Phone-Like Dialing, Camera Control, Echo Canceller

Introduction 1-3

Phone-Like Dialing

•VoicePoint+ connectivity for ease of dialing

For those not wanting to dial using the VisuaLink remote, an NEC VoicePoint+ can be connected to the VisuaLink. (The VoicePoint+ is a tabletop speakerphone unit for conferencing; providing standard keypad, built-in microphone and speaker.) With a VoicePoint+, dialing is as easy as placing a regular phone call. A standard analog phone set can also be used with VisuaLink.

To make dialing even easier, VisuaLink provides 130 speed-dial settings. Up to 130 most often used numbers for a videoconference can be preset in VisuaLink. For easy redial, 20 redial numbers are automatically stored for both incoming and outgoing calls

•local-end can set far-end presets

Camera Control

Nine different camera presets can be stored in VisuaLink. The presets allow camera position (pan & tilt), framing (zoom), and automatic focus for various positions in a videoconference. To make this easier, camera presets are stored under identifiable names. With this capability, each preset can store different camera settings matched to each named individual in the conference.

A standard feature of VisuaLink is camera voice tracking. Voice tracking automatically moves the camera to the person speaking by using one of the camera presets. Voice tracking automatically detects the audio from a person (from one of three microphones) and selects the preset stored for that person. The camera will then pan, tilt, zoom, and focus (using the preset) to show the person speaking. No longer is a videoconference technician needed to operate a camera controller or video switcher.

Echo Canceller

• connect up to 3 microphones

Voice quality is an important component in videoconferencing. Users will tolerate degraded video, but not degraded audio. The echo canceller improves audio voice quality by eliminating signal echo from long line communications and clipping caused by some narrow band systems.

•settings for higher frame rate for smoother motion, or lower frame rate for higher resolution

H.320 Videoconferencing Compliance

VisuaLink is designed to the International Telecommunications Union (ITU-T) H.320 standard for videoconferencing. Many claim to support this standard, but few products support all options of H.320.

VisuaLink is designed to fully support the H.320 standard. This overall standard includes the new option H.263 video standard for higher resolution low bandwidth processing; and the H.261 video standard for lower resolution high bandwidth processing (for compatibility with older systems). Also supported are the standards G.711, G.722, and G.728 for the audio element of videoconferencing.

VisuaLink incorporates the latest H.320 technology available and provides backward compatibility in one compact unit. (For additional information on H.320, see Part 3 of this manual: Technical Description - more on H.320 Videoconferencing.)

VisuaLink 128/384 General Description

128 specifications

The NEC 128 is a remarkable microprocessor that represents a significant leap in technological innovation during its time. Introduced in the early 1980s, this processor was designed to meet the demands of increasingly sophisticated computing tasks, primarily aimed at the burgeoning field of personal computing and embedded systems.

One of the standout features of the NEC 128 is its 16-bit architecture, which was quite advanced for its era. This architecture allows for a greater data throughput, enabling the handling of larger data sets and providing improved performance over its predecessors. The NEC 128 operates on a clock speed that typically ranges from 4 to 8 MHz, making it capable of executing instructions efficiently and swiftly, which was crucial for running more complex applications.

The processor is built using CMOS technology, which offers significant advantages in terms of power consumption compared to earlier bipolar technology. This characteristic made the NEC 128 not only suitable for desktop computing but also an appealing choice for battery-operated devices, enhancing its versatility. The use of CMOS allowed for a reduced heat output, contributing to the reliability and longevity of devices powered by this microprocessor.

Another noteworthy aspect of the NEC 128 is its support for a variety of addressing modes. This flexibility enables programmers to write more efficient and compact code, optimizing the use of memory resources. By supporting both immediate and indirect addressing, the NEC 128 allows for more dynamic programming, which is essential for developing applications that require real-time processing.

The processor's architecture also includes a robust instruction set that facilitates arithmetic operations, logical operations, and control flow management. This comprehensive instruction set is instrumental for developers, as it provides the necessary tools for creating a wide range of applications, from simple utilities to more complex software systems.

In summary, the NEC 128 microprocessor is characterized by its 16-bit architecture, efficient CMOS technology, and a versatile instruction set, making it a compelling choice for its era. Its combination of performance, power efficiency, and flexibility positioned it as a formidable player in the personal computing market and laid the groundwork for future advancements in microprocessor technology. With its various applications and features, the NEC 128 remains a noteworthy chapter in the history of computing.