SlideShare una empresa de Scribd logo
1 de 14
Descargar para leer sin conexión
1
TERM PAPER
ON
COGNITIVE RADIO
By
Rahul Mahajan (10BM60066)
MBA 1st
year, 2010-2012 batch
Vinod Gupta School of Management
IIT Kharagpur
rahulsm.27@gmail.com
2
ABSTRACT
The pervasive use of wireless technology has created an ever-increasing demand for more and more
spectrum. However the most recent studies highlight the fact that the current spectrum allocation method
is inefficient as the bands are underutilized.
There have been many technological developments to increase the efficiency of spectrum utilization. This
concentrated mainly on increasing the number of users in a frequency band. These developments are
evolutionary as such they evolve from the exiting technologies. However cognitive radio is one of recent
revolutionary advancement that promises to govern the future wireless world. It is considered to have a
profound effect the way we will mange, utilize and share radio spectrum in future.
In this paper the implications of cognitive radio for future management of spectrum is discussed.
INTRODUCTION
Currently in wireless communication, all around the world, the availability of spectrum is governed by
regulatory and licensing bodies. This is called as Static spectrum allocation. In this, the spectrum
available is divided into fixed bands and each band is dedicated for a particular service or wireless
technology. This dedicated allocation of spectrum to particular services leads to inefficient utilization of
spectrum. However the growing need for more and more bandwidth is resulting in spectrum scarcity.
Cognitive radio is the most promising solution which can address this problem.
What is cognitive radio?
The term cognitive radio (CR) was coined by Mitola in 1999 .Quoting the definition of cognitive radio in his
words as “the point in which wireless personal digital assistants (PDAs) and the related networks are
sufficiently computationally intelligent about radio resources and related computer-to-computer
communication to: (a) detect user communications needs as a function of user context and (b) to provide
radio resources and wireless services most appropriate to those needs”.
A cognitive radio can be considered as a system which continuously interacts with its environment to
evaluate the availability of resources and needs of users so as to efficiently utilize the spectrum available.
It does so by changing its operation parameters like frequency of operation, modulation and coding
technique etc
3
In essence the two most important features of cognitive radio are
1. Intelligent awareness - Being aware of the surrounding environment and continuously learning
from the user and environment needs
2. Re-configurability - Ability to make changes in the operating parameters like transmission or
reception in real time.
AN ANOLOGY The current spectrum allocation can be considered analogous in the way road traffic is
controlled with definite lanes and electronic signals, controlling and restricting the flow. The cognitive
radio can be considered analogous to a more distributed and self managed- regulated pedestrian traffic.
Why cognitive radio?
Globally wireless networks are increasingly facing bandwidth crisis .The spectrum available has become
a scarce resource. Today mobile communications are allowed only certain frequencies which are getting
crowded. As demand for new enhanced services like music, videos and internet are increasing day by
day requirement for bandwidth is far more then currently available. Hence fundamental problem facing
future wireless communication systems is where to find suitable carrier frequencies and bandwidths to
meet the predicted demand of future services.
However if one scans the radio spectrum, it would be found that
 Some frequencies are unutilized for most of the time
 Some frequencies are partially utilized
 Some frequencies are heavily loaded for most of the time
Thus the available spectrum is inefficiently utilized.
HOW
One can identify a range of frequencies dedicated to a particular user, but at a particular time and place
this frequencies are not being utilized. Cognitive radio exploits this to efficiently utilize the available
spectrum. With cognitive radio technology one can use all available frequency even those dedicated to
TV and Satellite. Intelligent devices will negotiate with each other in order to utilize the whole spectrum
available in the most efficient way.
4
A cognitive radio thus would require the following core capabilities
1. FLEXIBILITY AND AGILITY: Ability to dynamically change the operational parameters. Full
flexibility would be possible if cognitive radios are built on top a software-defined radio. An SDR is
a radio in which the transmission properties such as signal bandwidth, carrier frequency,
modulation, and network access are defined by software. In addition to SDR, another important
requirement to achieve flexibility is reconfigure-ability and wideband antenna technologies.
2. SENSING: Ability to scan the RF environment and measure the current state of the environment,
including spectral occupancy. Sensing is necessary if the device has to change its operation
based on its current knowledge of environment.
3. LEARNING: Ability to make sense out of what is being sensed and learn from it.
4. ADAPTABILITY: Ability to modify internal operational behavior based on the resultant analysis
of the new situation,
5. LOCATION AWARENESS: Ability to respond to spatially variant regulatory policies or spatially
variant spectrum availabilities.
Advantages
Cognitive radios thus results in
 Proper utilization of available spectrum
 Giving precedence to high priority communication
 Optimum power consumption
 Providing new services
5
KEY DRIVERS FOR COGNITIVE RADIO
DSA (DYNAMIC SYSTEM ALLOCATION)
Currently Static allocation model is deployed in which the portion of spectrum for a particular service is
always dedicated. This procedure ensures simplicity, guaranteed access to the licensee and better quality
of services. However deployment of cognitive networks call for a model in which if the licensee called the
primary user is not utilizing the band at a particular time then the secondary user can opportunistically use
the spectrum. This deployment called Dynamic Spectrum Access would open up vast amount of
spectrum.
The challenge lies in developing models that significantly improve spectrum efficiency without
compromising on the benefits of Static Allocation Model. How one would develop polices that would
ensure that the rights of licensee and quality of services are maintained. Also it must be economically
viable for manufactures to deploy DSA. The deployment of DSA possesses much technology, spectrum
policy and economic challenges.
CRN-(COGNITIVE RADIO NETWORKS)
Devices employing cognitive radios need to operate smoothly in multiple frequency bands. In addition
they must be able to decide which frequency band to use and configure the network appropriately.
Specifically, the devices need to agree on how to realize various physical, link, and network layer
functions in a way that makes best use of the available spectrum, while also satisfying the policy
constraints that apply in the selected band.
6
Cognitive Radio Networks (CRNs) are networks that would be able to sense their RF environment and
adapt themselves to achieve optimum efficiency. Wifi already use cognitive optimization (in terms of rate
adaptation) and spectrum agility. However the use is very restricted. For deployment of CR more robust
and aggressive adaptation techniques such as across wider spectrum band and radical runtime protocol
optimizations would be required.
SDR (Software Defined Radio)
Most of the radios today implement all the processing and protocol functions in hardware thereby limiting
runtime adaptability to very small changes. CRN would require a wireless device that is very flexible in
changing various protocol functions during runtime. For this SDR present an ideal platform.SDR would
enable deployment of several standards on the same hardware by reprogramming the software. In SDR
conversion of analog signal to digital signal takes place as early as possible at the front end while
conversion of digital signal to analog signal is done as late as possible at the back end. Hence much of
the processing takes place in the digital domain. Processing in digital domain is easy and enhances
devices flexibility and adaptability
However, due to the limitations of analog/digital converters, digital processing capacity and power
constraints, SDR are still not fully deployed. The flexibility offered by SDRs is very attractive, especially
