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DAttig ResearchPaper CognitiveRadios

Research Paper:
Cognitive Radios
Prepared by:
Dawna Lee Attig
Research Paper 2
The pervasiveness of Information Technology (IT), the Internet, World Wide Web, cell
phones and numerous other technologies have dramatically influenced the way work is
performed, as well as, revolutionized how information and technology is used. (Lau & Woods,
2008)(Fountain, 1998) As the technology uses become more widespread and convergence begins
to occur, users are requiring more personalized experiences, from the software that is used (e.g.
web browsers) to the cell phones in our pockets. More recently, a new concept, Software Radio,
has been gaining momentum and "emerging as a platform for multiband, multimode, personal
communication system" (Joseph Mitola & Gerald Q. Maguire, 1999, p. 13) and promising to
personalize a user's computer and cell phone experience even more.
As software radio moves into its second and third generation, Cognitive Radio (CR) is a
recent enhancement to this concept, "wherein the radio is aware of its environment and its
capabilities, is able to independently alter its physical layer behavior and is capable of following
complex adaptation strategies." (Neel, Reed, & Gilles, 2004, p. 2250) "Cognitive radios are
adaptive and extremely programmable, learning users' preferences and automatically adjusting to
changes in the operating environment." (Costlow, 2003) According to many, this new
"technology promises to achieve the vision of multimedia wireless services anywhere, anytime,
and with any device," (Curley, 2007) such as cell phones, and has been identified as essential to
the "future goals in key wireless-industry market segments, including commercial, public-safety,
and military sectors." (Curley, 2007) More specifically, military researchers want the security
and versatility that CR can provide and consumers want the benefits of a cell phone that can send
a message the cheapest way. (Costlow, 2003)
Research Paper 3
An analysis of the current literature on this topic espouses the numerous benefits to
cognitive radio; however, "turning the concept into commercial products is another story." (A.
Kountouris, C. Moy, & Rambaud, March 2000) The aim of this paper is to give a general
overview of cognitive radio, its technology and some of the current research issues regarding this
concept, as well as, those associated with its wide acceptance and commercialization, while
attempting to identify possible links between cognitive radio and the current paradigm from the
perspective of the private sector. In addition, this paper will draw up a few research questions
and discuss them in order to promote future research in business. In summary, this paper has a
dual objective: (i) provide a comprehensive overview of cognitive radio and the traditional; and,
(ii) provide a series of research questions on cloud computing and its adoption by the
commercial sector.
The body of this paper is organized into four major sections. First is an overview of
standard radio technology, a definition of Cognitive Radio and a brief discussion on the
similarities and differences between the two archetypes. The second section presents some
current issues regarding acceptance and commercialization. The next section presents some
research questions in reference to the adoption of cognitive radio. Finally, a review of related
work and a conclusion bring the paper to end.
Since its inception, the history of radio is the history of a technology that produced radio
instruments that use radio waves. (Unknown, 2009) At the start of radio development, radio was
called "wireless telegraphy," where "wireless" is a term that applies more to today's technology
than ever before, being known as "wireless communication" and becoming the preferred network
access method among telephony users. Moreover, "the wireless communications landscape is very diverse
Research Paper 4
and constantly evolving." (A. Kountouris, C. Moy, & Rambaud, March 2000, p. 1) This section reviews
the traditional wireless architecture and cognitive radio technology.
Traditional. According to Graf (1974), radio is defined as "the transmission of signals by
modulation of electromagnetic waves with frequencies below those of visible light." (p. 467)
Since its inception and commercialization, the radio has had numerous uses: Audio, Telephony,
Video, Navigation, Radar, Data (digital radio), Heating, Amateur radio service, Unlicensed radio
services, Radio control (RC). In addition, with each new use, radio has taken many forms but by
far, the most pervasive and ubiquitous are in the form of wireless networks and mobile
communications. According to the Radio page from Wikipedia, the free encyclopedia (2009),
"mobile phones transmit to a local cell site (transmitter/receiver) that ultimately connects to the
public switched telephone network (PSTN) through an optic fiber or microwave radio and other
network elements."(p. 30) (Figure 1)
Figure 1: Mobile Communications Architecture
(Anonymous, Voice and Fax over Internet Protocol (V/FoIP), 2007)
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The architecture that these mobile phones transmit over is defined as "a radio network
made up of a number of radio cells (or just cells) each served by at least one fixed-location
transceiver known as a cell site or a base station."(Anonymous, Cellular Network, 2009) This
concept is more specifically depicted in Figure 2. In addition, this architecture is built within "a
Figure 2: Cellular Network
(Anonymous, Cell Towers, 2005)
wireless communications landscape [that] is very diverse and constantly evolving…It is
characterized by things such as: multiple and evolving standards, different types of equipment
for subscribers and operator infrastructure, different and time varying transmission environments
(in-building, urban, open space, high or low terminal mobility, etc.)"(A. Kountouris, C. Moy, &
Rambaud, March 2000, p. 1) In addition, there are "various actors involved (subscribers, network
operators, service providers, equipment manufacturers) each with different motivations,
objectives and expectations from new technologies."(A. Kountouris, C. Moy, & Rambaud,
March 2000, p. 1)
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"Currently, the radio environment is transmitter-centric"(Haykin, 2005) meaning it is
largely a fixed operation in the transmitter. Moreover, "today’s wireless communications is
based on fixed communication standards…where the key [problems are] at the receiver side [and
consisting of] carrier synchronization, channel equalization, demodulation and channel
decoding." (Le, 2007, p. 48) Furthermore, "in traditional cell-phone systems, most of the
intelligence for efficient operation resides in the network," (Ashley, 2006, p. 72) where the level
of wireless coverage is extremely important. In sum, this radio environment is heavily dependent
on transmitter and receiver performance and the amount of coverage that is provided.
