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T-109.551 Research Seminar on Telecommunications Business IISOFTWARE DEFINED RADIOKai Kuikkaniemi 52676k 2.4.2003
T-109.551 Research Seminar on
Telecommunications Business II
Software defined radio
Kai Kuikkaniemi
52676k
2.4.2003
T-109.551 Research Seminar on Telecommunications Business IISOFTWARE DEFINED RADIOKai Kuikkaniemi 52676k 2.4.2003
1. INTRODUCTION..........................................................................................4
1.1 Software Defined Radio briefly.............................................................................4
1.2 History.....................................................................................................................4
1.3 Big picture (open architecture).............................................................................5
1.4 Driving forces..........................................................................................................6
1.5 Functional chain (from transmitter to receiver).................................................7
1.6 Tiers.........................................................................................................................9Tier 0. Hardware Radio..............................................................................................9Tier 1. Software Controlled Radio...........................................................................10Tier 2. Software Defined Radio...............................................................................10Tier 3. Ideal Software Defined Radio......................................................................10Tier 4. Ultimate Software Radio..............................................................................11
2. METHODOLOGY.......................................................................................11
2.1 Objective of the study..........................................................................................11
2.2 Research method..................................................................................................12
2.3 Structure of the study..........................................................................................12
3. TECHNOLOGY..........................................................................................12
3.1 Antennas................................................................................................................12
3.2 Hardware enablers [8].........................................................................................13RF enablers...............................................................................................................13Digital enablers........................................................................................................14
3.3 Software enablers [8]...........................................................................................14Software Communication Architecture (SCA)........................................................14Waveform Development Environment (WDE)........................................................15Radio Definition Language (RDL)..........................................................................15Radio Virtual Machine (RVM)................................................................................15
4. APPLICATIONS.........................................................................................16
4.1 Software phone.....................................................................................................16
4.2 Amateur radio......................................................................................................16
4.3 Military..................................................................................................................17
T-109.551 Research Seminar on Telecommunications Business IISOFTWARE DEFINED RADIOKai Kuikkaniemi 52676k 2.4.2003
4.4 Base stations..........................................................................................................18
4.5 Civil applications..................................................................................................18
5. BUSINESS.................................................................................................18
5.1 General business related advantages..................................................................18
5.2 Value propositions [10]........................................................................................19Benefits to Consumers:............................................................................................19Benefits to Operators:...............................................................................................19Benefits to Manufacturers:.......................................................................................19
5.3 Cost – Benefit analysis.........................................................................................20
5.4 Market overview...................................................................................................21
5.5 Timeline [12].........................................................................................................21
5.6 Future prospects...................................................................................................22
5.7 Secondary markets [3].........................................................................................22
6. CURRENT SITUATION..........................................................................23
6.1 Case examples of implementation.......................................................................23SPEAKEasy [13]......................................................................................................23CRC demo [14]........................................................................................................24Radical horizon [15].................................................................................................24SDRCT (SDR Communications Technologies) [16]...............................................24
6.2 Problems................................................................................................................24Hackers, disruption of current radio frequencies.....................................................24Regulatory point of view [3]....................................................................................25
6.3 Parallel development:..........................................................................................25GNU radio [17]........................................................................................................25Open radio platform [18]..........................................................................................25
7. CONCLUSION...........................................................................................26
REFERENCES...............................................................................................26
Abbreviations................................................................................................27
T-109.551 Research Seminar on Telecommunications Business IISOFTWARE DEFINED RADIOKai Kuikkaniemi 52676k 2.4.2003
1. Introduction
1.1 Software Defined Radio briefly
Software Defined Radio (SDR) is not, like normally in technical terms,
referring to any single technology, but the means the idea of controlling radio
functionality (operating frequencies, modulations) both in transmitter and/or
receiver side can be (is) manipulated with software. There are several
different levels (tiers) that SDR can be implemented (this is describer further
in chapter 1.6 Tiers), there are several different applications and in addition
there are also different architectures and methods how it can be done.
SDR has definite uses in future when the wireless networking environment
becomes more and more complex. But at the same time it could provide
benefits there are few technical and regulatory problems involving to SDR.
1.2 History
Origins of Software Defined Radio development comes from military
[1], where its flexibility was rather early in nineties found out to be very useful
quality. Currently still the largest implementations of SDR are related to US
military (see chapter 6.1 case SPEAKEasy).
Current radio architecture (even the digital one) basically dates back to
70’s. Meaning that for a long time the radio technology is based on similar
type of rigid component structure. SDR could be the first disruptive technology
in this area [2]. First ideas of SDR popped up already in the end of 80’s and it
was known in some extent already in beginning of 90’s. Currently SDR related
activities are orchestrated by SDRForum (www.sdrforum.org). SDRForum
was originally called Modular Multifunction Information Transfer System
(MMITS) Forum, which was rather ideological initiative covering wide range of
future technologies. But when the SDR started to lift of and became the most
important activity of MMITS it changed the name to SDRForum in order to
clarify its position and become more concrete instance.
T-109.551 Research Seminar on Telecommunications Business IISOFTWARE DEFINED RADIOKai Kuikkaniemi 52676k 2.4.2003
The development and ideology of SDR has clear analogy with the
development of multitasking in computers. The idea and the advantages of
the technology have been long known, but there are some critical points when
the technology becomes reality. Multitasking in PC’s required development of
both OS technology and hardware power. The driving forces why the SDR is
relevant now are discussed in chapter 1.4.
