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					GSM & CDMA AT WIKIPEDIA VIEW
W-CDMA
W-CDMA (Wideband Code Division Multiple Access) is a type of 3G cellular network. W-CDMA is the
higher speed transmission protocol used in the Japanese FOMA system and in the UMTS system, a third
generation follow-on to the 2G GSM networks deployed worldwide.

More technically, W-CDMA is a wideband spread-spectrum mobile air interface that utilizes the direct
sequence Code Division Multiple Access signalling method (or CDMA) to achieve higher speeds and
support more users compared to the implementation of time division multiplexing (TDMA) used by 2G
GSM networks

Only key features are cited below.


        Radio channels are 5MHz wide.
        Chip rate of 3.84 Mcps
        Supports two basic modes of duplex, frequency division and time division. Current systems use
frequency division, one frequency for uplink and one for downlink. For time division, FOMA uses sixteen
slots per radio frame, where as UMTS uses fifteen slots per radio frame.
        Employs coherent detection on uplink and downlink based on the use of pilot symbols.
        Supports inter-cell asynchronous operation.
        Variable mission on a 10 ms frame basis.
        Multicode transmission.
        Adaptive power control based on SIR (Signal-to-Interference Ratio).
        Multiuser detection and smart antennas can be used to increase capacity and coverage.
        Multiple types of handoff between different cells including soft handoff, softer handoff and hard
handoff.

        W-CDMA was developed by NTT DoCoMo as the air interface for their 3G network FOMA. Later
        NTT DoCoMo submitted the specification to the International Telecommunication Union (ITU) as
        a candidate for the international 3G standard known as IMT-2000. The ITU eventually accepted
        W-CDMA as part of the IMT-2000 family of 3G standards, as an alternative to CDMA2000,
        EDGE, and the short range DECT system. Later, W-CDMA was selected as the air interface for
        UMTS, the 3G successor to GSM.
        Code Division Multiple Access communication networks have been developed by a number of
        companies over the years, but development of cell-phone networks based on CDMA (prior to W-
        CDMA) was dominated by Qualcomm, the first company to succeed in developing a practical and
        cost-effective CDMA implementation for consumer cell phones, its early IS-95 air interface
        standard. IS-95 evolved into the current CDMA2000 (IS-856/IS-2000) standard.

        In the late 1990s, NTT DoCoMo began work on a new wide-band CDMA air interface for their
        planned 3G network FOMA. FOMA's air interface, called W-CDMA, was selected as the air
        interface for UMTS, a newer W-CDMA based system designed to be an easier upgrade for
        European GSM networks compared to FOMA. FOMA and UMTS use essentially the same air
        interface, but are different in other ways; thus, handsets are not 100% compatible between FOMA
        and UMTS, but roaming is supported.

        Qualcomm created an experimental wideband CDMA system called CDMA2000 3x which unified
        the W-CDMA (3GPP) and CDMA2000 (3GPP2) network technologies into a single design for a
        worldwide standard air interface. Compatibility with CDMA2000 would have beneficially enabled
        roaming on existing networks beyond Japan, since Qualcomm CDMA2000 networks are widely
        deployed, especially in the Americas, with coverage in 58 countries in 2006. However, divergent
        requirements resulted in the W-CDMA standard being retained and deployed.

        Despite incompatibilities with existing air-interface standards, the late introduction of this 3G
        system, and despite the high upgrade cost of deploying an all-new transmitter technology, W-
        CDMA has been adopted and deployed rapidly, especially in Japan, Europe and Asia, and is
        already deployed in over 55 countries as of 2006



UMTS, using W-CDMA, supports up to 14.0 Mbit/s data transfer rates in theory (with HSDPA), although at
the moment users in deployed networks can expect a performance up to 384 kbit/s for R99 handsets, and
3.6 Mbit/s for HSDPA handsets in the downlink connection. This is still much greater than the 9.6 kbit/s of
a single GSM error-corrected circuit switched data channel or multiple 9.6 kbit/s channels in HSCSD (14.4
kbit/s for CDMAOne), and—in competition to other network technologies such as CDMA2000, PHS or
WLAN—offers access to the World Wide Web and other data services on mobile devices.

Precursors to 3G are 2G mobile telephony systems, such as GSM, IS-95, PDC, PHS and other 2G
technologies deployed in different countries. In the case of GSM, there is an evolution path from 2G,
called GPRS, also known as 2.5G. GPRS supports a much better data rate (up to a theoretical maximum
of 140.8 kbit/s, though typical rates are closer to 56 kbit/s) and is packet switched rather than connection
oriented (circuit switched). It is deployed in many places where GSM is used. E-GPRS, or EDGE, is a
further evolution of GPRS and is based on more modern coding schemes. With EDGE the actual packet
data rates can reach around 180 kbit/s (effective). EDGE systems are often referred as "2.75G Systems".