Cognitive Radio. Before defining Cognitive Radio (CR), we must first review the
electromagnetic radio spectrum. "The electromagnetic radio spectrum is a natural resource, the
use of which by transmitters and receivers is licensed by governments."(Haykin, 2005, p. 201)
For example in the United States, "the Federal Communications Commission assigns users to
specific frequencies. These include the well-known AM, FM, shortwave and citizens bands and
VHF and UHF television channels, as well as hundreds of less familiar bands that serve cellular
and cordless telephones, GPS trackers, air traffic control radars, security alarms, radio-controlled
toys and the like."(Ashley, 2006)(See .Figure 3) According to Haykin's article Cognitive Radio:
Brain Empowered Wireless Communications (2005), "if we were to scan portions of the radio
spectrum including the revenue-rich urban areas, we would find that:
1) Some frequency bands in the spectrum are largely unoccupied most of the time;
2) Some other frequency bands are only partially occupied;
3) The remaining frequency bands are heavily used."(p. 201)
Given this inefficient spectrum usage, it has been posited that some secondary user, could access
unused and/or underutilized frequency bands at the right place and time and it is "cognitive
radio… [that] has been proposed as the means to promote the efficient use of the spectrum by
exploiting the existence of [gaps in the] spectrum." (Haykin, 2005, p. 201)
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Figure 3: Radio Frequency Spectrum
(Ashley, 2006, p. 71)
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Cognitive Radio (CR) is the next step in the evolution of an application of multi-radio
technology known as Software Defined Radio (SDR). According to Goleniewski (2007), SDR is
a "collection of hardware and software technologies that enable reconfigurable system
architectures for wireless networks and user terminals. [These] devices and equipment can be
dynamically programmed in software programming." (p. 691) The key feature here is
reconfigurability, in that "a single piece of hardware can perform different functions at different
times, depending on the software programming."(Goleniewski, 2007, p. 691) Moreover, SDR is
a "practical reality today, thanks to the convergence of two key technologies: digital radio, and
computer software."(Haykin, 2005, p. 202)
While it is helpful to understand SDR as the basis for Cognitive Radio, at this point, it is
helpful to define some terms/concepts. According to the Oxford English Dictionary (as cited by
Le, 2007), "cognitive" is "pertaining to cognition, or to the action or process in knowing," and
"cognition" is "the action or faculty of knowing taken in its widest sense, including sensation,
perception, etc. as distinguished from feeling and volition."(p. 20) Given these concepts
cognitive radio can be defined as
an intelligent wireless communication system that is aware of its surrounding
environment (i.e., outside world), and uses the methodology of understanding-bybuilding to learn from the environment and adapt its internal states to statistical variations
in the incoming RF stimuli by making corresponding changes in certain operating
parameters (e.g., transmit-power, carrier-frequency, and modulation strategy) in realtime, with two primary objectives in mind:
• highly reliable communications whenever and wherever needed;
• efficient utilization of the radio spectrum. (Haykin, 2005, p. 201)
More specifically, “a cognitive radio [is] an intelligent communication device that is aware of its
environment and application needs and can reconfigure itself to optimize quality of service.”(Le,
2007, p. 20)
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Figure 4: Cognitive Radio Network Architecture
(Anonymous, Cognitive Radio, 2007)
The Cognitive Radio network architecture, as shown in Figure 4, consists of three groups:
the primary network, CR network without infrastructure, and the CR network with infrastructure.