when prototyping and evaluating cognitive networking technology.
TECHNOLOGICAL TECHNIQUES
1. Signal processing - The signal processing problems that would be typical in CR would be
making inference about the transmitted information base on received signals in an unknown and
dynamically changing environment. Conventional processing methods are computationally complex.
However the recently emerged Bayesian signal processing promises a simpler solution
2. Dynamic programming- Dynamic programming broadly refers to solve large complex problem
by breaking them down into simpler steps. In cognitive environment dynamic programming would suffer
from exponentially increased computational algorithm and resource requirements.
3. Learning machines with feedback- One of the key aspects that will be development of
techniques that can learn from the information collected in the past and present .There are techniques
currently deployed to fine tune radio parameters but these are in very nascent stage. A lot of research
needs to be done on learning , reasoning and resulting intelligence in CR networks
4. Cross-layer protocol design. Currently in wireless network protocol design each layer is
designed and operated independently. In cross-layer protocol design adaptivity and optimization across
multiple layers of the protocol stack are needed. Each layer responds to variations local to that layer and
information from other layers with the aim of joint optimization of all protocol layers.
7
PRESENT SCENARIO –KEY PLAYERS
DISA- US Defense Information Systems Agency
The US Defense Information Systems Agency (DISA) is moving into the age of dynamic spectrum access
(DSA), which is the key near-term contribution of cognitive radio. DISA's Defense Spectrum Organization
(DSO) is the DoD center of excellence for spectrum management. The key DSO elements are
Global Electromagnetic Spectrum Information System Program Management Office (GEMSIS
PMO) Global Electromagnetic Spectrum Information System (GEMSIS) is the joint program of record that
will transform spectrum operations from a pre-planned and static frequency assignment into a dynamic,
responsive, and agile capability. GEMSIS is focused on increasing the efficiency of DoD spectrum use by
eliminating inefficient preplanned and static frequency assignment.
Joint Spectrum Center (JSC) JSC is a source of engineering expertise and services dedicated to
ensuring effective use of the electromagnetic spectrum. JSC provides services such as spectrum-
planning guidance, system integration, system vulnerability analysis, environmental analysis, test and
measurement support, operational support and spectrum management software development.
NOKIA
Nokia a market leader with the aim of improving user experiences for more innovative and integrated
telecommunication has already adapted cognitive radio within allocated spectrum bands to manage
heterogeneous more efficiently. Nokia research center is working extensively in this field
COGNITIVE ACCESS TO TV BANDS
In UK digital switchover is expected to be completed by 2012 that would require the TV stations to
convert from analogue to digital transmission. After the switchover a portion of TV analogue channels
would become vacant which be auctioned off by regulators to other services.
In addition there will be a number of TV channels in a given area that would not be used by DTV station
because such stations would not be able to operate without interference to adjacent channels.
However low power unlicensed device can operate on these vacant spaces that could not be used by
DTV due to interferences. These vacant TV channel care called white spaces. The proposed new rules
would, in principle allow the operation of both fixed and portable broadband devices on a non-interference
basis in this white spaces.
A preliminary study by Ofcom indicates that “at any one location, around 100 MHz on average is not
being used by DTT (Digital Terrestrial Television) and could, in principle be used by license-exempt
devices”
8
PROMOSING APPLICATION OF COGNITIVE
Cognitive radio has the potential to drastically alter the way we would mange our communication in the
future. Some of the promising applications are
1. Emergency Services Use of Cognitive Radio The public safety users have direct application
for cognitive radios. In conditions of emergency need for quality of service and interoperability
among various standards becomes vital. CR with there inherent ability to adapt and adjust to
different standards would help in such situation.
2. Low Cost Internet Access .The dynamic spectrum access model approach would enable
broadband access on the unused spectrums, thereby enabling lower Internet access cost by
drastically reducing cost component associated with purchase of spectrum.
3. Rural connectivity By deploying smart mesh CRN systems remote rural areas can be provided
connectivity.
4. New services Radio based advertising in which the user gets only relevant information
Application in public safety: Consider a situation during an emergency. Emergency situation generally
require great deal of co ordination of between different relief workers, fire brigade, police and other
concerned person. Chances of communication breakdown both internally and externally increase due to
lack of common standards and overburden of emergency bands.
Cognitive radio would help in such situation by prioritizing such communication and enabling
communication all standards.
Application in security: Imagine a situation in which a soldier has to only turn on the device which he is
carrying. Once engaged the cognitive radio will determine what spectrum to use, sense any disruptions in
the environment (jamming) and adjust accordingly.
Application in daily life: A flight entering into the borders of another country. Currently the radio
parameters need to be set by the pilot with the help of ground controllers as the standards for
communication are different in different countries With cognitive radios no human involvement would be
required
9
ECONOMIC ASPECTS OF COGNITIVE RADIOS
What would ultimately justify the functionality of cognitive radio into user equipment and the network
operator is economics
VALUE FOR THE PROVIDER
In many regions of world the telecom infrastructure is at its peak and to improve infrastructure density is
practically impossible. In order to support the demand for continuous growth cognitive radios can come
handy. More efficient use of spectrum in these regions would easily translate into revenue stream for the
network operators with increased users. Additionally they would also be able to offer more sophisticated
services and rich experience to end users.
In many regions of the world especially the rural area it is highly uneconomical to lay down fiber cables.
And generally broadcast TV source are generally very far from this users and as such there is nearly no
spectrum use. There are significant opportunities to provide telecom and internet service using this under
utilized section.
VALUE FOR THE USER
Ultimately it’s the end user that must feel or realize the incremental value that he would be benefiting from
by adopting cognitive radio. Cognitive radio envisions a learning radio that would be realizing user and
network requirements to determine performance. The sophisticated services that one would be able to
realize from having such flexibility are immense and would be truly helpful to subscribers.
Initial Cognitive radio would come at a slight higher cost to the end user. However this won’t deter
customer from availing this service as the benefits associated with it are lucrative enough to out weigh the
added cost. Cognitive radio has the potential of providing seamless connectivity anywhere anytime.
KEY DIFFERENTIATING FEATURE
The differentiating feature of successful service providers in the future would be one who accommodates
user’s current needs most efficiently. With cognitive radio a service provider would be able to bundle all
the services that a user can possibly demand (like Cellular WiFi Wimax Bluetooth video services etc.)
together. Based on user requirements and network resource the service provider would be able to
provide economical and seamless service.
10
ECONOMIC APPROACHES FOR IMPLEMENTATION OF
COGNITIVE RADIO NETWORKS
For implementation of CRN we need to understand the feasibility of various economic approaches as well
as the associated technical challenges. The licensed users are called primary users and the users of the
CRN are called secondary users. For peaceful existences of both accurate information of the usage of
spectrum is required .There are two different approaches that can be followed
