Cognitive Radio Systems and Software Defined Radio
Introduction: why are we interested?
Cognitive Radio (CR) is one of the most discussed topics in contemporary spectrum management. The discussion centres around how some dynamic intelligence, within receivers and assisted externally by regulatory databases, can use spectrum more efficiently than under conventional spectrum management systems. It is often associated with software-defined radio (SDR), where the radio’s key operating characteristics (as distinct from control over the radio’s operation itself) are defined largely in software.
Most current practical considerations of what Cognitive Radio could offer focus on overlaying its use on an existing, more conventional environment. Cognitive is therefore seen as a ’secondary’ use, coexisting with itself and with the primary service. However, cognitive techniques could also increase the effective capacity of bands designated for short-range devices.
What are we doing?
The ECC has been actively working since early 2009 to establish some common understanding as a step towards practical regulatory initiatives. The current activity is the following:
- Project team SE43 is seeking to define technical and operational requirements for cognitive radio systems in the ’white spaces’ of the UHF TV band.
- WG FM maintains a Correspondence Group looking at the strategic issues raised; it reports to the ECC itself.
You can read more on these activities related to CRS and SDR below, as well as about work the ECC and other groups have already done in this area. Click on the list to go straight to the relevant section. You can also read an article on Cognitive Radio in the June 2011 edition of the ECC Newsletter by clicking here.
Cognitive Radio Workshop (2 - 3 May 2012, Mainz, Germany) highlights progress and challenges
The ECC held a workshop jointly with the COST-TERRA research project on 2nd and 3rd May, in Mainz. More than 130 delegates heard about a wide range of industrial trials and initiatives, research work and regulatory progress towards enabling cognitive radio technology in Europe and elsewhere. You can see the presentation slides, including from the concluding session, on the event's own webpage. The event will provide very useful information for the ECC’s planning of its next phases of work on these technologies, which can significantly advance the efficiency of spectrum use.
SE43 was created at the 53rd meeting of WG SE in Hvar (Croatia). A dedicated page has been created on ECO web site SE43 web page. The activities of SE43 are devoted to the definition of technical and operational conditions of CRS in the white spaces of the 470-790 MHz band.
The 16th SE43 meeting took place on 11th-13th December 2012 in Helsinki, Finland and was devoted primarily to consideration of the comments received during Public Consultation on:
- draft ECC Reports 185 “Further definition of technical and operational requirements for the operation of white space devices in the band 470-790 MHz”
- draft ECC Report 186 “Technical and operational requirements for the operation of white space devices under geo-location approach”.
Both CEPT administrations and ECC observers have provided their comments in response to Public Consultation. There have been in total 4 responses to draft ECC Report 185 and 5 responses to draft ECC Report 186, either suggesting revisions to the text or requesting some clarification.
All the comments received have been successfully addressed by SE43.
No further meetings of SE43 are planned.
The details of the 16th meeting of SE43 can be found in its Minutes.
The Cognitive Radio (Spectrum Sensing) feature is now implemented in SEAMCAT. Further information on the algorithm and the manual are available here.
WG FM corner:
WG FM at their 74th meeting on 23 - 27 April 2012 in Bern (Switzerland) decided the following:
WGFM agreed on a summary and analysis of the answers to the questionnaire on PMSE protection in case of introduction of WSD in the 470-790 MHz band as well as a related liaison statement to WGSE and SE43.
WGFM established two new work items for the creation of two new ECC Reports:
1.To provide a master set of the overall requirements for all CEPT countries that will be needed to facilitate communication and interaction between a WSD and White Space Data Base;
2.To provide information on issues and requirements that need to be addressed when setting up a geo-location database and/or the management of independent database providers.
It was further agreed on the management of ASA (Authorised Shared Access) / LSA (Licensed Shared Access) in WGFM and on a first WGFM Report about the ASA/LSA concept.
In addition, WGFM agreed that the definition of LSA from RSPG should be retained at the present time.
