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ADHOC NETWORKS

By M.K.HAK

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INTRODUCTION Adhoc networks are formed by devices that are able to

communicate with each other using a wireless physicalmedium without having to resort to pre-existing networkinfrastructure.

These are also known as MANETS ie Mobile AdhocNetworks.

They are able to configure themselves on the fly without the

intervention of a centralized administration.

The terminals in ADHOC networks can function not only as end

systems (executing applications, sending information) as source

nodes and receiving the data as destination nodes.

They also act as intermediate system i.e. forwarding the packets from

the other nodes.

ADHOC networks are also called multi -hop wireless networks.

Fundamental characteristics of ADHOC networks


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It is therefore possible that two nodes will communicate

even when they are outside of each others transmission

Ranges ,Because the intermediate nodes will function as

Routers. That is why Wireless networks are called Multi-

hop AD-HAC networks

Compared to cellular networks ADHOC networks are more

capable to changing demands and physical conditions.Attenuation characteristics of wireless networks are non

linear.

Energy efficiency will be potentially superior and the

increased spatial reuse will yield superior capacity with

increased spectral efficiency.

These characteristics make ADHOC networks attractive and

is tightly linked to heterogeneous network and 4G

architecture.


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Challenges in adhoc networks The need for self configurability and flexibility at

various levels i.e. (Dynamic Routing or distributed MAC

arrangements). Gross layer optimization can significantly improve the

system performance.

Classification of AD-HOC Networks

Depending on their communication range the wirelessAD-HOC networks can be classified into BAN ( Bodyarea Networks these networks having a range of 2meters.) PAN ( Personal Area Networks having the rangeof 10 Meters) & WLAN ( Wireless Local Area networks

having the range of hundreds of meters) For WLAN the main option is the family of standards

i.e. IEEE 802.11

The main existing technology for implementing BANsand PANs is Bluetooth.


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The Fundamental characteristics of ADHOC networks

The fundamental characteristics of ADHOC Networks are thatthey are able to configure themselves on the fly without the

centralized intervention. The terminals in AD-HOC networks can function not only as end

systems ( Executing the applications, sending information as

source NODES & receiving the Data as destination nodes)

It is there fore possible that two nodes can communicate evenwhen they are outside each others transmission range because the

intermediate nodes will function as Routers. That is why ADHOC

networks are called Multi band ADHOC Networks.

These networks when compared with cellular networks are more

capable to changing traffic demands & physical conditions. The

attenuation characteristics of the wireless media are non linear,

energy efficiency will be potentially superior


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& the increased spatial re-use will yield superior capacity&thus increase the spectral efficiency. These characteristics makethe ADHOC networks .attractive for pervasive

communications, a concept that is tightly linked toheterogeneous networks & 4G architecture.

The need for self configurability & flexibility Configurability & flexibility at various levels ( for example

dynamic routing or distributed medium access control ) posesmany new challenges in wireless ADHOC networks, cross layeroptimization can significantly improve system performance.

Depending upon their communication range the WirelessADHOC Networks can be classified into BAN,( Body area

networks) PAN ( Personal area network) & WLAN ( Wirelesslocal area network)

The main existing technology for implementing BAN & PANnetworks is blue tooth & for WLAN the standard is I.E.E.E802.11


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Routing is the most active research field in the adhoc

networks as it is related with different communication layers

Minimizing the hops is no longer the objective of the routing

algorithm but optimization of multiple parameters such as

packets error rate over the route, energy consumption,

network survivability, routing overheads, possibility of

establishing a parallel route etc.

We compare the different types of proposed routing

algorithms & as an example we illustrate the functioning of

non location based on demand uni-cast routing protocol in

AD-HOC networks i .e DSR.

WE make use of different types of Protocols in AD-HOC

networks, for example two disjoint routes may have mutualinfluence if the node of one route is within the transmission

range of the node in the other route which has an impact on

the construction of parallel routes


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Power awareness: since most of the w/l terminals can be expected to have

limited energy storage, power awareness is veryimportant.