1.3 Big picture (open architecture)
Where is SDR’s position in the big transition that is taking place in
networking? Following analysis is based on FCC Chief Dale Natfeld’s views
when he was presenting his views on SDR [3].
The transition (or conversion) is taking place in many different areas, these
can be divided semi chronologically to following.
1. Conversion from analog to digital networks
2. Conversion from circuit switching to packet switching
3. Conversion from narrowband to broadband transmission
4. Improvements, or better reductions, in the transmission qualities (delay or
latency exhibited by networks utilizing packet switching)
5. Ability to deploy not only wired networks with these advanced capabilities,
but wireless networks as well
According to him these transitions clearly indicate that we are evolving to a
situation where we have high performance networks of networks. In addition
to high performance it is also important that the communication can take place
anytime, anyplace and in combination of several modes like voice, text, data,
and video. Besides the modes there are also different communication formats,
push, pull and multicast, just to name the most common.
The features I listed based on Natfeld’s analysis and my own are already with
fixed networks a complicated task. In wireless world some of the features
become even more dominant (and interesting and beneficial), but at the same
time the technological complexity increases. SDR could be a key element in
this wireless networking environments in order to manage and handle the
provision of all these various features. It is not a necessity and it is not a core
in any future standard, but at the same time it could be implemented to any of
those, for example to 3G.
T-109.551 Research Seminar on Telecommunications Business IISOFTWARE DEFINED RADIOKai Kuikkaniemi 52676k 2.4.2003
1.4 Driving forces
In this chapter I want to discuss the underlying driving forces that led to
development of SDR, and especially why SDR is relevant at this moment.
The first and the most important enabler of SDR is naturally new hardware. If
the hardware wouldn’t be that flexible and suitable to be programmed via
software, there would be no point in talking about SDR. SDR without suitable
hardware is just fantasy, so you see that Software Defined Radio doesn’t
mean that hardware is replaced, actually quite vice versa it sets rather high
demands for the hardware.
When we are talking about hardware there are two fundamental, sort of
abstract, parameters that should be kept separate. First of all components
must have a wide functional area (e.g. that antennas can operate in wide
frequency area, or that ADC can convert practically any signal efficiently).
Another important feature is that the hardware (especially DSPs) us
programmable and has proper interfaces. Programmable hardware has been
already used in various places for some time now (for example in radios, in
smaller functionalities).
In addition to hardware there are some software requirements for the SDR.
Basically SDR requires a real time software environment. Real time
environments have been around for some time already, but not until recently
there are also open sourced versions that have been suitable for initiative like
SDR. Meaning that the proprietary technology that for example army is using
is developed for some time already, but the market lead SDR development is
a semi “open” movement.
Besides the technology enablers there are also market push towards SDR.
First and foremost the important market push are the quickly developing radio
technologies. Both the operating frequency and the modulation change with
the increasing phase. It would be only natural that also devices could be later
on adapted to upcoming new environments. And at the same time there is all
the time upcoming new network setups (like UWB, 3G, HiperLAN etc…) the
old remain more or less, which results that (especially in future) there are
several parallel and concurrent networks available. Especially when these
network environments change drastically from place to place (meaning for
T-109.551 Research Seminar on Telecommunications Business IISOFTWARE DEFINED RADIOKai Kuikkaniemi 52676k 2.4.2003
example that the environment in US is different than in Europe) and in time to
time (e.g. secondary frequency markets which are discussed more in chapter
5).
SDR also enables sort of ideological thinking, meaning that with SDR there is
freedom and flexibility of new applications. If somebody has SDR enabled
base stations and terminals they can practically invent their own
communication standard, which is a great possibility in terms of innovations
and understanding. At the same time there is of course some problems
relating to possibility to hack existing networks (this is discussed more in
chapter 6 problems). The requirement for easily configurable and manageable
network structures comes more and more important when we start to think
SDR enabled AdHoc and P2P networks. One similar innovation in this area is
cognitive radio [4].
Last but not least the development of common, open and non-proprietary
standards and protocols, has been very important factor in order for SDR to
make sense. If the standards and protocols where closed, it would be much
less interesting to have easily adaptable devices. If one don’t know what is the
protocol, how can one adapt it devices in to it? Of course military and even
some business type application of SDR make sense already without open
protocols, but the biggest possibility of SDR to spread around and liberate
common person communication requires open protocols to tap in.
1.5 Functional chain (from transmitter to receiver)
In this chapter I explain the (digital) radio structure, meaning the components
used in order to transmit something over the air and then finally converting it
back it in to readable form. This is more or less the same as all common
digital wireless network structure, but it is very important to understand this
functional chain in order to understand where SDR has effect on and what is
SDR’s playground. The following is based on Techtargets [5] definition and bit
altering from normal it is tailored as a SDR definition.
A typical voice SDR transmitter, such as might be used in mobile two-way
radio or cellular telephone communication, consists of the following stages?
Those components that could be tailored and controlled with the software are
marked with an asterisk (*).
T-109.551 Research Seminar on Telecommunications Business IISOFTWARE DEFINED RADIOKai Kuikkaniemi 52676k 2.4.2003
1. Microphone and Audio amplifier are the input signal source. In case of
other modes of communication (like data) this would be replaced by some
other mechanism.
2. Analog-to-digital converter (ADC) converts the voice audio to ASCII data
*.