OPPORTUNISTIC SPECTRUM ACCESS: Secondary users scan the primary user spectrum to determine
any vacant spectra. Sensing becomes a critical issue.
RESOURCE TRADING: Primary user explicitly provides any relevant information to secondary users. By
allowing some monetary to primary users can get some monetary benefits by allowing secondary users to
use spectrum
In opportunistic spectrum access since there is no motivation for primary user it becomes difficult to
guarantee a peaceful coexistence of both. Hence a resource trading based approach is a better option
A combination of different economic approaches can be applied in order to have a resource trading based
spectrum sharing. These approaches are briefly described next
GAME THEORY It’s the study of cooperation and conflict among individuals or groups. It provides an
analytical framework for decision making based on this. It aims at maximum optimization of all resources
at same time protecting the interest of primary users.
PRICE THEORY For resource trade based spectrum sharing appropriate schemes for setting up the price
of the spectrum, formulating models that maximizes payoff to both primary users in terms of monetary
value and secondary users in terms of service is an important issue
MARKET THEORY -Stability would be required overall in order to have a feasible model
11
CHALLENGES IN DEPLOYMENT OF COGNITIVE RADIO
LEGAL HURDLES
Cognitive radio is an advanced technology. Successful implementation of such revolutionary technologies
in an economy and policy regime thrives heavily upon how and where it return value that too without
impeding other technologies or innovation. Thus the success of cognitive radios would greatly depend on
what policy changes would be required throughout the world and corresponding consequences. Research
would be required to support any proposed policy reform. Demonstration of improved performance over
the other technology is a must. Improved spectrum utilization and cost effectiveness must be visible to the
policy makers.
Implementation of cognitive radio requires a model with following requirements
 Sharing among equals, or giving some wireless systems primary rights and others secondary status.
 Cooperation among systems from different administration domains,
 Assumptions that systems are licensed or unlicensed or a mix of the two.
A proper research addressing critical issues such as how devices would operate in a given band, what
are the levels of risk involved in case of harmful interference, possibility of congestion and interferences
under different regulatory approaches, what be the role and responsibility of standard bodies, industry
and user groups, what would be the social and economic benefits and potential impact on business and
technological strategies would be required.
SECURITY RELATED ISSUE
Security would be one of the major concerns while deploying cognitive radio. In a system where radios
can decide how to use the available spectral resources proper identification and authentication is must.
Rouge player trying to cause major communication disruption would flourish. Mechanism would be
required to develop to identify such systems and deactivate or block them. Hence proper and successful
implementation of robust security measures becomes vital while deploying cognitive radios.
TECHNOLOGY HURDLES
Being aware of the environment cognitive radio chooses the best available option based on certain
performance parameters such as carrier frequency, type of modulation, antenna, power bandwidth etc.
This means that the radio would have to deal with different RF spectrum and baseband varieties at the
same time, thus requiring a more robust, efficient and reconfigurable hardware architecture. Clearly, the
introduction of this revolutionary paradigm poses many challenges across all layers of a cognitive radio
system design like spectrum sensing, interference management, resource allocation, RF design and
implementation issues.
12
1. SPECTRUM SENSING TECHNIQUES
One of the most important functions of cognitive radio is to sense its environment accurately and thereby
choose its operation parameter. Spectrum sensing has been identified as a key enabling cognitive radio
to not interfere with primary users, by reliability detecting primary user’s signals. And sensing is not
merely enough. Making sense out of what it being sensed is another all together different issue.
Sensing techniques available today are susceptible to changing levels of interference and noise levels.
Also these techniques can only detect the presence or absence of signal. They are not able to
differentiate whether the detected signal is a noise, interference or information carrying signal.
The hurdle lies in developing fast low-cost detecting techniques that are able to detect weak signals and
also differentiate between them.
2. HARDWARE DESIGN
Another major hurdle is designing of a flexible hardware that can be used for wideband sensing and
multiband communication purposes. Conventionally, in the design of RF circuit for radio certain
assumptions regarding interferes and worst case scenarios can be made fairly. This greatly eased the
design of hardware for a desired performance.
However cognitive radio operates in a dynamic environment. Additionally not having prior information on
the frequency of operation bandwidth and other operation parameters greatly complicates the situation. If
one follows the conventional approach it would lead to design of excessive circuit blocks thereby
increasing space, cost and complexity. Designing a flexible circuit giving a minimal level of performance
under all expected and unexpected scenarios becomes a challenge
3. ON CHIP IMPLEMENTATION
Designing the digital baseband processing of such a complex system also posses an uphill task. The
power usage would increase significantly due to increase in functionality. Also the memory requirement
would increase significantly due to operation in an unknown dynamically changing environment.
4. PROTOCOL ARCHITECTURES
The extreme flexible requirements of cognitive radios involve redesigning of network algorithms and
protocols. In particular cross layer algorithms that adapt to changes in quality, network structure, and
physical link availability would require an advanced management framework. Design of network protocols
that can enable cognitive devices to exchange key information like frequency coordination network
configuration transmission parameters would be critical.
13
THE WAY FORWARD
CURRENT SCENARIO FUTURE SCENARIO
 Cognitive radio would enable interaction between all types of radio devices
 A simple embedding of a radio in any object could mean interaction of all objects!!
 Verify and control your identity, online and offline all at the same time
 All time connectivity not only through network cells but also through formation of spontaneous networks
 New marketing strategy - Radio enabled advertising sends customized information to your phone in your
language
SUMMARY
In this paper we examined how cognitive radio can impact the way spectrum will be managed and
regulated in future. The concept of cognitive radio is promising to improve the utilization of spectrum. With
technological advancement in device cognitive and re-configurability capabilities we may see current
static spectrum management model completely disappear. Spectrum would be managed by a society of
intelligence cognitive devices which on behalf of their user would be continuously involved in
communication negotiation cooperation and trading.
This would require the need of formation of new regulation in the future. Many key technological,
economical and legal issue need to be explored before cognitive radios are fully deployed. Significant
new research is required to address these challenges. The potential for cognitive radio to make a
significant difference to wireless communications is immense. The key issue in the final evolution of
cognitive radio for any application would be-
• Trust by the users of cognitive radio;
• Trust by all other users who might be interfered with.
14
References
1. Radio electronics.com: Future of Cognitive Radio - an interview with Dr Joseph Mitola
2. Maziar Nekovee : Impact of Cognitive Radio on Future Management of Spectrum
3. Cristian Ianculescu: Cognitive radio and dynamic spectrum sharing
4. Dr. Bruce Fette, Ph.D. Cognitive radios: The future of SDR technology
5. Joseph Mitola Cognitive Radio: Making Software Radios More Personal
6. Sabita Maharjan · Yan Zhang · Stein Gjessing: Economic Approaches for Cognitive Radio
Networks
7. Angsuman Rudra Cognitive radio: An evolution from software radio
8. Nokia research center: http://research.nokia.com/

