neha 4g wireless network
DESCRIPTION
pankajTRANSCRIPT
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