3. Modulator that impresses the ASCII intelligence onto a radio-frequency
(RF) carrier *
4. Series of Amplifiers that boosts the RF carrier to the power level
necessary for transmission
5. Transmitting antenna
Resulting software manipulated digital radio signal
A typical receiver designed to intercept the above-described voice SDR signal
would employ the following stages, essentially reversing the transmitter's
action?
1. Receiving antenna
2. Superheterodyne system that boosts incoming RF signal strength and
converts it to a constant frequency.
3. Demodulator that separates the ASCII intelligence from the RF carrier *
4. Digital-to-analog converter (DAC) that generates a voice waveform from
the ASCII data *
5. Audio amplifier and speaker, earphone or headsets
This part would be replaced by some other components if the mode of
communication would be different.
Some of the following components (especially those marked with the asterisk)
are then further discussed in technology chapter (chapter 3).
T-109.551 Research Seminar on Telecommunications Business IISOFTWARE DEFINED RADIOKai Kuikkaniemi 52676k 2.4.2003
The image above (copyright SDRForum) shows what kind of structure a
typical SDR architecture would have. In the picture one can see how the
different levels in functional chain are tackled independently.
This next image is more detailed illustration of the same system than in the
previous image. Here one can also see the data and interaction flows
between the components.
1.6 Tiers
Already in the first chapter (1.1.) I mentioned how the SDR as a phenomenon
can take place in several different tiers. The following tier division is based on
SDRForums definitions and it basically reflects pretty well how they view the
SDR’s possibilities and development [6].
Tier 0. Hardware Radio
The tier 0 is not basically SDR at any ways, but is the most common current
situation of the radio devices. No provision is made for any changes of system
attributes except by physical intervention by the user or a service technician.
System operation is accomplished by use of switches, dials, and buttons, by
physically opening the covers, or by replacing the unit. This category also
applies to radios that have some specific functions operated remotely by
electromechanical means such as relays or servos. Internal use of software,
firmware, or computer processing elements still fits this definition if they
cannot be changed externally.
T-109.551 Research Seminar on Telecommunications Business IISOFTWARE DEFINED RADIOKai Kuikkaniemi 52676k 2.4.2003
Tier 1. Software Controlled Radio
Tier 1 is the most elemental level of SDR. Radios in this category have control
functionality implemented in software, but do not have the ability to change
attributes, such as modulation and frequency band without changing
hardware.
Tier 2. Software Defined Radio
The Tier 2 system provides a broad operational range (e.g. 20-500MHz, 1-
2GHz) under software control without hardware change. These systems are
typically characterized by a separate antenna system followed by some
wideband filtering, amplification, and down-conversion prior to receive analog-
to-digital conversion. The transmission chain provides the reverse function of
direct digital-to-analog conversion, analog up-conversion, filtering, and
amplification.
This front-end equipment represents a constraint on the frequency coverage
of the system, and its performance. It may be necessary to switch antennas to
obtain the entire frequency range. Except for these constraints, however, the
system is fully capable of covering a substantial frequency range and of
executing software to provide a variety of modulation techniques, wide-band
or narrow-band operation, communications security functions (such as
hopping), and meet the waveform performance requirements of relevant
legacy systems. An SDR is also capable of storing a large number of
waveforms or air interfaces, and of adding new ones to that storage through
either disk or on-line load.
Over-the-air software load is desirable, but not required in the definition. The
system software should also be capable of applying new or replacement
modules for added functionality or bug fixes without reloading the entire set of
software.
Tier 3. Ideal Software Defined Radio
This system has all of the capabilities of the Tier 2 system, but eliminates
analog amplification or heterodyne mixing prior to digital-analog conversion. It
provides dramatically improved performance by eliminating analog sources of
distortion and noise.
T-109.551 Research Seminar on Telecommunications Business IISOFTWARE DEFINED RADIOKai Kuikkaniemi 52676k 2.4.2003
Tier 4. Ultimate Software Radio
This system description is intended for comparison purposes rather than
implementation. It is a small lightweight component with very small current
drain that can easily be incorporated into personal devices. It requires no
external antenna, and no restrictions on operating frequency. It has a single
connector that delivers the desired information in the desired format, typically
digital. The connector also accepts information, uses it to modulate a signal,
and radiates that signal in the desired waveform or air interface. The ultimate
software radio also accepts control information through its connector to
operate and reconfigure the operating software. It can switch from one air
interface format to another in milliseconds, use GPS to track the users
location, store money using smartcard technology, or provide video so that
the user can watch a local broadcast station or receive a satellite
transmission. Further, it has a large amount internal processing capacity, so
with appropriate software it can perform a wide range of adaptive services for
its user.
2. Methodology
2.1 Objective of the study
This is a seminar paper for a Helsinki University of Technology (HUT)
Telecommunication and Multimedia laboratory. The seminar topic is wireless
networks, and the focus of the seminar is to analyse selected wireless
technologies business side in technology perspective.
This is the only paper in the seminar about SDR, so it is covering both the
technical introduction of the topic and some business landscape analysis.
Hence the title of the paper is simply SDR, referring that it is a general
introductory paper. The purpose of the paper is not to dwell in technical
details, but to provide comprehensive picture on the technology meanwhile
analysing its business impact. As SDR is a technology that doesn’t have yet
clear business case example the business side analysis is based mostly on
opinions and predictions.
