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3 List of IGCs
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0 General
Coordinator: Alain Sultan, MCC ([email protected])
Site: ftp://ftp.3gpp.org/TSG_SA/WG2_Arch/IGC
1 Bearer Services and QoS
Chair: Oscar Lopez-Torres, T-Mobil ([email protected])
Site: ftp://ftp.3gpp.org/TSG_SA/WG2_Arch/IGC/Bearer&QoS
reflector address: 3GPP_TSG_SA_IGC_Bearer&[email protected]
2 GSM/UMTS Interoperation and Mobility Management
Chair: François Courau, Alcatel ([email protected])
Site: ftp://ftp.3gpp.org/TSG_SA/WG2_Arch/IGC/GUinterop&MM
reflector address: 3GPP_TSG_SA_IGC_GUinterop&[email protected]
3 Location based services (LCS) and Cell Broadcast Services (CBS)
Chair: - LCS: Jan Kåll, Nokia ([email protected])
- CBS: Martin Güntermann, Mannesmann
Site: ftp://ftp.3gpp.org/TSG_SA/WG2_Arch/IGC/LCS
reflector address: [email protected]
4 Packet Architecture and Circuit Architecture
Chair: Ulrich Dropmann, Siemens ([email protected])
Site: ftp://ftp.3gpp.org/TSG_SA/WG2_Arch/IGC/PS&CS
reflector address: 3GPP_TSG_SA_IGC_PS&[email protected]
5 Security
Chair: Chris Pudney, Vodafone ([email protected])
Site: ftp://ftp.3gpp.org/TSG_SA/WG2_Arch/IGC/Security
reflector address: [email protected]
6 Services and Service platforms
Chair: Rob Schmersel, Ericsson ([email protected])
Site: ftp://ftp.3gpp.org/TSG_SA/WG2_Arch/IGC/Services
reflector address: [email protected]
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4 Scope of the IGCs
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4.1 Bearer Services and QoS
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[editor's note: the scope has to be revised to reflect more clearly that the IGC is only supervising the groups and not providing the actual technical work]
The scope is to provide a consistent definition of the Services and Bearer Services mapping throughout the system: UMTS bearers, bearer management in the control and user planes, for the circuit switched and packet domains.
Regarding QoS, the scope is to provide a comprehensive QoS model and mapping of parameters for the different interfaces, reference points, and layers (a two-dimensional approach) throughout the system.
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4.2 GSM/UMTS Interoperation and Mobility Management
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[editor's note: to be further elaborated by the IGC chairman]
Consistent UMTS/GSM interoperation
Mobility handling within the system, RRC and MM interaction, MAP, consistent mobility management
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4.3 Location based services (LCS) and Cell Broadcasting Services(CBS)
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The UMTS LCS and CBS inter group co-ordination ad hoc group shall co-ordinate the work on location services in UMTS and ensure that all 3GPP groups relevant for location services get involved in a timely manner. The ongoing work in T1P1.5 on GSM LCS Phase II shall be taken in account as well.
The UMTS LCS and CBS inter group co-ordination ad hoc group shall also co-ordinate the work on cell broadcasting services in UMTS and ensure that all 3GPP groups relevant for cell broadcasting services get involved in a timely manner.
The LCS and CBS ad hoc group shall evaluate the UMTS location services and cell broadcast services in order to identify what issues are to be standardized and what are the appropriate Work Groups for this and set up a time plan for the work.
The Location services feature in UMTS is mainly a release 2000 issue, but the LCS and CBS ad hoc shall also seek to identify what LCS system functions should be included in Release 99 and the affected WGs and specifications.
The Cell Broadcast Service (CBS) is a release 99 requirement and shall be provided seamlessly (as far as the user or the users terminal equipment is concerned) across the UMTS and GSM network in order to guarantee the continuity of the corresponding GSM services in UMTS.
LCS and CBS ad hoc reports to TSG SA WG2.The UMTS LCS IGC shall coordinate the work on location services in UMTS and ensure that all 3GPP groups relevant for location services get involved in a timely manner. The ongoing work in T1P1.5 on GSM LCS Phase II shall be taken in account as well.
The LCS IGC shall evaluate the UMTS location services in order to identify what issues are to be standardized and what are the appropriate Work Groups for this and set up a time plan for the work.
LCS in UMTS is mainly a release 2000 issue, but the LCS IGC ad hoc shall also seek to identify what LCS system functions should be included in Release 99 and the affected WGs and specifications.
LCS IGC ad hoc reports to TSG SA WG2.
Locationing and the location based services shall be considered.
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4.4 Packet Architecture and Circuit Architecture
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The technical scope of the “packet and circuit architecture IGC” is to work on the architecture of the packet and circuit domain and protocols.
It contains the following main areas:
1. The identification of new entities and interfaces of the overall system architecture
2. The determination of the principle protocol stacks of the user and control plane
3. Call control/session management related control plane issues
Examples of issues are of the area of “packet and circuit architecture” are (without indication of whether R99 and R00 issue):
• Multimedia architectural issues
• Multicall issues
• Location of the transcoder in the core network
• Identification of new interworking scenarios
• Evolving interworking functions to other networks
• Control plane architecture of the UTRAN
Not part of the “packet and circuit architecture” area are
architectural questions clearly associated with one of the other technical areas (Location Based Services, Services and Service platforms, Mobility Management&GSM/UMTS interoperation, Security, Bearer&QoS).
The IP/packet domain architecture and protocols
The PSTN/ISDN domain architecture and protocols
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4.5 Security
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This ad hoc group is intended to produce, maintain and monitor the work plan for the delivery of a consistent security specifications for release 99.
The work items being progressed in TSG-S3 are listed in the table below. Each work item addresses a particular security issue and is assigned a particular priority which includes whether or not the feature or mechanism should be specified in Release 99. This table is an updated version of a table presented to TSG-S#4 in Tdoc SP-99284.
Table 2 : Priorities of security work items assigned by TSG-S3
Work item
Priority
1
User identity confidentiality
The specification of an enhanced mechanism to help guard against active attacks against user identity confidentiality on the radio interface is essential in R99. Note that only the transport mechanism needs to be specified. The exact mechanism to protect the user identity can be home operator dependent. The specification of algorithm requirements and interfaces is also essential for R99, although the algorithms themselves can be home operator dependent and do not need to be specified.
2
Authentication and key agreement
The specification of an enhanced mechanism to help guard against active attacks on the radio interface is essential for R99. Furthermore, the specification of algorithm requirements and interfaces is also essential for R99, although the algorithms themselves can be home operator dependent and do not need to be specified.
3
Access link integrity protection
This is a new security mechanism in UMTS introduced to help guard against active attacks on the radio interface. The specification of the message authentication mechanism is essential in R99.
4
Access link confidentiality
The GSM ciphering mechanism cannot be used in the new access network and the GSM algorithms are unsuitable. The specification of a new ciphering mechanism and algorithm is essential in R99.
5
Network-wide encryption
Appropriate ‘hooks’ must be provided in the R99 specification so that network-wide encryption can be introduced in later releases. It may be possible to re-use the algorithm for ciphering in the UTRAN. If a new algorithm is required then its specification can be left to later releases providing that appropriate ‘hooks’ are incorporated into the R99 specification.
6
User equipment identification
TSG-S have recommended that TSG-S3 specify a secure mechanism in R99. The mechanism will require manufacturers to secure terminal identities and associated authentication data.
7
Core network signalling security
Although this is a high priority item, it is recognised that implementable specifications might not be achievable in R99. A cipher algorithm designed by ETSI SAGE for this purpose called BEANO is already available. Off-the-shelf algorithms are likely to be suitable for the message authentication functions.
8
Fraud information gathering system
The GSM mechanism can be used. Enhancements will be considered in later releases.
9
USIM application security
The GSM mechanisms can be used. Enhancements will be considered in later releases.
10
Visibility and configurability
An encryption indicator should be included in R99. Other items are of lower priority and will be considered in later releases.
11
Mobile Execution Environment Security
The GSM mechanisms will be enhanced in R99.
12
Location services
Specification of privacy mechanism is essential in R99. Can be largely based on GSM Location Services privacy mechanisms.
13
Lawful interception architecture
The specification of a lawful interception architecture is essential in R99. This architecture can be largely based on the GSM/GPRS architecture.
14
IP security
Impact not fully understood. Priority is unclear.
Owing to the requirements for both CS and PS ‘handover’ between UMTS and GSM and to the requirements to be able to perform roaming between GSM and UMTS networks, for all these items, dual mode UMTS/GSM operational aspects need to be considered.
Consistent security architecture
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4.6 Services and Service platforms
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The 3GPP Services and Service Platforms IGC is responsible for the following activities:
• establish a common understanding in 3GPP of the VHE and OSA work to be carried out for stage2 and 3 in 3GPP Release99;
• identify the appropriate working groups for carrying out the VHE and OSA work and ensure these groups get involved in a timely manner;
• coordinate the work on VHE and OSA in 3GPP;establish a time plan for the work.
WAP, VHE, Camel, OSA, Mexe, the consistent service and service generation platform concept
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5 Overall time plan
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[Ed. note: scope to be provided by the rapporteur]
Meeting
Date
Activity
SA2#9
October 25-29, 1999
Define overall workplan. Start work on identifying requirements and issues related to architectural and functional aspects as compared to R99 (TR 23.ywz)
SA2#10
Nov 29 –Dec 3, 1999
Identify additional requirements from architectural and functional aspects as compared to R99 (TR 23.ywz). Start definition of R00 documents.
SA1#6
Nov 29 - Dec 3, 1999
Start work on R00 Stage 1
SA#6
December 15-17, 1999
R99 finalized.
SA2#11
January 24-28, 2000
Refined version of TR. Review draft Stage 1 description. Start Project Plan work. Continue definition of R00 documents.
SA1#7
Feb 7-11, 2000
Refine R00 stage 1.
SA2#12
March 6-9, 2000
TR v 1.0.0. Review R00 Stage 1 description . Continue Project Plan work. Finilize definition of R00 documents. Based on the TR, start the CR process for S2’s technical specifications.
SA#7
March 15-17, 2000
R00 Stage 1 stable.
SA2#13
May 22-26, 2000
Work on TR discontinued. Finalize Project Plan work. Finalize definition of R00 documents. Continue the CR process.
