Japan Cell Phone Glossary
- What is Unlocked
Some cell phones are designed to use a Subscriber Identification
Module (SIM) card, or microchip that stores subscriber data.
The SIM card is issued by a carrier and provides cell service
by activating any phone into which it is inserted. A locked
phone, however, will only recognize a SIM card from a particular
carrier. If the cell phone is unlocked, it will recognize
a SIM card from any carrier. The "lock" is software setting
that keeps the cell phone "loyal" to one carrier.
In areas like the United States where carriers offer free
or deeply discounted phones with cell plans, the phones
are commonly locked so that they will not work with other
carriers. Carriers claim this is necessary to subsidize
the cost of the phones.
After a period of time, a carrier might agree to unlock
the phone upon request, perhaps charging a fee. However,
due to proprietary settings sometimes installed in locked
handsets, the phones don't always function correctly with
other carriers, even once unlocked. From the viewpoint of
the consumer, the practice of carriers locking phones and
using proprietary settings defeats many of the benefits
of SIM handsets. Complaints led to a class action suit filed
in California in June 2004 by American watchdog group Foundation
for Taxpayer and Consumer Rights (FTCR). Ideally phones
should be left unlocked or at least unlocked after the initial
The downside is that the price is commonly close to full
retail. Some consumers might find it tough to dish out big
bucks for a phone that they can get for free with a plan.
The advantage is that the third party unlocked phone should
work equally well with any carrier that uses SIM cards.
Unlocked cell phones are in such demand that third party
services will unlock your cell phone for a fee. This doesn't
guarantee the phone will always work correctly, as proprietary
settings might remain. There are also hacking instructions
online to unlock many models of phones, but a phone that
is unlocked improperly can be rendered inoperable.
Carriers operating on the GSM network use SIM cards. In
the United Sates, this includes Cingular Wireless, now one
with AT&T Wireless, and T-Mobile. Carriers that use the
competing CDMA network do not yet use card-enabled phones.
These carriers include Sprint PCS, Verizon and Virgin Mobile.
The CDMA equivalent of the SIM card - the R-UIM - will be
used by these carriers in the future. R-UIM cards are already
in use in some parts of Asia.
- What is Dual-band/Tri-band/Quad-band?
Dual-band - A dual-band phone operates
at both the 900 MHz and 1800 MHz spectrum. Dual-band works
in Europe, Africa, Asia, Australia, New Zealand and much
of South America.
Tri-band - A tri-band phone operates on
three frequency bands, 900 MHz, 1800 MHz and 1900 MHz, allowing
you to use it in Europe, Africa, Asia, nearly all of North
America, Australia and New Zealand
Quad-band - A quad-band phone allows you
to roam almost anywhere globally. It covers the 850 Mhz,
900 MHz, 1800 MHz and 1900 MHz frequency ranges. Many countries
in South America only have 850 MHz GSM service while both
1900 MHZ and 850 MHz GSM services are supported in the USA.
99% of all countries use the GSM standard. WE believe eventually
GSM will be the only cell phone standard in the world.
GSM (Global System for Mobile Communications) leads the
world as the fastest growing, most reliable and advanced
digital technology available in the marketplace today. GSM
provides integrated voice mail, high-speed data, fax, paging
and short message services capabilities. GSM customers enjoy
secure communications, and GSM offers unparalleled call
privacy and fraud prevention. As members of the GSM Global
Network, GSM subscribers can use their phones at home, across
town, across the continent, or around the world (except
for with country specific SIM cards). GSM operates on the
multiple spectrum frequency bands used around the world
- 1900MHZ, which is used in North America and 900MHz and
1800 MHz for other locations. Different mobile phone networks
operate at different frequencies, which mean that if you
wish to use your mobile phone outside your home country,
you generally need a handset that supports multiple frequency
bands. Make sure that the cellular phone you are interested
in is compatible with the GSM band of the country you will
use it in. GSM was first introduced in 1991. As of the end
of 1997, GSM service was available in more than 100 countries
and has become the de facto standard in Europe and Asia.