T-109.551 Research Seminar on Telecommunications Business IISOFTWARE DEFINED RADIOKai Kuikkaniemi 52676k 2.4.2003
2.2 Research method
The only research method in this study is literature review. There were no
suitable books available about the topic so all the sources are found from
Internet. One can criticize the validity of some sources, but most of the
authors are highly regarded specialist on field and as such their writings
should be valid.
2.3 Structure of the study
The study is basically divided in to four sections. First there was this rather
thick introduction (chapter 1). I wanted to have a long introduction because
not one needs to understand not only the technology, but also the idea,
ideology and the history of SDR before it is reasonable to discuss the
business implications.
Then comes this methodology section (current chapter 2), where I briefly go
through the academic framework I used, when I did this paper. In terms of
clarity the long first chapter doesn’t support the structure quite well, but there
is a disruption almost in the middle of subject to these academic details, but I
hope it doesn’t pull the readers too much away from the core of the study,
SDR that is.
Third section (chapters 4-6) is the body of the study, where I go through both
the technological and business analysis of the topic. Then finally there is the
fourth conclusions section (chapter 7). As this is a literature review type of
study with only common reasoning type of analysis, there are no significant
findings that can be concluded in the end. So the conclusion is merely a
summarizing type of final words for the study.
3. Technology
3.1 Antennas
Software radio design begins at the antenna. In order to fully utilize the
software radio approach it is important that antenna has good beam forming,
diversity and sectorization qualities [7], [8]. Wideband (WB) and ultra
wideband (UWB) antennas are antenna technologies, which enable
accessibility to multiple RF bands dynamically, sequentially or in parallel.
T-109.551 Research Seminar on Telecommunications Business IISOFTWARE DEFINED RADIOKai Kuikkaniemi 52676k 2.4.2003
These wideband antenna technologies are aligned with the development of
micro electro-mechanical systems (MEMS), which replace pin diodes, FETs
etc…. Advances in the simulation techniques enable better management of
these antenna technologies, when their behaviour in different situation can be
modelled before hand and the signal tailored to the antenna qualities.
Such technologies are known in military uses for some time now already, but
step-by-step they are becoming also affordable in commercial cases when the
demand of currently still niche products expands and the production cost of
these high-tech components decrease. Wideband antennas are key to the
successful deployment of software radio infrastructure.
3.2 Hardware enablers [8]
Basically also antenna should belong to this category, but I wanted to
emphasize the importance of the antenna as an enabler of well functioning
SDR, so I made own chapter for it. The hardware enablers can be roughly
divided in to two chapters RF enablers (which contains basically RF circuits,
antennas and MEMS) and to digital enablers (processing devices and
communication fibres).
RF enablers
When most of the current commercial radio devices work in a limited
frequency area (like GSM 900Mhz, and GSM dual band 900 + 1800Mhz
etc…) especially governmental regulated SDR systems should operate in a
rather frequency area from 2Mhz-2Ghz and even beyond (up to 5Ghz where
many new standards are aiming). This requires special features from RF
enabling hardware.
Multiband (MB) and multimode (MM) chipsets are current answer to the
requirements of the SDR. MEMS are the components that are backbone
enabling the order of magnitude improvements in MM/MB chipsets. Further
improvements are expected from novel RF signal processing methods.
MEMS can be used in various points (like explained already earlier) in these
new chipsets. Examples of components that MEMS can replace are bulky pin
diodes, super-wide field-effect transistors (FET) and vacuum tube relays
T-109.551 Research Seminar on Telecommunications Business IISOFTWARE DEFINED RADIOKai Kuikkaniemi 52676k 2.4.2003
(VTR) in antennas. They can also be used as high-performance miniature
inductors, capacitors, filters, T/R switches and diplexers in RF front ends.
Digital enablers
Advanced Field Programmable Gate Arrays (FPGA) product families are
providing “system-on-chip” feature. These technologies basically contain
embedded serial transceivers, RISC processor and some amount of
programmable memory. In the end they provide the digital front-end for
software configurable radio signal processing.
Parallel to FPGA’s there is the development of general purpose processing.
This basically means that a normal CPU’s would start to support SDR
functionality (Intel announced that their all chipsets would support SDR
functionality in the end on this decade! [9]). After there is enough processing
power, the next bottle next is the internal system communication. Current
technologies like PCI are not sufficient for high data rate requirements of most
advanced SDR systems. Different communication fabric technologies like
Raceaway and Skychannel are answer to this problem.
3.3 Software enablers [8]
Software enablers of SDR can be divided in to four categories. Software
Communication Architecture (SCA), Waveform Development Environment
(WDE), Radio Description Language (RDL) and Radio Virtual Machines. In
addition to this there is need for real time operating system (that was
discussed earlier) already.
Software Communication Architecture (SCA)
A new version of the SCA is under development by the Object Management
Group (OMG) Software Radio Domain Special Interest Group (SR-DSIG)
(http://swradio.omg.org/). This new SCA is being developed using the OMG
Model Driven Architecture (MDA). The new Platform Independent Model (PIM)
uses the JTRS SCA 2.2 as a Platform Specific Model (PSM) starting point,
and extends the current SCA behavioral models. The new PIM, and the
Minimum version which will follow, will probably be mapped to J2ME and
other platforms.
