Comparision of 3G Wireless Networks and 4G Wireless Networks:

By examining the two papers on 4G and 3G, namely wireless networks:
opportunities and challenges by Hassan Gobjuka, Verizon, 919 hidden bridge
irving, Tx 75038 and wireless network: opportunities and challenges emphasis
us to throw light on the differences between the two networks. This task is
being done in order to list out the drawbacks and merits of these two
evolutions of the networks and further to implement R&D research to bring
out their sparks in this modern era.
The differences are done on the following Index terms: Background
difference, definitions, technologies progress, speed/ rate of transmission,
switching technologies used, network, band width, design specification, QoS,
service and billing, features and capabilities.
Keywords: RAN, SONET, UTRAN, FLASH OFDM, CORE
NETWORK,SGSN
1. Introduction:
3G is also called third generation. It is named as such because it is the third generation
of the standards of telecommunication hardware. It is also the general technology for
mobile networking, passing the recent 2.5G. The technology is founded on the ITU or
International Telecommunication Union group of standards which belongs to the
IMT-2000.
4G is the fourth generation of mobile phone mobile communications standards. It
is a successor of the third generation (3G) standards. A 4G system provides mobile
ultra-broadband Internet access. 2 Arun Kumar et al
2. Background difference:
In 3g technology which is founded on the ITU or International Telecommunication
Union group of a standard which belongs to the IMT-2000 use W-CDMA technology.
It allows operators to provide users a bigger range of the latest services, as it gets
bigger network capacity via heightened spectral efficiency. The included services are
video calls, wide-area wireless voice telephone and broadband wireless information
all included within the mobile environment. Whereas 4G technology which was
started within cable television industry in 2009 which make users to explore new
downloading speeds and capabilities. The utilization of LTE mobile broadband
technology is an opportunity for the corporation to expand its horizons into 4G
territory, upstaging current 3G capabilities. The necessity for 4G networks is
associated with the increased utilization of data websites such as You Tube and
Facebook, which require tremendous bandwidth in order to be used successfully.
2.1 3G stands for 3rd generation while 4G stands for 4th generation:
3G is currently the world’s best connection method when it comes to mobile phones,
and especially mobile Internet. 3G stands for 3rd generation as it is just that in terms
of the evolutionary path of the mobile phone industry. 4G means 4th generation. This
is a set of standard that is being developed as a future successor of 3G in the very near
future.
Architectural difference: both the Figures below provide the key components of
these two architectures.

Several key differences in a LTE network enable more flexibility in its
architecture than in a 3G . A functional representation of 3G network architecture is
shown in Figure 1. In this network, the Base Terminal Station (BTS)/NodeBs
aggregate the radio access network (RAN) traffic and transport it over a mobile Comparision of 3G Wireless Networks and 4G Wireless Networks: 3
backhaul network to the Radio Network Controllers (RNCs)/Base Station Controller
(BSCs). Typically this transport is over T1/E1 copper facilities. If fiber is available at
or near the cell site, then the cell traffic is transported over SDH/SONET rings or,
more recently, a carrier Ethernet network when the eNodeBs are equipped with
IP/Ethernet interfaces. The bearer traffic from a number of RNCs/BSCs is
multiplexed at the Mobile Telephone Switching Office (MTSO) and then transported
via direct tunneling to the Gateway GPRS Serving Nodes (GGSNs) in the hub data
center. This transport is normally over a SDH/SONET ring or a carrier Ethernet
network. This tiered aggregation and transport structure lends itself to a point-to-point
network topology to minimize both the amount of aggregation equipment required
and the transport backhaul expense.