SA#8
June 21-23, 2000
R00 Stage 2 at least 80% complete. Project Plan approved. Definition of R00 documents approved.
SA2#14
September 4-8, 2000
Finilize R00 Stage 2 work.
SA#9
September 27-29, 2000
R00 work approved.
SA2#15
November 13-17, 2000
Start R01 work.
SA#10
December 13-15, 2000
R00 approved.
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6 Change history
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Version
Date
Subject/Comments
0.0.0
July 1999
Creation of document
0.1.0
August 1999
Inclusion of comments from SA2#7
0.2.0
September, 4th 1999
Inclusion of results from SA2#8: addition of scope of IGC Security, Bearer and QoS, PS and CS architecture, Services and Service Platform, LCS.
0.3.0
September, 23rd 1999
Addition of the chapter 3, deletion of the Annex on "Proposed Structure for all Inter Group Co-ordination work plans"
1.0.0
October, 7th 1999
Prepared for presentation to TSG SA#5 (content identical to v.0.0.3, except for some minor editorial corrections)
1.1.0
December, 2nd 1999
Addition of Overall time plan (as agreed in S2-99C16) and incorporation of BCS material
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3 Indicates TSG approved document under change control.
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y the second digit is incremented for all changes of substance, i.e. technical enhancements, corrections, updates, etc.
z the third digit is incremented when editorial only changes have been incorporated in the specification;
2 Introduction
The present document shall provide a work plan and study items as agreed within the 3GPP TSG RAN working group 4.
For the FDD mode, as proposed in the input paper of R4-99160 the items shown in that document absolutely need to be finalised by the Japanese regulatory organisation, Telecommunications Technical Council of Japan, by the end of June 1999 so that MPT will be able to legislate on schedule for the regulation for the 3G system of Japan.
For the TDD mode, some deviations in achieving the intermediate milestones are shown, compared to FDD. However, it is strictly intended to have the same final milestone kept for TDD as for FDD..
3 Meeting Schedule
The milestones used in this document are based on the following meeting schedule.
Year 1999
WG4 #4 : May 10 – May 12, Kista Stockholm, Sweden
WG4 #5 : June 14 – June 16, Miami Florida, USA
RAN #4 : June 17 – June 18, ditto
WG4 #6 : July 26 – July 29, South Queensferry Scotland, UK
WG4 #7 : September 7 – September 10, Makuhari Chiba, Japan
RAN #5 : October 6 – October 8, Kyongju, Korea
WG4 #8 : October 26 – October 29, Sophia Antipolis, France
WG4 #9 : December 6 7 – December 910, Bath, UK
RAN #6 : December 15 13 – December 1715, Sophia AntipolisNice, France
Year 2000
WG4 #10 : January 18 – January 21, San Jose, California, USA
WG4 #11 : February 28 – March 3, TBD
RAN #7 : March 13 – March 15, Madrid, Spain
WG4 #12 : May 22 – May 26, TBD
RAN #8 : June 19 – June 21, Dusseldorf, Germany
WG4 #13 : September 11 – September 16, TBD
RAN #9 : September 25 – September 27, TBD
WG4 #14 : November 27 – November 30, TBD
RAN #10 : December 11 – December 13, TBD, USA
Note that some of the future meetings have been re-scheduled.
4 Work Plan
Table 4 shows the agreed work plan for the TSG RAN WG4 and document status as well as of the issuance of this document.
Table 4:Work Plan
Specification number
WG4 #4
WG4 #5
RAN #4
WG4 #6
WG 4 #7
RAN #5
WG4 #8
WG4 #9
RAN #6
Remarks
25.101 - UE TX & RX (FDD)
1
2
3
25.104 - BTS TX & RX (FDD)
1
2
3
25.102 - UE TX & RX (TDD)
1
2
3
(1)
25.105 - BTS TX & RX (TDD)
1
2
3
(1)
25.103 - RF parameters
1
2
3
(2), (3)
25.133 - Support of RF parameters in Radio Resource Management (FDD)
2
3
(3)
25.123 - Support of RF parameters in Radio Resource Management (TDD)
2
3
(3)
25.141 - BS Conformance Test (FDD)
1
2
3
25.142 - BS Conformance Test (TDD)
1
2
3
25.113 - BS EMC
1
2
3
(2)
25.941 - Document Structure
1
2
3
25.942 - RF System Scenarios
1
2
3
Notes:
• 1 means the document is agreed as version 1.0.0 at RAN WG4
• 1 (underlined) means the document has already been agreed as version 1.0.00 at RAN WG4
• 2 means the document is agreed as version 2.0.0 at RAN WG4
• 2 (underlined) means the document has already been agreed as version 2.0.0 at RAN WG4
• 3 means the document is approved as version 3.0.0 at TSG RAN
• 3 (underlined) means the document has already been approved as version 3.0.0 at TSG RAN
• The version numbers must be understood based on the explanation in the section 8 “Document/version numbering” of the Report of the TSG-RAN meeting #3 [RP-99305].
(1) Milestone for version 3 has been brought in to be in line with PCG#2(99)21 in ver 1.1.0.
(2) (2) Agreed at the WG4 #7 meeting to push back the milestone for version 3 as seen in the table.
(3) Agreed at the WG4 #8 meeting to split 25.103 into two separate specifications, which are 25.133 for FDD and 25.123 for TDD.
5 Study Item
A table “Study Items for 25.xyz” shows all the items that have not been agreed or are tbd in that particular document as of the issuance of this 30.504 document. A mark X indicates that the marked item needs to be agreed and fixed by the indicated milestone. Moreover, X-marked milestones for the FDD mode are absolute deadlines.
5.1 25.101 (UE TX & RX for FDD)
Table 5-1 shows the agreed study items for the 25.101 specification document.
Table 5-1:Study Items for 25.101
Items
WG4 #4
WG4 #5
RAN #4
WG4 #6
WG 4 #7
RAN #5
WG4 #8
WG4 #9
RAN #6
Remarks
Frequency Bands and Channel Assignment
• TX-RX frequency separation
X
TX characteristics
• Max output power
X
• Closed loop power control in DL
X
• Power control steps
X
• Adjacent Channel Leakage Ratio (ACLR)
X
(1)
• Modulation Accuracy
X
• Peak code Domain error
X
RX characteristics
• Static reference sensitivity level
X
• Maximum input level
X
• Adjacent Channel Selectivity (ACS)
X
• Blocking characteristics
X
• Spurious response
X
• Intermodulation characteristics
X
Performance Requirement
• Test Environment (Packet switched data)
X
• Demodulation in non fading channel
X
• Demodulation of DTCH
X
• Inter-cell Soft Handover
X
• RX Synch. Characteristics
X
• Timing Characteristics
X
Notes:
• (1) Milestone was moved from WG4 #4 to WG4 #5 in ver 0.0.2.
5.2 25.104 (BTS TX & RX for FDD)
Table 5-2 shows the agreed study items for the 25.104 specification document.
Table 5-2:Study Items for 25.104
Items
WG4 #4
WG4 #5
RAN #4
WG4 #6
WG 4 #7
RAN #5
WG4 #8
WG4 #9
RAN #6
Remarks
Frequency Bands and Channel Assignment
• TX-RX frequency separation
X
TX characteristics
• BS Max output power
X
Extreme conditions
• Frequency Stability
X
• Output Power Dynamics
X
• Adjacent Channel Leakage Ratio (ACLR)
X
• Spurious Emissions
X
• Transmit Intermodulation
X
• Modulation Accuracy
X
• Peak code Domain error
X
RX characteristics
• Reference Sensitivity level
X
• Maximum frequency Deviation for Receiver Performance
X
• Dynamic Range
X
• Adjacent Channel Selectivity (ACS)
X
• Blocking characteristics
X
• Spurious response
X
• Intermodulation characteristics
X
• Spurious Emissions
X
Performance Requirement
• Performance in AWING Channel
X
• Performance in Multipath Fading Channels
X
5.3 25.102 (UE TX & RX for TDD)
Table 5-3 shows the agreed study items for the 25.102 specification document.
Table 5-3:Study Items for 25.102
Items
WG4 #4
WG4 #5
RAN #4
WG4 #6
WG 4 #7
RAN #5
WG4 #8
WG4 #9
RAN #6
Remarks
Frequency Bands and Channel Assignment
• Frequency Bands
X
TX characteristics
• Max output power
X
• UE frequency stability
X
• Open loop power control UL
X
• Closed power control UL
X
• Power control steps
X
• Power control cycles per second
X
• Minimum transmit output power
X
• Transmit on/off ratio/DTX
X
• Adjacent Channel Leakage Ratio (ACLR)
X
• Transmit intermodulation
X
• Modulation Accuracy
X
RX characteristics
• Static reference sensitivity level
X
• Maximum input level
X
• Adjacent Channel Selectivity (ACS)
X
• Blocking characteristics
X
• Spurious response
X
• Intermodulation characteristics
X
• Spurious emissions
X
Performance Requirement
• Test Environment
X
• Demodulation in non fading channel
X
• Demodulation of PCH/FACH/DTCH
X
• Multi-Link Performance
X
• RX Synch. Characteristics
X
• Interfrequency handover
X
• Timing Requirements
X
5.4 25.105 (BTS TX & RX for TDD)
Table 5-4 shows the agreed study items for the 25.105 specification document.
Table 5-4:Study Items 25.105
Items
WG4 #4
WG4 #5
RAN #4
WG4 #6
WG 4 #7
RAN #5
WG4 #8
WG4 #9
RAN #6
Remarks
Frequency Bands and Channel Assignment
• Frequency Bands
X
TX characteristics
• Max output power
X
Extreme Conditions
• UE Frequency Stability
X
• Open Loop Power Control UL
X
• Closed Power Control UL
X
• Power control steps
X
• Power Control Steps per Second
X
• Minimum Transmit Output Power
X
• Transmit on/off ratio/DTX
X
• Adjacent Channel Leakage Ratio (ACLR)
X
• Intermodulation Characteristics
X
• Modulation Accuracy
X
RX characteristics
• Static reference sensitivity level
X
• Maximum input level
X
• Adjacent Channel Selectivity (ACS)
X
• Blocking characteristics
X
• Spurious response
X
• Intermodulation characteristics
X
• Spurious Emissions
X
Performance Requirement
• Test Environment
X
• Demodulation in non fading channel
X
• Demodulation of PCH/FACH/DTCH
X
• Multi-Link Performance
X
• RX Synch. Characteristics
X
• Interfrequency handover
X
• Timing Characteristics
X
5.5 25.103 (RF Parameters)
Table 5-5 shows a first draft proposal for an updated version of study items for the 25.103 specification document.
