Features, Merits and Demerits

FEATURES and MERITS

• In 4G, the download speed is up to 100 Mbps for moving users and 1 Gbps for stationary users

• It will allow users to download a full-length movie within five minutes

• Users will also be able to stream high-definition television and radio to hand-held devices

• 4G is an adoption of packet switching instead of circuit switching in voice and video calls. With packet switching, resources are only used when there is information to be sent across 

• Better Data transfer rates and signal quality

• Support for interactive multimedia, voice, streaming video, Internet, and other broadband services

• IP based mobile system

• High speed, high capacity, and low cost per bit 

• Better scheduling and call admission control techniques

• Better spectral efficiency

DEMERITS

•  Battery Life of 4G enabled cell phones is shorter

•  Degradation of other broadband services

Infrastructure

INFRASTRUCTURE

Some possible standards for the 4G system are LTE, 802.20, WiMAX (802.16), HSDPA, TDD UMTS, UMTS and future versions of UMTS.

The design is that 4G is based on OFDM (Orthogonal Frequency Division Multiplexing) which is the key enabler of 4G technology. Other technological aspects of 4G are adaptive processing and smart antennas, both of which are used in 3G networks and will enhance the rates when used in with OFDM. 

Working of 4G communication system (Using OFDM):-

“Orthogonal FDM's spread spectrum technique” spreads the data over a lot of carriers that are spaced apart at precise frequencies. This spacing provides the "orthogonality" in this method which prevents the receivers/demodulators from seeing frequencies other than their own specific one. The main benefit of OFDM is high spectral efficiency and high resiliency to RF interference and the multi-path distortion is lower. This is handy because in a standard terrestrial broadcasting situation there are many multipath-channels.

Block diagram of the OFDM transceiver

Evolution of 4G

Evolution of 4G

ITU designed 4G in 2002 with the official name “3G Long-Term Evolutions” or 3.9G

The first commercial deployment was by Telia Sonera and NetCom

Telia Sonera branded the network “4G”

The modem devices on offer were manufactured by Samsung (dongle GT-B3710)

The network infrastructure were created by Huawei (in Oslo) and Ericsson (in Stockholm)

Pictorial representations of the evolution of mobile communication system

Evolution

Evolution of 4G in convergence

Data rate comparison

Need of 4G

     NEED OF 4G

     Now, the question arises... Why was 4G needed??? What led to its advent???

Well.. The answer is pretty simple.. The various drawbacks of the older generations of mobile communication system led to the advent of "4G mobile communication system"..

So here is a brief description about the various generations and their drawbacks.

1st Generation:-

1G was an analog system and was developed in the 70s.

First 1G mobile system Advance Mobile Phone System (AMPS) was launched by the US. It was based on FDMA that allowed users to make voice calls in 1 country.

Drawbacks-
Poor voice quality
Poor battery life
Large phone size
No security
Frequent call drops
Limited capacity and poor hand-off reliability

2nd Generation:-

2G phones use Global System for Mobile communications (GSM) and were first used in the early 90s in Europe.

GSM provides voice and limited data services and uses digital modulation for improved audio quality.

2G cellular system includes GSM, Digital AMPS (D-AMPS), Code-Division Multiple Access (CDMA), and Personal Digital Communication (PDC).

A new air interface called Enhanced Data GSM Environment (EDGE) has been developed specifically to meet the bandwidth needs of 3G. EDGE is a faster version of GSM wireless service.

3rd Generation:- 

The first pre-commercial trial network with 3G was launched by NTT DoCoMo in Tokyo (Japan) in May 2001. NTT DoCoMo launched the first commercial 3G network on 1 October 2001, using the WCDMA technology.

The idea behind 3G was to have a single network standard instead of the different types adopted in the US, Europe, and Asia. Telecommunications System (UMTS) or IMT-2000, sustained higher data rates and opened the door to many Internet style applications.
 

3G technology adds multimedia facilities to 2G phones by allowing video, audio, and graphics applications. Over 3G phones, you can watch streaming video or have video telephony

Drawbacks-

• High bandwidth spectrum requirement
• High licensing fees
• Expensive

Introduction

INTRODUCTION

     In telecommunications, 4G is the fourth generation of mobile phone communication standards. It is a successor of the third generation (3G) standards.

      A 4G system provides mobile ultra-broadband Internet access, for example to laptops with USB wireless modems, to smartphones, and to other mobile devices. Conceivable applications include amended mobile web access, IP telephony, gaming services, high-definition mobile TV, video conferencing and 3D television.

     Recently, Android and Windows-enabled cellular devices have fallen in the 4G category.

     The technology is currently available in some countries but it is still being perfected.

     The aim is to achieve “ultra broadband speed” – to be counted in gigabytes per second.