T-109.551 Research Seminar on Telecommunications Business IISOFTWARE DEFINED RADIOKai Kuikkaniemi 52676k 2.4.2003
One of the major benefits of a platform independent model (PIM) standard is
the ability to port the PIM to different platform specific models (PSM) using
CE, .NET, CORBA, or Java. A second major benefit is the ability to certify
compliance of various PSM’s. Since the PIM maps to PSM’s using basic OMG
technologies such as the UML and XML, and since these technologies are
capable of formal methods of proof, it is possible to formally prove compliance
of a PSM/PIM pair as long as the mappings themselves are done with formal
methods in mind (UML and XML).
Waveform Development Environment (WDE)
Impressive milestones have been reached in the WDE tools area, such as
waveform development systems. Some of these toolsets employ
“mainstream” simulation environments such as MATLAB and SIMULINK.
Because of the platform specific optimization of IP cores and DSP algorithms,
under some circumstances SIMULINK generated code on DSPs and FPGAs
may perform BETTER than when hand-coded. Related fields include Radio
Definition Language (RDL) and Radio Virtual Machines (RVM).
Radio Definition Language (RDL)
RDL is a higher order language originally used to "construct" a radio functional
model using RDL "building blocks". RDL is used to configure a flexible
modem, describe the desired signal processing graph, and give parameters
for each processing stage. It does NOT include implementations of signal
processing stages, nor is it a waveform specification language.
Radio Virtual Machine (RVM)
The RVM is a hardware abstraction, which can significantly accelerate time to
market. It brokers parallelism in multi-core, multiprocessor, and accelerated
designs. It allows the interoperability of multivendor, real-time intellectual
property at both 'whole-stack' level and 'stack-component' model.
T-109.551 Research Seminar on Telecommunications Business IISOFTWARE DEFINED RADIOKai Kuikkaniemi 52676k 2.4.2003
4. Applications
In this chapter I go quickly explain few key applications that SDR have. There
are also several other applications.
4.1 Software phone
SDR enabled wireless terminal, also called bit misleadingly a software phone,
is basically a phone type of device that supports multiple networks by using
SDR technology.
Basically this means that a single terminal support for example that a single
terminal, with a same bundled chip set could support cellular networks (2G to
3G, GSM, EDGE, GPRS, UMTS, CDMA and WCDMA), wireless LAN
networks (WLAN protocols such as 802.11 and HyperLAN) and personal area
networks (PANs like Bluetooth). In addition it could be also UWB (Ultra Wide
Band) enabled which is an alternative technology to WLAN and PAN with
some additional functionalities. And it could, with the same chipset even take
advantage of GPS (Global Positioning System) system, so enabling very high
precision location information.
There are of course some limitations, or better challenges, in order to achieve
all these functionalities, when there are for example both circuit switched and
packet switched network support in the same chipset. Still this is a very
interesting possibility, and when it is possible it clearly demonstrates the
advantages of SDR. If the chipset is build according to SDR ideology and it
supports fully all the frequencies, modulations, modes and protocol features in
this domain, the terminal can be quickly updated with software to support also
upcoming new networks, which are not mentioned here.
4.2 Amateur radio
Amateur radio [2] is perhaps the area where the biggest interest for
open SDR system origins. The community of radio amateur worldwide could
T-109.551 Research Seminar on Telecommunications Business IISOFTWARE DEFINED RADIOKai Kuikkaniemi 52676k 2.4.2003
start to use more the computer as an interface for their communication. This
community is experimenting all the time different models of and protocols of
communication, and they would just love if they would have an open platform
to tailor the chipset functionality to different setups. When they are currently
heavily limited to the features that their hardwired receivers and transmitters
can provide.
At the same time the open platform with the radio amateurs could really
liberate the communication environment, and potentially generate many new
interesting innovations when a large pool of people have access to radio
technologies, it contains also some problems. How to prevent radio amateurs
(radio hackers) from disrupting licensed traffic. This problem is further
discussed in the chapter 6.
4.3 Military
For example in US military they have been able to integrate all together 20-30
different radio technologies (up to 750.000 individual radios) together by using
SDR in some of the radios. So it is not a surprise that the leading edge of the
SDR developments origins from military and their suppliers.
For example voice bridges are very important application that has many
benefits in battlefields, and cannot be really implemented without SDR. “Voice
bridge” basically means that ad-hocly any two to more military instances
(patrols, vehicle telematics, plains and helicopters etc..) can create a
communication connection without having specifically the same systems in
place. SDR also enables better security when there is besides the encryption
also the changeability of protocols, frequencies and modulations enabled,
which can be used to protect the communication. Basically this means that
when a violated connection is perceived it is possible to change the whole
communication method on fly to something that cannot be immediately
intercepted. US military SDR application SpeakEASY is explained in more
detailed in chapter 6 where some other real world SDR cases are also
discussed.
In addition the military also advances very much international interoperability.
Now-a-days military campaigns most often are a co-operation of several
parties that have different kinds of communication systems. In order for these
T-109.551 Research Seminar on Telecommunications Business IISOFTWARE DEFINED RADIOKai Kuikkaniemi 52676k 2.4.2003
parties to collaborate they have to be able to quickly adopt to each other
methods, and here SDR can be the key.
4.4 Base stations
When the protocols are open, and there is available SDR type of architecture
and components, it is possible to build different kinds of base stations much
more easily than today. There are already some case examples, like SDRCT
(discussed in chapter 6 more), where a vendor has developed a Linux – SDR
based base station solution that is much more cheaper than the ones
currently in market.