Más contenido relacionado

La actualidad más candente

Cognitive Radio: When might it Become Economically and Technically Feasible?
Cognitive Radio: When might it Become Economically and Technically Feasible? Cognitive Radio: When might it Become Economically and Technically Feasible?
Cognitive Radio: When might it Become Economically and Technically Feasible? Jeffrey Funk
 
Welcome to International Journal of Engineering Research and Development (IJERD)
Welcome to International Journal of Engineering Research and Development (IJERD)Welcome to International Journal of Engineering Research and Development (IJERD)
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
 
Keith Nolan - Use Of Cognitive Radio To Improve Spectrum Usage Efficiency And...
Keith Nolan - Use Of Cognitive Radio To Improve Spectrum Usage Efficiency And...Keith Nolan - Use Of Cognitive Radio To Improve Spectrum Usage Efficiency And...
Keith Nolan - Use Of Cognitive Radio To Improve Spectrum Usage Efficiency And...Keith Nolan
 
Cognitive radio networks
Cognitive radio networksCognitive radio networks
Cognitive radio networksVatsala Sharma
 
OPPORTUNISTIC MULTIPLE ACCESS TECHNIQUES FOR COGNITIVE RADIO NETWORK
OPPORTUNISTIC MULTIPLE ACCESS TECHNIQUES FOR COGNITIVE RADIO NETWORKOPPORTUNISTIC MULTIPLE ACCESS TECHNIQUES FOR COGNITIVE RADIO NETWORK
OPPORTUNISTIC MULTIPLE ACCESS TECHNIQUES FOR COGNITIVE RADIO NETWORKPraktan Patil
 
Cognitive Radio
Cognitive Radio Cognitive Radio
Cognitive Radio RiyaSaini16
 
Cognitive Radio from a Mobile Operator's Perspective: System Performance and ...
Cognitive Radio from a Mobile Operator's Perspective: System Performance and ...Cognitive Radio from a Mobile Operator's Perspective: System Performance and ...
Cognitive Radio from a Mobile Operator's Perspective: System Performance and ...paalrg
 
Cognitive Radio, Introduction and Main Issues
Cognitive Radio, Introduction and Main IssuesCognitive Radio, Introduction and Main Issues
Cognitive Radio, Introduction and Main IssuesKuncoro Wastuwibowo
 
Cognitive radio networks
Cognitive radio networksCognitive radio networks
Cognitive radio networksAmeer Sameer
 
Alex Wyglinski - IEEE VTS UKRI - Cognitive radio - a panacea for RF spectrum...
Alex Wyglinski  - IEEE VTS UKRI - Cognitive radio - a panacea for RF spectrum...Alex Wyglinski  - IEEE VTS UKRI - Cognitive radio - a panacea for RF spectrum...
Alex Wyglinski - IEEE VTS UKRI - Cognitive radio - a panacea for RF spectrum...Keith Nolan
 
Cognitive Radio Network
Cognitive Radio Network Cognitive Radio Network
Cognitive Radio Network Dr Praveen Jain
 
Cognitive radio
Cognitive radioCognitive radio
Cognitive radioAli Nasr
 
Security threats in cognitive radio
Security threats in cognitive radioSecurity threats in cognitive radio
Security threats in cognitive radioNavya Shree
 

La actualidad más candente (17)

Cognitive Radio: When might it Become Economically and Technically Feasible?
Cognitive Radio: When might it Become Economically and Technically Feasible? Cognitive Radio: When might it Become Economically and Technically Feasible?
Cognitive Radio: When might it Become Economically and Technically Feasible?
 
Welcome to International Journal of Engineering Research and Development (IJERD)
Welcome to International Journal of Engineering Research and Development (IJERD)Welcome to International Journal of Engineering Research and Development (IJERD)
Welcome to International Journal of Engineering Research and Development (IJERD)
 
Keith Nolan - Use Of Cognitive Radio To Improve Spectrum Usage Efficiency And...
Keith Nolan - Use Of Cognitive Radio To Improve Spectrum Usage Efficiency And...Keith Nolan - Use Of Cognitive Radio To Improve Spectrum Usage Efficiency And...
Keith Nolan - Use Of Cognitive Radio To Improve Spectrum Usage Efficiency And...
 
Cognitive radio networks
Cognitive radio networksCognitive radio networks
Cognitive radio networks
 
OPPORTUNISTIC MULTIPLE ACCESS TECHNIQUES FOR COGNITIVE RADIO NETWORK
OPPORTUNISTIC MULTIPLE ACCESS TECHNIQUES FOR COGNITIVE RADIO NETWORKOPPORTUNISTIC MULTIPLE ACCESS TECHNIQUES FOR COGNITIVE RADIO NETWORK
OPPORTUNISTIC MULTIPLE ACCESS TECHNIQUES FOR COGNITIVE RADIO NETWORK
 
Cognitive Radio
Cognitive Radio Cognitive Radio
Cognitive Radio
 
What is Cognitive Radio?
What is Cognitive Radio? What is Cognitive Radio?
What is Cognitive Radio?
 
Cognitive Radio from a Mobile Operator's Perspective: System Performance and ...
Cognitive Radio from a Mobile Operator's Perspective: System Performance and ...Cognitive Radio from a Mobile Operator's Perspective: System Performance and ...
Cognitive Radio from a Mobile Operator's Perspective: System Performance and ...
 
COGNITIVE RADIO
COGNITIVE RADIOCOGNITIVE RADIO
COGNITIVE RADIO
 
Cognitive Radio, Introduction and Main Issues
Cognitive Radio, Introduction and Main IssuesCognitive Radio, Introduction and Main Issues
Cognitive Radio, Introduction and Main Issues
 
Cognitive radio networks
Cognitive radio networksCognitive radio networks
Cognitive radio networks
 
Alex Wyglinski - IEEE VTS UKRI - Cognitive radio - a panacea for RF spectrum...
Alex Wyglinski  - IEEE VTS UKRI - Cognitive radio - a panacea for RF spectrum...Alex Wyglinski  - IEEE VTS UKRI - Cognitive radio - a panacea for RF spectrum...
Alex Wyglinski - IEEE VTS UKRI - Cognitive radio - a panacea for RF spectrum...
 
Cognitive Radio Network
Cognitive Radio Network Cognitive Radio Network
Cognitive Radio Network
 
Cognitive radio
Cognitive radioCognitive radio
Cognitive radio
 
Security threats in cognitive radio
Security threats in cognitive radioSecurity threats in cognitive radio
Security threats in cognitive radio
 
Seminar report
Seminar reportSeminar report
Seminar report
 
Cognitive Radio
Cognitive RadioCognitive Radio
Cognitive Radio
 

Destacado

Internship Report on IT support to MIS at NCHD
Internship Report on IT support to MIS at NCHDInternship Report on IT support to MIS at NCHD
Internship Report on IT support to MIS at NCHDZafar Ahmad
 
MIS Report on CRM Dept. in automobile industry
MIS Report on CRM Dept. in automobile industryMIS Report on CRM Dept. in automobile industry
MIS Report on CRM Dept. in automobile industryABHIJEET SINHA
 
Role of mis in functional areas
Role of mis in functional areasRole of mis in functional areas
Role of mis in functional areasSATYABRATA PRADHAN
 
Application of mis in textile industry
Application of mis in textile industryApplication of mis in textile industry
Application of mis in textile industryMajharul Islam
 

Destacado (6)

An application of mis
An application of misAn application of mis
An application of mis
 
Internship Report on IT support to MIS at NCHD
Internship Report on IT support to MIS at NCHDInternship Report on IT support to MIS at NCHD
Internship Report on IT support to MIS at NCHD
 
MIS Report on CRM Dept. in automobile industry
MIS Report on CRM Dept. in automobile industryMIS Report on CRM Dept. in automobile industry
MIS Report on CRM Dept. in automobile industry
 
Role of mis in functional areas
Role of mis in functional areasRole of mis in functional areas
Role of mis in functional areas
 
Introduction to mis
Introduction to misIntroduction to mis
Introduction to mis
 
Application of mis in textile industry
Application of mis in textile industryApplication of mis in textile industry
Application of mis in textile industry
 