WGFM#75 agreed the ToR of the new PT FM53 on Reconfigurable Radio Systems (RRS) and Licensed Shared Access (LSA). The Chairman of FM53 is Mr Emmanuel Faussurier (France). PT FM53 continues the work of the former WGFM Correspondence Group CRS (Cognitive Radio Systems). Detailed information about activity of PT FM53 can be found here.
WGFM#75 agreed concerning the 2.3-2.4 GHz frequency band to work on a new regulatory framework. The LSA concept should be considered. The new WGFM Project Team FM52 works on this new regulations. Detailed information about activity of PT FM52 can be found here.
FM 53 corner:
WGFM created in 2012 Project Team FM53. This project team develops currently two new ECC Reports:
- WGFM PT FM53 has a work item for creation of a new ECC Report for TV-WSD (White Space Devices) using geo-location. The aim is to describe the overall regulatory framework for TV WSD using geo-location databases and guidance for national implementation.
- WGFM PT FM53 creates a new ECC Report on Licensed Shared Access Regulatory Framework considerations with the focus on the frequency band 2.3-2.4 GHz and LSA individual licensing for MFCN services in relation to incumbent governmental use. LSA may employ cognitive radio capabilities, e.g. geolocation databases complemented, if necessary, by sensing. In parallel, PT FM52 develops a new ECC Decision for MFCN in 2.3-2.4 GHz that will carry some LSA provisions in line with the framework developed in PT FM53. The LSA concept is a voluntary approach (as opposed to forced spectrum refarming) to provide access to spectrum for MFCN services in shorter time frames where possible (access FM53 webpage)
Issue A (Software defined radio): WRC-12 concluded that no changes to the Radio Regulations are necessary on Issue A and to suppress Resolution 956 (WRC-07).
Issue B (Cognitive Radio): WRC-12 concluded that no Changes to the Radio Regulation (Volumes 1 and 2) are necessary on Issue B and to suppress Resolution 956 (WRC-07). A new WRC Recommendation, Recommendation COM6/1 (WRC-12), has been included into the volume 3 of the RR.
ITU-R WP5D corner:
Working Party 5D at their meeting in India (12 – 19 October 2011) was able to finalise and agree the draft new Report ITU-R M.[IMT.CRS] ”Cognitive Radio Systems Specific to IMT Systems” . This was forwarded to Study Group 5 for approval.
Study Group 5 held its meeting in Geneva (21-23 November 2011) and approved ITU-R Report M.2242 “Cognitive Radio Systems specific for IMT Systems”.
ECC Correspondence Group corner:
Doc. ECC(09)136 was introduced by Margit Huhtala, Convener of the Correspondence group on CR at the ECC meeting (26-30 October 2009, Skopje, FYR of Macedonia). The Document summarises the work done by the group. As requested by the ECC the group has improved the wording of the tasks, added some more explanation in the section concerning applications, taken into account the experience with the pre-cognitive systems, outlined a roadmap with milestones for future work and considered its attribution within the ECC structure. The work done by SE43 and WG FM has also been taken into account. Emphasis was given to the improved Tasks 1 and 2 as well as on the established milestone plan. The tasks are foreseen as follows:
Task 1: Technical studies/analysis and compatibility issues.
Task 2: Regulatory mechanisms needed to facilitate introduction of CRS.
Task 3: Further to Task 1 and 2, study, if necessary, the impact of cognitive devices on current framework for placing equipment on the market, including assignment of responsibilities in the case of radio equipment (in particular if data bases in support of the geo-location are provided by third parties), and enforcement, in order to make proposals on the basis of these findings to the relevant bodies.
A roadmap with four stages until WRC-2012, to maximise the benefits of the CRS work in the ECC, was presented by the CG. The four stages given below are proposed to cover the work items of Task 1 (technical work and compatibility), Task 2 (regulatory work) and Task 3 (impact on current framework) as well as the foreseen applications and the on-going work within WG FM and SE43. Close co-operation between all stakeholders is necessary.
Stage 1: Identification of types of CRS applications, review of spectrum needs and existing spectrum usage (Task 1, work is ongoing within WG FM).
