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)

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

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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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8 ETSI TR 102 683 V1.1.1 (2009-09)
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 and terminals, try to find
secondary spectrum usage opportunities and establish communication.
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12 ETSI TR 102 683 V1.1.1 (2009-09)

Bi-directional
out-band CPC
RAT j RAT k
RAT m
RAT n
Secondary system
Figure 2: Example of the bi-directional out-band CPC application for
secondary spectrum usage communication
To establish communication, secondary system needs to reliably detect secondary spectrum usage opportunities. After
that, secondary base stations need to start offering wireless access service to secondary terminals, for example, to start
transmitting some broadcast messages. Finally, secondary terminals need to connect to secondary base stations to start
communication. Due to strong regulatory restrictions on secondary access, such procedure in general case will be much
more time and power-consuming than described before procedure in the procedure of terminal start-up. A bi-directional
out-band CPC can play an important role to improve this procedure.
CPC could deliver information on frequency bands allowed/available for secondary access in this geographic region.
This will greatly decrease the time for spectrum sensing and also will ensure that secondary system adhere to the
regulatory framework.
After such information is acquired by the secondary system, secondary terminals and/or base stations need to perform
accurate spectrum sensing in the specified frequency bands. To reduce time for spectrum sensing and to increase its
accuracy cooperative/collaborative sensing is very advantageous. When this sensing method is used, distributed sensors
(terminals and/or base stations) need to exchange sensing information to increase sensing reliability and/or reduce time
required to perform the detection of secondary spectrum usage opportunities. A bi-directional out-band CPC could be
used as means for such sensing information exchange.
Finally, the bi-directional out-band CPC could be used by secondary base stations and terminals to decide which part of
the spectrum should be used for communication, if, for example, multiple spectrum opportunities are detected.
4.1.3 Support for radio resource usage optimization
In a system operating an out-band CPC in a dedicated frequency band(s), the bandwidth of such system is expected to
be not very high. The bandwidth should be enough for delivering medium- and long-term changes in the radio
environment and for occasional bi-directional communication during secondary system usage and radio resource
optimization mechanisms.
On the other hand, in heterogeneous wireless environment with optional dynamic spectrum access and flexible
spectrum management features, collaboration between network and terminals is essential for radio resource usage
optimization. Such collaboration will typically include exchange of context information, policies, etc between network
and terminals, where such exchange could occur on the short-term time scale. Bandwidth requirements in this case
could be too high for out-band CPC.
In this context, a possible alternative to the use of the out-band CPC could be the in-band CPC, conveying CPC
information using a transmission mechanism (e.g. a logical channel) in the same radio access technologies that are used
for the user data transmission, and allowing to bear information to both uplink and downlink.
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13 ETSI TR 102 683 V1.1.1 (2009-09)
In-band CPC will not fully substitute out-band CPC, rather both channels will complement each other.
4.2 Functionalities and features of the CPC
The CPC could offer the following functionalities and features:
1) helping the mobile terminal to select the proper network depending on the specific conditions (e.g. desired
services, RAT availability, interference conditions, etc.), even providing support to Joint Radio Resource
Management (JRRM), enabling a more efficient use of the radio resources;
2) helping the secondary system to establish communication by indicating frequency bands allowed/available for
secondary usage, by providing means for sensing information exchange during spectrum sensing, and by
assisting in secondary system start-up;
3) providing support for an efficient use of the radio resource by forwarding radio resource usage policies from
the network to the terminals;
4) providing means for exchange of context information, policies, etc between network and terminal management
entities for spectrum usage optimization;
5) providing support to reconfigurability by allowing the terminal to identify the most convenient RAT to operate
with and to download software modules to reconfigure the terminal capabilities if necessary;
6) providing support to knowledge gathering by helping the terminal identify the specific frequencies, operators
and access technologies in a given region without the need to perform long time and energy consuming
spectrum scanning procedures;
7) helping the network provider to facilitate dynamic changes in the network deployment by informing the
terminals about the availability of new RATs/frequencies, thus providing support to dynamic network
planning (DNP) and advanced spectrum management (ASM) strategies;
8) releasing the benefits of secondary trading and flexible use, both in technical and in economic terms;
9) providing information of the current status of specific spectrum bands (e.g. used or unused).
4.3 Possible advantages of the CPC
By considering a CPC as described above, the following advantages are pointed out:
• simplifying the RAT selection procedure;
• improving secondary system start-up procedure;
• avoiding a large band scanning, possibly simplifying the terminal implementation (physical layer) for
manufacturers;
• the CPC concept seems relevant for the implementation of DSA/FSM schemes;
• enabling collaboration between network and terminal management entities for spectrum usage optimization;
• the CPC concept as a download channel could be useful to the operator and user in a roaming scenario where it
could be necessary to download a new protocol stack to connect to the network.
Finally, the CPC is shown to be a relevant part of cognitive networks as the radio enabler to help the access of the user
terminals to the multi-component radio network.
5 CPC Contents Definition
Clause 5.1 describes a model on what kind of information is stored on network side followed by options of the
organization of CPC geographical related information in clause 5.2. Then the following clauses describe for different
CPC-deployment cases, which parts of that information are transmitted over the CPC via the air-interface.
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14 ETSI TR 102 683 V1.1.1 (2009-09)
5.1 Information Model on the information stored on network
side
A general information model on the information relevant for the CPC stored on network side is shown in figure3.