Similar a Mis term paper updated

Mis term paper
Mis term paperMis term paper
Mis term paperrahulsm27
 
Mis term paper
Mis term paperMis term paper
Mis term paperrahulsm27
 
V5_I1_2016_Paper19.doc
V5_I1_2016_Paper19.docV5_I1_2016_Paper19.doc
V5_I1_2016_Paper19.docIIRindia
 
METHODS FOR DETECTING ENERGY AND SIGNALS IN COGNITIVE RADIO
METHODS FOR DETECTING ENERGY AND SIGNALS IN COGNITIVE RADIOMETHODS FOR DETECTING ENERGY AND SIGNALS IN COGNITIVE RADIO
METHODS FOR DETECTING ENERGY AND SIGNALS IN COGNITIVE RADIOIRJET Journal
 
APPLICATIONS OF COGNITIVE RADIO
APPLICATIONS OF COGNITIVE RADIOAPPLICATIONS OF COGNITIVE RADIO
APPLICATIONS OF COGNITIVE RADIOFAIZAN SHAFI
 
Frontiers of Wireless and Mobile Communications
Frontiers of Wireless and Mobile CommunicationsFrontiers of Wireless and Mobile Communications
Frontiers of Wireless and Mobile CommunicationsSai Varrshini
 
Project:- Spectral occupancy measurement and analysis for Cognitive Radio app...
Project:- Spectral occupancy measurement and analysis for Cognitive Radio app...Project:- Spectral occupancy measurement and analysis for Cognitive Radio app...
Project:- Spectral occupancy measurement and analysis for Cognitive Radio app...Aastha Bhardwaj
 
IRJET- Achieving Cognitive Radio for Improved Spectrum Utilization: An Implem...
IRJET- Achieving Cognitive Radio for Improved Spectrum Utilization: An Implem...IRJET- Achieving Cognitive Radio for Improved Spectrum Utilization: An Implem...
IRJET- Achieving Cognitive Radio for Improved Spectrum Utilization: An Implem...IRJET Journal
 
Dynamic Spectrum Allocation in Wireless sensor Networks
Dynamic Spectrum Allocation in Wireless sensor NetworksDynamic Spectrum Allocation in Wireless sensor Networks
Dynamic Spectrum Allocation in Wireless sensor NetworksIJMER
 
International Journal of Engineering Research and Development
International Journal of Engineering Research and DevelopmentInternational Journal of Engineering Research and Development
International Journal of Engineering Research and DevelopmentIJERD Editor
 
International Journal of Computational Engineering Research(IJCER)
International Journal of Computational Engineering Research(IJCER) International Journal of Computational Engineering Research(IJCER)
International Journal of Computational Engineering Research(IJCER) ijceronline
 
Frontiers of wireless and mobile communications v0.02
Frontiers of wireless and mobile communications v0.02Frontiers of wireless and mobile communications v0.02
Frontiers of wireless and mobile communications v0.02Sai Varrshini
 
Wireless Communication Advantages And Disadvantages
Wireless Communication Advantages And DisadvantagesWireless Communication Advantages And Disadvantages
Wireless Communication Advantages And DisadvantagesSara Harris
 
RF Planning and Optimization in GSM and UMTS Networks
RF Planning and Optimization in GSM and UMTS NetworksRF Planning and Optimization in GSM and UMTS Networks
RF Planning and Optimization in GSM and UMTS NetworksApurv Agrawal
 
SCALABILITY CONCERNS OF CHIRP SPREAD SPECTRUM FOR LPWAN APPLICATIONS
SCALABILITY CONCERNS OF CHIRP SPREAD SPECTRUM FOR LPWAN APPLICATIONSSCALABILITY CONCERNS OF CHIRP SPREAD SPECTRUM FOR LPWAN APPLICATIONS
SCALABILITY CONCERNS OF CHIRP SPREAD SPECTRUM FOR LPWAN APPLICATIONSijasuc
 
SCALABILITY CONCERNS OF CHIRP SPREAD SPECTRUM FOR LPWAN APPLICATIONS
SCALABILITY CONCERNS OF CHIRP SPREAD SPECTRUM FOR LPWAN APPLICATIONSSCALABILITY CONCERNS OF CHIRP SPREAD SPECTRUM FOR LPWAN APPLICATIONS
SCALABILITY CONCERNS OF CHIRP SPREAD SPECTRUM FOR LPWAN APPLICATIONSijasuc
 

Similar a Mis term paper updated (20)

Mis term paper
Mis term paperMis term paper
Mis term paper
 
Mis term paper
Mis term paperMis term paper
Mis term paper
 
V5_I1_2016_Paper19.doc
V5_I1_2016_Paper19.docV5_I1_2016_Paper19.doc
V5_I1_2016_Paper19.doc
 
METHODS FOR DETECTING ENERGY AND SIGNALS IN COGNITIVE RADIO
METHODS FOR DETECTING ENERGY AND SIGNALS IN COGNITIVE RADIOMETHODS FOR DETECTING ENERGY AND SIGNALS IN COGNITIVE RADIO
METHODS FOR DETECTING ENERGY AND SIGNALS IN COGNITIVE RADIO
 
APPLICATIONS OF COGNITIVE RADIO
APPLICATIONS OF COGNITIVE RADIOAPPLICATIONS OF COGNITIVE RADIO
APPLICATIONS OF COGNITIVE RADIO
 
Frontiers of Wireless and Mobile Communications
Frontiers of Wireless and Mobile CommunicationsFrontiers of Wireless and Mobile Communications
Frontiers of Wireless and Mobile Communications
 
Project:- Spectral occupancy measurement and analysis for Cognitive Radio app...
Project:- Spectral occupancy measurement and analysis for Cognitive Radio app...Project:- Spectral occupancy measurement and analysis for Cognitive Radio app...
Project:- Spectral occupancy measurement and analysis for Cognitive Radio app...
 
IRJET- Achieving Cognitive Radio for Improved Spectrum Utilization: An Implem...
IRJET- Achieving Cognitive Radio for Improved Spectrum Utilization: An Implem...IRJET- Achieving Cognitive Radio for Improved Spectrum Utilization: An Implem...
IRJET- Achieving Cognitive Radio for Improved Spectrum Utilization: An Implem...
 
