ETSI TR 102 683 V1.1.1 (2009-09)

Reconfigurable Radio Systems (RRS); Cognitive Pilot Channel (CPC)

DTR/RRS-03007

General Information

• Status: Published
• Publication Date: 24-Sep-2009
• Technical Committee: RRS 3 - RRS Security, Certification & Declaration of Conformity
• Current Stage: 12 - Completion
• Due Date: 28-Sep-2009
• Completion Date: 25-Sep-2009

Standards Content (Sample)

ETSI TR 102 683 V1.1.1 (2009-09)
Technical Report


Reconfigurable Radio Systems (RRS);
Cognitive Pilot Channel (CPC)

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2 ETSI TR 102 683 V1.1.1 (2009-09)



Reference
DTR/RRS-03007
Keywords
air interface, configuration, radio
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3 ETSI TR 102 683 V1.1.1 (2009-09)
Contents
Intellectual Property Rights . 5
Foreword . 5
Introduction . 5
1 Scope . 6
2 References . 6
2.1 Normative references . 6
2.2 Informative references . 6
3 Definitions and abbreviations . 7
3.1 Definitions . 7
3.2 Abbreviations . 8
4 Cognitive Pilot Channel (CPC): Concept and Motivation . 9
4.1 Baseline scenarios . 10
4.1.1 Support for terminal at start-up phase . 10
4.1.2 Support for secondary spectrum usage . 11
4.1.3 Support for radio resource usage optimization . 12
4.2 Functionalities and features of the CPC . 13
4.3 Possible advantages of the CPC . 13
5 CPC Contents Definition . 13
5.1 Information Model on the information stored on network side . 14
5.2 Organization of CPC geographical related information . 14
5.2.1 Mesh-based approach . 15
5.2.2 Coverage area approach . 15
5.3 CPC contents to support terminal start-up . 16
5.3.1 Content in the case of mesh-based approach . 16
5.3.2 Content in the case of coverage area approach . 16
5.4 CPC contents to support secondary spectrum usage . 17
5.5 CPC contents to support radio resource usage optimization . 17
6 Out-Band CPC . 18
6.1 Scope of the Out-band CPC . 18
6.2 Scenarios/deployments and use cases. 19
6.3 Feasibility studies on CPC access technologies . 21
6.3.1 GSM. 21
6.3.2 WiFi approach for Out-band CPC at switch on of a mobile . 22
6.4 Information delivery strategies . 22
6.4.1 Broadcast approach . 23
6.4.2 On-demand approach . 23
7 In-Band CPC . 24
7.1 Scope of the In-band CPC . 24
7.2 Scenarios/deployments and use cases. 25
7.3 Implementation options and Procedures . 26
7.3.1 Application Layer Implementation (IP-based CPC) . 26
7.3.2 Mapping on existing standards . 27
8 Combination of In-Band and Out-Band CPC . 27
9 Summary and Recommendations for Standardization . 28
Annex A: Downlink CPC dimensioning methodology . 30
Annex B: State of the art . 32
B.1 Overview on IEEE 1900.4 Information Model . . 32
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4 ETSI TR 102 683 V1.1.1 (2009-09)
B.2 Overview on 3GPP ANDSF Management Object . 35
History . 38