Since 2006, UMTS networks in many countries have been or are in the process of being upgraded with
High Speed Downlink Packet Access (HSDPA), sometimes known as 3.5G. Currently, HSDPA enables
downlink transfer speeds of up to 3.6 Mbit/s. Work is also progressing on improving the uplink transfer
speed with the High-Speed Uplink Packet Access (HSUPA). Longer term, the 3GPP Long Term Evolution
project plans to move UMTS to 4G speeds of 100 Mbit/s down and 50 Mbit/s up, using a next generation
air interface technology based upon OFDM.

UMTS supports mobile videoconferencing, although experience in Japan and elsewhere has shown that
user demand for video calls is not very high.

Other possible uses for UMTS include the downloading of music and video content, as well as live TV.




Evolusi WCDMA dengan HSDPA Wujudkan “Mobile Broadband” Jadi Kenyataan

JAKARTA – Evolusi WCDMA dari Ericsson adalah evolusi alami WCDMA (Wideband Code Division
Multiple Access), yang merupakan standar komunikasi bergerak generasi ketiga. Evolusi WCDMA
dimungkinkan dengan diperkenalkannya High Speed Downlink Packet Access (HSDPA). Langkah
evolusioner pertama ini akan meningkatkan downlink peak data rate hingga mencapai 14 Mbit/s dan lebih
dari dua kali lipat kapasitas sistim data dengan spektrum radio yang sama. Para operator sangat tertarik
dengan teknologi baru ini dan Ericsson baru-baru ini telah melakukan beberapa percobaan dengan
operator                                             di                                          dunia.
Evolusi WCDMA adalah wujud dari kepemimpinan Ericsson dalam sistem komunikasi bergerak.
Teknologi ini memungkinkan operator untuk menawarkan pelayanan mobile broadband yang canggih
seperti Internet dan akses Intranet perusahaan dengan kecepatan data yang sangat tinggi, di mana
audio, video Asafile atau dokumen yang besar dapat di-download dengan lebih cepat daripada dengan
menggunakan                              WCDMA                         yang                        ada.
Bagi pengguna, evolusi WCDMA dapat memenuhi keinginan konsumen untuk mendapatkan kepuasan
pelayanan komunikasi bergerak yang lebih baik. Bagi operator, teknologi ini merupakan jawaban dari
kebutuhan mereka akan kapasitas yang lebih besar, serta peningkatan efisiensi jaringan.

Nilai                                                                                        Tambah
Pengalaman yang didapat dari fase awal menunjukan bahwa sangatlah penting bagi operator untuk
dapat menawarkan nilai tambah yang besar bagi pelanggan, termasuk di antaranya kapasitas sistim yang
lebih besar. Inilah fokus dari langkah evolusioner pertama dari evolusi WCDMA. Langkah kedua dari
evolusi WCDMA antara lain adalah menyediakan fitur untuk melengkapi uplink dengan cakupan yang
lebih         luas,        dan         kecepatan         data        yang        lebih         tinggi.
Langkah pertama dari evolusi WCDMA adalah berdasarkan teknologi HSDPA (High Speed Downlink
Packet Access). Teknologi ini merupakan bagian yang tidak dapat dipisahkan dengan WCDMA dan
mengikuti standar WCDMA 3GPP keluaran 5. Standar ini antara lain mencakup format transmisi baru
bernama high-speed downlink shared channel yang memungkinkan pelayanan interaktif, latar belakang
dan                    streaming                   yang                  lebih                   baik.
Kelebihan yang ditawarkan HSDPA antara lain, meningkatkan layanan mobile data bagi pengguna,
dengan membuat waktu download menjadi lebih pendek melalui kecepatan data yang lebih tinggi (14
Mbits/peak                                                                                      rate).
HSDPA juga mengurangi keterlambatan (delay) dan memberikan respon yang lebih cepat saat pengguna
menggunakan aplikasi interaktif seperti mobile office atau akses Internet kecepatan tinggi, yang dapat
disertai pula dengan fasilitas gaming atau download audio dan video. Kelebihan lain HSDPA,
meningkatkan kapasitas sistim tanpa memerlukan spektrum frekuensi tambahan, sehingga pasti akan
mengurangi           biaya          layanan          mobile        data       secara         signifikan.
HSDPA hanya membutuhkan software upgrade pada WCDMA base station yang sudah ada. Hal ini
sesuai dengan tradisi Ericsson yang sudah dikenal di mana selalu menawarkan produk yang dapat
disesuaikan dengan perkembangan teknologi masa depan. Sebagai perbandingan, proses upgrade
jaringan WCDMA yang sudah ada untuk menjadi evolusi WCDMA dengan HSDPA, jauh lebih sederhana
dari pada implementasi EDGE (Enhanced Data Rates for Global Evolutiori) ke dalam jaringan GSM.
Ericsson percaya bahwa kecepatan data lebih tinggi yang ditawarkan oleh HSDPA pada awalnya pasti
akan memberikan keuntungan bagi pengguna korporat. Ini membuat WCDMA menjadi teknologi akses
yang lebih dipilih untuk mobile office dan aplikasi Internet yang membutuhkan kecepatan data tinggi, di
samping tersedianya keamanan, mobilitas dan kemudahan pemakaian. (tot)