Figure 3: CPC database information model
The following fields are considered in the CPC database information model:
• Root: The root of the database.
• Operator: There can be several operators. For each operator, some operator information (e.g. the name of the
operator) as well as policies on operator level are stored.
• RAN: Each operator can have several al radio access networks (RANs).
• Each RAN has a Radio Access Technology Type (RAT_TYPE), e.g. "GSM" "UMTS", "CDMA2000",
"WiMAX", "LTE", etc.
• Additionally, a Network-ID is stored for each RAN. This Network-ID can include e.g. the PLMN-identity in
case of GSM or UMTS or the SSID in the case of WiFi.
• Further on, policies on RAN level can also be included.
• Cell: Each RAN can have several cells. For each cell, the Cell-Id (e.g. Cell-identity for UMTS or BSSID in the
case of WiFi), the geographical location of the center of the cell (e.g. longitude, latitude), the cell-size,
frequency, cell-capabilities (e.g. cell capacity) and cell-status (including e.g. cell-load) can be stored.
• Further on, policies on cell level can also be included.
Policies are defined by the operator and are related to the operator's strategy regarding the management of traffic load
and radio resource and spectrum usage optimization, with respect to user's demands.
Moreover, some sensitive information may not be available in certain use cases.
5.2 Organization of CPC geographical related information
There is a need to organize the information delivered over the CPC according to the geographical area where this
information applies.
A difference can be made between two options differing on how they provide geographical related information:
• Mesh-based approach: The geographical area is divided in small zones, called meshes. In that case the CPC
should provide network information for each one of these meshes, being possibly transmitted over a wide zone
and therefore including a lot of meshes. Initial requirements evaluations seem to conclude that this solution
could require a very high amount of bandwidth.
• Coverage area approach: In this approach, the concept of mesh is not needed in defining the CPC content, and
the coverage area is provided for the different RATs. The following items could be provided in this approach:
operator information, related RATs and for each RAT, corresponding coverage area and frequency band(s)
information.
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15 ETSI TR 102 683 V1.1.1 (2009-09)
5.2.1 Mesh-based approach
In this approach, the CPC operates in a certain geographical area subdivided into meshes [i.4]. A mesh is defined as a
region where certain radio electrical commonalities can be identified (e.g. a certain frequency that is detected with a
power above a certain level in all the points of the mesh, etc.). The mesh is univocally defined by its geographic
coordinates, and its adequate size would depend on the minimum spatial resolution where the above commonalities can
be identified. The concept is illustrated in figure 4, where, for simplicity, square meshes of identical dimension have
been considered, although other approaches could exist based on e.g. dynamic definition of meshes with an adaptive
size.
Figure 4: CPC mesh-based approach
It can be logically inferred that there will be very likely little variations of the CPC information when moving from a
given mesh to a neighbouring one. From this observation, a possible optimized implementation of the concept to reduce
the required CPC bandwidth could be considered. The base station transmits all the information of a reference mesh and
for the other meshes the network would send the identifier of the reference mesh together with the delta CPC
information. The delta CPC information stands for the pieces of CPC information which differ from the information
corresponding to the reference mesh. This includes operators, RAT's and frequencies that appear or disappear in the
