| Satellite Mobile
Phone |
There are various satellite- supported mobile
phone networks. The oldest network, "Inmarsat", requires large
terminals. The "Iridium" network developed by Motorola and other
companies came out with much smaller terminals, proved to be
an economic failure, and is no longer in operation. In principle
the ITU specifications for IMT-2000 also provide for optional
satellite supply. They would come into question for UMTS supply
in sparsely populated areas, deserts, or on the open seas. Because
of the poor economic track record of satellite mobile phones
to date, however, no concrete steps for satellite use in future
UMTS networks are planned. |
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| Satellite network |
Network using radio frequencies relayed by satellite.
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| S-UMTS |
Stand for Satellite UMTS. A satellite-based system
that, independently of the terrestrial mobile networks and can
provide some of the ground based UMTS system's capabilities. |
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| SDMA |
Space Division Multiple Access , A technique makes
it possible to increase the capacity of a cellular mobile radio
system by taking advantage of spatial separation between users.
The base station does not transmit the signal to the entire
cell area, as in conventional access techniques, but concentrates
power in the direction of the mobile unit for which the signal
is directed, reducing it in the directions where other units
are present. |
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| Service provider |
The company that sends you bills and owns your
signature on a contract. |
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| SIM |
Subscriber Identity Module |
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| Smart Antenna |
It solve the capacity problems of mature mobile
cellular networks. By directing radio signals to an intended
target rather than broadcasting throughout the entire cell area,
they increase the network’s capacity. The more elaborate smart
antenna systems can communicate with multiple mobile stations
in the same cell, on the same channel, thereby exploiting their
spatial separation. |
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| SMS |
Short Message Service. Popularly known as "text
messages". Analysis said it will be the main revenue generator
for 3G operators. |
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| Spectrum |
The range of electromagnetic radio frequencies
used in the transmission of sound, data and television. |
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| Soft handoff |
In wireless communication, soft handoff refers
to the overlapping of repeater coverage zones, so that every
cell phone set is always well within range of at least one base
station. In some cases, mobile sets transmit signals to, and
receive signals from, more than one repeater at a time. |
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| Software radio |
An emerging technology which allows network operators
to simultaneously support multiple communications standards
(GSM, CDMA, W-CDMA, 3G etc) on the one network infrastructure
without begin bound by a particular standard. |
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| Streaming Media |
Technical term for digital audio or video transmissions
via the Internet. The sound and image data are sent as a data
stream to the subscriber, hence the term "streaming". A variety
of deferred data streams can be output from a streaming media
server on the Net. Each receiver can thus receive the same content
deferred. Normally, a packet- switched or asymmetric transmission
method is used. |
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| Switching |
On a telecommunications network, switching means
routing traffic by setting up temporary connections between
two or more network points. This is done by devices located
at different locations on the network, called switches (or exchanges).
The basic structure of a telecommunications network therefore
comprises transmission media, interconnected by exchanges. "Packet"
and "circuit" switching are two techniques used by telecommunications
networks. The first is used by IP networks, and the second by
traditional networks (PSTN). |
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| Symbian |
A joint venture originally set up by Ericsson,
Nokia and Psion to develop an industry standard operating system
for mobile multimedia terminals (EPOC). |
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| Synchronous |
Type of transmission in which the transmission
and reception of all data is synchronized by a common clock
and the data is usually transmitted in blocks rather than individual
characters. Can also mean that the data stream has the same
capacity in both directions. |
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| Synchronous mode |
standard for data transmission - data is transferred
without start and stop bits together with a clock signal to
synchronize the receiver. This mode gives higher data throughput
than asynchronous mode, but can be less secure. |
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