Dynamic Spectrum Allocation in Wireless sensor Networks
Dynamic Spectrum Allocation in Wireless sensor NetworksDynamic Spectrum Allocation in Wireless sensor Networks
Dynamic Spectrum Allocation in Wireless sensor Networks
 
International Journal of Engineering Research and Development
International Journal of Engineering Research and DevelopmentInternational Journal of Engineering Research and Development
International Journal of Engineering Research and Development
 
D1082731
D1082731D1082731
D1082731
 
Cm32546555
Cm32546555Cm32546555
Cm32546555
 
International Journal of Computational Engineering Research(IJCER)
International Journal of Computational Engineering Research(IJCER) International Journal of Computational Engineering Research(IJCER)
International Journal of Computational Engineering Research(IJCER)
 
Paper 1 2019
Paper 1 2019Paper 1 2019
Paper 1 2019
 
Frontiers of wireless and mobile communications v0.02
Frontiers of wireless and mobile communications v0.02Frontiers of wireless and mobile communications v0.02
Frontiers of wireless and mobile communications v0.02
 
Wireless Communication Advantages And Disadvantages
Wireless Communication Advantages And DisadvantagesWireless Communication Advantages And Disadvantages
Wireless Communication Advantages And Disadvantages
 
RF Planning and Optimization in GSM and UMTS Networks
RF Planning and Optimization in GSM and UMTS NetworksRF Planning and Optimization in GSM and UMTS Networks
RF Planning and Optimization in GSM and UMTS Networks
 
41 45
41 4541 45
41 45
 
SCALABILITY CONCERNS OF CHIRP SPREAD SPECTRUM FOR LPWAN APPLICATIONS
SCALABILITY CONCERNS OF CHIRP SPREAD SPECTRUM FOR LPWAN APPLICATIONSSCALABILITY CONCERNS OF CHIRP SPREAD SPECTRUM FOR LPWAN APPLICATIONS
SCALABILITY CONCERNS OF CHIRP SPREAD SPECTRUM FOR LPWAN APPLICATIONS
 
SCALABILITY CONCERNS OF CHIRP SPREAD SPECTRUM FOR LPWAN APPLICATIONS
SCALABILITY CONCERNS OF CHIRP SPREAD SPECTRUM FOR LPWAN APPLICATIONSSCALABILITY CONCERNS OF CHIRP SPREAD SPECTRUM FOR LPWAN APPLICATIONS
SCALABILITY CONCERNS OF CHIRP SPREAD SPECTRUM FOR LPWAN APPLICATIONS
 

