The Interactive Video Data Service (IVDS) system allows consumers to browse the Internet, request information on products or services, make purchases, indicate preferences, and perform other interactive applications. To provide this service, the IVDS system has three subsystems: Consumer Control (CC), Cell Repeater (CR), and Host subsystem. In the CC subsystem, an IVDS transceiver box is placed near a television set. Once the consumer sends a command to the transceiver box using a standard television/VCR/Cable remote control, the transceiver box receives information embedded in the television audio, and then transmits the information to the CR subsystem as a radio frequency (RF) spread spectrum message. The CR subsystem decodes the spread spectrum message and forwards it to the Host subsystem for processing. Located in the CR subsystem, a custom designed circuit board, called the decoder board, uses surface mounted components to decode and packetize the spread spectrum message for transfer to the CR main processor. This paper provides a functional description of the hardware components on the decoder board, and describes the hardware/software developed for interfacing the decoder board to the radio receiver and to the CR main processor. Hardware modifications were needed to correct timing problems between components. Software was developed to initialize the components for downconverting, despreading, and demodulating spread spectrum messages, and to packetize them for transfer to the CR main processor. This paper also discusses the tests used to verify both the performance of the decoder board software and the operation of the hardware components. / Master of Science

In this thesis, an Interactive Video Data Service (IVDS) is developed. This service provides a mechanism for television viewers to interact with the program they are watching. Possible interactions include purchasing products from home shopping programs and requesting information from advertisers. Within the project, two areas were focused upon: channel simulation and the Repeater Unit. Additionally, the overall system was discussed along with its background. The purpose of channel simulation was to demonstrate the viability of the unique communication channel model proposed for the IVDS system. This channel was implemented using uni-directional transmissions, without acknowledgments. The Repeater Unit was designed to be a message processing system, intended to relay messages from system users to the home office. The design entailed both hardware and software. The hardware requirements were for a high level design, while the software required not only design, but implementation. / Master of Science

Information, products and services can be requested and purchased via the Interactive Video Data Service (IVDS) system developed by The Center for Wireless Telecommunications, Virginia Tech. This system consists of three components - User control, Repeater unit and a Host program. The user requests a service using his/her television remote (User control). A transceiver (User control) located near the television set responds to user requests by extracting information hidden in the commercial's audio, and transmitting information to the repeater unit. The receiver unit decodes received messages and forwards them in capsules to the Host component. Thus the user requests are received by the host system. The repeater unit is a real-time operating system with its in-built hardware and software functions. Application specific software can be written using the existing software drivers and libraries (kernel) to decode and process messages. The Host program monitors and responds to received user messages. This thesis focuses on the repeater unit hardware setup and discusses the application software implementation developed to receive messages from the transceiver box and to retransmit the messages in a different format over the Internet. The software specifications included no incoming message loss, ability to statically hold 10000 user messages, time-stamp and location-stamp (using a GPS receiver) forwarded messages, scheduling messages for retransmission based on message priority, and retransmission using the point-to-point protocol (PPP) using a dial-up modem connection. In order to achieve better performance the existing software kernel was re-written in some sections. This thesis also discusses some of the system limitations from the repeater unit's perspective. / Master of Science

The Interactive Video and Data System is a multidisciplinary research project involving the creation of a means for people to interact with television and printed media without the addition of expensive hardware as required by most interactive systems available today. The IVDS system consists of a Consumer Control Unit which transmits user requests, a Repeater Unit which receives transmissions from the CCUs, and a Host System which takes appropriate actions for user demands. This thesis follows the evolution of the original CCU prototype as more capabilities are added and hardware platforms are changed, focusing on the addition of a bar code interface to the CCU. / Master of Science