This subject spans over several communication layers soattention is given to different power saving approaches.

The objectives are not only the reduction of transmissionpower but also the management of sleep states orextention of network survivability through the routing

which is energy aware ..

Use of TCP over wireless links poses many problems

& also it results in additional problems for wireless links.

Communication over wireless multi-hop networks inherits these problems

but also introduces some additional issues, the nodes mobility introduces

unfairness between TCP flows

Route failure leads to un-necessary congestion

control & MAC contention reduces throughput in the

long route


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1

However if the medium remains idle for this period the

station will go to the back off state.

When entering the back off state MS selects back off

interval (BI) between zero and the contention window

period (CW).

CW is the integer no of basic tine slots, if the medium

remains idle for the duration of BI time (i.e the value of

chosen BI minus the elapsed time since entering the back

off state).


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Carrier sensed multiple access technique/collision

detection. When the mobile gets a frame to transmit, it first senses the channel

to determine whether another MS is transmitting.

If MS senses the channel to be idle for a period which is equal to

the inter space frame, then it starts transmitting the frame.

When it senses the channel to be busy it will differ thetransmission and the station will keep on sensing the channel.

At the point of time when the media becomes idle the station will

continue sensing and will wait for the period which is equal to

inter frame space to elapse again. If the medium becomes busyduring this period, the station will go to the deffering state again.


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Collision will occur if two or more MSs select the same

BW provided the condition stated above , that the frame

coexist spatially at one or more of the receiving stations.

When the collision occurs the station that have caused

the collision senses the medium again for the inter frame

space and go again to back off state. Selecting a new BI.

Randomly with the value of contention window period

doubled

The other station which stored their remaining BI times

aAso waits for inter frame space and then go to the back off state.

Basic principal

Mobile devices communicate in Peer to Peer fashion.

Self organizing network without the need to fixed network

infrastructure.


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ADHOC NETWORKS

Medical sector : Monitoring of body functions and Implants.

Biological sector : Animal tracking , undersea exploration

Industrial sector : Remote sensing in power plants

Home automation : Remote monitoring of resources such asElectricity , Water and Gas

Aerospace sector : Sensor equipped Robots on a plant

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Key advantages :-

No expensive infrastructure must be involved.

Making use of unlicensed frequency spectrum.

Quick distribution of information around sender.

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KEY CHALLENGES

All network entities must be mobile

requirement of verydynamic technology.

Network functions must have high degree of adaptability

(mobility , outage).

No central entities

operation in completely distributed manner.

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ROUTING FOR ADHOC MOBILE

NETWORKS :

Well known routings are:

Link state routing

Distance vector routing

The Pro-active approach for routing

Always maintain all routes

Problems :

Topologies changes significant network traffic

Even when the route is not used

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UNICAST ROUTING PROTOCOLS :

Many protocols have been proposed some have been

invented specifically forMANETs other are adopted

from previously proposed protocols for wired networks.

No single protocol works well in all environments.

Some attempts made to develop adaptive protocols.

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ROUTING PROTOCOLS :

Proactive Protocols :

Determines the route independent of traffic pattern

Traditionally link state and distance vector routing

protocols are proactive

Reactive protocols :

Maintain routes only if needed

Hybrid protocols :

Combines Pro-active and re-active elements

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Position based protocols Use the geographic

position of nodes for forwarding decisions

Latency of route discovery

Proactive protocols may have lower latency since the

routes are maintained at all times

Reactive protocols may have higher latency because a

route from X to Y will be found only when X attempts tosend Y

Overhead of route discovery /maintenance

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Reactive protocols may have lower overhead since

routes are determined only if needed

Proactive protocols can (but not necessarily) result in

higher overhead due to continuous route updating

Which of the protocols achieve a better trade off depends

on the traffic and mobility patterns

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FLOODING FOR DATA DELIVERY

SenderSbroadcast data packet P to all neighbors

Each node receiving P forwards P to its neighbors

Sequence no's are used which avoid the possibility of

forwarding the same packet more than once

Packet P reaches the destination D provided that D is

reachable from senderS

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RELIABILITY OF ADHOC

NETWORKS

Wireless links are prone to errors

Either because of interference

Or because of collisions

(collision detection does not work for half duplex

networks)

