A technology developed by U.S. Robotics (now 3COM) for delivering data rates up to 56 Kbps over plain old telephone service (POTS). It was long believed that the maximum data transmission rate over copper telephone wires was 33.6 Kbps, but X2 achieves higher rates by taking advantage of the fact that most phone switching stations are connected by high-speed digital lines. X2 bypasses the normal digital-to-analog conversion and sends the digital data over the telephone wires directly to your modem where it is decoded.
3COM has announced that future X2 modems will conform to the new V.90 standard approved by the ITU. And users with older X2 modems may upgrade their modems to support V.90.
While X2 offers faster Internet access than normal modems, there are several caveats to using an X2 modem:
1. The high speeds are available only with downstream traffic (e.g., data sent to your computer). Upstream traffic is delivered using normal techniques, with a maximum speed of 40 Kbps.
2. To connect to the Internet at X2 speeds, your Internet Service Provider (ISP) must have a modem at the other end that supports V.90.
3. Even if your ISP supports V.90, you might not achieve maximum transmission rates due to noisy lines.
- Transaction Authority Markup Language
Shortened as XAML. XAML is a vendor-neutral standard developed jointly by Bowstreet, Hewlett-Packard, IBM, Oracle and Sun that is used to coordinate and process online business transactions. Based on XML, XAML uses a set of XML message formats and interaction models that Web services can use to provide business-level transactions that span multiple parties across […]
Short for Extensible Business Reporting Language, an XML-based specification for publishing the financial information of an enterprise. The standardization of the specification makes it easier for public and private companies to share information with each other and with industry analysts across all software formats and technologies, including the Internet. XBRL uses XML data tags based […]
Short for extended graphics array, a high-resolution graphics standard introduced by IBM in 1990. XGA was designed to replace the older 8514/A video standard. It provides the same resolutions (640 by 480 or 1024 by 768 pixels), but supports more simultaneous colors (65 thousand compared to 8514/A’s 256 colors). In addition, XGA allows monitors to […]
Short for Extensible Hypertext Markup Language, a hybrid between HTML and XMLspecifically designed for Net device displays. XHTML is a markup language written in XML; therefore, it is an XML application. XHTML uses three XML namespaces (used to qualify element and attributes names by associating them with namespaces identified by URI references. Namespaces prevent identically […]
XLR refers to a three-pin locking connector that is used in audio applications. In analog applications, particularly in some high-end consumer audio equipment, XLR connectors are used with balanced lines for optimal interference rejection. An XLR connector’s pins usually point in the direction of signal flow.