Table 5-5:Study Items for 25.103
Items
WG4 #4
WG4 #5
RAN #4
WG4 #6
WG 4 #7
RAN #5
WG4 #8
WG4 #9
RAN #6
Remarks
Idle Mode Tasks (FDD)
Cell Selection Scenario
• Cell selection delay – Text
X
• Cell selection delay - Value
X
Cell Re-Selection Scenario
• Cell re-selection delay – Text
X
• Cell re-selection delay – Value
X
• Cell List Size – Text
X
• Cell List Size – Value
X
• Maximum number of cells to be monitored – Text
X
• Maximum number of cells to be monitored – Value
X
• Cell Re-selection reaction time – Text
X
• Cell Re-selection reaction time – Value
X
RF Parameters used for Cell Re-Selection
X
PLMN Selection and Re-Selection Scenario – Text
X
PLMN Selection and Re-Selection Scenario – Values
X
Location Registration Scenario – Text
X
Location Registration Scenario – Values
X
Idle Mode Tasks (TDD)
Cell Selection Scenario
• Cell selection delay – Text
X
• Cell selection delay - Value
X
Cell Re-Selection Scenario
• Cell re-selection delay – Text
X
• Cell re-selection delay – Value
X
• Cell List Size – Text
X
• Cell List Size – Value
X
• Maximum number of cells to be monitored – Text
X
• Maximum number of cells to be monitored – Value
X
• Cell Re-selection reaction time – Text
X
• Cell Re-selection reaction time – Value
X
• RF Parameters used for Cell Re-Selection
X
PLMN Selection and Re-Selection Scenario – Text
X
PLMN Selection and Re-Selection Scenario – Values
X
Location Registration Scenario – Text
X
Location Registration Scenario – Values
X
RRC Connection Mobility
Handover 3G to 3G
FDD Soft/Softer Handover
• Maximum number of cells to be monitored – Text
X
• Maximum number of cells to be monitored – Value
X
• Measurement reporting delay – Text
X
• Measurement reporting delay – Value
X
• Active set dimension – Text
X
• Active set dimension – Value
X
• Active set update time interval – Text
X
• Active set update time interval – Value
X
• Frame offset Measurement Accuracy – Text
X
• Frame offset Measurement Accuracy – Value
X
FDD Inter-Frequency Handover
• Maximum number of cells/frequencies to be monitored – Text
X
• Maximum number of cells/frequencies to be monitored – Value
X
• Measurement reporting delay – Text
X
• Measurement reporting delay – Value
X
• Frame offset Measurement Accuracy – Text
X
• Frame offset Measurement Accuracy – Value
X
FDD/TDD Handover
• Requirements –Text
X
• Requirements - Values
X
• RF Parameters
X
TDD/TDD Handover
• Requirements –Text
X
• Requirements- Values
X
• RF Parameters
X
Radio Link Management
Link adaptation
• Link adaptation delay minimum requirement – Value
X
• Link adaptation accuracy minimum requirement – Value
X
Cell Update
X
URA Update
X
Admission Control (FDD)
X
Admission Control (TDD)
X
Radio Access Bearer Control (FDD)
X
Radio Access Bearer Control (TDD)
X
Dynamic Channel Allocation (FDD)
X
Dynamic Channel Allocation (TDD)
X
Radio Link Surveillance (FDD)
X
Radio Link Surveillance (TDD)
X
Radio Link Measurement Requirements – Text
X
Radio Link Measurement Requirements – Values
X
Radio Link Failure Requirements – Text
X
Radio Link Failure Requirements – Values
X
[Editor’s note: The above table was developed by the editor of the TS 25.103.]
5.6 25.141 (BS Conformance Test for FDD)
Table 5-6 shows the identified study items for the 25.141 specification document.
Table 5-6:Study Items for 25.141
Items
WG4 #4
WG4 #5
RAN #4
WG4 #6
WG 4 #7
RAN #5
WG4 #8
WG4 #9
RAN #6
Remarks
General test conditions and declarations
• BTS Configurations
X
Transmitter
• Base station maximum output power
X
• Frequency stability
X
• Clock Frequency accuracy
X
• Output power dynamics
X
• Transmitted RF carrier power versus time
X
• Output RF spectrum emissions
X
• Transmit intermodulation
X
Receiver characteristics
• General
X
• Test conditions and measurement methods
X
• Dynamic range
X
• Adjacent Channel Selectivity (ACS)
X
• Blocking characteristics
X
• Spurious response
X
• Spurious emissions
X
Performance requirement
• BS Dynamic reference sensitivity performance
X
[Editor’s note: The above table was developed by the editor based on the open item list included in TS 25.141 V1.0.4.]
5.7 25.142 (BS Conformance Test for TDD)
Table 5-7 shows the identified study items for the 25.142 specification document.
Table 5-7:Study Items for 25.142
Items
WG4 #4
WG4 #5
RAN #4
WG4 #6
WG 4 #7
RAN #5
WG4 #8
WG4 #9
RAN #6
Remarks
Transmitter characteristics
• Maximum output power
X
• Frequency stability
X
• Output power dynamics
X
• Transmitted ON/OFF ratio
X
• Output RF spectrum emissions
X
• Transmit intermodulation
X
• Modulation accuracy
X
Receiver characteristics
• Reference sensitivity level
X
• Dynamic range
X
• Adjacent Channel Selectivity (ACS)
X
• Blocking characteristics
X
• Spurious response
X
• Intermodulation characteristics
X
• Spurious emissions
X
• Timing advance (TA) requirements
X
Performance requirement
• Dynamic reference sensitivity performance
X
[Editor’s note: The above table was developed by the editor of the TS 25.142.]
5.8 25.113 (BS EMC)
Table 5-8 shows the identified study items for the 25.113 specification document.
Table 5-8:Study Items for 25.113
Items
WG4 #4
WG4 #5
RAN #4
WG4 #6
WG 4 #7
RAN #5
WG4 #8
WG4 #9
RAN #6
Remarks
Definitions, symbols and abbreviations
• Definition of: Loss of service & Loss of call
X
• Definition of:Transient phenomena & Continuous phenomena
X
Test Conditions
X
Performance Assessment
X
Performance Criteria
• Number of tests
X
• Self recovery
X
Applicability Overview
X
[Editor’s note: The above table was developed by the editor based on the open item list included in TS 25.113 V1.1.1.]
6 Open Item for Release 1999
A table in the following sub-sections shows all the open items that have been agreed in each specification document as of the issuance of the most updated documents. The contents are subject to change depending on further studies.
6.1 TS25.101 (UE TX & RX for FDD)
Table 6-1 shows the identified open items for the 25.101 specification document.
Table 6-1:Open Items for 25.101
Section number
Section description
Status
3.1
Definitions
Definition of average power ….
5.2
Frequency bands
The deployment of TDD in the 1920 MHz to 1980 MHz band is an open item
6.6.2.2
Adjacent Channel Leakage power Ratio (ACLR)
The possibility is being considered of dynamically relaxing the ACLR requirements for User Equipment(s) under conditions when this would not lead to significant interference (with respect to other system scenario or UMTS operators). This would be carried out under network control, primarily to facilitate reduction in UE power consumption.
6.4.2.1.1
Power control steps minimum requirement
The timing requirement for power control steps is FFS
6.4.2.1.1
Power control steps minimum requirement
The current text does not cover the case where a power command is a multiple of the step size defined in 6.4.3
RAN WG1 is currently;
• Analyzing the benefits of introduction of smaller step sizes (<1 dB>as an option
• Investigating the benefits of emulated step size which imply that changes in the output power occurs at a rate lower than the one defined in 6.4.5
6.8.3
Peak code domain error
Outstanding
7
Receiver characteristic
All tables need change due to harmonization and changes to the downlink measurement channels in measurement. Note that the requirements are unchanged.
6.2 TS25.104 (BTS TX & RX for FDD)
Table 6-2 shows the identified open items for the 25.104 specification document.
Table 6-2:Open Items for 25.104
Section number
Section description
Status
6.2.1
Base station max output power
Minimum requirement in extreme conditions is ffs.
6.3
Frequency accuracy
Should there also be an accuracy requirement on the clock rate? Alternatives are to either tie the clock rate to the frequency accuracy or to have a separate clock rate requirement.
6.4.2
Power control dynamic range
The need for this parameter to be specified should be confirmed.
The power control dynamic range necessary as a minimum requirement needs to be reviewed.
6.4.3
Total power dynamic range
The total power dynamic range necessary as a minimum requirement needs to be reviewed.
6.4.5
Primary CPICH power
Value is TBD. Details of the path loss estimation method is under study in WG1.
6.6.1
Occupied bandwidth
Measurement bandwidth for the total integrated power is ffs.
Is this section still required?
6.6.2.3
Protection outside a licensee’s frequency block
This requirement needs to be reviewed in content and application, since it is a regional requirement (FCC part 24.)
The current text is based closely on FCC part 24. It may be possible to clarify the requirement (to allow more consistent testing) by including parameters which are specific to UTRA, including:
• defining requirement as an absolute value.
• Defining the minimum carrier spacing from the edge of the licensee’s frequency block.
• Defining the –26dB bandwidth of the emission.
Defining the resolution bandwidth in the first 1MHz (the requirement would appear to be about 45kHz or greater; is it possible to perform this measurement with this value of resolution bandwidth?)
6.6.3.3.2
Co-existence with GSM 900; co-located base stations
Scenario calculations should be performed to confirm the requirement, currently –[98]dB.
6.6.3.4.2
Co-existence with DCS 1800; co-located base stations
Scenario calculations should be performed to confirm the requirement, currently –[98]dB.
6.8.2
Modulation accuracy
Further consideration is needed, especially for the multicode case.
6.8.3
Peak code domain error
The requirement is ffs.
