France Telecom Orange LTE EPC

StrategyOvercoming the technical challenges

Rémi Thomas

Director of the LTE EPC Programme in FT/Orange.

May 2012

2

Agenda

Drivers for an LTE/EPC launch

Some technical items

Some hints about the LTE/EPC launch roadmap

123

3

Drivers for an LTE/EPC launch

1 2 3

4

population 3G+ coverage% of network HSDPA/HSUPA enabled Yoy mobile data traffic growth

100%

90 %

X 1.2

Mobistar

100%

95 %

X 2.3

Orange France

100%

90%

X 1.8

Orange Spain

~ 90%

94 %

X 1.9

Orange Switzerland

100%59%

X 2.4

Orange Poland

100%

69%

X 1.8

Orange Slovakia

100%76%

Orange Moldova

100%

52%

X 1.5

Orange Romania

3G development is continuing3G+ coverage is becoming the standard in Europe

Services are delivered through a consistent utilisation of a single technology family:

GSM, EDGE, 3G (UMTS phase 1), HSDPA, HSUPA and HSPA+.

LTE EPC is our next technical step.

X 2.2

Orange Mobile Networks in

Europe: situation end of 2010

5

The trials confirmed the expected performance of LTE/EPC

Higher throughputs at the radio interface

Shorter response time

� Radio interface Throughput for a single user with a 20 MHz channel:

– Downlink in the optimal radio conditions: 100 Mbps

– Uplink in the optimal radio conditions: 30-50 Mbps

– Downlink at the cell edge: 3 to 9 Mbps

� Cell Capacity taking into account the different radio conditions with a 20 MHz channel

– Around 40 Mbps downlink can be shared between the different users utilising simultaneously the radio resource of a given cell equipped with a 20 MHz channel.

� LTE can deliver a very low latency experience

– This enables even the most demanding applications such as onlinegaming

� Idle to Active transition time

– To provide many users with an ‘always-on’ experience, LTE is designed with a low idle to active transition time (100ms).

– All UEs sit in an idle state when there is no data to transfer – but can be activated quickly when they need to communicate.

6

2G2G2G2G 3G3G3G3G LTELTELTELTE

packet

circuit� No more RNC

� It is the natural evolution for the

GSM/UMTS world; it has been

selected by IS95 operators as well

� Backward terminal compatibility;

multi modes operation

selection/reselection and

handover between LTE and 2G/3G

AccessAccessAccessAccess

networknetworknetworknetwork

CoreCoreCoreCore

networknetworknetworknetwork

packet

circuitpacket

RNC

nodeB

BSC

BTS

LTE eNodeB

LTE/EPC is the next step of the GSM/UMTS mobile networks

evolution. It is compatible with GSM/UMTS.

It is an all IP mobile with a packet domain only

� New radio interface, with various

bandwidth (typically 5 MHz, 10 MHz, 20

MHz)

� Support of FDD and TDD

� Improved efficiency compared to 3G

(high throughput UL&DL, lower latency,

higher cell capacity), providing tens of

Mbps for a 20 MHz channel

� Specified in many frequency

bands

� Packet onlyPacket onlyPacket onlyPacket only, no circuit modeno circuit modeno circuit modeno circuit mode

LTE launch will not be driven by a “killer application” but it will essentially be driven by

capacity needs.

LTE will as well improve the customer experience.

7

Some technical items- Voice for the LTE/EPC subscribers

- QoS features

- Self Organising Networks

- Roaming

- Devices

1 2 3

8

� Voice over CS

– Initially camping under E-UTRAN, when phone calls, they are transferred to 2G/3G CS

� CSFB requires the UE to be combined-attached to EPC and CS through SGs

– Similar to GPRS/IMSI Attach procedure

� When falling-back to 2G/3G CS for voice, DATA sessions (if available) are also transferred to 2G/3G PS, then

re-transferred to EPC once the call is released

� CSFB includes VOICE, LCS and USSD (and not only VOICE.)

– And SMS over SGs feature should be used.

� Since CSFB requires combined-attach and combined TAU/RAU � operators should be careful on how to

distribute the TAs and LAs

I

II

Delivering voice to LTE customers 1/5CSFB Architecture Overview

9

Delivering voice to LTE customers 2/5

� Solution for the launch and for roaming: CS Fallback (CSFB)

– UE is registered on LTE/EPC and on 2G/3G network (combined update)

– when receiving (or setting up) a call, UE handoffs to 2G/3G to establish a

CS call on 2G/3G

– SGs interface required between MSC and MME (like the Gs between SGSN

and MSC) to do combined location update, paging and HO signalling

between MME and MSC (also used for SMS)

– data session is also transferred to 2G/3G network (possible decreased

bitrate) or is dropped

� Target Architecture: VoIP managed by IMS and SRVCC to ensure service

continuity

10

Delivering voice to LTE customers 3/5Why IMS for LTE voice?