HSDPA

High-Speed Downlink Packet Access (HSDPA, also known as High-Speed Downlink Protocol
Access) is a 3G (third generation) mobile telephony communications protocol in the High-Speed Packet
Access (HSPA) family, which allows networks based on Universal Mobile Telecommunications System
(UMTS) to have higher data transfer speeds and capacity. Current HSDPA deployments support down-
link speeds of 1.8, 3.6, 7.2 and 14.4 Mbit/s, and can provide each customer with 30 gigabytes of data per
       [1]
month.       Further speed increases are planned for the near future. The networks are then to be upgraded
                                                                                   [1]
to Evolved HSPA, which provides speeds of 42 Mbit downlink in its first release.




HSPA

High-Speed Packet Access (HSPA) is a collection of mobile telephony protocols that extend and
improve the performance of existing UMTS protocols. Two standards HSDPA and HSUPA have been
established and a further standard HSOPA is being proposed.
The two existing standards (HSDPA and HSUPA) in the family provide increased performance by using
improved modulation schemes and by refining the protocols by which handsets and base stations
communicate. These improvements lead to a better utilization of the existing radio bandwidth provided by
UMTS

HSDPA provides improved down-link performance of up to 14.4 Mbit/s theoretically. Existing deployments
provide up to 7.2 Mbit/s in down-link. Up-link performance is a maximum of 384 kbit/s.

Service providers such as T-Mobile cap this rate to 1.4Mbit/s despite the fact that modern 3G handsets
are designed to handle speeds of up to 3.6 Mbit/s. Voice calls are usually prioritized over data transfer.
Croatian VIPnet network supports the speed of 7.2 Mbit/s in down-link.
FOMA

FOMA, officially short for Freedom of Mobile Multimedia Access, is the brand name for the 3G services
being offered by Japanese mobile phone operator NTT DoCoMo.

FOMA was the world's first W-CDMA 3G service when launched in 2001. FOMA is compatible with
standard UMTS, both via the radio link as well as via USIM card exchange, and hence provides several
alternative options for global roaming: either with or without change of handset. Since mobile services in
Japan are generally more advanced than in most other countries, e.g. FeliCa-i-Mode Wallet Phones, i-
Mode mobile data services etc, to obtain full benefit of FOMA services local Japanese handsets are used.
                                                              [citation needed]
Initially - as the first full-scale 3G service in the world                       - FOMA handsets were of experimental
character targeting early adopters, and were big, had poor battery life and the network covered the center
of Japan's largest towns only. For the first 1-2 years, FOMA was essentially an experimental service for
early adopters - mainly communication industry professionals.

Around March 2004, with almost full national coverage including subway stations and the inside of most
                  [citation needed]
major buildings                       , and with the introduction of DoCoMo's 900i series of handsets, FOMA
achieved the breakthrough into mass sales, and sales soared. As of September 2006, FOMA has over 29
million subscribers and is the fastest growing cellphone network in Japan




IMEI

The International Mobile Equipment Identity or IMEI (IPA /aɪ'mi:/) is a number unique to every GSM
and UMTS mobile phone. It is usually found printed on the phone underneath the battery and can also be
found by dialing the sequence *#06# into the phone.

The IMEI number is used by the GSM network to identify valid devices and therefore can be used to stop
a stolen phone from accessing the network. For example, if a mobile phone is stolen, the owner can call
his or her network provider and instruct them to "ban" the phone using its IMEI number. This renders the
phone useless, regardless of whether the phone's SIM is changed.