7.1
General
Definition of requirements for antenna diversity is ffs.
7.3
Dynamic range
The requirement (BER/FER, value and channel type) is ffs.
The effect of applying mast head LNAs to the dynamic range specification is ffs.
8
Performance requirement
Values are TBD.
Requirements for BS without dual receiver diversity is ffs.
6 or 8
Transmit diversity
Specification text for SSDT requirement is needed, unclear in what section or possibly in TS 25.103.
6.3 TS25.102 (UE TX & RX for TDD)
Table 6-3 shows the identified open items for the 25.102 specification document.
Table 6-3:Open Items for 25.102
Section number
Section description
Status
3
Definitions, Symbols, Abbreviations
Update required
5.2
Frequency bands
The deployment of TDD in the 1920 MHz to 1980 MHz band is an open item.
6.6.2.2.1
ACLR, Minimum requirement
The possibility is being considered of dynamically relaxing the ACP requirements for User Equipment(s) under conditions when this would not lead to significant interference (with respect to other system scenario or UMTS operators). This would be carried out under network control, primarily to facilitate reduction in UE power consumption.
6.7.2.1
Spectrum emission mask
Requirements for other than UE power class 21dBm
6.7.2.2
ACLR
Requirements for other than UE power class 21dBm
6.8
Transmit Intermodulation
Requirements for other than UE power class 21dBm
6.9.3
Peak Code Domain Error
Requirement to be defined.
7.5
ACS
Value in square brackets
7.9
Spurious Emissions
Values in square brackets
8
Performance Requirement
Values are TBD, update of structure needed.
Annex E2
Service Implementation Capabilities
For further study
6.4 TS25.105 (BTS TX & RX for TDD)
Table 6-4 shows the identified open items for the 25.105 specification document.
Table 6-4:Open Items for 25.105
Section number
Section description
Status
3
Definitions, symbols and abbreviations
Update needed
6.3
Frequency stability
Should there also be an accuracy requirement on the clock rate ? Alternatives are to either tie the clock rate to the frequency accuracy or to have a separate clock rate requirement.
6.4.3
Power control dynamic range
Redundant requirement included. The need for this parameter to be specified should be confirmed.
6.4.6
Power control cycles per second
Adaptation to 15 slots per frame needed, depending on WG1 specification, requirement needed ?
6.4.7
Perch channel power
Requirement for reference power in the cell is TBD.
6.6.2.1
Spectrum mask
Not included
6.6.2.2
ACLR
Values in square brackets
6.6.3.2.2
Co-existence with GSM 900; co-located base stations
Scenario calculations should be performed to confirm the requirement, currently [-98] dB.
6.6.3.3.2
Co-existence with GSM 1800; co-located base stations
Scenario calculations should be performed to confirm the requirement, currently [-98] dB.
7.3
Dynamic Range
Value in square brackets
7.4
ACS
Requirement is TBD.
7.8
Spurious Emissions
Values in square brackets
8
Performance Requirement
Values are TBD.
Requirement for BS without dual receiver diversity is ffs.
6.5 TS25.133 (Support of RF Parameters in Radio Resource Management for FDD)
Table 6-5 shows the identified open items for the 25.133 specification document.
Table 6-5:Open Items for 25.133
Section number
Section description
Status
[Editor’s note: The above table needs input from the editor of this specification]
6.6 TS25.123 (Support of RF Parameters in Radio Resource Management for TDD)
Table 6-6 shows the identified open items for the 25.123 specification document.
Table 6-6:Open Items for 25.123
Section number
Section description
Status
[Editor’s note: The above table needs input from the editor of this specification]
6.7 TS25.141 (BTS Conformance test for FDD)
Table 6-7 shows the identified open items for the 25.141 specification document.
Table 6-7:Open Items for 25.141
#
Section
Section description
Current status
Remarks
1
2
References
Shall be filled in later.
Some are added. (May not exhaustive)
2
3.1
Definitions
To be filled in later.
Some are added. (May not exhaustive)
3
3.2
Symbols
To be properly defined later.
Editorial. Shall be filled in later if needed
12
6.2.1
Base station maximum output power
Table 6.2.-1 and Table 6.2-2 should be filled in.
Remove Editor’s note, since measuring the total power is enough.
(Working assumption for power ratio for each channel shall be taken from AH1-DL discussion in Aug.30.)
13
6.3
Frequency stability
Test conditions shall be revised properly.
Adding draft text for it.
Q.1: Should Signal to be measured be modulated?
Q2: If it is the case, what kind of channel structure defined?
Q3: Are there any need to defiene “Frequency measuring equipment” as a “wide-bande frequency counter”?
14
6.4.2
Power control steps
There are some TBD parameters in the test conditions.
Revise description.
Q1: How to measure a particular DPCH shall be sprcified.
Q2: By what method (can spectrum analyzer do this?) shall be specified.
15
6.4.2.2
Minimum requirement
- Step size torelance is ffs.
To define the transmitter power as “code domain power” is ffs.
16
6.4.3
Power control dynamic range
There are some TBD parameters in the test conditions.
17
6.4.4
Minimum transmit power
There are some TBD parameters in the test conditions.
18
6.4.5
Total power dynamic range
There are some TBD parameters in the test conditions.
19
6.4.6
Power control cycles per second
There are some TBD parameters in the test conditions.
20
6.5
Transmitted RF carrier power versus time
Table 6.5-1 should be filled in.
21
6.5.4
Primary CPICH power
There are some TBD parameters in the test conditions.
22
6.6.1
Occupied bandwidth
Texts for measurement method are needed.
Table 6.6-1 should be filled in.
23
6.6.3
Spurious emissions
There are some TBD parameters in the test conditions. Table 6.6-3 and Table 6.6-4 should be filled in.
24
6.7
Transmit intermodulation
There are some TBD parameters in the test conditions. Further input for co-located cellular systems are needed.
34
8.2.1
Performance in AWGN channel
- BER (or FER) measurement method should be defined.
- There are some TBD parameters in Table 8.2-1
- Add description in Annex-A. Baseline text is taken from Annex A in [5].
(- Table 8.2-1 still requires further study.)
35
8.2.2.4[6.4.1.3]
Uplink power control
Text for this section is needed.
36
8.2.2.5[6.4.1.4]
Soft handover performance
FFS.
38
8.2.2.2
Performance without TPC
There are some TBD parameters in the table.
39
8.2.2.3
Performance with TPC
There are some TBD parameters in the table.
44
6.2.1.1
Test Conditions and measurement method
Which part of the code shll be measured should be specified.
45
6.4.2.1
Test conditions and measurement method
<Editor’s note: In whichh symbol rate, should measurement done shall be specified.>
46
6.4.2.1
Test conditions and measurement method
<Editor’s note: In whichh symbol rate, should measurement done shall be specified.>
47
6.4.3.1
Test conditions and measurement method
<Editor’s note: In whichh symbol rate, should measurement done shall be specified.>
48
6.4.4.1
Test conditions and measurement method
<Editor’s note: In whichh symbol rate, should measurement done shall be specified.>
49
6.4.5.1
Test conditions and measurement method
<Editor’s note: In whichh symbol rate, should measurement done shall be specified.>
50
6.4.6.1
Test conditions and measurement method
<Editor’s note: In whichh symbol rate, should measurement done shall be specified.>
51
6.9
Clock Frequency accuracy
Conformance requirement for it is F.F.S.
52
6.6.2.1
Spectrum emission mask
Test conditions and measurement methods are FFS. Description of minimum requirement shall be simplified.
6.8 TS25.142 (BTS Conformance test for TDD)
Table 6-8 shows the identified open items for the 25.142 specification document.
Table 6-8:Open Items for 25.142
Section number
Section description
Status
[Editor’s note: The above table needs input from the editor of this specification]
6.9 TS25.113 (BTS EMC)
Table 6-9 shows the identified open items for the 25.113 specification document.
Table 6-9:Open Items for 25.113
Section number
Section description
Status
3.1
Definition of:
Loss of service
Loss of call
Contributions invited.
3.1
Definition of:
Transient phenomena
Continuous phenomena
Editor to check if any generally accepted definition already exists
4
New text to be proposed by correspondence following WG4#7
5
New text to be proposed by correspondence following WG4#7
6.1, 6.2
Number of tests
The number of different bearers which need to be tested needs to be defined.
6.2
Self recovery
Conditions for “System operation self-recoverable” need to be defined.
7
New text to be approved by correspondence to identify relevant sections of Annex A for phenomena
7 Work Item for Release 2000
History
Document history
Date
Version
Comment
May 11th, 1999
0.0.1
Initial version as R4-99251 based on R4-99190 and R4-99252.
June 3rd, 1999
0.0.2
Revised the items pointed out at the WG4 #4 meeting.
Incorporated the Study Items shown in R4-99253.
June 16th, 1999
1.0.0
Table 5.5 was revised to incorporate agreed part of R4-99316.
July 15th, 1999
1.0.1
Minor editorial changes incorporated.
July 24th, 1999
1.1.0
Milestone change incorporated to be in line with PCG#2(99)21.
August 25th, 1999
1.2.0
Revised the meeting schedule for #9 meeting as agreed at #6 meeting and updated Table 4:Work Plan.
September 8th, 1999
1.3.0
Incorporated the following pages.
5.6 25.141 (BS CONFORMANCE TEST FOR FDD)
5.7 25.142 (BS CONFORMANCE TEST FOR TDD)
5.8 25.113 (BS EMC)
September 30th, 1999
1.4.0
Editorial error in Table 4 corrected.
Milestone change incorporated as agreed at the WG4 #7 meeting.
Updated the following pages.
5.5 25.103 (RF Parameters)
5.7 25.142 (BS CONFORMANCE TEST FOR TDD)
5.8 25.113 (BS EMC).
October 7th, 1999
1.4.0
Noted by TSG-RAN#5
October 27th, 1999
2.0.0
Table 4 updated to reflect the result of TSG RAN #5.
Meeting schedule for year 2000 incorporated.
December 5th, 1999
2.1.0
Meeting schedule for year 2000 updated.
December 10th, 1999
2.2.0
Table 4 updated to reflect the split of 25.103.
Created a new section of “6. Open Item for Release 1999” and text changes proposed in R4-99907 except the table for 25.103 were incorporated into that section.