present mesh with respect to the reference mesh. The network may determine the reference mesh as the one having the
most commonalities in terms of CPC content. The mobile terminal infers the CPC information by decoding the
information of the reference mesh and the delta CPC information corresponding to the mesh in which it is located.
5.2.2 Coverage area approach
In this approach the CPC content for a given geographical zone is organized taking into account the area, under-laying
CPC umbrella, where such information has to be considered valid.
For instance, in case the CPC information is related to availability of operator/RAT/frequency, as in Figure 2, the CPC
content will be organized e.g. per coverage area of each RAT.
It is worth to be noted that knowing the position of the mobile terminal is not a strict requirement for the CPC operation
using this approach, but a capability that enables higher efficiency in obtaining knowledge:
• in case positioning is not available, as long as the mobile terminal is able to receive the CPC information, the
information about the different regions in that area are available;
• in case positioning is available, a subset of the information at the actual position could be identified. The
mobile terminal could then use that information.
[RAT, f, BW]
CPC TRx
[RAT (t), f (t)]
3 3
[RAT (t), f (t)]
2 2
[RAT (t), f (t)]
1 1 ??
Figure 5: Example of CPC coverage area based approach
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16 ETSI TR 102 683 V1.1.1 (2009-09)
5.3 CPC contents to support terminal start-up
5.3.1 Content in the case of mesh-based approach
The information conveyed in the CPC for a given mesh is shown in [i.4]. In particular, for each mesh, location
information indicating the geographic coordinates is transmitted.
Similarly, the CPC indicates the list of available operators in the mesh, including, for each operator, the available RATs
and the corresponding frequency ranges per RAT (figure 6). In addition to this basic information, other optional
terminal-dependent aspects such as maximum transmitted power levels allowed depending on e.g. whether the terminal
is indoor or outdoor could also be included in the CPC.
The mesh-based approach has been evaluated and in some cases could require bit rate values in the order of hundreds of
Kbit/s (see [i.5]).
Figure 6: CPC information to be sent for each individual mesh [i.4]
5.3.2 Content in the case of coverage area approach
The structure of the basic CPC message to be conveyed is reported in figure 7.

OPERATOR_INFO
RAT_TYPE = GSM, UMTS,
WiMAX, LTE…
RAT_LIST
COVERAGE_EXTENSION
= LOCAL/GLOBAL
COVERAGE_AREA
(optional)
FREQ_LIST
Figure 7: CPC message structure
The following fields are considered in the CPC message structure. In the case of CPC Out-band solution, all the fields
reported below are considered. The structure includes:
• Operator information: operator identifier. This information is repeated for each Operator to be advertised by
the CPC.
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17 ETSI TR 102 683 V1.1.1 (2009-09)
• RAT list: for each operator, provide information on available RATs. This information is repeated for each RAT
of i-th Operator.
- RAT type: could be for instance "GSM", "UMTS", "CDMA2000", "WiMAX", "LTE", etc.
- Coverage extension: could be GLOBAL (i.e. wherever the CPC is received) or LOCAL (i.e. in a area
smaller than CPC coverage).
- Coverage area: to be provided in case of LOCAL coverage (e.g. reference geographical point).
- Frequency information: provide the list of frequencies used by the RAT.
In the case of CPC In-band solution, other fields could be added to the reported ones. Such fields could include Policies,
Context Information, etc.
Taking into account the same assumptions used for evaluating the mesh-based approach in [i
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