ETSI

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5 ETSI TR 102 683 V1.1.1 (2009-09)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (http://webapp.etsi.org/IPR/home.asp).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This Technical Report (TR) has been produced by ETSI Technical Committee Reconfigurable Radio Systems (RRS).
Introduction
The present document provides a feasibility study on defining and developing the concept of Cognitive Pilot
Channel (CPC) for reconfigurable radio systems to support and facilitate end-to-end connectivity in a heterogeneous
radio access environment where the available technologies are used in a flexible and dynamic manner in their spectrum
allocation context.
As a feasibility study the presented document provides basis for decision making at ETSI Board level on
standardization of some or all topics of the CPC.
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6 ETSI TR 102 683 V1.1.1 (2009-09)
1 Scope
The current trend for radiocommunications systems indicates a composite radio environment, where multiple Radio
Access Technologies (RATs) links may be available at the same time. In this context, the cognitive capability of the
terminals becomes increasingly a crucial point to enable optimization of the radio usage. In order to obtain knowledge
of its radio environment, a cognitive radio device may sense parts of the spectrum, which is necessary for its intention.
This task may result in a very time and power consuming operation, if the parts of the spectrum to be sensed are large.
In this context, the Cognitive Pilot Channel (CPC) solution could lead to a more efficient approach by conveying
elements of the necessary information to let the terminal obtain knowledge of e.g. the available frequency bands, RATs,
services, network policies, etc., through a kind of common pilot channel
Therefore, the present document aims at providing a study of the main concepts and possible implementations for the
CPC in order to improve the spectrum and radio resources utilization in Reconfigurable Radio Systems.
2 References
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific.
• For a specific reference, subsequent revisions do not apply.
• Non-specific reference may be made only to a complete document or a part thereof and only in the following
cases:
- if it is accepted that it will be possible to use all future changes of the referenced document for the
purposes of the referring document;
- for informative references.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
NOTE: While any hyperlinks included in this clause were valid at the time of publication ETSI cannot guarantee
their long term validity.
2.1 Normative references
The following referenced documents are indispensable for the application of the present document. For dated
references, only the edition cited applies. For non-specific references, the latest edition of the referenced document
(including any amendments) applies.
Not applicable.
2.2 Informative references
The following referenced documents are not essential to the use of the present document but they assist the user with
regard to a particular subject area. For non-specific references, the latest version of the referenced document (including
any amendments) applies.
[i.1] Inoue, M., Mahmud, K., Murakami, H., Hasegawa, M. and Morikawa: "Seamless Handover Using
Out-Of-Band Signaling in Wireless Overlay Networks," WPMC 2003, vol. 1,
pp. 186-190, October 2003.
[i.2] Inoue, M., Mahmud, K., Murakami, H., Hasegawa, M. and Morikawa: "Novel Out-Of-Band
Signaling for Seamless Interworking between Heterogeneous Networks," IEEE Wireless
Communication Magazine, vol. 11, no. 2, pp. 56-63, April 2004.
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7 ETSI TR 102 683 V1.1.1 (2009-09)
[i.3] Inoue, M., Mahmud, K., Murakami, H., Hasegawa, M. and Morikawa, H.: "Design and
Implementation of Out-Of-Band Signaling for Seamless Handover in Wireless Overlay
Networks," IEEE ICC 2004, pp. 3932-3936, June 2004.
[i.4] E2RII 2 Whitepaper: "The E2RII Flexible Spectrum Management (FSM) Framework and
Cognitive Pilot Channel (CPC) Concept - Technical and Business Analysis and
Recommendations".
[i.5] J. Pérez-Romero, O. Sallent, R. Agustí, L. Giupponi: "A Novel On-Demand Cognitive Pilot
Channel enabling Dynamic Spectrum Allocation", DySPAN '07, 17-20 April.
[i.6] ETSI TS 123 402: "Universal Mobile Telecommunications System (UMTS); LTE; Architecture
enhancements for non-3GPP accesses (3GPP TS 23.402 Release 8)".
[i.7] ETSI TS 124 312: "Universal Mobile Telecommunications System (UMTS); Access Network
Discovery and Selection Function (ANDSF) Management Object (MO); (3GPP TS 24.312
version 8.2.0 Release 8)".
[i.8] ETSI TS 144 018: "Digital cellular telecommunications system (Phase 2+); Mobile radio interface
layer 3 specification; Radio Resource Control (RRC) protocol (3GPP TS 44.018 Release 7)".
[i.9] OMA-ERELD-DM-V1-2: "Enabler Release Definition for OMA Device Management".
[i.10] IEEE 802.21: "Working Group for developing standards to enable handover and interoperability
between heterogeneous network types including both 802 and non 802 networks".
[i.11] IEEE 1900.4-2009: "IEEE Standard for Architectural Building Blocks Enabling Network-Device
Distributed Decision Making for Optimized Radio Resource Usage in Heterogeneous Wireless