High packet loss rate detrimental to transport layer

performance

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THE MECHANISM ARE NEEDED TO

INCREASE THE RELIABILITY :

Forward error correction (FEC) include the redundancy

in the packet

Automatic repeat request (ARQ) use acknowledgements

and re-transmission

ARQ for multi hop AD-HOC networks

Implicit assumptions :-

Packet loss is caused by interference or collisionsRetransmission seems to be appropriate

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WHAT HAPPENS IF PACKET LOSS OCCURS


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WHAT HAPPENS IF PACKET LOSS OCCURS

DUE TO A NODE LEAVING THE

TRANSMISSION RANGE

i. Multiple re-transmission before a sender gives up

ii. Massive increase in network congestion

Unlikely

No route discover strategies favor shortest (i.e.

minimal) path

Note:- Broadcast (used for rote discovery) are not

protected by ARQ

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PROBLEM WITH RANGES FOR MULTI-

HOP ADHOC NETWORKS :

1. Large interference , dramatically reduces the capacity

2. Ranges depend on the transmission rate

Low rate less vulnerable to interference

1. Broadcast use a lower rate than Uni casts in IEEE

802.11

( to make the transmission more reliable)

1. Broadcasts are used for route discovery

2. Uni casts used for data delivery

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SECURITY IN MOBILE ADHOC

NETWORKS

1. Security needs and threats30/08/

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Securityfeatures and need

Privacy/Anonymity

features andneed

Dependabilityfeatures and need

Subject /objectauthentication

Confidentiality sort off Availability

Data integrity No unauthorizeddissemation ofpersonal data

Availability

Accountability Location , Address,service privacy

NETWORK SECURITY SEEN AS


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NETWORK SECURITY SEEN AS

CUSTOMER-PROVIDER

RELATIONSHIP

End user perspective : wants secure end to end communication

Operator perspective : Has to provide secure n/w organization as

basis for offering a secure communication service

Attack types and building blocks of counter measures

Passive attack - Fabricating or stealing of packets

Get content - modification of packets

Profiling -Active attacks

Other types of attacks

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SECURITY GOALS WITH RESPECT TO

ADHOC ROUTING

Routing signaling cannot be spoofed

Fabricating routing messages can not be integrated in the

network

Routing messages cannot be altered in transit except

according to the normal functionality of the routing

protocol

Routing loops cannot be formed through malicious action

route cannot be re-directed from the shortest path by

malicious action

Managed open environment Unauthorized nodes should be excluded from route

computation and discovery

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Managed hostile environment

The network topology must be exposed neither to adversaries nor

to authorized nodes by the routing messages

The solutions for secure routing

ARAN : Authenticated routing for ADHOC networks

Assumptions : MOE (Managed Open Environment )

Trusted certificate server to its public key is known to all nodes

Each nodes has non certificate signed by T

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Counter measures used are :

Cryptography Monitoring

Difference in service classes and ADHOC network

1)Key managed infrastructure2)Intrusion detection

3)Single administration domain

4)Transiently unavailable

Only local monitoring

Multiple domains , no clear line of defense

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ADHOC SPECIFIC ATTACK TYPES ARE

AS FOLLOWS :

Equipment/battery : no obvious line of defense ,Side

channel attacks

Radio jamming

DLC : attacks on MAC , MAC address

Routing : no infrastructure support , no clear line of

defense

Co-ordination : based on principal of mutual assistance ,

simple attacks and packet drops

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Security procedures:

