IMOBIX presentation to APT Workshop on International Mobile Roaming (IMR) in Hong Kong (June 2011)

1. Evolution to 4G and Impacts on IMR
APT Workshop on IMR / Hong Kong, China / June, 2011
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2. Introduction
 This presentation’s scope is limited to an overview on LTE (4GSM)
deployment and its impact on International Mobile Roaming.
 Roaming LTE deployment is affected by both the complexity of
national implementation and the complexity of Multiple Network
Interoperability
 For the sake of clarification, the main challenges and impacts to be
reviewed are grouped as follows:
 Roaming Availability & Handsets
 Roaming Network Architecture
 Roaming Management
 Roaming Business Models
 Fraud and Security
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3. (Vo)LTE Standardization Roadmap
Standards approval processes across different Industry Associations might collide
with a major impact on LTE Roadmap. Roaming Frameworks standardization
currently scheduled for March 2012 could be delayed
User-network Network- Roaming Roaming Call Commercial
interface defined network interface Architecture, Jan Scenarios, May Framework
Apr 2010 defined Jun 2010 2011 2011 templates, Nov 2011
LIVE VoLTE
2010 2011 NETWORKS
2012
GSMA VoLTE initiative GSMA VoLTE demo GSMA VoLTE handset call GSMA and Multi-
announced at Mobile with CSL at Mobile Asia demo with Verizon at Service Forum VoLTE
World Congress Feb 2010 Congress, Nov 2010 Mobile World test event, Sep 2011
Congress, Feb 2011
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4. Roaming Availability & Handsets

5. Roaming Availability & Handsets
Roaming services and handset availability strongly depends on the
frequencies used by the visited network:
 Currently there are no global answers for LTE spectrum allocation
and harmonization.
 Differences of technology adoption across the world are a main
threat to global Roaming availability
 LTE-only Handsets are multimode and support both available
frequencies (FDD and TDD), however there may be a need for
“penta-band” LTE handsets (700/900/1800/1900/2600) for
international roaming.
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6. Roaming Availability & Handsets
LTE Duplex Schemes Compared
Item TDD FDD
Does not require paired spectrum as both Requires paired spectrum with sufficient
Paired Spectrum transmit and receive occur on the same frequency separation to allow
channel simultaneous transmission and reception
Substantially lower cost (no diplexer
Hardware cost needed) Diplexer is needed and cost is higher
Channel propagation is the same in both Different channel characteristic (use of
Channel reciprocity
directions different frequencies)
Fixed Capacity allocation as determined
UL / DL asymmetry
Dynamic UL/DL capacity allocation by local authority
Large Guard Periods are requested to
Guard period / Guard band avoid UL/DL clashes in case of big No issue associated with Guard Bands
distance; thus reducing capacity parameters
Discountinuous UL vs. DL transmission
Discontinuous Transmission
impacts negatively on RF performance Continuous Transmission applies
Base Stations should be constantly
Cross Slot Interface alligned (syncronized) to UL/DL Capacity
allocation changes Not applicable
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7. Roaming Availability & Handsets
FDD Scheme / Frequencies TDD Scheme / Frequencies
TDD Band FDD
Allocation (MHz) Main Regions of Use Uplink Downlink
Band
Number 3G Main Regions of Use
Numbe
(MHz) (MHz)
r
33 1900 - 1920 Asia (not Japan), Europe 1 1920 - 1980 2110 - 2170 √ Asia, Europe
2 1850 - 1910 1930 - 1990 √ Americas, Asia
34 2010 - 2025 Asia, Europe 3 1710 - 1785 1805 -1880 √ Americas, Asia, Europe
35 1850 - 1910 Americas 4 1710 - 1755 2110 - 2155 √ Americas
5 824 - 849 869 - 894 √ Americas
36 1930 - 1990 Americas 6 830 - 840 875 - 885 Japan
37 1910 - 1930 7 2500 - 2570 2620 - 2690 Asia, Europe
8 880 - 915 925 - 960 Asia, Europe
38 2570 - 2620 Europe 9 1749.9 - 1784.9 1844.9 - 1879.9 Japan
39 1880 - 1920 China 10 1710 - 1770 2110 - 2170 Americas
11 1427.9 - 1452.9 1475.9 - 1500.9 Japan
40 2300 - 2400 Asia, Europe 12 698 - 716 728 - 746 USA
41 3400 - 3600 USA 13 777 - 787 746 - 756 USA
14 788 - 798 758 - 768 USA
17 704 - 716 734 - 746 USA
 Coexistence of UMTS and LTE might be an issue 18 815 - 830 860 - 875 Japan
19 830 - 845 875 - 890 Japan
– CEPT Report 40. 20 832 - 862 791 - 821 Europe
 Use of existing spectrum by operators may 21 1447.9 - 1462.9 1495.5 - 1510.9
22 3410 - 3500 3510 - 3600
Japan
determine use of FDD or TDD.
 New spectrum allocations depend on regulatory
authorities
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8. Roaming Availability & Handsets
 LTE (S8) and 3G via GGSN (Gp) or PGW (Gp) or PGW (S4/S8)
 LTE (S8) and 3G via GGSN (Gp) or PGW (S4/S8)
 LTE (S8) and 3G via GGSN (Gp) or PGW (Gp)
 LTE (S8) and 3G via PGW (S4/S8) or PGW (Gp)
 LTE (S8) and 3G via PGW (S4/S8)
 LTE (S8) and 3G via PGW (Gp)
 LTE (S8) and GPRS (Gp)
 LTE only
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9. Roaming Availability & Handsets:
The Path Forward
 Regulators and Operators should work closely together on the allocation of frequencies
and bands that are compatible with top Partner Countries and consider intra and inter-
regional Roaming requirements
 During the LTE World Summit Orange, TeliaSonera and T-Mobile promoted the use of
1800MHz for rolling out LTE globally. This frequency band was identified as best
compromise between coverage and capacity.
 EU Digital Agenda Vice President Neelie Kroes announced that the EU will ensure
leveraged licensing across member countries in order to facilitate International Roaming
availability.
 The European Commission has established rules for licenses allocation that member
countries shall adopt by end of 2011. Among others, this Regulation promotes and sets
out the technical parameters for allowing the co-existence on the 900MHz and 1800MHz
bands of 2G, 3G and 4G/LTE/WiMAX services
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10. Roaming Network Architecture