Created a new section of “7. Work Item for Release 2000” with no content.
October 7th, 1999
1.4.0
Noted by TSG-RAN#5
Editor for 30.504 Work Plan and Study Items is:
Masaaki Iwasa
Motorola Japan Limited
Tel. : +81 (0)3 3280 8435
Fax : +81 (0)3 3440 3105
Email : [email protected]
This document is written in Microsoft Word 97.
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25.831
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3 Indicates TSG approved document under change control.
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y the second digit is incremented for all changes of substance, i.e. technical enhancements, corrections, updates, etc.
z the third digit is incremented when editorial only changes have been incorporated in the specification.
1 Scope
The scope of this Technical Report is to list technical features and functions of UTRAN (Study Items) that are currently assumed by TSG RAN WG3 to be outside the scope of UMTS Release 99, but that should be considered for future releases. Agreed technical descriptions of these features and functions are also included to the extent they are available.
2 References
The following documents contain provisions, which, through reference in this text, constitute provisions of the present document.
• References are either specific (identified by date of publication, edition number, version number, etc.) or non‑specific.
• For a specific reference, subsequent revisions do not apply.
• For a non-specific reference, the latest version applies.
• A non-specific reference to an ETS shall also be taken to refer to later versions published as an EN with the same number.
[1] TS 25.433 UTRAN Iub interface NBAP Signalling Specification
[2]
3 Definitions, symbols and abbreviations
3.1 Definitions
For the purposes of the present document, the [following] terms and definitions [given in ... and the following] apply.
3.2 Symbols
For the purposes of the present document, the following symbols apply:
3.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
4 Study item list
[Editor's Note: This chapter should include the list of the study items, i.e. the features and functions of UTRAN outside the scope of UMTS Release 99].
The study items outside the scope of UMTS Release 99 are the following (non exhaustive):
• Parallelism in the execution of NBAP procedures.
•
5 Parallelism in the execution of NBAP procedures
5.1 Feature/Function description and status
[Editor's Note: This section should include the description of the feature/function related to the study item and its status].
In release 99, it is a working assumption that there is only one ongoing procedure per UE context i.e. one NBAP procedure cannot be executed as long as another NBAP procedure for the same UE is still on going.
5.2 In further releases, it will be possible to have more than one on going NBAP procedure for a given UE, depending on the on going and the new procedures. Benefits and details are to be clarified.Impacts on specifications
5.2.1 Impacted specifications
[Editor's Note: This section should list the TSG RAN WG3 specifications, which are impacted by the feature/function].
Impacted RAN WG3 specifications are:
• TS 25.433 (NBAP Specification) [1]
5.2.2 Impacts on TS 25.433 (NBAP Specification)
[Editor's Note: This subsection should include agreed modifications, text and figures needed for that specification].
The following text is included in chapter 8.
8.x. Procedure management
Table x shows the support for parallel procedure execution by the NBAP protocol.
New
procedure
Ongoing
procedure
RL-
Setup
RL-Addition
RL-
Reconf (unsync)
RL-
Reconf
(Sync)
RL-
Deletion
RL-Setup
Not applicable
Not possible
RL-Addition
RL-Reconf (unsync)
Supported
RL-Reconf
(sync)
Not supported
RL-Deletion
Note: it is up to an implementation to actually support the parallelism offered by the NBAP protocol. Since all procedures are initiated by an RNC, this RNC can choose not to use the offered parallelism. A simple node_B implementation might choose to execute all procedures sequentially.
5.2.3 Impacts on specification 2
[Editor's Note: This subsection should include agreed modifications, text and figures needed for that specification].
6 Feature/Function description and status
[Editor's Note: This section should include the description of the feature/function related to the study item and its status].
6.1 Impacts on specifications
6.1.1 Impacted specifications
[Editor's Note: This section should list the TSG RAN WG3 specifications which are impacted by the feature/function].
6.1.2 Impacts on specification 1
[Editor's Note: This subsection should include agreed modifications, text and figures needed for that specification].
6.1.3 Impacts on specification 2
[Editor's Note: This subsection should include agreed modifications, text and figures needed for that specification].
7 Study item 2
8 History
Document history
V0.0.1
1999-05
Initial Specification Structure
V0.0.2
1999-06
Addition of study item 1 "Parallelism in the execution of NBAP procedures" according to RAN WG3#4 meeting, based on tdoc R3-99449.
V0.0.2
1999-06
Noted by TSG-RAN
Editor for 3GPP RAN TS 25.831 is:
Nicolas Drevon
Alcatel
Tel.: +33 1 3077 0916
Fax : +33 1 3077 9430
Email : [email protected]
This document is written in Microsoft Word version 7/97.
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fd9931b60fc241f651706643f1ed6e48
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33.900
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3 Indicates TSG approved document under change control.
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y the second digit is incremented for all changes of substance, i.e. technical enhancements, corrections, updates, etc.
z the third digit is incremented when editorial only changes have been incorporated in the specification;
2 Introduction
This document is intended to offer security guidance to those involved in 3GPP systems. All specifications have to take into account the cost and feasibility of security features and functions. Inevitably, some compromise is necessary, and so it is important to realise where possible risks and threats may exist. The document describes those security issues that have been identified in the formulation of the standards.
3 Scope
The present document gives a general description of the security architecture and features of 3rd Generation Security. It is intended to provide an overview of security, for detailed explanation and the actual standards the reader is referred to the appropriate standards.
It also serves the purpose of identifying the potential risks and threats that have been highlighted and require careful consideration when implementing a third generat6ion mobile system.
The document attempts to identify whether the security features and mechanism provided in the latest version of the 3G security architecture specification {1} address the 2G security weaknesses.
4 References
Reference to an ETS shall also be taken to refer to later versions published as an EN with the same number.
[1] 3G TS 33.102, 3G Security; Security Architecture, version 3.0.0
[2] 3G TS 33.120, 3G Security; Security Principles and Objectives, version 3.0.0
[3] 3G TS 21.133, 3G Security; Security Threats and Requirements, version 3.0.01
5 Definitions, symbols and abbreviations
5.1 Definitions
5.2 Symbols
5.3 Abbreviations
6 A brief overview of 3GPP Security
3GPP security was based on GSM security, with the following important changes:
• A change was made to defeat the false base station attack. The security mechanisms include a sequence number that ensures that the mobile can identify the network.
• Key lengths were increased to allow for the possibility of stronger algorithms for encryption and integrity.
• Mechanisms were included to support security within and between networks.
• Security is based within the switch rather than the base station as in GSM. Therefore links are protected between the base station and switch.
• Integrity mechanisms for the terminal identity (IMEI) have been designed in from the start, rather than that introduced late into GSM.
• The authentication algorithm has not been defined, but guidance on choice will be given.
• When roaming between networks, such as between a GSM and 3GPP, only the level of protection supported by the smart card will apply. Therefore a GSM smart card will not be protected against the false base station attack when in a 3GPP network.
7 Counteracting envisaged 3G attacks
Many of the security enhancements required to 2G systems are intended to counteract attacks which were not perceived to be feasible in 2G systems. This includes attacks that are, or are perceived to be, possible now or very soon because intruders have access to more computational capabilities, new equipment has become available, and the physical security of certain network elements is questioned.
In order to perform the attacks the intruder has to possess one or more of the following capabilities:
• Eavesdropping. This is the capability that the intruder eavesdrops signalling and data connections associated with other users. The required equipment is a modified MS.
• Impersonation of a user. This is the capability whereby the intruder sends signalling and/or user data to the network, in an attempt to make the network believe they originate from the target user. The required equipment is again a modified MS.
• Impersonation of the network. This is the capability whereby the intruder sends signalling and/or user data to the target user, in an attempt to make the target user believe they originate from a genuine network. The required equipment is modified BS.
• Man-in-the-middle. This is the capability whereby the intruder puts itself in between the target user and a genuine network and has the ability to eavesdrop, modify, delete, re-order, replay, and spoof signalling and user data messages exchanged between the two parties. The required equipment is modified BS in conjunction with a modified MS.
• Compromising authentication vectors in the network. The intruder possesses a compromised authentication vector, which may include challenge/response pairs, cipher keys and integrity keys. This data may have been obtained by compromising network nodes or by intercepting signalling messages on network links.
The first capability is the easiest to achieve the following capabilities are gradually more complex and require more investment by the attacker. Therefore, in general, an intruder having a certain capability is assumed also to have the capabilities positioned above that capability in the list. The first two capabilities were acknowledged in the design of 2G systems. 3G security however should thwart all five types of attacks.
In the following we consider several attacks to 3G systems which may not have been fully addressed in 2G systems and attempt to identify whether the security features and mechanisms provided in the latest version of the 3G security architecture specification counteracts each of these attacks.
7.1 Denial of service
We distinguish between the following denial of service attacks:
7.1.1 User de-registration request spoofing
Description:
An attack that requires a modified MS and exploits the weakness that the network cannot authenticate the messages it receives over the radio interface. The intruder spoofs a de-registration request (IMSI detach) to the network. The network de-registers the user from the visited location area and instructs the HLR to do the same. The user is subsequently unreachable for mobile terminated services.
Does 3G security architecture counteract the attack: Yes
Integrity protection of critical signalling messages protects against this attack. More specifically, data authentication and replay inhibition of the de-registration request allows the serving network to verify that the de-registration request is legitimate.
7.1.2 Location update request spoofing
Description:
An attack that requires a modified MS and exploits the weakness that the network cannot authenticate the messages it receives over the radio interface. Instead of the de-registration request, the user spoofs a location update request in a different location area from the one in which the user is roaming. The network registers in the new location area and the target user will be paged in that new area. The user is subsequently unreachable for mobile terminated services.
Does 3G security architecture counteract the attack: Yes
Integrity protection of critical signalling messages protects against this attack. More specifically, data authentication and replay inhibition of the location update request allows the serving network to verify that the location update request is legitimate.
7.1.3 Camping on a false BS
Description:
An attack that requires a modified BS and exploits the weakness that a user can be enticed to camp on a false base station. Once the target user camps on the radio channels of a false base station, the target user is out of reach of the paging signals of the serving network in which he is registered.