SDR could really open currently rather oligopolic base station markets. And
when the development would take place in multiple frontiers it could be really
beneficial for end customers in terms of price and functionality.
4.5 Civil applications
Similarly to military example also civil instances can advantage of SDR
system. Some of case examples of such are portable command station for
crisis management, inter-agency communications when desired and instant
routing of emergency information. For these needs there exists already Tetra
networks (a civil secure cellular digital networks, cousins to GSM), but they
are implemented only in few countries, and the further development phases of
Tetra could defiantly benefit from SDR.
5. Business
5.1 General business related advantages
When the hardware becomes more recyclable there is high potential for
significant life-cycle cost reductions. Over the air downloads of new features
and services as well as software patches enable that the both network and
terminals can quickly adopt and take advantage of new technologies [10].
Advanced networking capabilities to allow truly "portable" networks
And in the end the frequency space we have is very limited, and already now
there are clear cases where the frequency band has been exhausted. SDR
could enable much more efficient usage of frequency band by quickly
T-109.551 Research Seminar on Telecommunications Business IISOFTWARE DEFINED RADIOKai Kuikkaniemi 52676k 2.4.2003
adapting to utilize all available free spectrum. This is further discussed in
chapter of secondary
5.2 Value propositions [10]
In this chapter I go though the value propositions of identified by SDR in the
perspective of the three most important stakeholder groups, which are
customers, operators and manufacturers.
Benefits to Consumers:
Single SDR platform for multiple uses - allows customization and "true choice"
meanwhile enabling access to broad range of media, content & applications.
Basically this means ability to seamlessly roam across operator boundaries
and achieve true mobility.
SDR also offers the possibility of a richer set of features and services with an
easy upgrade path for a variety of hand held devices and increases the
lifetime of a hardware investment and provides insurance against
obsolescence.
Benefits to Operators:
SDR gives operators ability to roll out new services tailored to the various tiers
of users on common hardware platform. With it operator can create simpler
and faster test cases of new services and overall differentiate from other
operators. It lowers the life-cycle costs of handsets, reduces component count
and makes software upgrades of base-station faster and more flexible.
One significant point where SDR can help is that when currently service and
network operators have problems to identify others function with SDR type
common platform the division can be made more clearly. Basically it could
help operators to develop PC Internet business model to the wireless market
by addressing the sale of content versus connection time, which can be very
interesting route even tough it contains some possible problems also.
Benefits to Manufacturers:
For smaller vendors SDR offers ability to expand to new and adjacent markets
with common network solutions. It enhances the true use of advanced
T-109.551 Research Seminar on Telecommunications Business IISOFTWARE DEFINED RADIOKai Kuikkaniemi 52676k 2.4.2003
techniques for spectrum utilization using smart antennas and adaptive signal
processing. Currently the handsets are manufactured as is basis, and only
cosmetic changing can be done later on. SDR platform could enable new
business model in terms of "soft" additions of new features in terminals and
easy adaptation to partner with ASPs & ISPs for enhanced revenue streams,
which again might be a good thing but on the other hand manufacturers
revenue logic is very dependent now-a-days on selling continuously every 2-3
years new handset to customers. Anyways the capability to upgrade services,
features and security mechanisms over the air is very beneficial for
everybody. In the manufacturing side SDR chipset could lower product cost
due to reduced components (size reductions). At the same time for example
terminal manufacturers could open more their interfaces for developers
without introducing their core technology (software interface hides the
hardware technology).
5.3 Cost – Benefit analysis
According to Joseph Mitola [11] the cost benefit analysis for SDR could be
based on the following logic. Life cycle costs include R&D, acquisition and
operations and maintenance components. Key techniques in accurate
cost/benefit analysis include parameterizing the relationship between the
technical features of the system architecture (e.g. erlangs per square km), the
techncial architecture (e.g. the number of VME processing modules needed
per subscriber) and the projected revenue streams.
But still in the end in case of SDR everything comes down to chip cost.
Normally a dual-purpose chip cost (e.g. dual band GSM) around 1.5-1.7 times
the cost of single purpose chip [11]. Then when there are more than two
modes and or frequency areas that chip needs to function the cost increases
around again with respective incremental amount.
So if there are clear need to have a three or more network setups in a single
chip, and a SDR chip capable for those networks cost around a two times
more than single purpose chip, it is already profitable to turn in to SDR chip.
Currently the price of SDR chip is not quite there, but in time when the market
size increases it can clearly achieve such price performance.
T-109.551 Research Seminar on Telecommunications Business IISOFTWARE DEFINED RADIOKai Kuikkaniemi 52676k 2.4.2003
Another factor that is very important especially for smaller vendors and
instances that would like to start implementing SDR products is the availability
of COTS components. Currently components like MEMS are manufactured in
various places, but in order to penetrate the commercial markets actually even
the whole SDR enabled chip should become a COTS products, as well as
software components and platforms based on which the SDR chip can be
tailored.
5.4 Market overview
Worldwide interest and investment in the SDR technologies is growing
significantly, with key standardization and development efforts now taking
place throughout Europe, North America, Japan, Korea, and China. In
addition to the broad benefits listed in chapters above, SDR technologies offer
unique benefits to players on every tier of the value chain [10].
Governing bodies like FCC (discussed in next chapter) are already heavily
analysing SDR products and in SDR Forum there are currently 122 member
companies and organisation (not Nokia, just to point out in Finnish
perspective), which contribute to the forum activities monetarily and otherwise.