Route

Signed discovery packet (RDP) propagates to sought

destination

Destination sends back signed route reply (REP)

At each hop the following action is taken

Validation of original signature

Validation of last hop signature

When last hop is neither source nor destination

replace the last hop signature by your own

signature

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ARAN (authentication routing for ADHOC

networks )

check list :

Unauthorized participation , managed by trusted

authority

Spoofed route signaling everything is signed

Fabricated routing messages

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AD-HOC Routing Protocols

It is a convention or standard that controls how nodes decide whichway to route packets between computing devices in a mobile AD-

HOC networks In AD-HOC networks nodes are not familiar with the topology but

instead they have to discover it

The new nodes can announce their presence & should keep onlistening to the announcements made by the neighbors

The node learns about neighbors which are nearer to them & howto reach them & may announce how to reach them.

AD-HOC protocols can also be used Literally

The following is the list of AD-HOC routing Protocols

Pro-active (Table driven routing)

Reactive ( On demand routing)


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Flow Oriented Routing

Adaptable Routing. ( Situation aware)

Hybrid Routing ( Both pro-active & reactive routing)

Hierarchal Routing Geographical Routing

Power Aware Routing

Multicast Routing

Geographical Multicast Routing

Other Protocol classes

External Links

Pro-active ( Table driven Routing )This type of protocolmaintains fresh list of destinations& their routes byperiodically distributing routing tables throughout thenetwork

The main disadvantages of such algorithms are


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1) Respective amount of Data for Maintenance

Slow reaction of re-structure or failure

The examples of Pro-active algorithms are AWDS( Ad-hoc wireless distribution service)

Layer 2 wireless mesh routing protocol

BABEL. A protocol inspired by DSDV. With faster

convergence & trans link quality estimation. CGSR( Clustered gateway switch routing protocol)

DFR ( direction forward routing)

DBF ( Distributed Bellman Ford routing Protocol)

DBDF (Highly dynamic distribution seeking vector)

HSR ( Hierarchical state routing Protocol)

IRRP( Intra-zone routing protocol & some others)

Ant based routing algorithm for mobile AD-HOC


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Ant based routing algorithm for mobile AD HOCnetworks

Admission control enable on demand routing protocol

Flow oriented routingThis type of protocol finds a route on demand by

following present flows

One option is to uni-cast consecutively whenforwarding Data while promoting a new link. The main

disadvantages of such algorithms are 1)It takes a long time while exploring a new route

without the prior knowledge

May prefer to the entries of existing traffic to

compensate for missing knowledge en-routes ADAPTIVE ( Situation aware routing) This type of

protocol combines the advantage of PRO-Active & re

Reactive Protocols)( On demand routing)


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Reactive Protocols)( On demand routing)This type of protocol finds a route on demand by flooding

the network with the route request packets.

The main disadvantage of such algorithms are i) High latency time in route finding

Excessive flooding which can lead to Network clogging

Examples of reactive algorithms are

1) SENCAST 2) Multi -rate AD-HOC on demand Distance Vector Routing

Protocol

Reliable Ad-Hoc on demand distance vector routingprotocol.

MEPA ( Minimum exposed path to the attacks inmobile AD-HOC networks

Routing is initially established with some pro-actively


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Routing is initially established with some pro activelyprospectively routes & then serves the demand forsome additionally activated nodes through reactiveflooding


Advantages depends upon the amount of nodesactivated

Reaction to traffic demand depends upon thegradient of traffic volume


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OFDM For UMB OFDM is a form of transmission that uses a

large number of closed spaced carriers that

are modulated with low Rate data .Normallythese signals would be expected to interferewith each other but there is no mutualinterference because these signals are madeorthogonal to each other

This is achieved by having the carrier spacingequal to the reciprocal to the Symbol period &there will be no mutual Interference

The Data to be transmitted is split across allthe carriers

If some of the carriers are lost due to multi-path effect, the Data can be re-constructedby using error correction techniques


