Md. Bahadur Ali
GM (Finance & Accounts)
Network
technology plays a significant role in the science and business area.
Scientists innovate and develop some new technologies to fit businesses’ needs
and to satisfy people’s demands. The first generation, 1G wireless mobile
communication systems, was introduced in the early 1980s and completed in the
early 1990s. 1G wireless was analog and supported the first generation of analog
cell phones with the speeds up to 2.4kbps. The second generation, 2G system,
fielded in the late 1980s and finished in the late 1990s, was planned mainly
for voice transmission with digital signal and the speeds up to 64kbps. The
third generation, 3G wireless system, was developed in the late 1990s and might
be well-done in the late 2000s. 3G is not only provided the transmission speeds
from 125kbps to 2Mbps, but also included many services, such as global roaming,
superior voice quality and data always add-on. The fourth generation (4G) is a
conceptual framework and a discussion point to address future needs of a high
seed wireless network that can transmit multimedia and data to and interface
with wire-line backbone network perfectly just raised in 2002. The speeds of 4G
can theoretically be promised up to 1Gbps. The beyond will be 5G with
incredible transmission speed with no limitation for access and zone size.
The
main distinguishing factors between 3G and 4G will be data rates, services,
transmission ways, access technology to the internet, the compatibility to
interface with wire-line backbone network, quality of service and security. 4G
should support at least 100 Mbps peak rates in full-mobility wide area coverage
and 1Gbps in low-mobility local area coverage. The speeds of 3G can be up to
2Mbps, which is much slower than the speeds of 4G. For the service, 3G
marketing is difficult to roam globally and interoperate across networks, yet
4G will be a global standard that provides global mobility and service
portability so that service provider will not longer be limited by
single-system. In order words, 4G should be able to provided very smooth global
roaming ubiquitously with lower cost. Furthermore, 3G is based on a wide-area
concept applying circuit and packet switching for transmission with limited
access technology, such as WCDMA, CDMA and TD-SDMA. However, the 4G standard will
base on broadband IP-based packet switching method of transmission with
seamlessly access convergence. It means that 4G integrated all access
technologies, services and applications can unlimitedly be run through wireless
backbone over wire-line backbone using IP address. In the other words, 4G will
bring us almost perfect real world wireless or called “wwww: World Wide Wireless
Web.
Comparison among technologies (Generations)
|
Generation
|
Definition
|
Throughput/
Speed
|
Technology
|
Time period
|
Features
|
|
1G
|
Analog
|
14.4Kbps (peak)
|
AMPS, NMT, TACS
|
1970-1980
|
During 1G Wireless phones are used
for voice only
|
|
2G
|
Digital Narrow band circuit data
|
9.6/14.4 Kbps
|
TDMA, CDMA
|
1990-2000
|
2G capabilities are achieved by
allowing multiple users on a single channel via multiplexing. During 2G
Cellular phones are used for data also along with voice.
|
|
2.5G
|
Packet Data
|
171.2 Kbps (peak) 20-40 Kbps
|
GPRS
|
2001-2004
|
In 2.5G the internet becomes popular
and data becomes more relevant. 2.5G multimedia services and streaming starts
to show growth.
|
|
3G
|
Digital Broadband Packet Data
|
3.1 Mbps (peak) 500-700 Kbps
|
CDMA 2000 (1xRTT, EVDO) UMTS, EDGE
|
2004-2005
|
3G has Multimedia services support
along with streaming are more popular. In 3G, Universal access and
portability across different device types are made possible. (Telephones, PDA,s,
etc.
|
|
3.5G
|
Packet Data
|
14.4 Mbps (peak) 1-3 Mbps
|
HSPA
|
2006-2010
|
3.5G supports higher throughput and
speeds to support higher data needs of the consumers.
|
|
4G
|
Digital Broadband Packet All IP Very
high throughput
|
100-300 Mbps (peak) 3-5 Mbps 100 Mbps
(Wi-Fi)
|
WiMax
LTE
Wi-Fi
|
Now (Read more on Transitioning to
4G)
|
Speeds for 4G are further increased
to keep up with data access demand used by various services. High definition
streaming is now supported in 4G.
|
|
5G
|
Not Yet
|
Probably gigabits
|
Not Yet
|
Soon (probably 2020)
|
Currently there is no 5G technology
deployed. When this becomes available it will provide very high speeds to the
consumers.