Short for wide-band CDMA (Code-Division Multiple Access),
a 3G technology that increases data transmission rates in
GSM systems by using the CDMA air interface instead of TDMA.
WCDMA is based on CDMA and is the technology used in UMTS.
WCDMA was adopted as a standard by the ITU under the name
"IMT-2000 direct spread".
Short for Code-Division Multiple Access, a digital cellular
technology that uses spread-spectrum techniques. Unlike
competing systems, such as GSM, that use TDMA, CDMA does
not assign a specific frequency to each user. Instead, every
channel uses the full available spectrum. Individual conversations
are encoded with a pseudo-random digital sequence. CDMA
consistently provides better capacity for voice and data
communications than other commercial mobile technologies,
allowing more subscribers to connect at any given time,
and it is the common platform on which 3G technologies are
CDMA is a military technology first used during World War
II by English allies to foil German attempts at jamming
transmissions. The allies decided to transmit over several
frequencies, instead of one, making it difficult for the
Germans to pick up the complete signal. Because Qualcomm
created communications chips for CDMA technology, it was
privy to the classified information. Once the information
became public, Qualcomm claimed patents on the technology
and became the first to commercialize it.
3G is an ITU specification for the third generation (analog
cellular was the first generation, digital PCS the second)
of mobile communications technology. 3G promises increased
bandwidth, up to 384 Kbps when a device is stationary or
moving at pedestrian speed, 128 Kbps in a car, and 2 Mbps
in fixed applications. 3G will work over wireless air interfaces
such as GSM, TDMA, and CDMA. The new EDGE air interface
has been developed specifically to meet the bandwidth needs
A SIM card or Subscriber Identity Module is a portable memory
chip used in some models of cellular telephones. The SIM
card makes it easy to switch to a new phone by simply sliding
the SIM out of the old phone and into the new one. The SIM
holds personal identity information, cell phone number,
phone book, text messages and other data. It can be thought
of as a mini hard disk that automatically activates the
phone into which it is inserted.
A SIM card can come in very handy. For example, let's say
your phone runs out of battery power at a friend's house.
Assuming you both have SIM-based phones, you can remove
the SIM card from your phone and slide it into your friend's
phone to make your call.
Your carrier processes the call as if it were made from
your phone, so it won't count against your friend's minutes.
If you upgrade your phone there's no hassle involved. The
SIM card is all you need. Just slide it into the new phone
and you're good to go. You can even keep multiple phones
for different purposes. An inexpensive phone in the glove
compartment, for example, for emergency use, one phone for
work and another for home. Just slide your SIM card into
whatever phone you wish to use.
High-end cell phones can be very attractive and somewhat
pricey. If you invest in an expensive phone you might want
to keep it awhile. Using a SIM card, it is even possible
to switch carriers and continue to use the same phone. The
new carrier will simply issue you their own SIM card. The
phone must be unlocked, however, and operate on the new
carrier's frequency or band.
A SIM card provides an even bigger advantage for international
travelers -- simply take your phone with you and buy a local
SIM card with minutes. For example, a traveler from the
U.S. staying in the U.K. can purchase a SIM card across
the pond. Now the phone can be used to call throughout England
without paying international roaming charges from the carrier
SIM cards are used with carriers that operate on the Global
System for Mobile Communication (GSM) network. The competing
network is Code Division Multiple Access (CDMA), a technology
created by U.S. Company Qualcomm. As of fall 2005, CDMA
cell phones and CDMA carriers do not support SIM cards in
most parts of the world, though this is changing. A CDMA
SIM card called the R-UIM (Re-Useable Identification Module)
was made available in China in 2002, and will eventually
be available worldwide. Expectations for the future include
a cell phone market that supports both SIM (GSM) and R-UIM
(CDMA) cards by default.
