an output port of the microcomputer, a microphone and preamplifier, a differential output audio amplifier, a relay controlled by the microcomputer to switch the differential output audio amplifier on and off a daisy chain cable connected to other response keypads and a site controller, an RS-485 serial input/output to interface the microcomputer to the daisy chain cable, a switching regulator to provide five volts to the logic circuits, and a separate three-terminal linear regulator to supply five volts to the audio circuits.

Abstract: An apparatus of the present invention includes a viewer response system comprising a host site and at least one remote site interconnected by a satellite channel for host-to-remote video, an X.25 communications channel for message exchanges establishing a virtual circuit between each remote and the host site, and a dial-up public phone network channel that allows the host site to dial a remote site in response to a person at the remote site wanting to speak on the system to another person at the host site. A touch screen monitor at the host site allows the other person to sequence through electronic notecards that function as presentation cue cards. Questions can be formatted on remote site monitors and keypad terminals for each person at each remote site to allow real-time responses to be entered. A computer supporting the host site computes and displays remote site status and person's responses.