Access Networks", February 27, 2009.
[i.12] ETSI TS 122 278: "Universal Mobile Telecommunications System (UMTS); LTE; Service
requirements for the Evolved Packet System (EPS) (3GPP TS 22.278 Release 8)".
[i.13] ETSI TS 125 331: "Universal Mobile Telecommunications System (UMTS); Radio Resource
Control (RRC); Protocol specification (3GPP TS 25.331 Release 8)".
[i.14] ETSI TR 102 682: "Reconfigurable Radio Systems (RRS); Functional Architecture (FA) for the
Management and Control of Reconfigurable Radio Systems".
[i.15] O. Sallent, J. Pérez-Romero, P. Goria, E. Buracchini, A. Trogolo, K. Tsagkaris, P. Demestichas:
"Cognitive Pilot Channel: A Radio Enabler for Spectrum Awareness and optimized Radio
Resource Management", ICT Summit 2009.
[i.16] IEEE 802.11b: "Supplement to IEEE Standard for Information technology - Telecommunications
and information exchange between systems - Local and metropolitan area networks - Specific
requirements - Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY)
specifications: Higher-Speed Physical Layer Extension in the 2.4 GHz Band".
[i.17] IEEE 1900.6: "IEEE1900.6 Working Group on Spectrum Sensing Interfaces and Data Structure
for Dynamic Spectrum Access and other Advanced Radiocommunication Systems".
NOTE: Available at: http://grouper.ieee.org/groups/scc41/6/.
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
Cognitive Pilot Channel (CPC): channel which conveys the elements of necessary information facilitating the
operations of Cognitive Radio Systems
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Cognitive Radio System (CR): radio system, which has the following capabilities:
• to obtain the knowledge of radio operational environment and established policies and to monitor usage
patterns and users' needs;
• to dynamically and autonomously adjust its operational parameters and protocols according to this knowledge
in order to achieve predefined objectives, e.g. more efficient utilization of spectrum; and
• to learn from the results of its actions in order to further improve its performance.
NOTE 1: Radio operational environment encompasses radio and geographical environments, and internal states of
the Cognitive Radio System.
NOTE 2: To obtain knowledge encompasses, for instance, by sensing the spectrum, by using knowledge data base,
by user collaboration, or by broadcasting and receiving of control information.
NOTE 3: Cognitive Radio System comprises a set of entities able to communicate with each other (e.g. network
and terminal entities and management entities).
NOTE 4: Radio system is typically designed to use certain radio frequency band(s) and it includes agreed schemes
for multiple access, modulation, channel and data coding as well as control protocols for all radio layers
needed to maintain user data links between adjacent radio devices.
Software Defined Radio (SDR): radio in which the RF operating parameters including, but not limited to, frequency
range, modulation type, or output power can be set or altered by software, and/or the technique by which this is
achieved
NOTE 1: Excludes changes to operating parameters which occur during the normal pre-installed and predetermined
operation of a radio according to a system specification or standard.
NOTE 2: SDR is an implementation technique applicable to many radio technologies and standards.
NOTE 3: SDR techniques are applicable to both transmitters and receivers.
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AICPC Acquisition Indicator CPC
ANDSF Access Network Discovery and Selection Functions
ASM Advanced Spectrum Management
BCH Broadcast Channel
BSSID Basic Service Set Identifier
Cell-Id Cell Identity
CN Cognitive Network
CPC Cognitive Pilot Channel
CPICH Common Pilot Channel
CWN Composite Wireless Network
DBCPC Downlink Broadcast CPC
DDF Device Description Framework
DM Device Management
DNP Dynamic Network Planning
DODCPC Downlink OPn-Demand CPC
DSA Dynamic Spectrum Allocation
DVB-H Digital Video Broadcast - Handheld
ECA policy Event-Condition-Action policy
FDMA Frequency Division Multiple Access
FSM Flexible Spectrum Management
GPRS General Packet Radio System
GSM Global System for Mobile communications
JRRM Joint Radio Resource Management
L1 Layer 1 (physical layer)
L2 Layer 2 (data link layer)
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9 ETSI TR 102 683 V1.1.1 (2009-09)
LTE Long Term Evolution
MIH Multimedia Independent Handover
MIH-IS MIH Information Service
MO Management Objects
MT Mobile Terminal
O&M Operation and Maintenance
OMA Open Mobile Alliance
PLMN Public Land Mobile Network
RACPC Random Access CPC
RAN Radio Access Network
RAT Radio Access Technology
RF Radio Frequency
RR Radio Resource
RRM Radio Resource Management
RRS Reconfigurable Radio System
SDR Software Defined Radio
SSID Service Set IDentification
TDMA Time Division Multiple Access
TRx Transceiver
UE User Equipment
UMTS Universal Mobile Telecommunication System
WiFi Wireless Fidelity
NOTE: IEEE 802.11b [i.16] wireless networking.
WIMAX Worldwide Interoperability for Microwave Access
4 Cognitive Pilot Channel (CPC): Concept and
Motivation
In today's composite radio environment, where radio-communications are developing in such a way that more and more
services are proposed, with more and more various technologies and radio interfaces, a crucial point to enable