In a 3G pre-Release 8 network, the RNCs and SGSNs are designed to support
both the signaling and bearer plane processing and bandwidth requirements. The
emphasis in the design for these network elements is in providing the processing
necessary to support the high subscriber counts and Packet Data Protocol PDP
contexts as the bandwidth requirements for delivery of the initial 3G data services
(text and e-mail) were not significant. Since the data services that typically ran over
these systems is not real-time neither QoS or latency was an issue. Therefore, the
placement of these elements is usually in locations that primarily meet the PDP
context and network latency requirements. Thus, the current 3G packet core
architecture is typically a centralized network design with the GGSNs deployed in
major data centers, and all the data services are backhauled from the SGSNs which
are strategically deployed in regional serving offices. Because the aggregate
bandwidth for these services did not increase significantly until the past few years, the
backhaul transport costs were manageable and could be supported with leased TDM
or lower rate OC-n/STM-n interfaces.

Fig2: 4G architechture
Above fig.2 provides a high-level functional representation of a LTE/4G network.
This network is composed of three major sub-networks: the Evolved Universal
Terrestrial Radio Access Networks (eUTRAN),which provides the air interface and
local mobility management of the user equipment (UE), the evolved packet core
(EPC), and the broadband backhaul network that provides the aggregation of cell
traffic and transport back to the EPC. The 3GPP LTE standards defined the EPC as a
set of logical data and control plane functions that can be implemented either as
integrated or as separate network elements. The four EPC functions are: the Serving 4 Arun Kumar et al
Gateway (SGW), the Packet Data Network Gateway (PGW) that supports the data or
bearer traffic; and the Mobility Management Entity (MME) and the Policy Charging
and Rules Function (PCRF) which support the dynamic mobility management and
policy control traffic. The backhaul network either is owned by the wireless operator
or is leased from a third party backhaul access provider. Any number of transport
technologies can be used for backhaul including packet microwave, packet optical,
Carrier Ethernet, IP/MPLS, GPON and xDSL.
3. Network.
3G technologies are in widespread use while 4G compliant technologies are still in
the horizon:
The biggest difference between the two is in the existence of compliant
technologies. There are a bunch of technologies that fall under 3G, including
WCDMA, EV-DO, and HSPA among others. Although a lot of mobile phone
companies are quick to dub their technologies as 4G, such as LTE, WiMax, and
UMB, none of these are actually compliant to the specifications set forth by the 4G
standard. These technologies are often referred to as Pre-4G or 3.9G.
3.1 4G speeds are much faster compared to 3G:
4G speeds are meant to exceed that of 3G. Current 3G speeds are topped out at
14Mbps downlink and 5.8Mbps uplink. To be able to qualify as a 4G technology,
speeds of up to 100Mbps must be reached for a moving user and 1Gbps for a
stationary user. So far, these speeds are only reachable with wired LANs. The fourth
generation is faster, it is said to be four times faster than its predecessor. This allows
for a connection speed more comparable to DSL and home cable networks. It is great
news for those completing work and accomplishing important tasks away from their
home and office. When uploading large documents and communicating via the
internet, a fast connection is important. Whereas 3g doesn’t favour such speed as
compared to that of 4G.
3.2 3G is a mix of circuit and packet switching network while 4G is only a packet
switching network:
Another key change in 4G is the abandonment of circuit switching. 3G technologies
use a hybrid of circuit switching and packet switching. Circuit switching is a very old
technology that has been used in telephone systems for a very long time. The
downside to this technology is that it ties up the resource for as long as the connection
is kept up. Packet switching is a technology that is very prevalent in computer
networks but has since appeared in mobile phones as well. With packet switching,
resources are only used when there is information to be sent across. The efficiency of
packet switching allows the mobile phone company to squeeze more conversations
into the same bandwidth. 4G technologies would no longer utilize circuit switching
even for voice calls and video calls. All information that is passed around would be
packet switched to enhance efficiency.Comparision of 3G Wireless Networks and 4G Wireless Networks: 5
3.3 Network:
Another difference between the two is the network. When the 3G was introduced, cell
phone users were finally able to talk and access data at the same time and with higher
data rates. This allowed for a better full service for cell phone users wishing to access
the internet. And what is even greater is the 4G data rates are expected to be even
higher. Users will have the capability of accessing more data at higher speeds while
talking on their cell phone. In addition, the fourth generation permits more data
transmission of such services as games and multimedia. It also allows a larger amount
of internet support.
