|
S |
|
S-Band |
The frequency spectrum near 2 GHz used for land based microwave
and some mobile satellite communications. |
|
Service Charge |
The amount customers pay each month to receive wireless service.
This amount is fixed, and to be paid monthly regardless of how
much or how little customers use their wireless phones. |
|
Service Plan |
The rate plan you select when choosing a wireless phone service.
A service plan typically consists of a monthly base rate for
access to the system and a fixed amount of minutes per month.
Service plans are designed to provide the most cost-effective
rates for different types and amounts of usage by the cellular
subscriber. |
|
Short Message Service (SMS) |
The transmission of short alphanumeric text-messages to and from
a mobile phone, fax machine and/or IP address. Messages must be
no longer than 160 alphanumeric characters and contain no images
or graphics. Once a message is sent, it is received by a Short
Message Service Center (SMSC), which must then get it to the
appropriate mobile device. |
|
Short Message Service Center (SMSC) |
The hardware device submitting the messages. Currently, SMSC
devices support binary formats. |
|
SIM Card |
A
small printed circuit board that must be inserted in any GSM-based
mobile phone when signing on as a subscriber. It contains
subscriber details, security information and memory for a
personal directory of numbers. The card can be a small plug-in
type or sized as a credit-card but has the same functionality.
The SIM card also stores data that identifies the caller to the
network service provider. |
|
Simple Network Paging Protocol (SNPP) |
A
sequence of commands and replies where pages are delivered to
individual paging terminals. The most obvious benefit is the
elimination of the need for modems and phone lines to produce
alphanumeric pages, and the ease of delivery of pages to
terminals in other cities or countries. |
|
Simulcast |
A
signaling technique that broadcasts the same signal over
multiple sites in a network. |
|
Sleep Mode |
Designed to conserve battery life, this mode automatically turns
off a terminal after it has been unused for a specified period
of time. The unit is reactivated when the keypad is touched. |
|
Smart Antenna |
An
antenna system that focuses its beam on a desired signal to
reduce interference. A wireless network employs smart antennas
at its base stations in an effort to reduce the number of
dropped calls, improve call quality and improve channel
capacity. |
|
Smart Card |
A
plastic card containing important data about a person's identity
to allow access to a network or premises. Also, a card
containing subscriber information, often inserted into GSM
phones for roaming in different countries. |
|
Smart Phone |
A
class of wireless phone handsets with many features, and often a
keyboard. What makes the phone "smart" is its ability to handle
data, not only voice calls. |
|
Soft Handoff |
When two base stations -- one in the cell site where the phone
is located and the other in the cell site to which the
conversation is being passed - both hold onto the call until the
handoff is completed. The first cell site does not cut off the
conversation until it receives information that the second is
maintaining the call. |
|
Soft Key |
A
key below the phone's main display panel that performs special
functions. |
|
Space Division Multiple Access (SDMA) |
A
variation of TDMA and CDMA that potentially will be used in
high-bandwidth, third-generation wireless products. |
|
Specialized Mobile Radio (SMR) |
Dispatch service ("walkie-talkie-type" service used by taxis,
delivery trucks, etc.). SMR providers in the United States
operate in the 800 MHz and 900 MHz frequency bands. |
|
Specific Absorption Rate (SAR) |
A
measure of the rate at which RF energy is absorbed by the body. |
|
Spectrum |
The range of electromagnetic radio frequencies used in the
transmission of sound, data and television. |
|
Spectrum Allocation |
Federal government assignment of a range of frequencies for a
category of use or uses. For example, the FCC allocated the 1900
MHz band for personal communications services. Allocation,
accomplished in FCC proceedings, tracks new technology
development. However, the FCC can shift existing allocations to
respond to changes in spectrum demand. |
|
Spectrum Assignment |
Federal government authorization for use of specific frequencies
or frequency pairs within a given allocation, at specific
geographic locations. |
|
Spectrum Cap |
A
limit to the allocated spectrum designated for a specific
service. |
|
Spread Spectrum |
Initially devised for military use, this radio transmission
technology "spreads" information over greater bandwidth than
necessary to resist jamming and other interference. |
|
Standby Time |
The amount of time you can leave your fully charged cellular