11. 2G/3G Roaming
Voice Roaming Data Roaming Data services
Core Core
Network Network
Home Network Home Network
SS7
Visited Network Visited Network
Other networks
Radio Core Radio Core
Access Network Access Network
• Voice traffic routed directly from the visited network. • Data traffic routed directly to home network via GRX.
• Optimized path for QoS. • Enables control of data sessions.
• Signaling via SS7 for subscription/mobility management.
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12. Roaming Network Architecture Impact
 LTE Roaming - Main differences from 3GSM Roaming are:
- New Network Elements - New Protocols
- New Interfaces
Data services
No more SS7 Signaling  Legacy solution.
Signaling over IPX Core  Home operator maintains control.
Network
Home Network
IPX
Visited Network
Core  New option to route delay sensitive services
Radio Access
Network via visited network.
 Challenges:
Data services  Is this acceptable to operators?
 Customer experience/customer
control?
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13. Roaming Architecture
HSS PCRF
Gx Rx
S6a
PDN SGi Operator’s IP
Gateway Services
(e.g. IMS, PSS etc.)
HPLMN
VPLMN
UTRAN S8
SGSN  In LTE there is only IP roaming
GERAN
S12
S3
S4
 The signaling protocol is not MAP/SS7
S1-MME
MME anymore but is a Diameter Application
S10
S11
 Diameter is an IP based protocol
“ LTE - Uu ” Serving
Gateway
standardized by IETF
UE E-UTRAN
S1-U
Home routed traffic-using GTP-based S8
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14. Roaming Network Architecture Impact
 LTE was originally thought to be a purely IP based cellular data service.
Recently defined standards for of Voice and SMS services over LTE (VoLTE)
are under revision due to Roaming feasibility. Major impact was identified
with:
 Calls handover between networks with multiple technologies
 Optimal Routing for Roaming voice calls
 Security and Fraud threat audit
 Increased need for VoLTE quality
 Flexibility of LTE implementation options represents a threat to
interoperability. Solutions implemented today might need substantial
assessment for future impacts on interoperability and IMR.
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15. Roaming Network Architecture Impact:
The Path Forward
 Mobile Operators need to monitor on-going changes in LTE standards and
ensure Roaming requirements are taken into account during the planning
phase
 LTE implementation option(s) should be submitted for expert review and
Roaming requirements should be considered
 Current LTE Roaming standards are still subject to dynamic changes. Mobile
Operators need to keep up-to-date with developments during the current
planning phase
 LTE network capacity planning must be reviewed with LTE Roaming
deployment in mind
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16. Roaming Management Impact

