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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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The main disadvantages of such algorithms are
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
The main disadvantages of such algorithms are
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).