Read the differences
between various mobile technologies being used internationally: GSM, CDMA,
TDMA, EVDO, UMTS and HSPA+. They form the core of wireless networks worldwide.
GSM (Global System for
Mobile Communications)
GSM is a standard set
developed by European Telecommunications Standards Institute (ETSI) to describe
technologies for second generation (2G) digital cellular networks. The GSM
standard is more improved after the development of third generation (3G) UMTS
standard developed by the 3GPP.
CDMA (Code Division
Multiple Access)
CDMA is a channel
access method used by various radio communication technologies. It should not
be confused with the mobile phone standards called cdma One, CDMA2000 (the 3G
evolution of cdma One) and WCDMA (the 3G standard used by GSM carriers), which
are often referred to as simply CDMA, and use CDMA as an underlying channel
access method.
TDMA (Time Division
Multiple Access)
TDMA is a channel
access method for shared medium networks. It allows several users to share the
same frequency channel by dividing the signal into different time slots. The
users transmit in rapid succession, one after the other, each using its own
time slot. This allows multiple stations to share the same transmission medium
(e.g. radio frequency channel) while using only a part of its channel capacity.
TDMA is used in the digital 2G cellular systems 2G cellular systems such as
Global System for Mobile Communications (GSM), Personal Digital Cellular (PDC)
and iDEN standard for cellular phones.
EVDO (Evolution-Data
Optimized or Evolution-Data Only)
EVDO is a
telecommunications standard for the wireless transmission of data through radio
signals, typically for broadband Internet access. It uses multiplexing
techniques including code division multiple access (CDMA) as well as time
division multiplexing (TDM) to maximize both individual user's throughput and
the overall system throughput. It has been adopted by many mobile phone service
providers around the world – particularly those previously employing CDMA
networks. EVDO was designed as an evolution of the CDA2000 standard that would
support high data rates and could be deployed alongside a wireless carrier's
voice services.
UMTS (Universal Mobile
Telecommunications System)
UMTS is a third
generation mobile cellular technology for networks based on the GSM standard.
Developed by the 3GPP (3rd Generation Partnership Project), UMTS is a component
of the International Telecommunication Union IMT-2000 standard set and compares
with the CDMA2000 standard set for networks based on the competing cdma One
technology. UMTS employs Wideband Code Division Multiple Access (W-CDMA) radio
access technology to offer greater spectral efficiency and bandwidth to mobile
network operators. UMTS specifies a complete network system, covering the radio
access network (UMTS Terrestial Radio Access Network, or UTRAN), the core
network (Mobile Application Part, or MAP) and the authentication of users via
SIM cards. The technology described in UMTS is sometimes also referred to as
Freedom of Mobile Multimedia Access (FOMA) or 3GSM.
HSPA+, Or Evolved
High-Speed Packet Access
HSPA or HSPA+ is a
technical standard for wireless, broadband telecommunication. HSPA+ enhances
the widely used WCDMA based 3G networks with higher speeds for the end user
that are comparable to the newer LTE networks. HSPA+ was first defined in the
technical standard 3GPP release 7 and expanded further in later releases. HSPA+
provides an evolution of High Speed Packet Access High Speed Packet Access
provides data rates up to 168 Megabits per second (M bit/s) to the mobile
device and 22 M bit/s from the mobile device.