portable or transportable phone turned on before the phone will
completely discharge the batteries. See Talk Time. |
|
Stratospheric Platform |
Blimp-like platform for wireless telephone service in urban
areas. |
|
Strongest Signal |
The concept that a wireless 911 call should be routed to the
cell site with the strongest link to the phone, regardless of
which carrier holds the caller as a customer. A shortcoming is
that strength of the call's setup link isn't always equal to
that of the link the cell assigns for voice traffic because the
latter can be weaker. |
|
Subscriber Fraud |
Securing wireless service with intent to avoid payment. This is
different from bad debt, which occurs when a known person or
company has a payment obligation overdue and the debt cannot be
collected. |
|
Subscriber Identity Module (SIM) |
A
card inserted into a GSM/TDMA or GSM-only handset containing
subscriber-related data. The card contains 18 digits for GSM
markets and 20 digits for TDMA markets. |
|
Subscriber Profiling |
Compiling subscriber usage information (such as frequency of
calls, locations called to or from and monthly airtime usage),
to identify potentially fraudulent use or to identify customers
likely to terminate service. This information can also be used
to target customers when marketing a carrier's product and
service offerings. |
|
Switch |
A
mechanical, electrical or electronic device that opens or closes
circuits, completes or breaks an electrical path, or selects
paths or circuits. |
|
T |
|
Talk Time |
The length of time you can talk on your portable or
transportable cellular phone without recharging the battery. The
battery capacity of a cellular portable or transportable is
usually expressed in terms of so many minutes of talk time or so
many hours of standby time. When you're talking, the phone draws
additional power from the battery. See Standby Time. |
|
TD-CDMA |
A
3G proposal combining elements of TDMA and CDMA. |
|
Telecommunications |
The transmission of words, sounds, or images, usually over great
distances, in the form of electromagnetic energy, for example by
telegraph, telephone, radio, or television. |
|
Telecommunications Industry Association (TIA) |
The United States' telecommunications standards making body. |
|
Telematics |
The integration of wireless communications, vehicle monitoring
systems and location devices. |
|
Telematics Control Unit (TCU) |
The embedded vehicle control unit that communicates with the
automobile controls, GPS satellite and customer service center
to provide Telematics features to a driver. |
|
Telephone Network |
The system of wires, fiber-optic cables, satellites, and
transmission towers that transmit telephone messages from caller
to receiver. |
|
Telephone Transmission Tower |
A
telephone base station located on top of a tall, free-standing
structure. |
|
Telephony |
Originally meaning voice (analog) communication by telephone
(land line), this term has come to encompass virtually all
telecommunications, because virtually all telecommunications can
be done over or while connected to a telephone line. |
|
Termination Charges |
Fees that wireless telephone companies pay to complete calls on
wireline phone networks or vice versa. |
|
Third Generation (3G) |
A
new wireless standard promising increased capacity and
high-speed data applications up to two megabits. Third
generation wireless employ wideband frequency carriers and a
CDMA air interface. Networks must be able to transmit wireless
data at 144 kilobits per second at mobile user speeds.
Implemented in Europe as UMTS and CDMA2000 in North America, its
goals are high-quality multimedia and advanced global roaming
(in house, cellular, satellite, etc.). |
|
Time Division Multiple Access (TDMA) |
A
method of digital wireless communications transmission allowing
a large number of users to access a single radio-frequency
channel without interference. Each user is given a unique time
slot within each channel. SMS Mobile Originate has now gone live
on several TDMA networks around the world including Telecom New
Zealand, Midwest Wireless USA, Algar Telecom Brazil and Cellcom
Israel. Other TDMA network operators such as AT&T Wireless in
the U.S. have launched SMS nationally. |
|
Total Access Communication System (TACS) |
European analog cellular. |
|
Transceiver |
Equipment to handle the broadcast and reception of radio signals
with network or subscriber equipment. |
Tri-Band
|
A
network infrastructure or wireless phone designed to operate in
three frequency bands: 800 MHz, 900 MHz and 1800MHz. |
Tri-Mode
|
Phones that work on three modes GSM, TDMA and analog. |
Triangulation
|
The process of pinning down a caller's location using three or
more radio receivers, a compass and a map. |
Trunking
|
Spectrum-efficient technology that establishes a queue to handle
demand for voice or data channels. |