Stage 2: Feasibility study, addressing identified CRS applications (Task 1, work is ongoing within WG FM and SE43).
Stage 3: Identification of bands and regulation, addressing identified CRS applications (work is ongoing within WG FM and SE43, Task 1 and 2).
Stage 4: Impact on current regulatory framework for equipment (Task 2 and 3).
ECC appreciated this comprehensive response from the CG and decided to continue in accordance with the proposed roadmap. The Report of the Correspondence Group can be downloaded here.
ETSI TC RSS corner:
There is ongoing activity within ETSI TC RSS on CRS and SDR standardisation (link to the ETSI TC RSS).
ETSI RRS TC created the following four WGs, in which the technical discussions are organized and reports are produced:
- WG1 (System Aspects (SA)) focuses on system aspects and develops proposals from a system aspects point of view for a common framework in RRS TC with the aim to guarantee coherence among the different RRS TC WGs and to avoid overlapping and gaps between related activities.
- WG2 (Radio Equipment Architecture (REA)) focuses on SDR technology with a particular interest in radio equipment architecture and proposes common reference architectures for SDR/CR radio equipment (mobile handset devices, radio base stations, etc.), related interfaces, and so on.
- WG3 (Cognitive Management and Control) focuses on cognitive management and control; the group collects and defines the system functionalities for reconfigurable radio systems related to spectrum management and joint radio resource management across heterogeneous access technologies. Furthermore, the group has developed a functional architecture for the management and control of reconfigurable radio systems as well as a report on the CPC as an enabler to support the management of the RRS.
- WG4 (Public Safety) focuses on public safety and collects and defines the related RRS requirements from relevant stakeholders in the public safety and defense domain. The group defines the system aspects for the applications of RRS in public safety and defense.
The RAS (Radio Access and Spectrum) Cluster Workshop took place on the 28th January 2010. The setup of the workshop was FP7 projects on Cognitive Radio and Spectrum Sharing presenting their technology concepts and discussed regulatory implications. The workshop’s presentations are available on the webpage of the Workshop.
Some of the following projects have been finalized and some have been recently launched:
- End-to-End Efficiency (E3) project was finalised in December 2009. The key objective of it was to transform current wireless system infrastructures into an integrated, scalable and efficiently managed Beyond-3rd-Generation (B3G) cognitive system framework, which ensures seamless access to applications and services and exploits the full diversity of corresponding heterogeneous systems. In the course of the project collaborative and autonomous algorithms were developed.
- PHYDYAS (Physical Layer for Dynamic Spectrum Access and Cognitive Radio). A short term objective is to develop and demonstrate algorithms for single and multiantenna terminals, scalability and adaptivity, and multiple accesses. The proposed technique is a filter bank-based multicarrier (FBMC) which offers high spectrum resolution and can provide independent sub-channels, while maintaining or enhancing the high data rate capability. Critical aspect is that sub-channels (so-called sub-carriers) can be independent. Spectrum sensing and transmitting can be performed simultaneously.
- SENDORA (Sensor Network for Dynamic and Cognitive Radio) – main motivation of the project is that radio spectrum is a scarce resource but is paradoxically under-utilized in some frequency bands. Start date = 1st January 2008; duration: 36 months. Innovative idea is to perform sensing and control interference level at the same time. Objective is develop a technology able to reuse the licensed but unused spectrum in an opportunistic manner, operating as secondary system in the considered bands.
Approach is to develop SENDORA Wireless Sensor Network aided to Cognitive Radio network. network and provide himself the secondary system with transmission opportunities. Selected scenario: nomadic broadband access in urban and suburban areas. Start date 01.01.2008; duration: 36 months.
- SACRA (Spectrum and Energy Efficiency through multi-band Cognitive Radio). Motivation of the project is to study and demonstrate spectrum and energy efficient communications through multi-band cognitive radio. Project was launched on 01.01.2010; duration is 36 months.