"The primary network is referred to as the legacy network that has an exclusive right to a certain
spectrum band [(e.g. common cellular and TV broadcast networks)]. In contrast the CR network
[with infrastructure] does not have a license to operate in the desired band." (Lee, Chowdbury, &
Vuran, 2009, p. 6) Next, the CR network [without infrastructure] is a cooperative ad hoc network
in which "the users communicate with each other without any fixed infrastructure"(Haykin,
2005, p. 209) and do not have a license to operate in the desired band. Furthermore, it is the CR
user that “will complete a transmission despite interference and other obstacles, by jumping
between open frequencies as they become available.”(Ashley, 2006, p. 70)(See Figure 5, next
page) Lastly, the CR environment is one of “real-time interactions between transmitter and
receiver in an adaptive manner.”(Haykin, 2005, p. 203)
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Figure 5: Spectrum Shuffling
(Ashley, 2006, p. 70)
This architecture is in addition to the current common mobile network architecture, i.e.
the primary network. It is characterized by a single standard, generic hardware/radio platform,
where there are no "subscribers" or operator infrastructure, regardless of time and transmission
environments and consists of "real-time interactions between the transmitter and receiver in an
adaptive manner."(Haykin, 2005, p. 203) In contrast to the traditional network, a CR network is
independent of provider, network and environment. Lastly and most importantly, this is a
“wireless architecture in which the communication system does not operate in a fixed assigned
Research Paper 11
band, but rather searches and finds an appropriate band.” (Sahai, Hoven, & Tandra, 2004, p. 1)
Moreover, this paradigm challenges the spectrum crisis. "One can see that CR does not need a
dedicated cellular network to connect a user via wireless internet to other devices… [And] the
need for a long-term contract with a cellular-service provider diminishes."(Ashley, 2006, p. 72)
Future Research
"To succeed, businesses must continually surge forward and produce new and better
ideas. In an era of globalization and the expanding dominance of the internet, organizations
express their fundamental business strategies through information technology." (Krishnan, K.
Ananth, 2008, p. 4) It is widely accepted that the key to success in any business is through
innovation and in the last twenty years, much of the success has been through innovation in the
area of information technology and telecommunications. Moreover, these innovations have taken
us from the internet and mobile computing to the latest cutting-edge technology, Cognitive
Radio. "Just as the emergence of cell-phone technology has led to wide social and business
consequences, cognitive radio's adoption will induce similar changes as advanced devices exploit
the wireless web to displace now traditional cell phones." (Ashley, 2006, p. 73)
“Development of cognitive radio is still at a conceptual stage. Nevertheless, as we look to
the future, we see that cognitive radio has the potential for making a significant difference to the
way in which the radio spectrum can be accessed with improved utilization of the spectrum as a
primary objective. Indeed, given its potential, cognitive radio can be justifiably described as a
‘disruptive, but unobtrusive technology.’”(Haykin, 2005, pp. 202-203) The purpose of this
research is to identify the conditions necessary for organizations to adopt Cognitive Radio
architecture by determining the important driving factors of that adoption. In order to
accommodate the purpose of this research, we suggest research questions concerning two
Research Paper 12
different groups of organizations: domestic to international and SME to Large Enterprise. We
then suggest two hypotheses for each question that will “contribute [toward] filling the existing
gaps and constitutes [another] step in the direction of more comprehensive future research.”
(Nieto & Tse, 2006, p. 260) What follows next are the research questions and the hypotheses.
Q1. Are the conditions for a Domestic Corporation to move from the traditional
phone system to a Cognitive Radio system different for an International Corporation?
Given the telecommunication industry’s inability to make the Plain Old Telephone
Service (POTS) available to every person everywhere, while “cellular radio network
infrastructures are growing at a tremendous rate [and] people are purchasing mobile phone
contracts because they provide a useful and relatively cheap service. The services provided by
network operators are being extended to include data services. Geographical coverage of
networks is enlarged by means of global roaming,”(Walter & Kritzinger, n.d.) as well as
becoming fundamental to the global economy. As technology is constantly evolving, the next
enhancement on the traditional mobile phone is the cognitive radio. This new technology “holds
the promise of a new frontier in wireless communications,”(Haykin, 2005, p. 218) with endless
possibilities and open to virtually anyone, consumers and businesses alike. However, whether for
the good or bad, there is a struggle between those that want to continue with the traditional
architecture or the current cellular system and those that want and need the latest technology.
