There are two main cellular network technologies: GSM and CDMA. Major carriers like Sprint, Verizon, and T-Mobile use one or the other. Understanding the differences between GSM and CDMA, such as coverage, data speeds, and roaming capabilities, allows consumers to choose the preferable network for their needs.

2. In cellular service there are two main competing network
technologies:
Global System for Mobile Communications (GSM) and
Code Division Multiple Access (CDMA).
Cellular carriers including Sprint PCS, Cingular Wireless,
Verizon and T-Mobile use one or the other.
Understanding the difference between GSM and CDMA will
allow you to choose a carrier that uses the preferable network
technology for your needs.

3. The GSM Association is an international organization
founded in 1987, dedicated to providing, developing, and
overseeing the worldwide wireless standard of GSM.
 CDMA, a proprietary standard designed by Qualcomm
in the United States, has been the dominant network
standard for North America and parts of Asia.
However, GSM networks continue to make inroads in
the United States, as CDMA networks make progress in
other parts of the world.
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dma-technology

4. GSM: History
 Developed by Group Spéciale Mobile (founded 1982)
which was an initiative of CEPT ( Conference of European
Post and Telecommunication )
 Aim : to replace the incompatible analog system
 Presently the responsibility of GSM standardization resides
with special mobile group under ETSI ( European
telecommunication Standards Institute )
Full set of specifications phase-I became available in 1990
 Under ETSI, GSM is named as “ Global System for Mobile
communication “.

5. CDMA: History
 In July 1985, seven industry veterans, decided they wanted to
build “Quality Communications” and outlined a plan that has
evolved into one of the telecommunications industry’s greatest
start-up success stories: Qualcomm Incorporated.
 Introduction in 1988, OmniTRACS has grown into the largest
satellite-based commercial mobile system for the transportation
industry today.
 In 1989, the Telecommunications Industry Association (TIA)
endorsed a digital technology called Time Division Multiple
Access (TDMA ).
 Qualcomm introduced Code Division Multiple Access (CDMA),
a superior technology for wireless and data products that
changed the global face of wireless communications forever.

6.  Coverage:
The most important factor is getting service in the areas
you will be using your phone.
Upon viewing competitors' coverage maps you may
discover that only GSM or CDMA carriers offer cellular
service in your area.
If so, there is no decision to be made, but most people will
find that they do have a choice.

7. Data Transfer Speed:
With the advent of cellular phones doing double and triple
duty as streaming video devices, podcast receivers and email
devices, speed is important to those who use the phone for
more than making calls.
CDMA has been traditionally faster than GSM, though
both technologies continue to rapidly leapfrog along this
path.
Both boast "3G" standards, or 3rd generation
technologies.

8. What is 2G ?
 Second Generation (2G) wireless cellular mobile
services was a step ahead of First Generation( 1G)
services by providing the facility of short message
service(SMS) unlike 1G that had its prime focus on
verbal communication. A typical 2G G.S.M network
service ranges from 800/900MHz or 1800/1900
spectrum.

9. How is 2G different from 3G?
 In comparison to 2G customers will have to pay a
relatively high license fee for 3G.
 The network construction and maintenance for 3G is
much expensive than 2G.
 From the point of view of customers, expenditure will
be excessively high if they make access to various
facets of 3G.

10. How 3G Works
 3G technology is the modified form of second
generation it is better to say that all the best features of
different versions of 2nd generation are combined into
third generation.
 Resultantly 3G Technology is known as Smartphone
with high data transfer rate, WiFi hotspots
connectivity and multimedia features.
 Three important technologies which make the 3G
standard are CDMA 2000, WCDMA (UMTS), and TDSCDMA.

11. Main 3G Services
 The point to be noted is that 3G gives clarity of voice as
well can talk with out any disturbance.
 Not only these but also have entertainments such as
Fast Communication, Internet, Mobile T.V, Video
Conferencing, Video Calls, Multi Media Messaging
Service (MMS), 3D gaming, Multi-Gaming etc are also
available with 3G phones.

12. Main 4G Features
 Technology has come up with the latest of its type
namely 4G
 Fourth Generation that is 4G in addition to that of the
services of 3G some additional features such as MultiMedia Newspapers, also to watch T.V programs with
the clarity as to that of an ordinary T.V. In addition, we
can send Data much faster that that of the previous
generations.

13. EVDO, also known as CDMA2000, is CDMA's answer
to the need for speed with a downstream rate of about 2
megabits per second, though some reports suggest real
world speeds are closer to 300-700 kilobits per second
(kbps).
GSM's answer is EDGE (Enhanced Data Rates for
GSM Evolution), which boasts data rates of up to 384
kbps with real world speeds reported closer to 70-140
kbps.

14. With added technologies still in the works that
include UMTS (Universal Mobile Telephone Standard)
and HSDPA (High Speed Downlink Packet Access),
speeds reportedly increase to about 275—380 kbps.
This technology is also known as W-CDMA, but is
incompatible with CDMA networks.
An EDGE-ready phone is required.
In the case of EVDO, theoretical high traffic can
degrade speed and performance, while the EDGE
network is more susceptible to interference.

15. Subscriber Identity Module (SIM) cards:
Only GSM phones use SIM cards.
The removable SIM card allows phones to be instantly
activated, interchanged, swapped out and upgraded, all
without carrier intervention.
The SIM itself is tied to the network, rather than the
actual phone.
Phones that are card-enabled can be used with any
GSM carrier.

16.  Some CDMA2000 cell phones support R-UIM cards
(Removable User Identity Module) which are used to store
account information and contact lists.
 If you want to change your phone, you have to contact your
carrier and have them reprogram your new phone.
 Also need to re-enter your contact list and calendar
information into your new phone.
 CDMA phones are slowly catching up with R-UIM cards, but
cell phones that make use of this technology as still rare.

17. Outline

18. CDMA
TECHN
OLOGY
outline

19. Roaming:
 For the most part, both networks have fairly concentrated
coverage in major cities and along major highways.
GSM carriers, however, have roaming contracts with other
GSM carriers, allowing wider coverage of more rural areas,
generally speaking, often without roaming charges to the
customer.
CDMA networks may not cover rural areas as well as
GSM carriers, and though they may contract with GSM
cells for roaming in more rural areas, the charge to the
customer will generally be significantly higher.

20. Which technology is the best ?
 If you travel a lot to foreign countries, you might want to opt for a
GSM phone for a better coverage.
 If you intend to use the phone for mobile web browsing,
watching television or downloading MP3s, you might be better
off with a CDMA phone.
 If you do, a GSM phone is best for you since you can swap the
SIM card to a new device without having to re-enter your
personal data.

22.  Today, CDMA and its core principles provide the backbone for
wireless communications.
 “Films
have a certain place in a certain time period,
but technology is forever.” - Hedy Lamarr

23. THANK YOU