optimization of radio resource usage is appearing to be the cognitive capability of the network and terminal, in order to
switch to the most appropriate technology and frequency for the required service.
For instance, what is reported above becomes more relevant in a flexible spectrum management framework (where the
spectrum allocated to the different RATs is foreseen to change dynamically within a range of different frequencies).
The spectrum awareness arises as a basic challenge in a generic scenario, where a number of transceivers even with
flexible time-varying assignment of operating frequency and/or RAT are deployed. Spectrum awareness from the
mobile's perspective refers to the mechanisms allowing the terminal to obtain knowledge of the communication means
available at a given time and place, both at switch-on stage as well as during on-going operation.
In this context, collaboration between network and terminals is very important.
In order to provide such collaboration, the concept of a Cognitive Pilot Channel (CPC) has been developed [i.1] to [i.4].
CPC can be advantageous in different scenarios.
A mobile terminal may use the CPC during one or both of the following phases:
• "start-up" phase: turning on, the terminal detects (e.g. on one or more well-known frequencies) the CPC and
optionally could determine its geographical information by making use of some positioning system. The CPC
detection will depend on the specific CPC implementation in terms of the physical resources being used. After
detecting and synchronizing with the CPC, the terminal retrieves the CPC information corresponding to the
area where it is located, which completes the procedure. Information retrieved by the mobile terminal is
sufficient to initiate a communication session optimized to time, situation and location. In this phase, the CPC
delivers relevant information with regard to operators, frequency bands, and RATs in the terminal location.
During the start-up phase beginning at "switch on" of the mobile terminal, the mobile terminal is searching for
a candidate network to camp on.
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10 ETSI TR 102 683 V1.1.1 (2009-09)
• "ongoing" phase: as soon as the terminal is registered to (or "camped on") a network, it leaves the "start-up"
phase and is in the "on-going" phase situation. When the terminal is camped on to a network, a periodic check
of the information forwarded by the CPC may be useful to rapidly detect changes in the environment due to
either variations of the mobile position or network reconfigurations. In this phase, the same information of the
"start-up" phase could be delivered by the CPC with additional data, such as services, load situation, etc. The
ongoing phase ends when the mobile is no longer registered ("camped on") on any network.
The CPC can be advantageous in different various scenarios:
• In a first exemplary scenario, in order to obtain knowledge of the terminal radio environment, the sensing of
the parts of the spectrum within the considered reachable frequency range (e.g. from 400 MHz up to 6 GHz)
may be applied, but this could be a very time- and power-consuming operation. As an illustrative example,
assuming GSM channels in a total scanned bandwidth of 550 MHz, in [i.4] scanning times of around
450 seconds (only including layer 1 detection) are mentioned. In this context, CPC can convey the necessary
information to let the terminal know the status of radio channel occupancy through a kind of common pilot
channel. This could considerably decrease time and power consumption.
• In another exemplary scenario, a secondary system may be searching for secondary spectrum usage
opportunities to start communication. The CPC can be used to exchange sensing information between
terminals, as well as between terminals and base stations in order to perform collaborative/cooperative sensing.
This could greatly improve spectrum sensing characteristics, such as increase detection probability, reduce
detection time, etc.
• In the third exemplary scenario, network and terminals are in a state other than start-up. In this case CPC could
be used to provide necessary level of collaboration between network and terminals for a better support of
different RRM optimization procedures and for optional dynamic spectrum access and flexible spectrum
management.
For the purpose of these exemplary scenarios, two CPC deployment options can be considered. The first one, out-band
CPC, considers that a channel outside the bands assigned to component Radio Access Technologies provides CPC
service. The second one, in-band CPC, uses a transmission mechanism (e.g. logical channel) within the technologies of
the heterogeneous radio environment to provide CPC services. For further details and explanations please refer to
clauses 6 and 7.
Considering the definitions reported, the Table 1 below indicates in which situations, out-band and in-band CPC can be
applied, (where "OK" means possible situation and "NO" means impossible situation), considering "downlink only"
CPC and bidirectional CPC.
Table 1: CPC typology
Start-up Ongoing
out-band in-band out-band in-band
Downlink only OK NO OK OK
Bidirectional OK NO OK OK
NOTE: During the ongoing phase, the terminal may use the in-band CPC for bidirectional
communication, while, in parallel, may receive information delivered by the out-band CPC.