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ULTRA MOBILE BROAD BAND Ultra Mobile Broad Band is the name for the next

evolution for CDMA 2000 cellulartelecommunication system which is run under theauspices of 3G PP-2

UMB cellular system promises to provide verymuch faster Data transfer Speeds & enables the

system to compete with other Mobile Broad Bandsystems including WI-MAX& WI-FI

The Aim for UMB includes making significantincreases to the user Data Rates when compared

with existing CDMA 2000 cellular technologiesThere will be increase in the System capacity &

lowering the cost per bit Data transfer

Enhancement to the existing services,


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g ,possibility of new applications & the ability touse new spectrum applications so that UMBcan compete with new applications of 4G

standards such as WI-MAX & preventingthem from gaining the foothold in the Market

The UMB broad band standards are to beexpected by now & the new systems Using

UMB are expected to be available in themarket by the middle of 2010

UMB Salient Features UMB offers many new salient feature &

techniques that enable it to compete withnew 7 other emerging technologies

Data Rates of over 275 Mbps in the downlink& over 75 Mbps in the up-link

Uses an OFDM/OFDMA air Interface


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Uses F.D.D

Possesses an IP network architecture

Has a scalable bandwidth between 1.25 MHz-20 MHz( NB OFDM/OFDMA systems are well suited for wide &scalable bandwidth.

Supports flat, mixed & diluted network architecture

The UMB system is supposed to provide the significantleap in terms of capability when compared to theexisting CDMA 2000 based systems.

The plan is to make UMB operate alongside CDMA2000 1X& CDMA 2000 1X EV-DO & it will offer

seamless handoff to & from these services . In this way a phased roll-out of services can be

offered

UMB air Interface


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A number of new technologies are being used within the airinterface of UMB

One of the key technology is OFDM. This technology enables theUMB to carry high Data Rates& also enables the network to usewide & variable Bandwidth according to the requirement of thelink

OFDMA or Orthogonal frequency division multiple Access usesOFDM as basis of the modulation scheme ,but has been modifiedto cellular communication system including UMB to provide the

means of multi-path effects while still being able to providemeans of Access to multiple users

MIMO For UMB UMB system also uses MIMO. As well as SDMA (Space division

Multiple Access) These are the advanced antenna techniques toprovide even greater capacity coverage & quality in deploymentswith multiple Antennas. By using the multi-paths present in anyreal Radio Path

They effectively enable the channel capacity to be increased Forbeyond to be predicted when using a single Antenna

UMB higher layers


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g y The new UMB standard utilizes sophisticated control mechanism

along with MIMO & SDMA to allow the transmission of variablelength packets for each application based upon end to end

system capabilities & in QOS. IN this way the system can beoptimized according to the prevailing conditions & therequirement of each user

UMB IP based structure UMB also supports large variety of services that require

extremely low latencies, low jitter& increased spectralefficiencies besides passing packet data & IP.

UMB results in supporting the large X-section of advancedmobile Broad Band services by delivering low rate , low latencyvoice traffic at one end of the spectrum& ultra high speed

latency insensitive broadband data traffic It offers better performance for many of the new services being

conceived

In not too distant future of digital technology, people


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g gy p pwill be sharing voice Data video & multimediaservices among the network consumer electronicsPCs & mobile devices throughout the home & even

remotely. For example the users will be able tostream video content from a PC or consumerelectronic devices such as a camcorder DVD playeror a personal video recorder to a flat screen HDTV

(high-definition television) display without the use ofany wires.

A leading candidate for enabling this capability isultra wideband (UWB), a wireless technologydesigned for short range, personal area network, or(PANs). This year, UWB is making the transition fromlaboratories to standardization, a key step towardthe development of real world products.