Does 3G security architecture counteract the attack: No
The security architecture does not counteract this attack. However, the denial of service in this case only persists for as long as the attacker is active unlike the above attacks which persist beyond the moment where intervention by the attacker stops. These attacks are comparable to radio jamming which is very difficult to counteract effectively in any radio system.
7.1.4 Camping on a false BS/MS
Description:
An attack that requires a modified BS/MS and exploits the weakness that a user can be enticed to camp on a false base station. A false BS/MS can act as a repeater for some time and can relay some requests in between the network and the target user, but subsequently modify or ignore certain service requests and/or paging messages related to the target user.
Does 3G security architecture counteract the attack: No
The security architecture does not prevent a false BS/MS relaying messages between the network and the target user, nether does it prevent the false BS/MS ignoring certain service requests and/or paging requests. Integrity protection of critical message may however help to prevent some denial of service attacks, which are induced by modifying certain messages. Again, the denial of service in this case only persists for as long as the attacker is active unlike the above attacks, which persist beyond the moment where intervention by the attacker stops. These attacks are comparable to radio jamming which is very difficult to counteract effectively in any radio system.
7.2 Identity catching
We identify the following types of attacks against the user identity confidentiality:
7.2.1 Passive identity catching
Description:
A passive attack that requires a modified MS and exploits the weakness that the network may sometimes request the user to send its identity in cleartext.
Does 3G security architecture counteract the attack: Yes
The identity confidentiality mechanism counteracts this attack. The use of temporary identities allocated by the serving network makes passive eavesdropping inefficient since the user must wait for a new registration or a mismatch in the serving network database before he can capture the user’s permanent identity in plaintext. The inefficiency of this attack given the likely rewards to the attacker would make this scenario unlikely. (Note however that the permanent identity may be protected in the event of new registrations or serving network database failure in order to guard against more efficient active attacks.)
7.2.2 Active identity catching
Description:
An active attack that requires a modified BS and exploits the weakness that the network may request the MS to send its permanent user identity in cleartext. An intruder entices the target user to camp on its false BS and subsequently requests the target user to send its permanent user identity in cleartext perhaps by forcing a new registration or by claiming a temporary identity mismatch due to database failure.
Does 3G security architecture counteract the attack: Yes
The identity confidentiality mechanism counteracts this attack by using an encryption key shared by a group of users to protect the user identity in the event of new registrations or temporary identity database failure in the serving network. Note however that the size of the groups should be chosen carefully: too small and the group identify may compromise the user identity itself; too large and the group encryption key might be vulnerable to attack.
7.3 Impersonation of the network
We identify the following attacks with the objective of impersonating a genuine network. The ultimate aim of such attacks is usually to eavesdrop on user data (see section 2.4), or to send the user information that he subsequently believes to originate from a genuine network or user with whom he is connected through that network.
7.3.1 Impersonation of the network by suppressing encryption between the target user and the intruder
Description:
An attack that requires a modified BS and that exploits the weakness that the MS cannot authenticate messages received over the radio interface. The target user is enticed to camp on the false BS. When the intruder or the target user initiates a service, the intruder does not enable encryption by spoofing the cipher mode command. The intruder maintains the call as long as it is required or as long as his attack remains undetected.
Does 3G security architecture counteract the attack: Yes
A mandatory cipher mode command with message authentication and replay inhibition allows the mobile to verify that encryption has not been suppressed by an attacker.
7.3.2 Impersonation of the network by suppressing encryption between the target user and the true network
Description:
An attack that requires a modified BS/MS and that exploits the weakness that the network cannot authenticate messages received over the radio interface. The target user is enticed to camp on the false BS/MS. When a call is set-up the false BS/MS modifies the ciphering capabilities of the MS to make it appear to the network that a genuine incompatibility exists between the network and the mobile station. The network may then decide to establish an un-enciphered connection. After the decision not to cipher has been taken, the intruder cuts the connection with the network and impersonates the network to the target user.
Does 3G security architecture counteract the attack: Yes
A mobile station classmark with message authentication and replay inhibition allows the network to verify that encryption has not been suppressed by an attacker.
7.3.3 Impersonation of the network by forcing the use of a compromised cipher key
Description:
An attack that requires a modified BS and the possession by the intruder of a compromised authentication vector and thus exploits the weakness that the user has no control upon the cipher key. The target user is enticed to camp on the false BS/MS. When a call is set-up the false BS/MS forces the use of a compromised cipher key on the mobile user. The intruder maintains the call as long as it is required or as long as his attack remains undetected.
Does 3G security architecture counteract the attack: Yes
The presence of a sequence number in the challenge allows the USIM to verify the freshness of the cipher key to help guard against forced re-use of a compromised authentication vector. However, the architecture does not protect against force use of compromised authentication vectors which have not yet been used to authenticate the USIM. Thus, the network is still vulnerable to attacks using compromised authentication vectors which have been intercepted between generation in the authentication centre and use or destruction in the serving network.
The user must trust the SN (transitively via the HE) to handle authentication vectors securely. For instance, an attacker with a false BS may work in collusion with an SN to intercept unused authentication vectors, or the SN may expose itself to undue risks because it stockpiles large numbers of authentication vectors before they need to be used.
7.4 Eavesdropping on user data
We identify the following attacks with the objective of eavesdropping on user data which is transmitted through the genuine network to the intended recipient.
7.4.1 Eavesdropping on user data by suppressing encryption between the target user and the intruder
Description:
An attack that requires a modified BS/MS and that exploits the weakness that the MS cannot authenticate messages received over the radio interface. The target user is enticed to camp on the false BS. When the target user or the intruder initiates a call the network does not enable encryption by spoofing the cipher mode command. The attacker however sets up his own connection with the genuine network using his own subscription. The attacker may then subsequently eavesdrop on the transmitted user data.
Does 3G security architecture counteract the attack: Yes
A mandatory cipher mode command with message authentication and replay inhibition allows the mobile to verify that encryption has not been suppressed by an attacker.
7.4.2 Eavesdropping on user data by suppression of encryption between the target user and the true network
Description:
An attack that requires a modified BS/MS and that exploits the weakness that the network cannot authenticate messages received over the radio interface. The target user is enticed to camp on the false BS/MS. When the target user or the genuine network sets up a connection, the false BS/MS modifies the ciphering capabilities of the MS to make it appear to the network that a genuine incompatibility exists between the network and the mobile station. The network may then decide to establish an un-enciphered connection. After the decision not to cipher has been taken, the intruder may eavesdrop on the user data.
Does 3G security architecture counteract the attack: Yes
Message authentication and replay inhibition of the mobile’s ciphering capabilities allows the network to verify that encryption has not been suppressed by an attacker.
7.4.3 Eavesdropping on user data by forcing the use of a compromised cipher key
Description:
An attack that requires a modified BS/MS and the possession by the intruder of a compromised authentication vector and thus exploits the weakness that the user has no control the cipher key. The target user is enticed to camp on the false BS/MS. When the target user or the intruder set-up a service, the false BS/MS forces the use of a compromised cipher key on the mobile user while it builds up a connection with the genuine network using its own subscription.
Does 3G security architecture counteract the attack: Yes
The presence of a sequence number in the challenge allows the USIM to verify the freshness of the cipher key to help guard against forced re-use of a compromised authentication vector. However, the architecture does not protect against force use of compromised authentication vectors, which have not yet been used to authenticate the USIM. Thus, the network is still vulnerable to attacks using compromised authentication vectors, which have been intercepted between generation in the authentication centre and use and destruction in the serving network.
The user must trust the SN (transitively via the HE) to handle authentication vectors securely. For instance, an attacker with a false BS may work in collusion with an SN to intercept unused authentication vectors, or the SN may expose itself to undue risks because it stockpiles large numbers of authentication vectors before they need to be used.
7.5 Impersonation of the user
7.5.1 Impersonation of the user through the use of by the network of a compromised authentication vector
Description:
An attack that requires a modified MS and the possession by the intruder of a compromised authentication vector which is intended to be used by the network to authenticate a legitimate user. The intruder uses that data to impersonate the target user towards the network and the other party.
Does 3G security architecture counteract the attack: Yes
The presence of a sequence number in the challenge means that authentication vectors cannot be re-used to authenticate USIMs. This helps to reduce the opportunity of using a compromised authentication vector to impersonate the target user. However, the network is still vulnerable to attacks using compromised authentication vectors, which have been intercepted between generation in the authentication centre and use and destruction in the serving network.
The user must trust the SN (transitively via the HE) to handle authentication vectors securely. For instance, an attacker with a false BS may work in collusion with an SN to intercept unused authentication vectors, or the SN may expose itself to undue risks because it stockpiles large numbers of authentication vectors before they need to be used.
7.5.2 Impersonation of the user through the use by the network of an eavesdropped authentication response
Description:
An attack that requires a modified MS and exploits the weakness that an authentication vector may be used several times. The intruder eavesdrops on the authentication response sent by the user and uses that when the same challenge is sent later on. Subsequently, ciphering has to be avoided by any of the mechanisms described above. The intruder uses the eavesdropped response data to impersonate the target user towards the network and the other party.
Does 3G security architecture counteract the attack: Yes
The presence of a sequence number in the challenge means that authentication vectors cannot be re-used to authenticate USIMs.
7.5.3 Hijacking outgoing calls in networks with encryption disabled
Description:
This attack requires a modified BS/MS. While the target user camps on the false base station, the intruder pages the target user for an incoming call. The user then initiates the call set-up procedure, which the intruder allows to occur between the serving network and the target user, modifying the signalling elements such that for the serving network it appears as if the target user wants to set-up a mobile originated call. The network does not enable encryption. After authentication the intruder cuts the connection with the target user, and subsequently uses the connection with the network to make fraudulent calls on the target user’s subscription.
Does 3G security architecture counteract the attack: Partly
Integrity protection of critical signalling messages protects against this attack. More specifically, data authentication and replay inhibition of the connection set-up request allows the serving network to verify that the request is legitimate. In addition, periodic integrity protected messages during a connection helps protect against hijacking of un-enciphered connections after the initial connection establishment. However, hijacking the channel between periodic integrity protection messages is still possible, although this may be of limited use to attackers. In general, connections with ciphering disabled will always be vulnerable to some degree of channel hijacking.