- What is Pre-Paid
A pre-paid phone card is a card you purchase to make long
distance phone calls. Many people use a pre-paid phone card
because of the cards convenience - it can be used anywhere
and, because you pay in advance, there is no bill. Pre-paid
phone cards are popular among travelers, students, people
who frequently call overseas, and those who haven¡¯t selected
a preferred long distance telephone company. In addition,
pre-paid phone cards are sold in convenient places, such
as newsstands, post offices, and stores. What are Unlocked
Short for Systems Management Server, a set of tools from
Microsoft that assists in managing PCs connected to a local-area
network (LAN). SMS enables a network administrator to create
an inventory of all the hardware and software on the network
and to store it in an SMS database. Using this database,
SMS can then perform software distribution and installation
over the LAN. SMS also enables a network administrator to
perform diagnostic tests on PCs attached to the LAN.
SMS runs under Windows NT but can manage PCs running DOS,
all varieties of Windows, and OS/2, as well as Macintosh
Short for Short Message Service Similar to paging, SMS is
a service for sending short text messages to mobile phones.
Also known as EMS (Expanded Memory Specification), expanded
memory is a technique for utilizing more than 1MB of main
memory in DOS -based computers. The limit of 1MB is built
into the DOS operating system. The upper 384K is reserved
for special purposes, leaving just 640K of conventional
memory for programs.
There are several versions of EMS. The original versions,
called EMS 3.0 and 3.2, enable programs to use an additional
8MB of memory, but for data only. An improved version developed
by AST, Quadram and Ashton-Tate is known as EEMS (Extended
EEMS enables programs to use extra memory for code as well
as for data. The most recent version of EMS (created in
1987) is known as EMS 4.0 or LIM 4.0, LIM being the initials
of the three companies that developed the specification:
Lotus, Intel, and Microsoft. EMS 4.0 raises the available
amount of memory to 32MB.
Until the release of Microsoft Windows 3.0 in 1990, expanded
memory was the preferred way to add memory to a PC. The
alternative method, called extended memory, was less flexible
and could be used only by special programs such as RAM disks.
Windows 3.0 and all later versions of Windows, however,
contain an extended memory manager that enables programs
to use extended memory without interfering with one another.
In addition, Windows can simulate expanded memory for those
programs that need it (by using the EMM386.EXE driver).
Abbreviated as EMS, an application-level extension to SMS
for cellular phones available on GSM, TDMA and CDMA networks.
An EMS-enabled mobile phone can send and receive messages
that have special text formatting (such as bold or italic),
animations, pictures, icons, sound effects and special ring
EMS messages that are sent to devices that do not support
it will be displayed as SMS transmissions.
EMS, also referred to as Enhanced Messaging Service, is
cross-industry collaboration between Ericsson, Motorola,
Siemens and Alcatel, among others.
Also see SMS and MMS.
Short for Multimedia Message Service.
Abbreviated as MMS, Multimedia Message Service is a store-and-forward
method of transmitting graphics, video clips, sound files
and short text messages over wireless networks using the
WAP protocol. Carriers deploy special servers, dubbed MMS
Centers (MMSCs) to implement the offerings on their systems.
MMS also supports e-mail addressing, so the device can send
e-mails directly to an e-mail address. The most common use
of MMS is for communication between mobile phones.
PHS (Personal Handyphone System) is a low-powered wireless
phone technology developed in Japan and rather different
from other cellular phone technologies.
¡¤ Designed as dual-mode phone between public wireless network
and home (or corporate) phone line.
¡¤ Data communication in 32k/64kbps circuit switching or
32k/128k/256kbps packet exchange.
¡¤ Can be used even in subway stations or underground arcades
because cell stations are relatively small and can be installed
PHS has been deployed in Japan since mid-1990's; now also
in China, Taiwan, Thailand (where called PCT) etc. Today
PHS is considered as low-cost data communication service
rather than voice phone in Japan. Unlimited data communication
plans are available