Recent industry achievements with UWB range from


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researchers showing proof-of concept demos, to formationof industry working groupsthat will define the UWB physicallayer (PHY) and MAC layer and application that will run ontop of the radio platform. In the U.S., the Federal

Communication Commission (FCC) has mandated that UWBradio transmission can legally operate in the range from3.1GHz to 10.6 GHz, at a transmit power of -41dBm/MHz.Japanese regulators have issued the first UQWB experimentlicense allowing the operation of a UWB transmitter in

Japan.

Digital Home Requirements

Why is UWB considered by many to be the next big thingin the wireless space? For one thing, it allows for high datathroughput with low power consumption for distances ofless than 10 meter, which is very applicable to the digitalhome requirements.

An example application of UWB would be bringing a mobile devicelike a portable media player (PMP) in proximity to a content source


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like a portable media player (PMP) in proximity to a content sourcelike PC, Laptop or external hand disk drive Once an authentication&authorization is established, the device & PC can perform bulk datatransfer of Video files onto the PMP for later viewing

Within the consumer electronics industry, there is the demand forconnecting various devices such as DVDs HDTVs Set Top BoxesPVRs, Stereos, Camcorders digital cameras & other CE devices .Wireless use is the Key Factor for adoption in this Category

UWB technology A traditional UWB transmitter sends billions of pulses across a very

wide spectrum of frequency which is several GHz in bandwidth.The corresponding receiver then translates the pulses into Data bylistening to the familiar pulse sequence sent by the transmitterspecifically UWB is the technology that occupies the bandwidth ofgreater than or equal to 500 MHz or greater than 20% of thecentral frequency.

Modern UWB systems use normally (OFDM) to occupy these verylarge Bandwidths In addition the use of multiple bands incombination with OFDM modulation can provide significantadvantage to traditional UWB system

In the Multi-band OFDM approach, the available


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spectrum of 7.5 GHz is divided into several 528 MHzbands. This allows selective implementation ofbands at a certain frequency ranges while leaving

the other parts of the spectrum un-used Thedynamic ability of the radio to operate in certainareas of the spectrum is important, because it canadapt to regularity constraints imposed by the

governments around the World

ULTRA WIDE BAND


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Beyond the corporate walls MOTOROLA enterprisesMesh networks

Mesh technologies provide convenient , flexible

scalable & cost effective extensions of corporatenetworks in the areas that are typically too hard tocable

UWB is a radio technology that can be used at verylow energy levels for short range high bandwidthcommunication, by using a large portion of theRadio spectrum.

It is used for radar imaging. Recently it has been

used in sensor Data collection, precision locating &tracking applications

UWB communication does not interfere with othertraditional operators

In this way it is able to offer better performance for many ofth i b i i d


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the new services being conceived

ULTRA WIDE BAND

Beyond the corporate walls MOTOROLA enterprises Meshnetworks

Mesh technologies provide convenient , flexible scalable &cost effective extensions of corporate networks in the areasthat are typically too hard to cable

UWB is a radio technology that can be used at very lowenergy levels for short range high bandwidth communication,by using a large portion of the Radio spectrum.

It is used for radar imaging. Recently it has been used in

sensor Data collection, precision locating & trackingapplications

UWB communication does not interfere with other traditionaloperators

It may not be possible to bear for traditional system


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It may not be possible to bear for traditional systemdesign &may effect the stability of workingcommunication systems

UWB transmits signals across much widerfrequency than conventional systems& are usuallyvery difficult to detect

The amount of spectrum occupied by a UWB signalis at least 25%of the center frequency i.e UWBsignal centered at 2 GHz would be 1 GHz

The most common technique to generate a UWBsignal is to transmit pulses It communicates within a short distance with high

accuracy efficiency & Speed..