Unlike the Electronic Serial Number or MEID of CDMA and other wireless networks, the IMEI is only used
to identify the device, and has no permanent or semi-permanent relation to the subscriber. Instead, the
subscriber is identified by transmission of an IMSI number, which is stored on a SIM card which can (in
theory) be transferred to any handset. However, many network and security features are enabled by
knowing the current device being used by a subscriber.

The IMEI (14 digits plus check digit) or IMEISV (16 digits) includes information on the origin, model, and
serial number of the device. The structure of the IMEI/SV are specified in 3GPP TS 23.003. The model
and origin comprise the initial 8-digit portion of the IMEI/SV, known as the Type Allocation Code (TAC).
The remainder of the IMEI is manufacturer-defined, with a Luhn check digit at the end (which is never
transmitted).

As of 2004, the format of the IMEI is AA-BBBBBB-CCCCCC-D, although it may not always be displayed
this way. The IMEISV drops the Luhn check digit in favour of an additional 2 digits for the Software
Version Number (SVN) in the format AA-BBBBBB-CCCCCC-EE

AA                       BBBBBB                       CCCCCC               D                        EE
Reporting        Body The remainder                 of Serial sequence of Luhn check digit of Software Version
Identifier, indicating the TAC                         the model          the entire number Number (SVN).
the GSMA-approved                                                         (or zero)
group that allocated
the model TAC

Prior to 2002, the TAC was 6 digits long and followed by a two-digit Final Assembly Code (FAC), which
was a manufacturer-specific code indicating the location of the device's construction.

For example the IMEI code 35-209900-176148-1 or IMEISV code 35-209900-176148-23 tells us the
following:
TAC:     352099    so        it   was      issued     by   the   BABT    and   has    the   allocation   number    2099
FAC: 00 so it was numbered during the transition phase from the old format to the new format (described
below)
SNR:           176148             -        uniquely        identifying     a         unit      of        this     model
CD:          1          so            it       is          a       GSM         Phase           2         or       higher
SVN: 23 - The 'software version number' identifying the revision of the software installed on the phone. 99
is reserved.

The format changed from April 1, 2004 when the Final Assembly Code ceased to exist and the Type
Approval Code increases to eight digits in length and became known as the Type Allocation Code. From
January 1, 2003 until this time the FAC for all phones was 00.

The Reporting Body Identifier is allocated by the Global Decimal Administrator; the first two digits must be
decimal (ie less than 0xA0) for it to be an IMEI and not an MEID.

The new CDMA Mobile Equipment Identifier (MEID) uses the same basic format as the IMEI.



On many devices the IMEI number can be retrieved by entering *#06#. The IMEI number of a GSM
device can be retrieved by sending the command AT+CGSN. For more information refer the 3GPP TS
27.007, Section 5.4 /2/ standards document.
Retrieving IMEI Information from a Sony or Sony Ericsson handset can be done by entering these keys:
Right * Left Left * Left * (Other service menu items will be presented with this key combination).

The IMEI information can be retrieved from most Nokia mobile phones by pressing *#92702689#
(*#WAR0ANTY#), this opens the warranty menu in which the first item is the serial number (the IMEI).
The warranty menu also shows other information such as the date the phone was made and the life timer
of the phone.

The IMEI can frequently be displayed through phone menus, under a section titled 'System Information',
'Device', 'Phone Info' or similar. Many phones also have the IMEI listed on a label in the battery
compartment.



Many countries have acknowledged the use of the IMEI in reducing the effect of mobile phone theft,
                                                            [citation needed]
which has increased exponentially over the last few years                   . For example, in the United Kingdom
under the Mobile Telephones (Re-programming) Act, changing the IMEI of a phone, or possessing
equipment that can change it, is considered an offence under some circumstances.

There is a misunderstanding amongst some regulators that the existence of a formally allocated IMEI
number range to a GSM terminal implies that the terminal is approved or complies with regulatory
requirements. This is not the case. The linkage between regulatory approval and IMEI allocation was
removed in April 2000 with the introduction of the European R&TTE Directive. Since that date, IMEIs
have been allocated by BABT (acting on behalf of the GSM Association) to legitimate GSM terminal
manufacturers without the need to provide evidence of approval.

