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 Solutions > Applied Panel Computing > eHome/Smart Home Networking |
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eHome/Smart Home Networking |
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802.11 refers to a family of specifications developed by the
IEEE for wireless LAN technology. 802.11 specifies an over-the-air
interface between a wireless client and a base station or
between two wireless clients. The IEEE accepted the specification
in 1997.
There are several specifications in the 802.11 family:
· 802.11 --
applies to wireless LANs and provides 1 or 2 Mbps transmission
in the 2.4 GHz band using either frequency hopping spread
spectrum (FHSS) or direct sequence spread spectrum (DSSS).
· 802.11a -- an
extension to 802.11 that applies to wireless LANs and provides
up to 54 Mbps in the 5GHz band. 802.11a uses an orthogonal
frequency division multiplexing encoding scheme rather than
FHSS or DSSS.
· 802.11b
-- (also referred
to as 802.11 High Rate or Wi-Fi) -- an extension to 802.11
that applies to wireless LANS and provides 11 Mbps transmission
(with a fallback to 5.5, 2 and 1 Mbps) in the 2.4 GHz band.
802.11b uses only DSSS. 802.11b was a 1999 ratification to
the original 802.11 standard, allowing wireless functionality
comparable to Ethernet.
· 802.11g --
applies to wireless LANs and provides 20+
Mbps in the 2.4 GHz band.
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Bluetooth
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Bluetooth refers to a short-range radio technology aimed at
simplifying communications among Net devices and between devices
and the Internet. It also aims to simplify data synchronization
between Net devices and other computers.
Products with Bluetooth technology must be qualified and pass
interoperability testing by the Bluetooth Special Interest
Group prior to release.
The Bluetooth 1.0 specification consists of two documents:
the Foundation Core, which provides design specifications,
and the Foundation Profile, which provides interoperability
guidelines.
Bluetooth's founding members include Ericsson, IBM, Intel,
Nokia and Toshiba.
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H.323
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A standard approved by the International Telecommunication
Union (ITU) that defines how audiovisual conferencing data
is transmitted across networks. In theory, H.323 should enable
users to participate in the same conference even though they
are using different videoconferencing applications. Although
most videoconferencing vendors have announced that their products
will conform to H.323, it's too early to say whether such
adherence will actually result in interoperability.
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H.324
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A suite of standards approved by the International Telecommunications
Union (ITU) that defines videoconferencing over analog (POTS)
telephone wires. One of the main components of H.324 is the
V.80 protocol that specifies how modems should handle streaming
audio and video data.
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HomePNA
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Also referred to as HPNA. A de facto home networking standard
developed by the Home Phoneline Networking Alliance. This
technology allows all the components of a home to interact
over the home's existing telephone wiring without disturbing
the existing voice or fax services.
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HomeRF
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Short for home radio frequency. Designed specifically for
wireless networks in homes - in contrast to 802.11, which
was created for use in businesses -- HomeRF networks are designed
to be more affordable to home users than other wireless technologies.
Based on frequency hopping and using radio frequency waves
for the transmission of voice and data, HomeRF has a range
of up to 150 feet. HomeRF uses Shared Wireless Access Protocol.
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IEEE 1394
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A very fast external bus standard that supports data transfer
rates of up to 400 Mbps (400 million bits per second). Products
supporting the 1394 standard go under different names, depending
on the company. Apple, which originally developed the technology,
uses the trademarked name FireWire. Other companies use other
names, such as i.link and Lynx, to describe their 1394 products.
A single 1394 port can be used to connect up 63 external devices.
In addition to its high speed, 1394 also supports isochronous
data -- delivering data at a guaranteed rate. This makes it
ideal for devices that need to transfer high levels of data
in real-time, such as video devices.
Although extremely fast and flexible, 1394 is also expensive.
Like USB, 1394 supports both Plug-and-Play and hot plugging,
and also provides power to peripheral devices.
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Internet Phone
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A popular Voice on the Net (VON). There are actually two different
products called Internet Phone, one produced by Intel and
the other developed by VocalTec Ltd.
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Internet
Telephony(VoIP)
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A category of hardware and software that enables people to
use the Internet as the transmission medium for telephone
calls. For users who have free, or fixed-price Internet access,
Internet telephony software essentially provides free telephone
calls anywhere in the world. To date, however, Internet telephony
does not offer the same quality of telephone service as direct
telephone connections.
There are many Internet telephony applications available.