3.4 Bandwidth:
The next difference between the third and fourth generation to is bandwidth. At first
glance, the bandwidth of both 3G and 4G are the same, numbered at between 5 and 20
MHz. However, the rate of data is what makes the difference between the two. While
the data rate of the third generation only goes up to 2 Mbps, the fourth goes all the
way up to between 100 Mbps to 1 Gbps.
4. Design specification:
The 3G technology provides both circuit design and packet design. Circuit design,
being the oldest, has greater ability to hold the connection for a longer duration. On
the other hand the packet design is a wireless technology and is the core part of
internet data transmission. The combination of these two patterns helps 3G
technology to perform better and faster. However, the 4G technology is kept free from
circuit design with an intention to gives nanosecond wings to data transfer and so has
packet design only.
4.1 Data transmission rate (performance delivered):
3G system is based on wideband CDMA that operates in 5 MHz of bandwidth and
can produce download data rates of typically 384 kb/s under normal conditions and up
to 2 Mb/s in some instances.3g phone standards have been expanded and enhanced to
further expand data speed and capacity. The WCDMA phones have added high speed
packet access (HSPA) that use higher level QAM modulation to get speeds up to 21
or 42 Mb/s downlink (cell site to phone) and up to 7 and/or 14 Mb/s uplink (phone to
cell site).whereas in 4G also known as LTE uses a completely different radio
technology. Instead of CDMA, it uses orthogonal frequency division multiplexing
(OFDM) and OFDM access. This modulation technique divides a channel usually 5,
10 or 20 MHz wide into smaller subchannels or subcarriers each 15 kHz wide. Each is
modulated with part of the data. The fast data is divided into slower streams that
modulate the subcarriers with one of several modulation schemes like QPSK or
16QAM. It also defines multiple input multiple output (MIMO) operation that uses
several transmitter-receiver-antennas. The data stream is divided between the
antennas to boost speed and to make the link more reliable. Using OFDM and MIMO
lets LTE deliver data at a rate to 100 Mb/s downstream and 50 Mb/s upstream under
the best conditions. In 4G the theoretical upper data rate is 1 Gb/s. That remains to be 6 Arun Kumar et al
seen in practice.
4.2 Quality of service:
In 3G, network based Qos depends on following factor to provide a satisfactorily
service as: Throughput, Packet Loss Rate, Packet Loss Rate, reliability and delay.
Where as in 4G With respect to network quality, many telecommunications providers
are promising that there will be enhanced connectivity, and the quality of data that is
transmitted across the network will be of the highest possible quality. The main
challenge that 4G networks are facing is integrating non-IP-based and IP-based
devices. It is known that devices that are not IP address based are generally used for
services such as VoIP. On the other hand, devices that are IP address based are used
for data delivery. 4G networks will serve both types of devices.
4.3 Service and Billing:
3G networks that are capable of supporting an ever-increasing variety of data services
from streaming video, to gaming, to proprietary business applications, to mobile
commerce transactions for tangible goods and services. However, as 3G finally makes
it into the mainstream, its success is inextricably linked to how the
CSPs(Communications Service Providers) charge and bill for services in ways that
are both intuitive and acceptable to the end user while also being relevant to the
CSP’s costs and billing capabilities. Where as in 4G managing user accounts and
billing them has become much more complicated with 4G networks. This is mainly
due to heterogeneity of 4G networks and the frequent interaction of service providers.
4.4 Features and capabilities:
3G has features with Speed of mobile communication in 3G ranges from 600-800
Kbit/sec.Also it provides high quality wireless sound and facilitates with global
roaming. It accommodates distance surveillance and enables mobile TV. Whereas the
ambitious goal of 4G is to allow everyone to access the Internet anytime and
everywhere. The provided connection to Internet will allow users to access all type of
services including text, databases, and multimedia. 4G will also provide higher
bandwidth, data rate, lower authentication overhead, and will ensure the service is
constantly provided to the user without any disruption.