|
How
4G works:
In
the 4G wireless networks, each node will be assigned a 4G-IP address (based on
IPv6), which will be formed by a permanent “home IP address and a dynamic”
care-of address that represents its actual location. When a device (computer)
in the Internet wants to communicate with another device (cell phone) in the
wireless network, the computer will send a packet to the 4G-IP address of the
cell phone targeting on its home address. Then a directory server on the cell
phone’s home network will forward this packet to the cell phone’s care-of
address through a tunnel, mobile IP; moreover, the directory server will also
inform the computer that the cell phone’s care-of address (real location), so
next packets can be sent to the cell phone directly. The idea is that the 4G-IP
address (IPv6) can carry more information than the IP address (IPv4) that we
use right now. IPv6 means Internet Protocol Version 6 including 128 bits, which
is 4 times more than 32bits IP address in IPv4. 32 bits IP address looks like
this 216.37.129.9 or 11011000.00100101.10000001.00001001 (32bits). However, the
IP address in IPv6 version will be 4 times of IPv4; it looks like 216.37.129.9,
79.23.178.229, 65.198.2.10, 192.168.5.120. It includes 4 sets of IPv4 address
defined in different functions and usages. In previous example for the case,
the first set of the IP address (216.37.129.9) cab be defined to be the “home
address purpose. It just likes the normal IP address that we use for addressing
in the Internet and network. The second set of the IP address (79.23.178.229)
can be declared as the “care-of address. It is the address set up for the
communication from cell phones to computers. After these addresses from cell
and PC established a link, care-of address will instead of home address; it
means that communication channel will switch from the first set to the set to
the second set of the IPv6 address. The third set of the IP address
(65.198.2.10) can be signed as a tunnel (mobile IP address). It is the
communication channel to wire-line network and wireless network. An agent, a
directory server, between the cell phones and PC will use this mobile IP
address to establish a channel to cell phones. Then, the last set of IP address
(192.168.5.120) can be local network address for virtual private network (VPN)
sharing purpose. In this rich data IP address, software can use them to
distinguish different services and to communicate and combine with other
network areas, such as computer (PC) and cell phones network in the case of the
example. In addition, the table bellow is a basic comparison of IPv6 and IPv4
showing that how IPv6 richer than IPv4 in data containing capacity. Moreover,
in 4G wireless network, not only has it IPv6 transmission protocol, but also be
supported by OFDM, MC-CDMA, LAS-CDMA, UWB and Network-LMDS.
OFDM
stands for Orthogonal Frequency Division Multiplexing, transmitting large
amounts of digital data over a radio wave. OFDM works by splitting the radio signal
into multiple smaller sub-signals that are then transmitted simultaneously at
different frequencies to the receiver. In the other words, OFDM is a digital
modulation technology in which in one time symbol waveform, more than thousands
of orthogonal waves are multiplexed for increasing signal strength. This is
good for high bandwidth digital data transition. In OFDM, two wireless devices
will establish a connection tunnel before they start their communication.
Therefore, after making a connection between a certain target, the radio signal
will split into many smaller sub-signals with accurate direction to the target.
MS-CDMA
stands for Multi-Carrier Code Division Multiple Access, which is actually OFDM
with a CDMA overlay. The users are multiplexed with orthogonal codes to
distinguish users in MS-CDMA and single-carrier CDMA systems. It allows
flexible system design between cellular system and signal cell system. However,
in MC-CDMA, each user can be allocated several codes, where the data is spread in
time or frequency.
LAS-CDMA,
Large Area Synchronized Code Division Multiple Access, is developed by LinkAir
Communication, a patented 4G wireless technology. “Las-CDMA enables high-speed
data and increases voice capacity and the latest innovative solution,
Code-Division Duplex (CDD), merges the highly spectral efficient LAS-CDMA
technology with the superior data transmission characteristics of Time-Division
Duplex (TDD) This resulting combination makes CDD to be the most spectrally
efficient, high-capacity duplex system available today. In the 4G area,
LAS-CDMA is played as a global transmission protocol (“World Cell) as showing
in the following picture, Zone size. It means that if the distance is too for
to two wireless devices, they have to use this protocol with IPv6 to establish
their connection.
In
4G technologies, UWB radio can help solve the multi-path fading issues by using
very short electrical pulses to across all frequencies at once. However, UWB
can only be used indoor or underground because of its low-power requirement.
Thus, UWB has to be used with OFDM, which can transmit large among of digital
data with multi-path algorithm; OFDM running outdoor, UWB running indoor to
ensure signal strength purpose. In the 4G wireless technology, UWB will be
played as “Pico Cell of very limited distance in the buildings.”
The
Network-LMDS, Local
Multipoint
The
idea of the complementation of IPv6, OFDM, MC-CDMA, LAS-CDMA, UWB and
Network-LMDS can be arranged in different zone size. IPv6 can be designed for
running in the all area because it is basic protocol for address issue LAS-CDMA
can be designed for the global area as zone 1, world cell. OFDM and MC-CDMA can
be designed for running in the wide area (zone 3), called Macro cell.
Network-LMDS in Zone 2, Micro cell and UWB is in Zone 1, Pico cell. Based on
above transmission protocol, we knew that each of them has its drawback(s) in
somewhere; although the complementation with all of them, it is not perfect yet
go implement 4G’s great idea. Academic research and experiments are still
required for further developing of 4G in the following few to 10 years.
Conclusion:
Nowadays,
wireless technology is getting popular and important in the network and the
Internet field. In this paper, I briefly introduced the history background of
1G to 5G, compared the differences of 3G and 4G, and illustrated how 4G may
work for more convenient and powerful in the future. 4G just right started from
2002 and there are many standards and technologies, which are still in
developing process. Therefore, no one can really sure what the future 4G will
look like and what services it will offer to people. However, we can get the
general idea about 4G from academic research; 4G is the evolution based on 3G’s
limitation and it will fulfill the idea of wwww. World Wide Wireless Web,
offering more services and smooth global roaming with inexpensive cost.
References:
- Internet
- Mr.
Mirza Ahmed Hussain, Ex Dir. BTTB.