Mis term paper updated

  • 1. 1 TERM PAPER ON COGNITIVE RADIO By Rahul Mahajan (10BM60066) MBA 1st year, 2010-2012 batch Vinod Gupta School of Management IIT Kharagpur rahulsm.27@gmail.com
  • 2. 2 ABSTRACT The pervasive use of wireless technology has created an ever-increasing demand for more and more spectrum. However the most recent studies highlight the fact that the current spectrum allocation method is inefficient as the bands are underutilized. There have been many technological developments to increase the efficiency of spectrum utilization. This concentrated mainly on increasing the number of users in a frequency band. These developments are evolutionary as such they evolve from the exiting technologies. However cognitive radio is one of recent revolutionary advancement that promises to govern the future wireless world. It is considered to have a profound effect the way we will mange, utilize and share radio spectrum in future. In this paper the implications of cognitive radio for future management of spectrum is discussed. INTRODUCTION Currently in wireless communication, all around the world, the availability of spectrum is governed by regulatory and licensing bodies. This is called as Static spectrum allocation. In this, the spectrum available is divided into fixed bands and each band is dedicated for a particular service or wireless technology. This dedicated allocation of spectrum to particular services leads to inefficient utilization of spectrum. However the growing need for more and more bandwidth is resulting in spectrum scarcity. Cognitive radio is the most promising solution which can address this problem. What is cognitive radio? The term cognitive radio (CR) was coined by Mitola in 1999 .Quoting the definition of cognitive radio in his words as “the point in which wireless personal digital assistants (PDAs) and the related networks are sufficiently computationally intelligent about radio resources and related computer-to-computer communication to: (a) detect user communications needs as a function of user context and (b) to provide radio resources and wireless services most appropriate to those needs”. A cognitive radio can be considered as a system which continuously interacts with its environment to evaluate the availability of resources and needs of users so as to efficiently utilize the spectrum available. It does so by changing its operation parameters like frequency of operation, modulation and coding technique etc
  • 3. 3 In essence the two most important features of cognitive radio are 1. Intelligent awareness - Being aware of the surrounding environment and continuously learning from the user and environment needs 2. Re-configurability - Ability to make changes in the operating parameters like transmission or reception in real time. AN ANOLOGY The current spectrum allocation can be considered analogous in the way road traffic is controlled with definite lanes and electronic signals, controlling and restricting the flow. The cognitive radio can be considered analogous to a more distributed and self managed- regulated pedestrian traffic. Why cognitive radio? Globally wireless networks are increasingly facing bandwidth crisis .The spectrum available has become a scarce resource. Today mobile communications are allowed only certain frequencies which are getting crowded. As demand for new enhanced services like music, videos and internet are increasing day by day requirement for bandwidth is far more then currently available. Hence fundamental problem facing future wireless communication systems is where to find suitable carrier frequencies and bandwidths to meet the predicted demand of future services. However if one scans the radio spectrum, it would be found that  Some frequencies are unutilized for most of the time  Some frequencies are partially utilized  Some frequencies are heavily loaded for most of the time Thus the available spectrum is inefficiently utilized. HOW One can identify a range of frequencies dedicated to a particular user, but at a particular time and place this frequencies are not being utilized. Cognitive radio exploits this to efficiently utilize the available spectrum. With cognitive radio technology one can use all available frequency even those dedicated to TV and Satellite. Intelligent devices will negotiate with each other in order to utilize the whole spectrum available in the most efficient way.
  • 4. 4 A cognitive radio thus would require the following core capabilities 1. FLEXIBILITY AND AGILITY: Ability to dynamically change the operational parameters. Full flexibility would be possible if cognitive radios are built on top a software-defined radio. An SDR is a radio in which the transmission properties such as signal bandwidth, carrier frequency, modulation, and network access are defined by software. In addition to SDR, another important requirement to achieve flexibility is reconfigure-ability and wideband antenna technologies. 2. SENSING: Ability to scan the RF environment and measure the current state of the environment, including spectral occupancy. Sensing is necessary if the device has to change its operation based on its current knowledge of environment. 3. LEARNING: Ability to make sense out of what is being sensed and learn from it. 4. ADAPTABILITY: Ability to modify internal operational behavior based on the resultant analysis of the new situation, 5. LOCATION AWARENESS: Ability to respond to spatially variant regulatory policies or spatially variant spectrum availabilities. Advantages Cognitive radios thus results in  Proper utilization of available spectrum  Giving precedence to high priority communication  Optimum power consumption  Providing new services
  • 5. 5 KEY DRIVERS FOR COGNITIVE RADIO DSA (DYNAMIC SYSTEM ALLOCATION) Currently Static allocation model is deployed in which the portion of spectrum for a particular service is always dedicated. This procedure ensures simplicity, guaranteed access to the licensee and better quality of services. However deployment of cognitive networks call for a model in which if the licensee called the primary user is not utilizing the band at a particular time then the secondary user can opportunistically use the spectrum. This deployment called Dynamic Spectrum Access would open up vast amount of spectrum. The challenge lies in developing models that significantly improve spectrum efficiency without compromising on the benefits of Static Allocation Model. How one would develop polices that would ensure that the rights of licensee and quality of services are maintained. Also it must be economically viable for manufactures to deploy DSA. The deployment of DSA possesses much technology, spectrum policy and economic challenges. CRN-(COGNITIVE RADIO NETWORKS) Devices employing cognitive radios need to operate smoothly in multiple frequency bands. In addition they must be able to decide which frequency band to use and configure the network appropriately. Specifically, the devices need to agree on how to realize various physical, link, and network layer functions in a way that makes best use of the available spectrum, while also satisfying the policy constraints that apply in the selected band.
  • 6. 6 Cognitive Radio Networks (CRNs) are networks that would be able to sense their RF environment and adapt themselves to achieve optimum efficiency. Wifi already use cognitive optimization (in terms of rate adaptation) and spectrum agility. However the use is very restricted. For deployment of CR more robust and aggressive adaptation techniques such as across wider spectrum band and radical runtime protocol optimizations would be required. SDR (Software Defined Radio) Most of the radios today implement all the processing and protocol functions in hardware thereby limiting runtime adaptability to very small changes. CRN would require a wireless device that is very flexible in changing various protocol functions during runtime. For this SDR present an ideal platform.SDR would enable deployment of several standards on the same hardware by reprogramming the software. In SDR conversion of analog signal to digital signal takes place as early as possible at the front end while conversion of digital signal to analog signal is done as late as possible at the back end. Hence much of the processing takes place in the digital domain. Processing in digital domain is easy and enhances devices flexibility and adaptability However, due to the limitations of analog/digital converters, digital processing capacity and power constraints, SDR are still not fully deployed. The flexibility offered by SDRs is very attractive, especially when prototyping and evaluating cognitive networking technology. TECHNOLOGICAL TECHNIQUES 1. Signal processing - The signal processing problems that would be typical in CR would be making inference about the transmitted information base on received signals in an unknown and dynamically changing environment. Conventional processing methods are computationally complex. However the recently emerged Bayesian signal processing promises a simpler solution 2. Dynamic programming- Dynamic programming broadly refers to solve large complex problem by breaking them down into simpler steps. In cognitive environment dynamic programming would suffer from exponentially increased computational algorithm and resource requirements. 3. Learning machines with feedback- One of the key aspects that will be development of techniques that can learn from the information collected in the past and present .There are techniques currently deployed to fine tune radio parameters but these are in very nascent stage. A lot of research needs to be done on learning , reasoning and resulting intelligence in CR networks 4. Cross-layer protocol design. Currently in wireless network protocol design each layer is designed and operated independently. In cross-layer protocol design adaptivity and optimization across multiple layers of the protocol stack are needed. Each layer responds to variations local to that layer and information from other layers with the aim of joint optimization of all protocol layers.
  • 7. 7 PRESENT SCENARIO –KEY PLAYERS DISA- US Defense Information Systems Agency The US Defense Information Systems Agency (DISA) is moving into the age of dynamic spectrum access (DSA), which is the key near-term contribution of cognitive radio. DISA's Defense Spectrum Organization (DSO) is the DoD center of excellence for spectrum management. The key DSO elements are Global Electromagnetic Spectrum Information System Program Management Office (GEMSIS PMO) Global Electromagnetic Spectrum Information System (GEMSIS) is the joint program of record that will transform spectrum operations from a pre-planned and static frequency assignment into a dynamic, responsive, and agile capability. GEMSIS is focused on increasing the efficiency of DoD spectrum use by eliminating inefficient preplanned and static frequency assignment. Joint Spectrum Center (JSC) JSC is a source of engineering expertise and services dedicated to ensuring effective use of the electromagnetic spectrum. JSC provides services such as spectrum- planning guidance, system integration, system vulnerability analysis, environmental analysis, test and measurement support, operational support and spectrum management software development. NOKIA Nokia a market leader with the aim of improving user experiences for more innovative and integrated telecommunication has already adapted cognitive radio within allocated spectrum bands to manage heterogeneous more efficiently. Nokia research center is working extensively in this field COGNITIVE ACCESS TO TV BANDS In UK digital switchover is expected to be completed by 2012 that would require the TV stations to convert from analogue to digital transmission. After the switchover a portion of TV analogue channels would become vacant which be auctioned off by regulators to other services. In addition there will be a number of TV channels in a given area that would not be used by DTV station because such stations would not be able to operate without interference to adjacent channels. However low power unlicensed device can operate on these vacant spaces that could not be used by DTV due to interferences. These vacant TV channel care called white spaces. The proposed new rules would, in principle allow the operation of both fixed and portable broadband devices on a non-interference basis in this white spaces. A preliminary study by Ofcom indicates that “at any one location, around 100 MHz on average is not being used by DTT (Digital Terrestrial Television) and could, in principle be used by license-exempt devices”
