4G Wireless Networks

ST.FRANCIS DE SALES COLLEGEElectron IC City Hebbgodi

Bangalore

NEHA PRESENTATION

Prepared by

NEHA PANDEYNEHA PANDEY

Outline

Introduction What is 4G?

What's New in 4G?

3G vs. 4G

4G Network Features

How 4G works

Challenges

Summary

What is 4G?

A wireless access technology and is the successor of 3G.

Called "3G and Beyond".

Enables seamless roaming between technologies.

Plans on releasing the first commercial network in 2010.

NTT DoCoMo Company is testing 4G communication at 100 Mbps while moving, and 1 Gbps while stationary.

What's New in 4G?

Entirely packet-switched networks.

All network elements are digital.

Higher bandwidths to provide multimedia services at lower cost (up to 100Mbps).

Tight network security.

Features of 4G Networks

4G networks are all-IP (Internet Protocol) based heterogeneous networks

This will allow users to: Select any system at

any time and any where

Use Multiple systems at the same time (e.g. GPS and WLANs and CDMA)

A wide range of applications using only one 4G integrated terminal

Features of 4G Networks (cont.)

Support interactive multimedia services: teleconferencing, wireless Internet, etc.

Wider bandwidths, higher bit rates.

Global mobility and service portability.

Low cost.

Scalability of mobile networks (>10 times the capacity of 3G).

3G (including 2.5G) 4G

Major Requirement Driving Architecture 

Predominantly voice driven - data was always add on

Converged data and voice over IP

Network Architecture Wide area cell-based Hybrid - Integration of Wireless LAN (WiFi, Bluetooth) and wide area

Speeds 384 Kbps to 2 Mbps 20 to 100 Mbps in mobile mode

Frequency Band Dependent on country or continent (1800-2400 MHz)

Higher frequency bands (2-8 GHz)

Bandwidth 5-20 MHz 100 MHz (or more)

Switching Design Basis Circuit and Packet All digital with packetized voice

Access Technologies W-CDMA, 1xRTT, Edge OFDM and MC-CDMA (Multi Carrier CDMA)

Forward Error Correction Convolution rate 1/2, 1/3 Concatenated coding scheme

Component Design Optimized antenna design, multi-band adapters 

multi-band adapters Smarter Antennas, software multiband and wideband radios

IP  A number of air link protocols, including IP 5.0 

All IP (IP6.0)

From : www.mobileinfo.com

3G vs. 4G

How 4G works (working principle)

The IP address is based on IPv6.

IPv4: X . X . X . X (32 bits)

example: 216.37.129.9

IPv6: 4 × IPv4 (128 bits)

example: 216.37.129.9 , 79.23.178.229 , 65.198.2.10 , 192.168.5.120

home address

care-of address

mobile IP address

local network address

IPv4 vs. IPv6

IPv4 IPv6

Structure 32 bits 128 bits

Security Poor security Enhance security

Function Addressing1. Multi-fun. and mobile fun. are built-in

2. Plug & Play (Auto-Configuration)

HAPS

Services

Content

GSM

UMTS

WLANBluetooth

Satellite

Wireline or WirelessNetworks(Internet)

Very wide area

Wide area Metropolitan area Local areaPersonal

area

Direct SequenceFrequency Hopping

WCDMATD-CDMA

TDMAFDD

OFDMTDD

OFDM Unspecified

ADSL

The 4G mobile network(s)

Home Add.

Mobile IP Add.Care-of Add.

Care-of Add.

4G Systems Challenges

To migrate current systems to 4G with the features mentioned previously, researchers are facing a number of challenges

These challenges are grouped into the following different aspects: Accessing Different Networks:

Multimode Devices Overlay Network

Terminal Mobility Location Management Handoff Management

One of the most challenging problems facing deployment of 4G technology is how to access several and different mobile and wireless networks

There are two possible architecturesMultimode DevicesOverlay Network

4G Wireless Networks ChallengesFirst Challenge: Accessing Different Networks

A single physical terminal with multiple interfaces to access the different wireless networks

Advantages: Improve call completion Expand coverage area Reliable coverage in case of

network, link or switch failure Disadvantages:

Complexity in the hardware of the device

Handoff Mechanism:

Performed by the user, device or network

First Challenge: Accessing Different Networks1. Multimode Devices Architecture

To reduce the complexity of the hardware in the device the most promising technology is to adapt the software radio approach

BPF LNA ADC

reprogrammable

Baseband

DSP

User

Analogue Digital

An ideal software radio system

Multimode Devices Architecture (cont.)

Analog/digital converter bandpass filter Low noise amplifier

High number of antennas: Still It is impossible to have just one antenna and one LNA to cover the bands of all 4G wireless networks

The low speed of ADCs. the speed of the fastest current ADC is still two to three times slower than required

Challenges in software radio technology

Multimode Devices Architecture (cont.)

A user accesses an overlay network consisting of several UAPs

UAPs Functions: Select a wireless network based

on availability and user choices Store IPs of user, network and

devices Advantages:

Simplify hardware of device Supports single billing

Disadvantages: More network devices

Handoff Mechanism between UAPs:

Performed by overlay network rather than the user or device

First Challenge: Accessing Different Networks2. Overlay Network Architecture

4G Wireless Networks ChallengesSecond Challenge: Terminal Mobility

In order to provide wireless services at any time and anywhere, terminal mobility is a must in 4G infrastructure

Terminal mobility allows mobile clients to roam across geographical boundaries of the wireless networks

There are two main issues in terminal mobility: location management handoff management

The system tracks and locates a mobile terminal for possible connection

Location management involves handing all the information about Roaming terminals such as original and current

location cells Authentication information QoS capabilities

Second Challenge: Terminal Mobility 1. Location Management

Second Challenge: Terminal Mobility2. Handoff Management

Maintain ongoing communication when the terminal roams

IP changes during handoff :

216.37.129.9,

home address care-of address mobile IP address local network address

79.23.178.229,

IPv6 within the same cell:

65.198.2.10, 192.168.5.120

Second Challenge: Terminal Mobility2. Handoff Management

216.37.129.9,

home address care-of address mobile IP address local network address

79.23.178.229,

IPv6 when the terminal roams to another cell:

65.198.2.10, 192.168.5.120

• Horizontal handoff is performed when the terminal moves from one cell to another within the same wireless system.

• Vertical handoff is performed when the terminal moves between two different wireless systems (e.g., from WLAN to GSM) .

Handoff Management (cont.)

Handoff Management Challenges

Vertical & Horizontal handoff will increase System load (increasing control packets) Packet losses Handover latency

Hard correct handoff time: because measuring handoffs is done among different wireless systems

Challenges in Handoff Management

Summary The key concept behind 4G systems is

integrating their capacities with all of the existing mobile technologies through advanced technologies

The IP address system used in 4G is based on the new technology IPv6.

4G networks is still in the development stage, and in order to utilize their new features too many challenges must be overcome