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Current 3G systems are evolving into 4G. As a pathwayto4G 3GPP is currently developing Long Term Evolution(LTP) standards & 3GPP2 is working on ULTRA Mobile

Broad Band (UMB) Standard. i.e I.E.E.E 802.16 StandardWI-MAX

It is also gaining attention as a solution to 4Gproblems

In air interface techniques all three systems useOFDMA based multi-carrier modulation& MIMOtechniques & also other advanced features togreatly improve the mobile services

The techniques which are mostly thought of beyond

3G are OFDMA, SC-CDMA, MIMO, FFR (FractionalFrequency Re-Use & advance coding)

..

UWB is a license free spectrum sharing technique


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where the transmitted RF energy is spread over awide bandwidth so that the interference to theexisting user is kept at minimum.

Driven largely by UWB technology high speed shortrange wireless personal area networks (WPANS) areexpected to profile rate in the coming Years

A Band hopping OFDM transmission method

developed by the Wireless media alliance &Standardized by ECMA has gained the significantsupport for developing high Rate (WPANS)

One key application for the technology is cable

replacement for universal serial BUS(USB) 2..0devices

In addition I.E.E.E 802.15 & ECMA have formed taskgroups aimed at developing new specifications forwireless connectivity in 60 GHz frequency band.

60 GHz band offers a large amount of BW ( Up to 7 GHZ) &l d t it li it & th f h th t ti l


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relaxed transmit power limits & therefore has the potentialto meet the demand for multi Gega bit Data Rates

Although at such high frequency the smaller Antenna Size

makes the technique very attractive, but Antenna sectorswitching & beam forming may be required.

Applications Due to extremely low emission levels currently allowed by

regulatory agencies UWB systems tend to be short rangesystems which can be used for Indoor working

Due to the short duration of UWB pulses it is easier toengineer extremely high data rates.

Conventional OFDM technology can be used subject to the

minimum Bandwidth requirement High data rate UWB can enable wireless monitors, the

efficient transfer of Data from digital camcoders,

Wireless printing of Digital pictures from a Camera withoutthe need of inter ening personal computer


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the need of intervening personal computer

UWB is used as a part of location systems & real timelocation systems. The precision capabilities combined with

very low power makes it ideal for certain radio frequencysensitive environments such as hospitals & health care

UWB is also used to see through the Walls precision radarimaging technology, precision radio imaging technology,precision locating & tracking i.e using distance

measurements between the radios.& precision time ofarrival based localization approaches. It exhibits excellentefficiency with a special capacity of approximately10 POWER13BIT/S/SQUARE METER

UWB HAS BEEN A PROPOSED TECHNOLOGY FOR USE IN PERSONALAREA NETWORKS & APPEARED IN THE ieee 802.15.3ADRAFT PANSTANDARD UWB has been having the Limited Success Due to high costof implementation & performance

The fastest data rate publicly shown over UWB is


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The fastest data rate publicly shown over UWB isnow an impressive 252Mbps at the rate of 480Mbps is expected to be shown in the not to distantfuture.

Requirements for the digital home include highspeed data transfer for multimedia content short-range connectivity for transfer to other devices, lowpower consumption due to limited battery capacityand low complexity and cost due to market pricingpressure and alternate wired connectivity options.

Transfer of video from a camcorder to aentertainment P.C is one scenario.

The second one is to have the view of photos fromusers still camera removing all the wires to theprinter, scanner, mass storage devices and video

cameras located in home offices.

Closed related is wireless connectivity for consumerdevices Portable customer appliances audio video


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devices. Portable customer appliances, audio- videodevices such as D.V camcorders , digital stillcameras , portable MP3 players , HDTV displays ,Personnel video recorders, entertainments P.Cs and

emerging personnel video players are likelycandidates for the early UWB.

Wider Applications of UWB

The concept of UWB radio spans different applicationsand industries and has been coined as the commonUWB radio platform.

The UWB along with the convergence layer becomesthe transport mechanism some of which are currentlywired. Some of the more notable applications that willoperate on top of the common UWB platform would bewireless universal serial bus (WUSB) IEEE 1394, thenext generation of Bluetooth universal plug and play(UPNP).

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