While there are numerous concerns regarding a firm's adoption of cognitive radio, such
as, security and privacy, support, interoperability and compliance, these concerns are the same
for those with the current systems. However, international markets have standardized the current
cellular paradigm, in a way that the US domestic market can only dream of. In addition, just as
there are concerns for adoption, there are important factors that could firms to invest in cognitive
Research Paper 13
radio. Consequently, looking at these driving factors could contribute toward an answer to
question one. It follows that we have the following hypothesis.
H1a: The driving factors for adopting Cognitive Radio are the same for Domestic and
International firms.
Another side to the question is whether one type of firm, domestic and international
adopts cognitive radio at the same or different rates. “The decisions concerning the future of
cognitive radio technology are shaping up as a battle between two giant business sectors: the
cell-phone and telecommunications industry versus ‘the Internet industry,’ which includes
Microsoft, Intel, Google, Internet Service providers and consumer computer firms. Although
entrenched interests may resist it, progress toward cognitive radio seems likely because the
relative chaos and inflexibility of unregulated radio bands…could be avoided.” What follows is
the next hypothesis to help answer our question.
H1b: Domestic and International firms adopt Cognitive Radio at the same rate.
Q2. Are the conditions for an SME to move from the traditional phone system to a
Cognitive Radio system different for an Enterprise Organization?
While the cell phone is fairly ubiquitous around the globe, not all business SME and
Enterprise alike have moved their entire telecommunications over to a cellular network.
However, given today’s economic and technological environment, this may never happen. Just
as the POTS was never “taken to the ends of the earth,” the cellular network system may not be
adopted completely by all businesses either. Nevertheless, if progress toward cognitive radio is
made because of economics and efficiencies, then which type of organization, SME or
Enterprise, will move to the new technology first? As in the first question, there are important
factors driving businesses of all sizes to accept a cognitive radio system, but are they the same
for SMEs and large enterprise and what would be the rate of adoption. What follows are two
hypothesis to help answer our question.
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H2a: The driving factors for adopting Cognitive Radio are the same for SMEs and
Enterprise firms.
H2b: SMEs and Enterprise firms adopt Cognitive Radio at the same rate.
Related Work
“Cognitive radio design is [a] highly multi-disciplinary research area, combining artificial
intelligence, wireless communications, computer science, spectrum regulations, and service
marketing, and many others…[In addition,] CR technology mainly involves three fields, the
policy domain, the radio domain and the user domain.”(Le, Chapter 2: Cognitive Radio System
Architecture, 2007, p. 25) Regardless, cognitive radio is a relatively new term and while its
forbear, software defined radio, is more widely known, the terms that have gained the most
traction are mobile and cellular phones. While Haykin, Sahai, et. al., Kountouris, et.al. present
their understanding of cognitive radio and a definition that is reasonable and a review of the
characteristics (Haykin, 2005; Sahai, et.al, n.d.; Kountouris, et.al, n.d.), the seminal,
groundbreaking work done on Cognitive Radio was presented by Joseph Mitola III in his
dissertation, Cognitive Radio An Integrated Agent Architecture for Software Defined
Radio.(Mitola, 2000) Other articles focus on the various forms of implementation. (Mitola, 1999;
Cabric, et.al., n.d.)
While it would be a natural assumption that cognitive radio is the next step in the
evolution of cellular technology, there are entrenched interests is staying with the status quo.
There have been a few headlines in Scientific American and IEEE Intelligent Systems, for
example "Cognitive Radios will Adapt to Users," (Costlow, 2003) and "Cognitive Radio"
(Ashley, 2006) However, the Academic literature has not focused at all on the adoption and
usage of cognitive radio in the private sector and considering the market potential and
Research Paper 15
possibilities of application of this new technology to business processes, few authors have
focused on these issues
“Cognitive radio has received significant interest as a technology that could enable
improved performance and more efficient spectrum usage.”(Neel, Reed, & Gilles, 2004)
Moreover, its potential to make a significant difference in wireless communications is immense.
“Under current regulations, users in the middle of nowhere are prohibited from using the unused
spectrum bands, even if there are no receivers in the vicinity that might be interfered
with.”(Sahai, Hoven, & Tandra, 2004, p. 1) However, the FCC Spectrum Policy Task Force a
paradigm shift in November of 2002, in which there should be a shift away from fixed operations
to real-time interactions between transmitter and receiver in an adaptive manner.(Haykin, 2005,
p. 203) And, with that it appears the FCC could be moving in the right direction toward cognitive
radio. “However, the key issue that will shape the evolution of cognitive radio in the course of
time, be that for [commercial] or military applications, is trust, which is two-fold:
trust by the users of cognitive radio;
trust by all other users who might be interfered with.” (Haykin, 2005, p. 218)
Research Paper 16
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