Table 1: comparison between 3G and 4G.
Specifications 3G 4G
Frequency Band 1.8 – 2.5 GHz 2 – 8 GHz
Bandwidth 5-20 MHz 5-20 MHz
Data rate Up to 2Mbps 20 Mbps or more
Access Wideband CDMAMulti-carrier – CDMA or OFDM(TDMA)
FEC Turbo-codes Concatenated codes
Switching Circuit/Packet PacketComparision of 3G Wireless Networks and 4G Wireless Networks: 7
Table2: Comparison in brief:
Attributes ↓ 3G 4G
Data Throughput: Up to 3.1mbps 3to5mbps but potential estimated at
a range of 10 to300 mbps.
Peak Upload Rate: 50 Mbit/s 50 Mbit/s
Peak Download
Rate:
100Mbit/s 1Gbit/s
Switching
Technique:
packet switching
/circuit switch
packet switching, message
switching
Network
Architecture:
Wide Area Cell Based Integration of wireless LAN and
Wide area.
Services And
Applications:
CDMA 2000, UMTS,
EDGE etc
Wimax2 and LTE-Advance
Forward error
correction (FEC):
3G uses Turbo codes
for error correction
Concatenated codes are used for
error correctionsin4G.
Frequency Band: 1.8 – 2.5GHz 2 – 8GHz
5. Conclusion
1. For better performance we have to make 3G as IP based which will allow
higher data transmission rate.
2. We have to use only packet switching so that we can achieve higher internet
speed eliminating circuit switching which makes internet speed slow.
3. To have the better performance we have to use OFDM technology with QPSK
and 16 QAM modulation rather than simple QAM modulation technology.
4. The 3G should be integrated with the IP based technology so that it can have
the tremendous data transmission and support VoIP as well.
5. We have to increase the band width of the 3G networks by using technology
such as orthogonal frequency division.
6. If we are able to integrate it with the wireless LAN for better quality of
service.
7. At an early stage the Flash-OFDM (Fast low-latency access with seamless
handoff orthogonal frequency division multiplexing (Flash-OFDM), also
referred to as F-OFDM) system was expected to be further developed into a
4G standard.
8. No source suggests peak download and upload rates of more than the 1 Gbps
to be offered by ITU-R's definition of 4G systems. If any further generation
appears, and reflects these prognoses, the major difference from a user point of
view between 4G and next Generation techniques must be something else than
increased maximum throughput; for example lower battery consumption,
lower outage probability (better coverage), high bit rates in larger portions of
the coverage area, cheaper or no traffic fees due to low infrastructure 8 Arun Kumar et al
deployment costs, or higher aggregate capacity for many simultaneous users
(i.e. higher system level spectral efficiency).
6. REFERENCES:
[1] TSG RAN wg4 tr25.942 version 1.0.0, wireless intelligent network ,March
2004.
[2] J.thorner ,- Intelligent network, Artech House ,1994.
[3] Hassan Gobjuka , “4G wireless Networks Opportunities and challenges “
Verizon ,919 hidden Ridge Irving ,TX75038.
[4] Prasad ,R and Munoz ,L.” WLAN and WPANs towards 4G Wireless”Artech
House ,March 2003
[5] J.thorer,- Intelligent network ,Artech House ,1994.
[6] S.Tabbane ,”An alternative strategy for location tracking” IEEE.J select Areas
commun , vol.13 no.5 June 1995,pp,880-892.
[7] TRA, “3G Network Aspects,” Understanding 3G Wireless Mobile
Communications Proceedings, 1998.
[8] S. Bali, and J. Korah, “Quality of Service in 3G Wireless Networks,” a project
paper submitted to ECE5556, Virginia Tech, 2001.
[9] R. Prasad, T. Ojanpera, “An Overview of CDMA Evolution toward Wideband
CDMA,” IEEE Communications Surveys, vol. 1, no. 1, Fourth Quarter 1988,
pp. 2-28.