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Term
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Description
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R (Rate) Reference Point
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Provides a non-ISDN interface between user equipment that
is not ISDN capable and ISDN adapter equipment. Examples include
RS232, V.35, and X.21.
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Radio Spectrum
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Radio spectrum consists of radio waves of different frequencies
(for example, 900 MHz, 2.4GHz, 5GHz). All radio spectra are
regulated, with some licensed and others unlicensed. This
technique sends a message as a series of computer codes. However,
since the signal is stretched out over a broad frequency band,
the receiver only needs to receive a part of the transmitted
signal to reconstruct the original message.
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Radio wave
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A combination of electric and magnetic fields varying at
a radio frequency and traveling through space at the speed
of light.
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RADSL
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Rate-adaptive ADSL - ADSL version where modems test line
at start up and adapt to fastest possible speed. All DSL modems
based on DMT are inherently rate-adaptive.
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RAM
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Pronounced ramm, acronym for Random Access Memory, a type
of computer memory that can be accessed randomly; that is,
any byte of memory can be accessed without touching the preceding
bytes. RAM is the most common type of memory found in computers
and other devices, such as printers. There are 2 kinds of
RAM: SRAM and DRAM.
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Random access
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Reading locations directly without having to read in a particular
sequence.
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Raster Image
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An image defined as a set of dots/pixels in a column-and-row
format. See also Bitmap.
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Rasterization
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The process of converting data and command received from
a computer into a bitmap containing an image to be printed.
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Readback
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It is the process of verifying the contents of the programmed
device against the actual programming file. It is done to
verify that the device is programmed with the correct design
file and that it is functioning properly.
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RealNetworks
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Based in Seattle, RealNetworks is the pioneer and current
market leader in streaming media technology on the Internet
According to the company, their technology is used to deliver
content on more than 85% of all streaming media enabled Web
pages. The company derives its revenue from the delivery of
software products including authoring tools, streaming media
servers, and players; as well as streaming media delivery
services.
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Real-Time
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The actual time in which a program or event takes place.
In computing, real time refers to an operating mode under
which data is received and processed and the results returned
so quickly that the process appears instantaneous to the user.
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Reed Solomon
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Predefined decoding standards such as ATSC, IES-308 and DVB.
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Reference Design
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Free design that shows how to create an application by giving
a complete example. Customers then use this example to create
their own design.
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Registry (HAVi)
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One of the Software Elements that comprise the basic mechanisms
in HAVi to achieve interoperability. Each element provides
a certain functionality. The Software Elements that are needed
for interoperability between HAVi devices are the Messaging
System, the Registry, the Event Manager, the Resource Manager,
the Stream Manager and the DCM.
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Remote Access
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The ability of transmission points to gain access to a computer
which is at a different location.
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Remote User Interface (HAVi)
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A Remote User Interface enables a user to interact with an
application via any HAVi device in the network that has a
display. For example, a user could program the VCR in the
living room from his TV in the bedroom, again, regardless
of which manufacturer made either device.
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Rendering
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The process of translating high-level print commands into
a raster image.
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Repeater
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In a data network, a repeater can relay messages between
subnetworks that use different protocols or cable types. Hubs
can operate as repeaters by relaying messages to all connected
computers. A repeater however does not have the capability
to do the intelligent routing performed by bridges and routers,
and simply extends cabling distances by regenerating signals
to continue its propagation, usually increasing total distance
or coverage area.
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Repeater
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A repeater is a network device that repeats a signal from
one port onto the other ports to which it is connected . Repeaters
are low-level devices that amplify or regenerate weak signals.
A repeater merely passes along bits of data, even if a data
frame is corrupt. A repeater does not filter or interpret
anything; instead, it merely repeats a signal, passing all
network traffic in all directions.
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Resident Font
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Any font which is built-in to a printer by the manufacturer
as one of the standard features.
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Residential Gateway, Home Gateway, Home Servers
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A device that provides the connection between the Internet
backbone (broadband access and the home network or a home/SOHO
LAN. The gateway is dedicated to the task of a router and
generally performs protocol conversion between the Internet
backbone and the home network, data translation or conversion,
and message handling. A gateway is also considered a node
on the Internet
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Resolution
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Number of pixels per unit of area. A display with a finer
grid contains more pixels and thus has a higher resolution,
capable of reproducing more detail in an image.