7.5.4 Hijacking outgoing calls in networks with encryption enabled
Description:
This attack requires a modified BS/MS. In addition to the previous attack this time the intruder has to attempt to suppress encryption by modification of the message in which the MS informs the network of its ciphering capabilities.
Does 3G security architecture counteract the attack: Yes
Integrity protection of critical signalling messages protects against this attack. More specifically, data authentication and replay inhibition of the MS station classmark and the connection set-up request helps prevent suppression of encryption and allows the serving network to verify that the request is legitimate.
7.5.5 Hijacking incoming calls in networks with encryption disabled
Description:
This attack requires a modified BS/MS. While the target user camps on the false base station, an associate of the intruder makes a call to the target user’s number. The intruder acts as a relay between the network and the target user until authentication and call set-up has been performed between target user and serving network. The network does not enable encryption. After authentication and call set-up the intruder releases the target user, and subsequently uses the connection to answer the call made by his associate. The target user will have to pay for the roaming leg.
Does 3G security architecture counteract the attack: Partly
Integrity protection of critical signalling messages protects against this attack. More specifically, data authentication and replay inhibition of the connection accept message allows the serving network to verify that the request is legitimate. In addition, periodic integrity protected messages during a connection helps protect against hijacking of un-enciphered connections after the initial connection establishment. However, hijacking the channel between periodic integrity protection messages is still possible, although this may be of limited use to attackers. In general, connections with ciphering disabled will always be vulnerable to some degree of channel hijacking.
7.5.6 Hijacking incoming calls in networks with encryption enabled
Description:
This attack requires a modified BS/MS. In addition to the previous attack this time the intruder has to suppress encryption.
Does 3G security architecture counteract the attack: Yes
Integrity protection of critical signalling messages protects against this attack. More specifically, data authentication and replay inhibition of the MS station classmark and the connection accept message helps prevent suppression of encryption and allows the serving network to verify that the connection accept is legitimate.
8 Network issues
8.1 Security policy
8.1.1 Access control policy
Access control policy with respect to 3GPP network elements should be consistent with general access control policy as defined in the particular operator’s security policy. As a basis, the following rules should apply:
1. In granting users access rights to 3GPP networks elements or supporting IT systems the following principles should be followed:
• every employee should only have access to those resources necessary for the completion of the work-related tasks set,
• the “positive access control” principle should be applied, meaning it shall be assumed that an employee is authorised to carry out only those operations for which he has obtained authority,
• The right of access to resources should be granted only at the moment when it is actually necessary and should be rescinded when no longer necessary for the completion of work-related tasks.
2. Operator’s employees should be made responsible for the secure storing and use of access control executive components entrusted to them (badges, cards). Access control executive components should not be stored together with a computer used to access the network element or IT system.
3. Every user of a given system should be provided with an identification (log-in name, account name) that is unique within the framework or the Company. The following principles apply:
• a user’s identification on its own should not be sufficient for granting access authority,
• an identification should not give any indication of the user’s authority within the system,
• The use of forms of group identification should only be admissible in exceptional circumstances.
Granting of full or very wide rights of access to resources should be limited and strictly controlled.
8.2 Secure network elements interconnection
3GPP network elements must provide means for remote management, maintenance and communication with IT systems (e.g. the billing system). Often an operator’s corporate computer network is used for this purpose. This considerably lower infrastructure costs but poses significant security threats for 3GPP system entities. If no security is applied, usually each user of corporate network can try to access remotely a 3GPP network element, provided its network address is known.
As a principle, 3GPP network elements should be separated, at least logically, from an operator’s corporate computer network. A unique username and password should identify each employee who is authorised to access to network element. Proper application and system logs should be maintained, reviewed and protected.
Remote access to network entities should be, subject to the operator’s security policy, protected from eavesdropping and session hijacking.
Physical access to 3GPP network elements should be controlled by appropriate physical security measures. It is advisable that physical location of network elements be treated as protected information.
8.3 Communications node security
To countermeasure the threats described in this document an operator should define and implement proper security measures. The following section specifies the desirable security features that any 3GPP Network Element (NE), Network System (NS), Operations System (OS) or Data Communications Network (DCN) should provide in order to reduce the risk of potentially service affecting security compromises. The term “3GPP node” in the following section is used to imply a NE, NS, OS, or a DCN and its nodes.
8.3.1 Identification
Each operations related process running in the 3GPP node should be associated with the corresponding user-ID (so that an audit trail can be established if there is a need).
The 3GPP node should disable a user-ID if it has remained inactive (i.e., never used) over a specified time period.
8.3.2 Authentication
All Operations, Administration, Maintenance and Provisioning (OAM&P) input ports of the 3GPP node (including direct, dial-up and network access) should require authentication of a session requester, without any provision for a bypass mechanism.
A single stored password entry (e.g., in a password file) should not be allowed to be shared by multiple user-IDs. However, the 3GPP node should not prevent a user from choosing (unknowingly) a password that is already being used by some other user. Nor should the 3GPP node volunteer this information to either user.
Passwords should be stored in a one-way encrypted form, and should not be retrievable by any user including managers or administrators (of system and security). Also, there should be no clear text display (on a device such as a screen, typewriter, or printer) of a password at any time (e.g., login, file dump, etc.).
The 3GPP node should allow passwords to be user changeable (requiring re-authentication), and should require that the user change it the first time he/she establishes a session with the password assigned to him/her. The default should be non-trivial in nature, ideally random.
The password should have an “ageing” feature, and it should have a complexity requirement to make it not easily guessed. The 3GPP node should not accept common words or names as valid passwords. Also, it should not allow a recently obsolete password to be readily reselected by the said user.
8.3.3 System Access Control
The 3GPP node should not allow access to any session requester unless identified and authenticated. There should be no default mechanism to circumvent it.
The 3GPP node should not allow any session to be established via a port that is not authorised to accept input commands. For example, if an output port receives a login request, the 3GPP node should not respond.
The entire login procedure should be allowed to be completed without interruption, even if incorrect parameters (such as an incorrect user-ID or an incorrect password) are entered, and no “help message” should be transmitted to the session requester as to whom part of the authentication is incorrect. The only information to be conveyed at the end of the login attempt is that the login is invalid.
After a specified number of incorrect login attempts carried out in succession, the 3GPP node should lock out the channel and raise an alarm in real time for the administrator.
Before the session begins, the 3GPP node should provide a warning message explicitly alerting the user of the consequences of unauthorised access and use.
At the beginning of the session, the 3GPP node should display the date and time of the user’s last successful access and the number of unsuccessful attempts, if any, that have been made to establish a session since the last successful access.
There should be a “time-out” feature - i.e., the 3GPP node should disconnect or re-authenticated users after a specified time interval during which no messages were exchanged. Also, there should be a mechanism for user-initiated keyboard locking.
The 3GPP node should provide a mechanism to end a session through a secure logoff procedure. If a session gets interrupted due to reasons such as time-out, power failure, link disconnection, etc., the port should be dropped immediately.
For dial-up access over untrusted channels, authentication involving one time passwords should be required (e.g., smart card, etc.).
8.3.4 Resource Access Control
Access to resources should be controlled on the basis of “privilege” (i.e., access permission) associated with user-ID and channel. It should not be based on a “password” associated with the access function, because that password will have to be necessarily shared among all users requiring such access. Neither should encryption be used as a primary access control mechanism (though encryption may be used to enhance it).
The granularity of resource access control should be such that for each resource it should be possible to grant (or deny) access privilege to any single user (or a prescribed group of users). For example, the control should be adequately fine-grained so that user access and channel access can be restricted on the basis of commands, database views (i.e., objects), records (i.e., object instances), and fields (i.e., attributes).
If external entities - e.g., customers, are allowed access to the resources, each 3GPP node’s resource (e.g., proprietary data) should be protected from access by unauthorised persons.
Executable/loadable/fetchable software should be access controlled for overwrite, update, and execution rights.
8.3.5 Accountability and Audit
The 3GPP node should generate a security log containing information sufficient for after-the-fact investigation of loss or impropriety.
The security log should be protected from unauthorized access. No user should be allowed to modify or delete a security log. There should be no mechanism to disable the security log. There should be an alarm in real time if the security log does not function properly.
The security log should, as a minimum, record events such as:
• all sessions established,
• invalid user authentication attempts,
• unauthorized attempts to access resources (including data and transactions),
• changes in users’ security profiles and attributes,
• changes in access rights to resources,
• changes in the 3GPP node security configuration,
• And modification of 3GPP node software.
For each such event, the record should, as a minimum, include date and time of event, initiator of the event such as: user-ID, terminal, port, network address, etc., names of resources accessed, and success or failure of the event.
Actual or attempted passwords should not be recorded in the security log
There should be audit tools to produce exception reports, summary reports, and detailed reports on specifiable data items, users, or communication facilities.
8.3.6 Security Administration
The 3GPP node should support functions for the “management” of security related data (e.g., security parameters such as user-IDs, passwords, privileges, etc.) as “separate” from other user functions. Security administration should be reserved only for an appropriate administrator.
The administrator should be able to display all currently logged-in users as well as a list of all authorised user-IDs.
The administrator should be able to independently and selectively monitor, in real time, the actions of any one or more users based on respective user-IDs, terminals, ports, or network addresses.
The administrator should be able to identify all resources owned by or accessible to any specific user along with the associated access privileges.
The administrator should be able to enter, edit, delete or retrieve all attributes of a user-ID (except for a password, which should not be retrievable).
The administrator should limit the use of a “null password” during system login on a per user or per port basis (i.e., during new release installation).
The administrator should be able to save the security log for safe storage, so that it is not written over when the buffer is full.
All security parameters (e.g., password-ageing interval, time-out interval, and various alarm conditions) should be specifiable and adjustable by the administrator. This implies that the 3GPP node should not have any security parameters hard coded.
8.3.7 Documentation
Any 3GPP node supplier/vendor should provide documentation on security considerations for administrators, operators, and users. They can be stand-alone documents or sections incorporated in appropriate vendor manuals.
The administrator’s guide should contain items such as: functions and privileges that need to be controlled to secure the facility, proper usage of security audit tools, procedures for examining and maintaining audit files, procedures for periodic saving and backup of security logs, recommendations on setting the minimum access permissions on all files, directories, and databases, guidelines on security assessment techniques.
