Third Generation (3G) mobile devices
and services will transform wireless communications into on-line, real-time
connectivity. 3G wireless technology will allow an individual to have immediate
access to location-specific services that offer information on demand. The
first generation of mobile phones consisted of the analog models that emerged
in the early 1980s. The second generation of digital mobile phones appeared
about ten years later along with the first digital mobile networks. During the
second generation, the mobile telecommunications industry experienced
exponential growth both in terms of subscribers as well as new types of
value-added services. Mobile phones are rapidly becoming the preferred means of
personal communication, creating the world's largest consumer electronics
industry.
The rapid and efficient deployment of
new wireless data and Internet services has emerged as a critical priority for
communications equipment manufacturers. Network components that enable wireless
data services are fundamental to the next-generation network infrastructure.
Wireless data services are expected to see the same explosive growth in demand
that Internet services and wireless voice services have seen in recent years.
Third Generation (3G) Wireless
Networks 3G wireless technology represents the convergence of various 2G
wireless telecommunications systems into a single global system that includes
both terrestrial and satellite components. One ofthe most important aspects of
3G wireless technology is its ability to unify existing cellular standards,
such as CDMA, GSM, and TDMA, under one umbrella. The following three air interface
modes accomplish this result: wideband CDMA, CDMA2000 and the Universal
Wireless Communication (UWC-136) interfaces. Wideband CDMA (W-CDMA) is
compatible with the current 2G GSM networks prevalent in Europe and parts of
Asia. W-CDMA will require bandwidth of between 5Mhz and 10 Mhz, making it a suitable platform for higher
capacity applications. It can be overlaid onto existing GSM, TDMA (IS-36) and
IS95 networks. Subscribers are likely to access 3G wireless services initially
via dual band terminal devices. W-CDMA networks will be used for high-capacity
applications and 2G digital wireless systems will be used for voice calls.
The second radio interface is CDMA2000
which is backward compatible with the second generation CDMA IS-95 standard
predominantly used in US. The third radio interface, Universal Wireless
Communications – UWC-136, also called IS-136HS, was proposed by the TIA and designed
to comply with ANSI-136, the North American TDMA standard. 3G wireless networks
consist of a Radio Access Network (RAN) and a core network. The core network
consists of a packet-switched domain, which includes 3G SGSNs and
GGSNs, which provide the same functionality that they provide in a GPRS
system, and a circuit-switched domain, which includes 3G MSC for switching of
voice calls. Charging for services and access is done through the Charging
Gateway Function (CGF), which is also part of the core network. RAN functionality
is independent from the core network functionality. The access network provides a core network
technology independent access for mobile terminals to different types of core networks
and network services. Either core network domain can access any appropriate RAN
service; e.g. it should be possible to access a “speech” radio access bearer
from the packetswitched domain. Below is the achitecture of third generation wireless systems.
Initial coverage
Initially, 3G wireless technology will
be deployed as "islands" in business areas where more capacity and
advanced services are demanded. A complete evolution to 3G wireless technology is
mandated by the end of 2000 in Japan (mostly due to capacity
requirements) and by the end of 2001 in Europe. NTT DoCoMo is deploying 3G
wireless services in Japan in the third quarter
of 2000. In contrast, there is no similar mandate in North America and
it is more likely that competition will drive the deployment of 3G wireless
technology in that region. For example,
Nextel Communications has announced
that it will be deploying 3G wireless services in North America during the
fourth quarter of 2000. The implementation of 3G wireless systems raises several
critical issues, such as the successful backward compatibility to air
interfaces as well as to deployed infrastructure.
Interworking with 2G and 2G+ Wireless
Networks
The existence of legacy networks in
most regions of the world highlights the challenge that communications
equipment manufacturers face when implementing next-generation wireless technology. Compatibility and interworking between the
new 3G wireless systems and the old legacy networks must be achieved in order
to ensure the acceptance of new 3G wireless technology by service providers and
end-users.
The existing core technology used in
mobile networks is based on traditional circuit-switched technology for
delivery of voice services. However, this traditional technology is inefficient
for the delivery of multimedia services. The core switches for next-generation
of mobile networks will be based on packet-switched technology which is better
suited for data and multimedia services
The rapid and efficient deployment of
new wireless data and Internet services has emerged as a critical priority for
communications equipment manufacturers. Network components that enable wireless
data services are fundamental to the next-generation network infrastructure.