  • 8. 8 PROMOSING APPLICATION OF COGNITIVE Cognitive radio has the potential to drastically alter the way we would mange our communication in the future. Some of the promising applications are 1. Emergency Services Use of Cognitive Radio The public safety users have direct application for cognitive radios. In conditions of emergency need for quality of service and interoperability among various standards becomes vital. CR with there inherent ability to adapt and adjust to different standards would help in such situation. 2. Low Cost Internet Access .The dynamic spectrum access model approach would enable broadband access on the unused spectrums, thereby enabling lower Internet access cost by drastically reducing cost component associated with purchase of spectrum. 3. Rural connectivity By deploying smart mesh CRN systems remote rural areas can be provided connectivity. 4. New services Radio based advertising in which the user gets only relevant information Application in public safety: Consider a situation during an emergency. Emergency situation generally require great deal of co ordination of between different relief workers, fire brigade, police and other concerned person. Chances of communication breakdown both internally and externally increase due to lack of common standards and overburden of emergency bands. Cognitive radio would help in such situation by prioritizing such communication and enabling communication all standards. Application in security: Imagine a situation in which a soldier has to only turn on the device which he is carrying. Once engaged the cognitive radio will determine what spectrum to use, sense any disruptions in the environment (jamming) and adjust accordingly. Application in daily life: A flight entering into the borders of another country. Currently the radio parameters need to be set by the pilot with the help of ground controllers as the standards for communication are different in different countries With cognitive radios no human involvement would be required
  • 9. 9 ECONOMIC ASPECTS OF COGNITIVE RADIOS What would ultimately justify the functionality of cognitive radio into user equipment and the network operator is economics VALUE FOR THE PROVIDER In many regions of world the telecom infrastructure is at its peak and to improve infrastructure density is practically impossible. In order to support the demand for continuous growth cognitive radios can come handy. More efficient use of spectrum in these regions would easily translate into revenue stream for the network operators with increased users. Additionally they would also be able to offer more sophisticated services and rich experience to end users. In many regions of the world especially the rural area it is highly uneconomical to lay down fiber cables. And generally broadcast TV source are generally very far from this users and as such there is nearly no spectrum use. There are significant opportunities to provide telecom and internet service using this under utilized section. VALUE FOR THE USER Ultimately it’s the end user that must feel or realize the incremental value that he would be benefiting from by adopting cognitive radio. Cognitive radio envisions a learning radio that would be realizing user and network requirements to determine performance. The sophisticated services that one would be able to realize from having such flexibility are immense and would be truly helpful to subscribers. Initial Cognitive radio would come at a slight higher cost to the end user. However this won’t deter customer from availing this service as the benefits associated with it are lucrative enough to out weigh the added cost. Cognitive radio has the potential of providing seamless connectivity anywhere anytime. KEY DIFFERENTIATING FEATURE The differentiating feature of successful service providers in the future would be one who accommodates user’s current needs most efficiently. With cognitive radio a service provider would be able to bundle all the services that a user can possibly demand (like Cellular WiFi Wimax Bluetooth video services etc.) together. Based on user requirements and network resource the service provider would be able to provide economical and seamless service.
  • 10. 10 ECONOMIC APPROACHES FOR IMPLEMENTATION OF COGNITIVE RADIO NETWORKS For implementation of CRN we need to understand the feasibility of various economic approaches as well as the associated technical challenges. The licensed users are called primary users and the users of the CRN are called secondary users. For peaceful existences of both accurate information of the usage of spectrum is required .There are two different approaches that can be followed OPPORTUNISTIC SPECTRUM ACCESS: Secondary users scan the primary user spectrum to determine any vacant spectra. Sensing becomes a critical issue. RESOURCE TRADING: Primary user explicitly provides any relevant information to secondary users. By allowing some monetary to primary users can get some monetary benefits by allowing secondary users to use spectrum In opportunistic spectrum access since there is no motivation for primary user it becomes difficult to guarantee a peaceful coexistence of both. Hence a resource trading based approach is a better option A combination of different economic approaches can be applied in order to have a resource trading based spectrum sharing. These approaches are briefly described next GAME THEORY It’s the study of cooperation and conflict among individuals or groups. It provides an analytical framework for decision making based on this. It aims at maximum optimization of all resources at same time protecting the interest of primary users. PRICE THEORY For resource trade based spectrum sharing appropriate schemes for setting up the price of the spectrum, formulating models that maximizes payoff to both primary users in terms of monetary value and secondary users in terms of service is an important issue MARKET THEORY -Stability would be required overall in order to have a feasible model
  • 11. 11 CHALLENGES IN DEPLOYMENT OF COGNITIVE RADIO LEGAL HURDLES Cognitive radio is an advanced technology. Successful implementation of such revolutionary technologies in an economy and policy regime thrives heavily upon how and where it return value that too without impeding other technologies or innovation. Thus the success of cognitive radios would greatly depend on what policy changes would be required throughout the world and corresponding consequences. Research would be required to support any proposed policy reform. Demonstration of improved performance over the other technology is a must. Improved spectrum utilization and cost effectiveness must be visible to the policy makers. Implementation of cognitive radio requires a model with following requirements  Sharing among equals, or giving some wireless systems primary rights and others secondary status.  Cooperation among systems from different administration domains,  Assumptions that systems are licensed or unlicensed or a mix of the two. A proper research addressing critical issues such as how devices would operate in a given band, what are the levels of risk involved in case of harmful interference, possibility of congestion and interferences under different regulatory approaches, what be the role and responsibility of standard bodies, industry and user groups, what would be the social and economic benefits and potential impact on business and technological strategies would be required. SECURITY RELATED ISSUE Security would be one of the major concerns while deploying cognitive radio. In a system where radios can decide how to use the available spectral resources proper identification and authentication is must. Rouge player trying to cause major communication disruption would flourish. Mechanism would be required to develop to identify such systems and deactivate or block them. Hence proper and successful implementation of robust security measures becomes vital while deploying cognitive radios. TECHNOLOGY HURDLES Being aware of the environment cognitive radio chooses the best available option based on certain performance parameters such as carrier frequency, type of modulation, antenna, power bandwidth etc. This means that the radio would have to deal with different RF spectrum and baseband varieties at the same time, thus requiring a more robust, efficient and reconfigurable hardware architecture. Clearly, the introduction of this revolutionary paradigm poses many challenges across all layers of a cognitive radio system design like spectrum sensing, interference management, resource allocation, RF design and implementation issues.
  • 12. 12 1. SPECTRUM SENSING TECHNIQUES One of the most important functions of cognitive radio is to sense its environment accurately and thereby choose its operation parameter. Spectrum sensing has been identified as a key enabling cognitive radio to not interfere with primary users, by reliability detecting primary user’s signals. And sensing is not merely enough. Making sense out of what it being sensed is another all together different issue. Sensing techniques available today are susceptible to changing levels of interference and noise levels. Also these techniques can only detect the presence or absence of signal. They are not able to differentiate whether the detected signal is a noise, interference or information carrying signal. The hurdle lies in developing fast low-cost detecting techniques that are able to detect weak signals and also differentiate between them. 2. HARDWARE DESIGN Another major hurdle is designing of a flexible hardware that can be used for wideband sensing and multiband communication purposes. Conventionally, in the design of RF circuit for radio certain assumptions regarding interferes and worst case scenarios can be made fairly. This greatly eased the design of hardware for a desired performance. However cognitive radio operates in a dynamic environment. Additionally not having prior information on the frequency of operation bandwidth and other operation parameters greatly complicates the situation. If one follows the conventional approach it would lead to design of excessive circuit blocks thereby increasing space, cost and complexity. Designing a flexible circuit giving a minimal level of performance under all expected and unexpected scenarios becomes a challenge 3. ON CHIP IMPLEMENTATION Designing the digital baseband processing of such a complex system also posses an uphill task. The power usage would increase significantly due to increase in functionality. Also the memory requirement would increase significantly due to operation in an unknown dynamically changing environment. 4. PROTOCOL ARCHITECTURES The extreme flexible requirements of cognitive radios involve redesigning of network algorithms and protocols. In particular cross layer algorithms that adapt to changes in quality, network structure, and physical link availability would require an advanced management framework. Design of network protocols that can enable cognitive devices to exchange key information like frequency coordination network configuration transmission parameters would be critical.
  • 13. 13 THE WAY FORWARD CURRENT SCENARIO FUTURE SCENARIO  Cognitive radio would enable interaction between all types of radio devices  A simple embedding of a radio in any object could mean interaction of all objects!!  Verify and control your identity, online and offline all at the same time  All time connectivity not only through network cells but also through formation of spontaneous networks  New marketing strategy - Radio enabled advertising sends customized information to your phone in your language SUMMARY In this paper we examined how cognitive radio can impact the way spectrum will be managed and regulated in future. The concept of cognitive radio is promising to improve the utilization of spectrum. With technological advancement in device cognitive and re-configurability capabilities we may see current static spectrum management model completely disappear. Spectrum would be managed by a society of intelligence cognitive devices which on behalf of their user would be continuously involved in communication negotiation cooperation and trading. This would require the need of formation of new regulation in the future. Many key technological, economical and legal issue need to be explored before cognitive radios are fully deployed. Significant new research is required to address these challenges. The potential for cognitive radio to make a significant difference to wireless communications is immense. The key issue in the final evolution of cognitive radio for any application would be- • Trust by the users of cognitive radio; • Trust by all other users who might be interfered with.
  • 14. 14 References 1. Radio electronics.com: Future of Cognitive Radio - an interview with Dr Joseph Mitola 2. Maziar Nekovee : Impact of Cognitive Radio on Future Management of Spectrum 3. Cristian Ianculescu: Cognitive radio and dynamic spectrum sharing 4. Dr. Bruce Fette, Ph.D. Cognitive radios: The future of SDR technology 5. Joseph Mitola Cognitive Radio: Making Software Radios More Personal 6. Sabita Maharjan · Yan Zhang · Stein Gjessing: Economic Approaches for Cognitive Radio Networks 7. Angsuman Rudra Cognitive radio: An evolution from software radio 8. Nokia research center: http://research.nokia.com/