Most of the companies that are developing already actual products are doing
that for military or are technological spin-offs of military research for
commercial purposes. There are few cases explained in next chapter.
5.5 Timeline [12]
Based on (again) SDRForums market estimates the ramp-up of SDR
technology market introduction has already began in the beginning of the
millennium. According to them they are expecting a major boost in SDR
technology with the 3G and 4G cellular networks. In their estimates the 3G is
scheduled to have been ongoing already, which is, as we know, not true. In
that perspective it is rather speculative that can SDR penetrate in mass
markets, as expected, within next few years. It remains to be seen what
wireless technologies ramp-up and when, but good thing for SDR is that if and
when the network environment becomes more complex “network of networks”
it really doesn’t matter what protocols, modes and frequencies are used, SDR
is in all cases a very promising technology.
T-109.551 Research Seminar on Telecommunications Business IISOFTWARE DEFINED RADIOKai Kuikkaniemi 52676k 2.4.2003
5.6 Future prospects
In this chapter I would like to draw some future visions what SDR enable
“network of networks” mean. I have referred to Joseph Mitola already before.
He has a vision of cognitive radio [13], which would be base on SDR type of
technologies. The idea in cognitive radio is that all radio equipments would
sense all the time surroundings and communicate with each other in order to
create the most efficient and robust networking conditions. For example
pacemaker could have alternative operating frequencies, which could be
immediately taken in to use if the primary operating frequency is occupied
otherwise.
Basically SDR is a logical step in intelligent radio networks where the base
stations provide different capacities and functionalities in different places and
terminals can adapt to these network conditions intelligently without user
intervention in order to maximize the wireless usability. At the same time
different mobile network components (mainly terminals) could form ad-hoc
new networks to satisfy some temporary communication needs.
5.7 Secondary markets [3]
Secondary bandwidth markets is interesting new concept in order to business
vice utilize the network capacity at its maximum. Basically it means that
primary buyers purchase the operating licence for the frequency bandwidth,
but in the secondary markets they could resell parts (that they don’t need or
other parties can provide better value added) of the bandwidth to other
players.
Basically this would require some kind of network broker, which would
manage the secondary markets and sell the frequency space-time of the
primary operator to secondary operators. Good example where such
secondary markets would be very beneficial would be for example irregular
events, like Olympics, that have an exceptional need for all different
bandwidths. During the time of Olympics the organisers would lease the
needed network capacity in the secondary markets in order to have a wireless
project management network in function. For these secondary markets there
is need to have easily configurable terminals and other network components
T-109.551 Research Seminar on Telecommunications Business IISOFTWARE DEFINED RADIOKai Kuikkaniemi 52676k 2.4.2003
in order to maximize the usage of continuously changing network conditions
(the same equipments could be then used in the other side of the world for
some other event in completely different network conditions right after
Olympics). Here SDR could again be a key technology.
6. Current situation
In previous chapter I explained the business environment of SDR by using
mostly future projections and possibilities as a starting point. In this chapter I
go through the realism of current situation with the SDR. How it is used, what
are the problems it is facing and some parallel (basically complementing)
development projects.
6.1 Case examples of implementation
First I would like to introduce you few most relevant real world implementation
case examples of SDR. This is no way a comprehensive list, but only few of
the most promising cases.
SPEAKEasy [13]
SPEAKEasy is the US military development project of SDR, that started
already in mid 90’s and is now already in second phase of implementation.
The key vision in SPEAKEasy development was to build the “PC of the
Communications World”. This basically means a fully programmable
waveform and COMSEC for Voice, Multimedia and Networking Use. It is
designed to be multiband system operating continuously in the bandwidth
area from 2 to 400Mhz. It has both open modular hardware and software
architecture, which has been a basis for first commercial installations also. It
supports also legacy systems.
Lessons learned from the first phase where that the open environment is very
important in order to quickly respond to further development needs. The
system uses exceptionally cutting edge technologies so apparently the first
implementation was rather expensive. They found out, that in the beginning
the system was “over-designed”. This refers most probably to, that it wasn’t
enough flexible for all the time growing requirements needs.
T-109.551 Research Seminar on Telecommunications Business IISOFTWARE DEFINED RADIOKai Kuikkaniemi 52676k 2.4.2003
CRC demo [14]
Communications Research Centre Canada (CRC) and Defence Research &
Development Canada (DRDC) where the first ones to show a commercial
demo of SDR radio environment. This was done in November 2002. Originally
CRC had an idea to convert the SCA used in SPEAKEasy as to a commercial
open source platform and demonstrate a simple voice call over it. In the demo
they actually where able to do Digital Audio Broadcast (DAB), which satisfied
many parties that where speculative about the how big are the difficulties
related to SDR platforms. This CRC demo can be regarded as a starting point
for commercial SDR applications.
Radical horizon [15]
Radical horizon is the one of the first companies providing the commercial
SDR solution. Their solution is called Flexcell and it is a multiband and
multiprotocol architecture targeted for simultaneous 2G and 3G networks. As
in SDR systems in general their benefits are low cost and easy
configuration/adaptability.
SDRCT (SDR Communications Technologies) [16]
SDRCT has bit similar solution than Radical Horizon. Their focus is bit more
on the SDR related operating system side. That is why they are targeting their
solution also to developers in addition to operators. The name of the product
is SpctruCell and it has more on security issues concerned derivative PC4
that is targeted to military customers.