Some, like CoolTalk and NetMeeting, come bundled with popular
Web browsers. Others are stand-alone products. Internet telephony
products are sometimes called IP telephony, Voice over the
Internet (VOI) or Voice over IP (VOIP) products.
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IrDA
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Short for Infrared Data Association, a group of device manufacturers
that developed a standard for transmitting data via infrared
light waves. Increasingly, computers and other devices (such
as printers) come with IrDA ports. This enables you to transfer
data from one device to another without any cables. For example,
if both your laptop computer and printer have IrDA ports,
you can simply put your computer in front of the printer and
output a document, without needing to connect the two with
a cable.
IrDA ports support roughly the same transmission rates as
traditional parallel ports. The only restrictions on their
use is that the two devices must be within a few feet of each
other and there must be a clear line of sight between them.
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Netmeeting
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A product developed by Microsoft Corporation that enables
groups to teleconference using the Internet as the transmission
medium. NetMeeting supports Voice on the Net, chat sessions,
a whiteboard, and application sharing. It's built into Microsoft's
Internet Explorer Web browser.
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SIP
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Short for Session Initiated Protocol, or Session Initiation
Protocol, a signaling protocol for Internet conferencing,
telephony, presence, events notification and instant messaging.
The protocol initiates call setup, routing, authentication
and other feature messages to endpoints within an IP domain.
Source: Webopedia Web Site
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Teleconference
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(1) To hold a conference via a telephone or network connection.
Computers have given new meaning to the term because they
allow groups to do much more than just talk. Once a teleconference
is established, the group can share applications and mark
up a common whiteboard. There are many teleconferencing applications
that work over private networks. One of the first to operate
over the Internet is Microsoft's NetMeeting.
Also see videoconferencing.
(2) To deliver live events via satellite to geographically
dispersed downlink sites.
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VDSL
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Very High Speed Digital Subscriber Line transmits data in
the 13 Mbps - 55 Mbps range over short distances, usually
between 1000 and 4500 feet (300 - 1500 meters), of twisted
pair copper wire. The shorter the distance, the faster the
connection
As the final length of cable into the home or office, VDSL
connects to neighborhood Optical Network Units (ONUs), which
connect to the central office's main fiber network backbone.
This architecture will allow VDSL users to access the maximum
bandwidth available through normal phone lines.
VDSL is currently going through a standards issue, so it isn't
widely deployed yet. The VDSL alliance favors a line coding
scheme based on Discrete Multitone (DMT), a multi-carrier
system that is more compatible with existing ADSL technology.
The VDSL coalition favors a line coding scheme based on Quadature
Amplitude Modulation (QAM), a single-carrier system that is
less expensive and consumes less power.
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Videoconferencing
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Conducting a conference between two or more participants at
different sites by using computer networks to transmit audio
and video data. For example, a point-to-point (two-person)
video conferencing system works much like a video telephone.
Each participant has a video camera, microphone, and speakers
mounted on his or her computer. As the two participants speak
to one another, their voices are carried over the network
and delivered to the other's speakers, and whatever images
appear in front of the video camera appear in a window on
the other participant's monitor.
Multipoint videoconferencing allows three or more participants
to sit in a virtual conference room and communicate as if
they were sitting right next to each other. Until the mid
90s, the hardware costs made videoconferencing prohibitively
expensive for most organizations, but that situation is changing
rapidly. Many analysts believe that videoconferencing will
be one of the fastest-growing segments of the computer industry
in the latter half of the decade.
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Wi-Fi
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Short for wireless fidelity and is meant to be used generically
when referring of any type of 802.11 network, whether 802.11b,
802.11a, dual-band, etc. The term is promulgated by the Wi-Fi
Alliance.
Any products tested and approved as "Wi-Fi Certified"
(a registered trademark) by the Wi-Fi Alliance are certified
as interoperable with each other, even if they are from different
manufacturers. A user with a "Wi-Fi Certified" product
can use any brand of access point with any other brand of
client hardware that also is certified. Typically, however,
any Wi-Fi product using the same radio frequency (for example,
2.5GHz for 802.11b or 11g, 5GHz for 802.11a) will work with
any other, even if not "Wi-Fi Certified."
Formerly, the term "Wi-Fi" was used only in place
of the 2.4GHz 802.11b standard, in the same way that "Ethernet"
is used in place of IEEE 802.3. The Alliance expanded the
generic use of the term in an attempt to stop confusion about
wireless LAN interoperability.
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WLAN
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Acronym for wireless local-area network. Also referred to
as LAWN. A type of local-area network that uses high-frequency
radio waves rather than wires to communicate between nodes.
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