Other countries use different approaches when dealing with phone theft. For example, mobile operators
in Singapore are not required by the regulator to implement phone blocking or tracing systems, IMEI-
based or other. The regulator has expressed its doubts on the real effectiveness of this kind of systems in
the context of the mobile market in Singapore. Instead, mobile operators are encouraged to take
measures such as the immediate suspension of service and the replacement of SIM cards in case of loss
or theft



When mobile equipment is stolen or lost, the operator or owner will typically contact the Central
Equipment Identity Register (CEIR) which blacklists the device in all operator switches so that it will in
effect become unusable, making theft of mobile equipment a useless business.

The IMEI number is not supposed to be easy to change, making the CEIR blacklisting effective. However
this is not
                                       "New IMEIs can be programmed into stolen handsets and 10% of
                                       IMEIs are not unique." According to a BT-Cellnet spokesman quoted
                                       by the BBC. [2]
                                       Facilities do not exist to unblock numbers listed in error on all
                                       networks. This is possible in the UK, however, where the user who
                                       initially blocked the IMEI must quote a password chosen at the time
                                       the block was applied.

        High-Speed Downlink Packet Access (HSDPA) adalah sebuah protokol telepon genggam dan
        kadangkala disebut sebagai teknologi 3,5G. Teknologi ini dikembangkan dari WCDMA sama
        seperti EV-DO mengembangkan CDMA2000. HSDPA memberikan jalur evolusi untuk jaringan
        Universal Mobile Telecommunications System (UMTS) yang akan dapat memberikan kapasitas
        data yang lebih besar (sampai 14,4 Mbit/detik arah turun). HSDPA merupakan evolusi dari
        standar W-CDMA dan dirancang untuk meningkatkan kecepatan transfer data 5x lebih tinggi.
        HSDPA memdefinisikan sebuah saluran W-CDMa yang baru, yaitu high-speed downlink shared
        channel (HS-DSCH) yang cara operasinya berbeda dengan saluran W-CDMA yang ada
        sekarang, tetapi hanya digunakan dalam komunikasi arah bawah menuju telepon genggam.

Mobile Equipment Identifiers (MEIDs) are globally unique numbers identifying a physical piece of
CDMA mobile station equipment. The number format is defined by the 3GPP2 standard S.R0048 but in
practical terms it is an IMEI with a two-digit hexadecimal prefix.




An MEID is 56 bits long (14 hex or 18 decimal digits). It consists of three fields, including an 8-bit regional
code (RR), a 24-bit manufacturer code, and a 24-bit manufacturer-assigned serial number.

The MEID replaces the Electronic Serial Number (ESN) which has been exhausted. Special Pseudo
ESNs (pESNs) can be computed from an MEID for backward compatibility. A Pseudo ESN (pESN) has
0x80 as its Manufacturer Code, followed by 24 bits of the SHA-1 hash of the 56 bit MEID. As of
TIA/EIA/IS-41 Revision D and TIA/EIA/IS-2000 Rev C ESN is still a required field in many messages. In
these cases pESN can be used in the ESN field and the MEID specified in the new MEID field (if any).




Administration
The separation between International Mobile Equipment Identifiers (IMEIs) used by GSM/UTMS and
MEIDs is based on the number ranges. There are two administrators; the Global Decimal Administrator
(GDA) for IMEIs and the Global Hexadecimal Administrator (GHA).

As of August 2006, the TIA acts as the Global Hexadecimal Administrator (GHA) to assign MEID code
prefixes (0xA0 and up), and the GSM Association acts as the Global Decimal Administrator.
http://www.babt.com/gsm-imei-number-allocation.asp

The middle ground between IMEIs and MEIDs is for inter-standard "worldphone" devices. These devices
will have an IMEI with a prefix of 0x99. The GDA has responsibility for the allocation of these IMEIs, since
they are decimal numbers.

Display Formats

There are two standard formats for MEIDs, and both can include an optional check-digit. This is defined
by 3GPP2 standard X.S0008.

The hexadecimal form is specified to be 14 digits grouped together. A check-digit can be calculated using
a modified Luhn algorithm and appended to the end. The check-digit is never transmitted or stored.

The decimal form is specified to be 18 digits grouped in a 5 5 4 4 pattern. A check-digit can be calculated
using a modified Luhn algorithm and appended to the end. The Luhn algorithm is different from the one
used for the hexadecimal form.

pESN Conflicts

Because the pESN is formed by a hash on the MEID there is the potential for hash collisions. These will
have relatively severe impacts on a pure ESN-only network as the ESN is used for the calculation of the
Public Long Code Mask (PLCM) used for communication with the base-station. Duplicates within the
same base-station area will result in call setup and page failures.

The probability of a collision has been investigated although further analysis using the birthday paradox
may produce different results.

				
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