Main objective: study and demonstration of spectrum and energy efficient communications through multi-band cognitive radio. Possible scenario: mobile broadband communications on several separate bands. Target bands: 2.6 GHz and upper part of UHF band.
- ARAGORN (Adaptive Reconfigurable Access and Generic Interfaces in Radio Networks). Duration: January 2008 – June 2010. Project explores CR principles in ISM-band domain. Increase efficiency through cooperation and cognitive radio principle. To invent in the existing architecture the cognitive radio manager (CRM) and investigate what are its inherent components. The opportunity of the usage of the white spaces is dependent on the given thresholds to depict or measure ‘gaps’.
- FARAMIR (Flexible and spectrum-Aware Radio Access through Measurements and Modelling). The project was recently launched. It will mainly deal with measurements.
- EUWB (Coexisting Short Range Radio by Advanced Ultra-Wideband Radio Technology). Time schedule: 01.04.2008 – 31.03.2011. Objectives of EUWB are to explore the economic potential of the Ultra-Wideband (UWB) radio technology, extend the UWB concept with advanced cognitive radio, multi-band/multimode networking and multiple antenna system concepts; reliable data link between sensor and control unit; reduce cable harness complexity. Implementation is planned for automotive UWB frontends and antenna concepts. Methods include short term (spectrum sensing with its challenges like long scanning time because of the wide range and changing environment) and long term (co-operative spectrum sensing).
- WALTER (Wireless Alliance for Testing Experiment and Research). Project was started in 2008 and was finalised in the end of 2009. Main objective was fulfilled. Test beds were developed to measure UWB signal in order to allow conformity assessment to the devices to be presented on the market.
- SAPHYRE (Sharing Physical Resources: Mechanisms and Implementations for Wireless Networks). Project was recently launched, consists of 6 Work Packages. The main topics emphasised in the SAPHYRE project are: self-organising infrastructure sharing, new adaptive spectrum sharing models, efficient autonomous co-ordination, and high spectral efficiency. “Innovation idea is to pave the way for paradigm change from exclusive resource allocation to voluntary physical resource sharing”. Technical platform will be created based on Broadband wireless experimental system which belongs to Fraunhofer Institute.
- QoSMOS (Quality of Service and Mobility driven cognitive radio Systems). Project was started on 01.01.2010. The main objective is to provide a platform for efficient radio access to future networks. Some challenges for CR implementation such as sensing; spectrum portfolio database; other mitigation technique methods will be studied.
Following opportunities for Cognitive Radio can be studied further such as home and street coverage; smart metering / grid; rural access; cellular extension; public safety; TV white spaces.
- QUASAR (Quantitative Assessment of Secondary Spectrum Access). Following scenarios and use cases for a secondary system will be investigated: 1) Mobile broadband access; 2) High-speed Rural broadband; 3) Next generation home networks; 4) Cellular deployments with low/high towers; 5) Backhauling; 6) Emergency services /ad hoc networks.
Following frequencies for white space usage will be considered: broadcasting bands; radar bands; satellite bands. the decision about cellular bands is under consideration.
Expected output of the Project will be to asses the amount of “white spaces” and its usefulness. Secondary system performance and white space availability map.
- CoGEU (Cognitive radio systems for efficient sharing of TV white spaces in EUropean context). Duration 36 months (January 2010-December 2012).
CoGEU will consider a centralized architecture with a spectrum broker. The spectrum broker controls the amount of bandwidth and power assigned to each user in order to keep the desired QoS and interference below the interference limits. Project combines geolocation databases and sensing techniques for incumbent detection and determining usable channels in TVWS.
CoGEU approach: 1) emulate possible scenario; 2) develop software to calculate possible amount of spectrum and check the correctness of the approach; 3) combine geolocation and sensing techniques.
Information about meetings related to cognitive radio within CEPT is available in the ECC Meeting calendar.
ECO contact for Cognitive Radio related enquiries: Stella Lyubchenko (ECO) e-mail firstname.lastname@example.org or phone +45 33 89 63 09
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Updated: 30 January 2015, 15:13