� VoIP is the only solution to support voice over LTE/EPC

– because there is no Circuit Switched (CS) domain on LTE/EPC

� IMS is the recommended VoIP solution to support voice over

LTE/EPC because

– only standard solution

– allows handover to 2G/3G CS domain (SR VCC)

– allows development of new multimedia services and

convergence with other access networks

11

Delivering voice to LTE customers 4/5IMS challenges for voice over LTE

� Although most of relevant features will be defined in 3GPP R9/R10, still a

lot to be defined/agreed for proper interworking

– OneVoice, Voice over LTE project in GSMA

� Managing the E2E QoS of IMS voice over LTE/EPC is completely different

(and more complex) than CS voice

� Migration of current CS services to IMS domain

– Supplementary services, IN services …

– consistency of voice service from user experience point of view on different

access networks

� Complexity and performance of SR VCC

12

Delivering voice to LTE customers 5/5A summary

target

architecture

� VoIP is to be steered by IMS, with efficient use of radio

resources and IMS-enabled support of advanced services.

� IMS is the target solution for real time convergent services.

� Challenge: migration of existing features/services which are

delivered today by a cs based infrastructure

handover � At the border of LTE coverage, SR-VCC will provide hand-over

to 2G and 3G coverage by same operator

roaming

� International roaming with 2G-3G networks is warranted

� All LTE terminals will be multimode terminals, therefore at least

benefit from voice service on legacy networks

migratory

solution

� Fall back on 3G network for voice, as standardized by 3GPP

(use of CSFB) according to the NGMN Recommendation

� This will be the first solution to deliver voice service to the LTE

subscribers;

� ChallengeChallengeChallengeChallenge: ensuring an acceptable call establishment delay and

avoiding impacts on the data services.

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QoS management, QoS features 1/3

� QoS management on LTE/EPC: service and user differentiation is

natively possible

– QoS management features and equipment, are natively standardised for

LTE/EPC networks, which was not the case for 3G.

– QoS management is performed at core network level; handset role is

only to accept network commands.

– As a consequence, service and user differentiation can be implemented

from the first commercial launches.

� Basic Quality of Service

– LTE- EPC system is able to handle single or multiple simultaneous

Guaranteed Bit Rates (GBR) & Maximum Bit Rates.

– When necessary, throughput of non-GBR bearers will have to be

sacrificed. In case of severe congestion, when some GBR services have

to be deteriorated, the system starts with those having the lowest

Allocation & Retention Profile.

14

6 LSTI Trials6 LSTI Trials6 LSTI Trials6 LSTI Trials in both FDD & TDD have demonstrated that the LTE- EPC

system is able to handle single or multiple simultaneous Guaranteed Bit

Rates & Maximum Bit Rates.

GBR setting can be successfully maintained. When necessary, throughput of

non-GBR bearers will have to be sacrificed. In case of severe congestion,

when some GBR services have to be deteriorated, the system starts with

those having the lowest Allocation & Retention Profile.

1 -All UEs with default bearer2 -UE1 with GBR (7 Mbps)3 -All UEs with default bearer4 -UE2 with GBR (7 Mbps)…

0123456789

0 100 200 300 400 500Time (s)

Thr

ough

put (

Mbp

s) UE1 UE2 UE3 UE4QoS differentiation in UL

1 2 3 4

QoS management, QoS features 2/3

Tests results of Basic Quality of Service features

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QoS management, QoS features 3/3Examples of possible QoS management strategies on LTE/EPC networks

� No QoS differentiation, as on legacy networks : best effort QoS whatever the

service and the user and no “QoS differentiated” offers proposed to our

customers

Even in this case, the question of maximum authorized bit rate is raised: maximum

offered by LTE technical capabilities (max. bit rate in downlink up to 100Mbits/s!) as

in legacy networks or application of a different maximum bit rate?

� Light QoS differentiation : put different priorities and Maximum Bit Rates on

different services and/or users to protect statistically these sessions in case of

congestion

Example: higher priority and bit rates for premium users

� Advanced QoS differentiation : implement guaranteed QoS for some specific

services and/or users and use it as a differentiator in the offers

Example: guaranteed QoS for Voice over IP or streaming services for ensuring a very good

quality on this type of services, even in case of congestion

� Choices shall be performed by each operator.