The operator’s guide should contain procedures necessary to initially start the 3GPP node in a secure manner and to resume secure operation after any lapse that may have occurred.
The user’s guide should describe the protection mechanisms that are non-transparent to the user, should explain their purpose, and provide guidelines on their use. It should not contain any information that could jeopardise the security of the 3GPP node if made public.
Passwords should be stored in a one-way encrypted form, and should not be retrievable by any user including managers or administrators (of system and security). Also, there should be no clear text display (on a device such as a screen, typewriter, or printer) of a password at any time (e.g., login, file dump, etc.).
The 3GPP node should allow passwords to be user changeable (requiring reauthentication), and should require that the user change it the first time he/she establishes a session with the password assigned to him/her. The default should be non-trivial in nature, ideally random.
9 Inter Network Security
9.1 Signalling system Number 7
Mobile networks primarily use Signaling System no. 7 (SS7) for communication between networks for such activities as authentication, location update, and supplementary services and call control. The messages unique to 3GPP are MAP messages.
The security of the global SS7 network as a transport system for signaling messages e.g. authentication and supplementary services such as call forwarding is open to major compromise.
The problem with the current SS7 system is that messages can be altered, injected or deleted into the global SS7 networks in an uncontrolled manner.
In the past, SS7 traffic was passed between major PTO’s covered under treaty organization and the number of operators was relatively small and the risk of compromise was low.
Networks are getting smaller and more numerous. Opportunities for unintentional mishaps will increase, as will the opportunities for hackers and other abusers of networks.
With the increase in different types of operators and the increase in the number of interconnection circuits there is an ever-growing loss of control of security of the signaling networks.
There is also exponential growth in the use of interconnection between the telecommunication networks and the Internet .The IT community now has many protocol converters for conversion of SS7 data to IP, primarily for the transportation of voice and data over the IP networks. In addition new services such as those based on IN will lead to a growing use of the SS7 network for general data transfers.
There have been a number of incidents from accidental action, which have damaged a network. To date, there have been very few deliberate actions.
The availability of cheap PC based equipment that can be used to access networks and the ready availability of access gateways on the Internet will lead to compromise of SS7 signaling and this will effect mobile operators.
The risk of attack has been recognised in the USA at the highest level of the President’s office indicating concern on SS7. It is understood that the T1, an American group is seriously considering the issue.
For the network operator there is some policing of incoming signaling on most switches already, but this is dependent on the make of switch as well as on the way the switch is configured by operators.
Some engineering equipment is not substantially different from other advanced protocol analysers in terms of its fraud potential, but is more intelligent and can be programmed more easily.
The SS7 network as presently engineered is insecure. It is vitally important that network operators ensure that signaling screening of SS7 incoming messages takes place at the entry points to their networks and that operations and maintenance systems alert against unusual SS7 messages. There are a number of messages that can have a significant effect on the operation of the network and inappropriate messages should be controlled at entry point.
Network operators network security engineers should on a regular basis carry out monitoring of signaling links for these inappropriate messages. In signing agreements with roaming partners and carrying out roaming testing, review of messages and also to seek appropriate confirmation that network operators are also screening incoming SS7 messages their networks to ensure that no rouge messages appear.
In summary there is no adequate security left in SS7. Mobile operators need to protect them selves from attack from hackers and inadvertent action that could stop a network or networks operating correctly.
Operators should note that HPLMN control over a subscriber roaming in a VPLMN using different MAP release could be limited. To avoid this, operators should assure that their roaming partners use the current MAP version, as specified by the 3GPP Association.
10 Intra network security
10.1 3GPP Network elements and interfaces
Unauthorised, local or remote access to 3GPP network elements can result in access to confidential data stored by system entities, unauthorised access to services and resources, misuse of the network element to gain access to data or services or denial of service. The following section gives an outline of potential threats related to attacks on 3GPP network elements and recommendations.
10.1.1 Home Location Register - HLR
An unauthorised access to HLR could result in activating subscribers not seen by the billing system, thus not chargeable. Services may also be activated or deactivated for each subscriber, thus allowing unauthorised access to services or denial of service attacks. In certain circumstances it is possible to use Man-Machine (MM) commands to monitor other HLR user’s action - this would also often allow for unauthorised access to data.
An operator should not rely on the fact that an intruder’s knowledge on particular vendor’s MM language will be limited. Those attacks can be performed both by external intruders and by operator’s employees.
Access control to HLRs should be based on user profiles, using at least a unique username and a password as authentication data. Remote access to HLR should be protected from eavesdropping, source and destination spoofing and session hijacking. An operator may therefore wish to limit the range of protocols available for communication with HLR..
10.1.2 Authentication Centre - AuC
An intruder who gains direct access to an AuC can effectively clone all subscribers whose data he had access to.
Number of employees having physical and logical access to AuC should be limited. From security point of view it is then reasonable to use an AuC which is not integrated with HLR.
Operators should carefully consider the need for encryption of AuC data. Some vendors use default encryption, the algorithm being proprietary and confidential. It should be noted that strength of such encryption could be questionable.
If decided to use an add-on ciphering facility, attention should be paid to cryptographic key management. Careless use of such equipment could even lower AuC security.
Authentication triplets can be obtained from AuC by masquerading as another system entity (namely HLR). The threat is present when HLR and AuC are physically separated.
10.1.3 Mobile Switching Centre - MSC
An MSC is one of the most important nodes of any 3GPP network. It handles all calls incoming to, or originating from subscribers visiting the given switch area. Unauthorised, local or remote, access to an MSC would likely result in the loss of confidentiality of user data, unauthorised access to services or denial of service for large numbers of subscribers.
It is strongly recommended that access to MSCs is restricted, both in terms of physical and logical access. It is also recommended that their physical location is not made public.
When co-located, several MSCs should be independent (i.e. separated power, transmission,) in order to limit the impacts from accidents on one particular MSC (e.g. fire).
10.1.4 3GPP network interfaces
An intruder gaining access to 3GPP network interfaces would primary gain access to information sent on the interface targeted. However, playing denial-of-service attacks would also be feasible - dependent on how the interface is technically realised (e.g. cable or wireless).
Telecommunication networks are usually designed with necessary redundancy, allowing for reconfiguration in case of loss of a link or links. From security point of view it is particularly important to foresee alternate connection paths where links vulnerable to denial-of-service attacks (e.g., microwave links susceptible to jamming) are in use.
10.1.5 Billing system / Customer Care system
Billing/customer care systems are critical for maintaining the business continuity of a 3GPP Operator.
Unauthorised access to the billing or customer care system could result in
• loss of revenue due to manipulated CDRs (on the mediation device/billing system level)
• unauthorised applying of service discounts (customer care system level), unauthorised access to services (false subscriptions)
• and even denial of service - by repeated launching of resource - consuming system jobs.
Attention should be paid to the fact that access rights to the billing/customer care system are often granted to temporary employees.
As 3GPP network operators should introduce proper access control mechanisms, coherent with the Operator’s general security policy. In particular, it would be advisable to:
• Control the access to the billing data on the database level.
• All users of the billing system should be authenticated by the billing database and access rights should be granted by the database upon successful authentication. Relaying on the application-to-database authentication leaves the database open for a skilled attacker.
• Review the activation process.
The same employee should not carry out both tasks; data verification should involve a trusted employee. Activation should be made only upon confirmation of the person verifying the data entered.
11 User Module and Smart Card
If a 3GPP SIM is integrated on a multi-application smart card, there should be sufficient guarantees that the Ki cannot be read or used by any application other than the 3GPP application. Also there should be clear and secure procedures for placing applications and information on the smart card, ensuring that 3GPP information cannot be changed in an unauthorised way. There should be clear responsibilities and procedures for dealing with stolen or malfunctioning cards.
The importance of secure management of Ki’s is already detailed above. In addition it is important that SIM status lists are kept up to date and that operators define measures to detect and investigate the misuse of SIMs. There should be procedures to replace SIMs, for example at the end of their validity period, and to deal with stolen SIMs. It is particularly important that individual operators devise and operate secure SIM management processes with their SIM suppliers and throughout the SIM distribution channel.
12 Algorithms
12.1 Authentication algorithm
3GPP does not define a standard authentication algorithm, allowing operators to choose their own versions, which comply with the published standards. However, in order to help operators guidelines are available as to how to develop a suitable algorithm. The authentication algorithm is contained within the smart card.
The individual key for each IMSI must be chosen to be random, and must be protected in order to prevent the user from being duplicated. Throughout the security process Ki should be protected.
12.2 Confidentiality algorithm
3GPP defines a standard confidentiality algorithm, which is contained within all mobiles, and protects user data from the mobile to the serving node. This is not only over the radio path as in GSM, but also continues back over the links to the serving node.
The confidentiality algorithm, called Kasumi, is expected to be published.
13 Services
There are many value-added services within the ETSI standards, which will sometimes, when wrongly implemented or interpreted, can be used for fraud.
For example, call forwarding can be set which will then allow calls made to a mobile to be sent to expensive destination numbers. This could be done, for example, by ringing a mobile customer and getting them to put in a call forward number themselves by persuading them that they are testing the mobile.
Many other similar problems exist, such as follow-me services, voicemail, and explicit call transfer. It is to expected that as the services offered by 3GPP become more complex (and include for example Internet connectivity, packet data services as well as MExE which runs code on the mobile, and Java multi application smart cards) then the problem can only become worse.
Operators should ensure that they look carefully at every new network feature and service product to ensure that such problems will not occur in their networks.
13.1 Location services
The location service feature in 3GPP depends on the accuracy of the mechanism used within the mobile equipment. It cannot be though of as accurate, as the mobile software can be modified, or the GPS (Global Positioning System by Satellite) could be displaced by a differential input.
13.2 Mobile Execution Environment - MExE
The ability to remotely modify remote and run code on a mobile clearly introduces a security risk. In the case of MExE it is up to the user to determine if a possible security risk is introduced, and stop the action from taking place. It is to be expected that a smart attacker will be able to introduce code that will fool a user into setting up services or connection that will compromise them or result them in losing money.
14 Index
15
16 History
Document history
1.0.0
Oct 1999
Publication as first draft to 3GPP TSG SA WG3 Security
1.1.0
Nov 1999
Presented at No 6 for information
1.2.0
Jan 2000
Presented at No 10 for comment
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