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Resource Manager (HAVi)
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The Resource Manager is a powerful feature that handles possible
resource conflicts, such as when applications want to control
the same DCM. The Resource Manager allows for the possibility
of sharing devices. The sharing function is determined by
the devices themselves. An example is a set-top box that can
simultaneously select different TV programs in the same Transport
Stream. The Resource Manager also handles conflicts that could
occur, such as when multiple applications attempt to program
a VCR (so called Scheduled Actions), or if there are conflicts
that arise due to HAVi network resource or bandwidth issues.
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RF
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Radio Frequency. A generic term for radio-based technology
and is usually referred to whenever a signal is radiated through
the air. It is the portion of the electromagnetic spectrum
with frequencies between 3 kHz and 300 GHz. This corresponds
to wavelengths between 30 kilometers and 0.3 millimeter. The
international unit for measuring frequency is Hertz (Hz),
which is equivalent to the older unit of cycles per second.
One Megahertz (MHz) is one million Hertz. One Giga-Hertz (GHz)
is one billion Hertz. For reference: the standard US electrical
power frequency is 60 Hz, the AM broadcast radio frequency
band is 0.55 -1.6 MHz, the FM broadcast radio frequency band
is 88-108 MHz, and microwave ovens typically operate at 2.45
GHz. Typically RF are frequencies from 20 kHz to 3 GHz. Literally,
any and all frequencies that can be radiated as an electromagnetic
wave.
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RGB
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A type of color display output signal comprised of separately
controllable red, green, and blue signals; as opposed to composite
video, in which signals are combined prior to output. RGB
monitors typically offer higher resolution than composite
monitors.
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RISC
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Pronounced risk, acronym for Reduced Instruction Set Computer,
a type of microprocessor that recognizes a relatively limited
number of instructions.
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RJ-11
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RJ-11-Standard 4. Wire connectors for phone lines.
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RJ-45
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An "RJ-45" connector is used on Ethernet twisted pair links.
This includes the 10Base-T, 100Base-TX, 100Base-T4, 100Base-T2,
and 1000Base-T physical layer types. An RJ-45 connector has
8-pins, and may also be referred to as an "8-pin Modular Connector".
A male RJ-45 "plug" is mounted on each end of the twisted
pair cable. A female RJ-45 "jack" or "receptacle" is integrated
into the Ethernet hub or NIC.
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Roaming
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The means by which a collection of networks allow for a mobile
terminal to get connected/associated and use the services
of the network. The movement of a wireless node (portable
communications device) between two microcells, thus providing
the ability of going from (between) one access point to another
without having to re-establish the connection. Roaming usually
occurs in infrastructure networks built around multiple access
points.
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ROM
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Acronym for Read Only Memory. Used for information storage
that can be accessed but not modified.
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route/routing
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Software process of determining how to connect different
parts of the FPGA to obtain the desired functionality.
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Router
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A router is a networking device involved in protocol- independent,
LAN-to-LAN internetwork traffic management . Routers use the
Network Layer Protocol Information within each packet to "route"
it from one destination or LAN to another A router must support
Layer 3 networking protocols such as IP and IPX and routing
protocols such as RIP and OSPF. This means that a router must
be able to recognize all the different Network Layer Protocols
that may be used on the networks it is linking together. Routers
communicate with one another to determine the best route through
the complex connections of many LANs to increase speed and
cut down on network traffic. A router will decide whether
to forward a packet by looking at the protocol level addresses
(for instance, TCP/IP addresses) rather than the MAC address.
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RPM
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Acronym for Relationally Placed Macro. Design method often
used to enhance or control the performance of a circuit by
defining how the logic should be structured in an FPGA.
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RS-232
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A popular connection standard for wired Serial data communications.
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RSA
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A public-key cryptographic system used for encryption and
authentication. It was invented in 1977 and named for its
inventors: Ron Rivest, Adi Shamir, and Leonard Adleman.
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RSA RC-4
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Variable key-size stream cipher algorithm designed by RSA
Inc.
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RSVP
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ReSerVation Protocol. A method being developed by the IETF
to assist in providing quality-of-service (QoS) characteristics
to communications over an IP network. The name indicates that
it allows the end-stations to reserve bandwidth on the network.
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