Wireless data services are expected to see the same explosive growth in demand
that Internet services and wireless voice services have seen in recent years.
Third Generation (3G) Wireless
Networks 3G wireless technology represents the convergence of various 2G
wireless telecommunications systems into a single global system that includes
both terrestrial and satellite components. One ofthe most important aspects of
3G wireless technology is its ability to unify existing cellular standards,
such as CDMA, GSM, and TDMA, under one umbrella. The following three air interface
modes accomplish this result: wideband CDMA, CDMA2000 and the Universal
Wireless Communication (UWC-136) interfaces. Wideband CDMA (W-CDMA) is
compatible with the current 2G GSM networks prevalent in Europe and parts of
Asia. W-CDMA will require bandwidth of between 5Mhz and 10 Mhz, making it a suitable platform for higher
capacity applications. It can be overlaid onto existing GSM, TDMA (IS-36) and
IS95 networks. Subscribers are likely to access 3G wireless services initially
via dual band terminal devices. W-CDMA networks will be used for high-capacity
applications and 2G digital wireless systems will be used for voice calls.
The second radio interface is CDMA2000
which is backward compatible with the second generation CDMA IS-95 standard
predominantly used in US. The third radio interface, Universal Wireless
Communications – UWC-136, also called IS-136HS, was proposed by the TIA and designed
to comply with ANSI-136, the North American TDMA standard. 3G wireless networks
consist of a Radio Access Network (RAN) and a core network. The core network
consists of a packet-switched domain, which includes 3G SGSNs and
GGSNs, which provide the same functionality that they provide in a GPRS
system, and a circuit-switched domain, which includes 3G MSC for switching of
voice calls. Charging for services and access is done through the Charging
Gateway Function (CGF), which is also part of the core network. RAN functionality
is independent from the core network functionality. The access network provides a core network
technology independent access for mobile terminals to different types of core networks
and network services. Either core network domain can access any appropriate RAN
service; e.g. it should be possible to access a “speech” radio access bearer
from the packetswitched domain.
What
Is Special about EDGE?
EDGE is a new modulation scheme
that is more bandwidth efficient than the GMSK modulation
scheme used in the GSM standard.
It provides a promising migration strategy for HSCSD and
GPRS. The technology defines a new
physical layer: 8−PSK modulation, instead of GMSK. 8−PSK enables each pulse to
carry 3 bits of information versus the GMSK 1−bit−per−pulse rate. Therefore,EDGE
has the potential to increase the data rate of existing GSM systems by a factor
of three.
UMTS is a part of the ITU's IMT−2000
vision of a global family of 3G mobile communications
systems. UMTS will play a key role
in creating the future mass market for high−quality wireless
multimedia communications that
will approach 2 billion users worldwide by the year 2010.
UMTS is a modular concept that
takes full advantage of the trend of converging existing and future information
networks, devices, and services, and the potential synergies that can be
derived from such convergence. UMTS will move mobile communications forward
from where we are today into the 3G services and will deliver speech, data,
pictures, graphics, video communication, and other wideband information direct
to people on the move. UMTS is one of the major new 3G mobile communications
systems being developed within the framework, which has been defined by the ITU
and is known as IMT−2000.
WCDMA is an ITU standard derived
from CDMA and is officially known as IMT−2000 direct spread. WCDMA is a 3G
mobile wireless technology offering much higher data speeds to mobile and portable
wireless devices than commonly offered in today's market. WCDMA can support
mobile/portable voice, images, data, and video communications at up to 2 Mbps
(local area access) or 384 Kbps (wide area access). The input signals are
digitized and transmitted in coded, spread−spectrum mode over a broad range of
frequencies. A 5 MHz wide carrier is used, compared with a 200 kHz wide carrier
for narrowband CDMA.
Mobile
Internet — A Way of Life
The mobile Internet is about to
enter our daily lives in a big way. It will change the way we keep in touch
with our friends and family, the way we do business, the way we shop, the way
we access entertainment, and the way we conduct our personal finances.
The Internet is already a part of
daily life for most of us, giving us access to a vast range of
information and online services
from our desktop computers. As a way of conducting business, it is also of
growing importance to the global economy. Unlike today's fixed Internet, the
mobile Internet will give us access to these services and applications wherever
we are, whenever it suits us, from personal mobile devices.
Sources:
http://www.satmagazine.com
http://www.dryaseen.pk
Broadband Telecommunications Handbook