17. Roaming Management Impact
 New interfaces will have to be integrated into the Roaming Agreements: The
new environment requires legal framework assessment and the creation of
new documents
 Requirements and capabilities associated with roaming hubbing are being
analyzed
 Mandatory Automated Agreements (technical & commercial details) update
procedure (also called RAEX) does not currently support LTE
 Major efforts are being invested across the GSM Association Working Groups
to upgrade/assess all Permanent Reference Documents (PRDs) related to the
Roaming contracts
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18. Roaming Agreements Impact:
The Path Forward
 MVNOs should support GSMAs initiative for developments of standards
and minimize interoperability risks by ensuring GSMA standards
implementation
 Review current Roaming Operational procedures and verify scalability to
an LTE Roaming environment
 Vendor services contracts should be reviewed and analyzed for LTE
scalability ASAP (especially related to SLAs, volume based pricing, long
term committments)
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19. Roaming Business Model

20. Roaming Business Models Impact
 Current LTE architecture does not support certain Roaming scenarios, thus
restricting business models options.
 The recently adopted ‘Activity based’ retail charging (f.i. Facebook, Youtube,
Google browsing included in a bundle) may not be feasible in an LTE Roaming
environment
 In this LTE migration phase, operators tend to keep a conservative approach
towards wholesale business models so that charging principles will not
present major changes
 Revenue Assurance mechanisms and required reporting will have to be
assessed for the new LTE environment
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21. Fraud & Security

22. Fraud & Security Impact
 The merger of mobile, fixed and internet networks are now
opening a once protected infrastructure
 Development of Internet Innovations such as Social
Networking will enable access to ‘vulnerable’ operators
contact and Network Privileges
 SIM server technology used in GSM gateway (SIM box) bypass
could be used to relocate SIM cards in an international
extension of fraud
 Major risks are associated to Premium Rate Numbers usage in
a VoLTE environment (IRSF)
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23. Fraud & Security Impact
 Fraud reduction measures are currently under discussion. Current
procedures (Near Real Time Roaming Data Exchange) might be adapted
but a debate on alternative solutions is still ongoing.
NRTRDE CONs NRTRDE PROs
 Home Operator has full control  NRTRDE principles and
on traffic so that Anti Fraud framework are ready
procedures can be easily  Vendors promise small costs
implemented ‘in-network’ impact
 Alternative solutions present
 NRTRDE is commonly out-
gaps in case of CS-LTE calls
sourced to a vendor thus with a handover
negative impact on general costs
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24. Fraud & Security Impact
 Current GSM and UMTS security measures & methods are
being reviewed
 Newer security algorithms, longer keys are needed
 Extended key hierarchy is required
 New features, addressing new scenarios:
 Home evolved Node B
 Relay Node
 New topics
 Machine-Type Communication, Single Sign-On,
Protection against Unsolicited Communication over IMS
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25. Conclusion

26. Conclusion
 A large number of implementation options are planned for LTE
based on current standards.
 This flexibility constitutes a threat to interoperability which fully
depends on set-up and migration compatibility.
 While LTE Data Roaming Framework can be finalized soon, VoLte
Roaming standardization, which is planned for March 2012, will be
subjected to further delays.
 Current wholesale and retail roaming pricing paradigms to not
support the potential shift of services and volumes for LTE roaming.
 Potential customer impacts (similar to what happened with
migration from 2G to 3G), but with much higher degree of technical
complexity, greater difficulty to resolve, and larger potential
commercial impact.
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27. Conclusion
Operators are very concerned about LTE Roaming commercial
impacts, such as:
 Additional complexities recently discovered related to VoLTE that were not
taken into account during initial standards planning
 Required 3GPP LTE architecture changes are on-going while over 20
operators have already launched LTE services.
 New assessments will be required for those operators that are/will be LTE
provisioned before 2012
 Due to the general trend in deceasing roaming prices (regulation etc. …)
and consequent budget cuts, many operators are choosing to delay or
freeze LTE roaming launch
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28. Contact
IMOBIX
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Jeff Hunter
Mobile: +1 (954) 865-8832
Main: +1 (954) 323-6767
jhunter@imobix.com
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