4.1 Baseline scenarios
4.1.1 Support for terminal at start-up phase
Figure 1 represents an example of the typical scenario of application of the out-band CPC: a heterogeneous or multi-
RAT context is shown. Switching on, the mobile communication terminal has not any knowledge of the most
appropriate RAT in that geographic area where it is located, or which frequency ranges the RATs existing in that
specific geographic area exploit.
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11 ETSI TR 102 683 V1.1.1 (2009-09)

Figure 1: Example of the out-band CPC application at terminal start-up
in the heterogeneous environment context
The mobile terminal will need to initiate a communication in a spectrum context which could be unknown due to
dynamic reallocation mechanisms (also encompassing Dynamic Spectrum Allocation (DSA) and Flexible Spectrum
Management (FSM) schemes), without requiring an excessive complexity .
In case the information about the service areas of deployed RATs within the considered frequency range reachable from
a cognitive radio mobile terminal is unavailable, it would be necessary for the terminal to scan the whole frequency
range in order to know the spectrum constellation. However, this is a huge power- and time-consuming effort, and
sometimes it might not even be effective, as in the "hidden-node" or in the "receive-only device" cases.
In this scenario, the mobile terminal could be provided with the sufficient information via a Cognitive Pilot
Channel (CPC), in order to initiate a communication session appropriately. The CPC delivers relevant information e.g.
available operators, RATs, etc. in the terminal location.
In principle, the CPC covers the geographical areas using a cellular approach. In each CPC-cell, information related to
the spectrum status in the cell's area is delivers, such as:
• indication on bands currently assigned to cellular-like and wireless systems (e.g. GSM, UMTS,
LTE/LTE-Advanced, WiMAX, DVB-H, WiFi); additionally, also pilot/broadcast channel details for different
cellular-like and wireless systems could be provided (e.g. BCH carrier for GSM system, CPICH carrier for
UMTS system, beacon channel for WiFi).
• indication on current status of specific bands of spectrum (e.g. used or not used).
4.1.2 Support for secondary spectrum usage
Figure 2 shows an example of using an out-band CPC for initiating secondary spectrum usage communication. Again,
heterogeneous and multi-RAT environment exists. Secondary system, including base stations
...