6.2 Problems
Hackers, disruption of current radio frequencies
When SDR systems becomes widely available to small developer
communities like previously introduced radio amateurs, there is a problem of
them to accessing existing networks and disrupting licensed network traffic.
There are some ideas how to prevent this from happening, like restrictions
and limitations in the software, but so far there is no consensus or clear vision
how this should be done.
T-109.551 Research Seminar on Telecommunications Business IISOFTWARE DEFINED RADIOKai Kuikkaniemi 52676k 2.4.2003
Basically if there would be open source SDR platform, operating systems and
programming components available for example to 3G environment it would
be more than easy for a individual coder/tech guy to build devices that could
seriously damage the traffic in this frequency spectrum, hence generating
denial of network service for other customers and in worst case also security
leaks.
Regulatory point of view [3]
Naturally the biggest question among regulators is how to avoid SDR
disrupting current radio frequencies? Meaning how to control and monitor
hackering and illegal activities. When in earlier chapter it was quickly
explained how easy it would be to disrupt 3G networks, in addition concern for
public bodies and operators rise when they now that they have no means
what so ever to really monitor and identify this illegal activity.
In general at least FCC states that they are “very interested in the area and
look forward to its potential application”. Especially in the perspective of
secondary markets the governing bodies see that SDR may become very
beneficial.
6.3 Parallel development:
GNU radio [17]
GNU radio is basically an open source community working under GPL licence
to build SDR like platform. Currently their focus seems to be in amateur radio
and HDTV decoding side. In HDTV SDR could also provide interesting new
application when a simple radio receivers connected to computer could be
used to capture and demodulate the HDTV broadcasts.
Open radio platform [18]
Open radio platform is a France based initiative to develop SDR type
environment and components for that support 3G. It is develop in cooperation
with 3GPP. The initial focus areas of Open Radio Platform are educational
and research oriented. But in long term they are looking forward to develop
also commercial applications based on it.
T-109.551 Research Seminar on Telecommunications Business IISOFTWARE DEFINED RADIOKai Kuikkaniemi 52676k 2.4.2003
7. Conclusion
Software Defined Radio (SDR) is an idea of changing hard coded radio
circuits in to software programmable ones. In a tomorrows complex
networking environment such approach contains several benefits like the
flexibility of introducing new standards, maximizing the bandwidth utilization
and opening the network development for bigger pool of vendors and
developers.
Openness is one key fundamental of SDR initiative, which basically means
that more and more instances would have access to understand, utilize and
further develop network technologies. SDR is not limited to any specific
technology, but the solution areas vary from amateur radio and military
application to a cellular networks and short- range wireless networks.
SDR is an idea that can materialize in many different levels depending on
which components used in the RF-circuits and modulation processors support
software controlling.
References
1. http://www.arrl.org/tis/info/sdr.html
2. http://www.smartmobs.com/archives/000339.html
3. Trends in the field of networks Software Defined Radio: A Regulator's
Perspective Dale N. Hatfield Chief, Office on Engineering and
Technology Federal Communications Commission At SDR Forum 19th
General MeetingSeattle, Washington
http://www.fcc.gov/oet/speeches/sdrforumsph.html
4. http://ourworld.compuserve.com/homepages/jmitola/cognitiv.htm
5. http://searchnetworking.techtarget.com/sDefinition/
0,,sid7_gci333184,00.html
6. http://www.sdrforum.org/tech_comm/definitions.html
7. http://ourworld.compuserve.com/homepages/jmitola/seven.htm
8. http://www.sdrforum.org/public/approved/
03_a_0002_v0_00_rd_sum_01_30_03.pdf
T-109.551 Research Seminar on Telecommunications Business IISOFTWARE DEFINED RADIOKai Kuikkaniemi 52676k 2.4.2003
9. Intel CTO Pat Gelsinger at Intel Developer Forum (IDF, 2/28/02, San
Francisco)
10.http://www.sdrforum.org/mrkts_comm/value.html
11.http://ourworld.compuserve.com/homepages/jmitola/costbene.htm
12.http://www.sdrforum.org/mrkts_comm/adoption.html
13.http://www.its.bldrdoc.gov/meetings/art/art98/slides98/bons/bons_s.pdf
14.http://www.crc.ca/en/html/crc/home/mediadesk/sca_demo
15.www.radicalhorizon.com
16.www.sdrct.com
17.http://www.gnu.org/software/gnuradio/gnuradio.html
18.http://www.wireless3g4free.com/
Abbreviations
2G – Second generation mobile phone networks e.g. GSM
3G – Third generation mobile phone networks e.g. UMTS
ADC – Analogue to Digital Converter
ASCII – American Standard Code for Information Interchange
COMSEC – COMmon wealth SECurity
COTS – Commercial Of The Shelf
DAC – Digital to Analogue Converter
DSP – Digital Signal Processor
FCC – Federal Communications Commission
FPGA - Field Programmable Gate Arrays
GNU – Recursive acronym Gnu is Not Unix
HDTV – High Definition TV
MEMS – Micro Electro-Mechanical Systems
RF – Radio Frequency
T-109.551 Research Seminar on Telecommunications Business IISOFTWARE DEFINED RADIOKai Kuikkaniemi 52676k 2.4.2003
SDR – Software Defined Radio
UWB – Ultra Wide Band
WB – Wide Band