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SON Features

Self-Organizing Networks

� SON features allow to automate some Network functions and some OA&M functions

� SON functions can be activated during:

� Network Deployment

Self-configuration features: Plug & Play eNodeBs

Automated PCI Configuration : Automatic configuration of the Physical Cell IDs

Automatic Neighbour Relation management - ANR : Allowing ENodeBs to build and to maintain neighbour relationships

� Network Operations

– Self-Healing (i.e. auto-repair)

� Network Optimization; some examples:

– Mobility Load balancing optimisation

– RACH Optimisation

– Coverage and capacity optimization

– …

� It will be indispensable to test and optimise these features before we could be able relying on them

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Implementing roaming in the LTE/EPC networks 1/2

� The first step will consist in providing roaming for the data only

services

– The relevant 3GPP specifications and GSMA deliverables have been

completed.

– New nodes shall be deployed in the Core Networks

� Then CSFB voice will utilise both the present 2G/3G roaming and the

LTE/EPC roaming.

� Then VoLTE will be implemented according to the GSMA deliverables

– IR92 (UE to IMS core interface)

– IR88 (LTE roaming)

– IR65 (IMS roaming)

� These specifications shall allow an handling specific to the voice

service and distinct from the data services

18

Implementing roaming in the LTE/EPC networks 2/2LTE roaming architecture for data services

PDN Gw is required

because a GGSN

does not support S8

A combined

HLR/HSS is required

to cope with

authentication and

mobility in LTE/3G/2G

A Diameter Edge

Agent is required to

route signaling

between PLMN

19

LTE Devices

� All LTE devices shall comprise at least:

– GSM/EDGE on 4 bands

– UMTS/HSPA on 3 bands

– And LTE on some bands:

-> The first implementations should include at least 4 bands for LTE

- Bands 3 (1800 MHz), 20 (800 MHz) and 7 (2600 MHz) are indispensable for the LTE roaming in Europe

- World roaming will be in some cases ensured by fall back on UMTS/HSPA

- More than 4 LTE bands shall be implemented in a near future

-> High frequency bands = capacity in the urban areas

-> Low frequency bands = improve coverage (rural areas, indoor coverage)

� We need LTE devices implementing CSFB voice according to the options recommended by NGMN

� Then the LTE devices shall implement VoIP in a near future

– This implementation shall be compliant to the 3GPP specifications and to the VoLTE requirements outlined in the GSMA deliverables

� The devices shall support the SON features (e.g. ANR and MDT)

20

Some hints about the LTE/EPC

launch roadmap

1 2 3

Spectrum auctions planning

800 MHz

Band still partially occupied after auction

Band free to use after auction

1.8 GHz2.6 GHz

2013

UK

Belgium

France

Done

H1 2013

Poland

Q3 2012

Slovakia

2012

Moldova**

Done

Spain

spectrum trading

Armenia

2013

Egypt

?

H1 2012

H1 2013

Done

2013

April 2012

900 MHz

Done

2.1 GHz

Done

Q3 2012

Portugal

Done

Done

Done

Done

Done 2013

Done

Q2 2012

Q2 2012

Luxembourg*

* Beauty contest

** Administrative assignment

DoneJul 2012

Romania

Jul 2012

H2 2012

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Tasks towards a commercial launch

� The spectrum allocation schedule allows some deployment in 2012

� We depend on the spectrum allocations schedule; in addition we want to

ensure first time right and leverage the LTE efficiency to improve customer

quality and decrease cost to serve

� As a consequence different tasks shall be completed before an LTE/EPC

commercial launch

� Radio Aspects– Optimisation

– SON features

� Interworking between the LTE EPC network and the legacy networks (2G

and 3G).– 3G/LTE features shall be tested and optimised

� Services migration– SMS services which shall be available from Day 1 using SMS over SGs

– Voice service: CSFB; target solution will rely on IMS/SRVCC

� Implementing the QoS differentiation features; ensuring End to End QoS

Marketing and economic requirements will drive commercial launch. The main

driver for LTE commercial launch is still the need of network capacity for mobile

data.

23

Some achievements and plans for the near future

� Orange Moldova deployed an LTE trial network which covers Chisinau, the Capital City of the country.

– This network delivers to friendly testers the end to end performance (throughput, latency) expected from the LTE technology.

– The commercial launch will be possible as soon as the licence is awarded.

� The auction process for the 800 MHz and 2600 MHz bands has not yet been launched in UK and will not conclude until 2013 Q1/2In the mean time EE aim to start roll out using LTE 1800 to provide service in 2012

– Clearance from OFCOM regarding the use of 1800 MHz for LTE is awaited

� Orange France are rolling out LTE

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� For their contributions to my presentation, it is my pleasure to thank some

colleagues of mine :

Yves BELLEGO

Frédéric BONNIN

Serge DANAN

Laurent DUBESSET

Nathalie JOLLIVET

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thank you

merci

danke

obrigado

graciasgrazie

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