The Best That LTE Can Be

White paper from
www.femtoforum.org
Todd Mersch
Femto Forum - Promotional Council
Director, Continuous Computing

© Femto Forum Ltd. 2010
© Femto Forum Ltd. 2011 1

Overview
• About Femto Forum
• Motivations for femtocells
• Industry support for LTE femtocells
• The case for LTE femtocells
• Business Case
• Performance
• Services
• Deployment Approaches
• Conclusions


The Femto Forum Aims
• Promoting & enabling femtocells Ecosystem Development
• Not-for-profit, founded in 2007 Market Education
• Independent, Inclusive, International Driving open standards

End to end
system providers

Other
Network enablers
Elements

Products

Components
and So ware

 60 operators covering 1.7 billion mobile  74 providers of femtocell technology
subscribers – 33% of total

Why Femtocells?
• Dramatic growth in mobile broadband
• Consumers increasingly sensitive to coverage for both voice and data–
especially at home and in the office
• Operators need to meet this demand – but quickly and at reduced cost-
per-bit

Explosion of internet Exponential growth of Traffic increasingly
connected devices mobile data traffic indoors
On the move
Out of home / office

>80% indoors
Office
Source: Signals Research Group

Home

Source: Informa


Shannon vs. Moore The Shannon – Moore Divide:
Moore
Shannon channel capacity
• Reaching limits with LTE
Divide
Moore‟s Law: still doubling
• Data-hungry devices
Shannon
• MIMO
LTE
LTE-Advanced
• Carrier aggregation
• Spectrum?

Exponential Problem NEEDS Exponential Solution

What are femtocells?
• Low-power access points…
…using mature mobile technology
…in licensed spectrum
…generating coverage and capacity
…over internet-grade backhaul
…at low prices
…with full operator management
…self-organising, self-managing Generic Femto Network Architecture

Standards in place for:
• Applications include:
• UMTS
• Residential
• LTE
• Enterprise
• CDMA
• Hot spot
• WiMAX
• Metro

Cell Size Shrinkage!

Macrocell
Capacity

Microcell /
Picocell
Greater
Femto

Femtocell

Coverage

Macro Topology Hierarchical Cell Structure

Courtesy AirHop Communications

Coverage Era Capacity Era

1990 2010

“The need for 4G picocells and femtocells to enhance coverage and boost
capacity in hotspots is one of the important principles for Verizon's LTE Network”
-- Verizon Wireless CTO

LTE Femtocells:
Meeting NGMN Recommendations
Cost-optimised indoor node
design - “The NGMN RAN shall
be designed in a way that it allows
a large-scale deployment of Virtually a
cost-optimised plug-and-play femtocell
NGMN-only indoor radio
equipment at a price level of definition
commercial quality WLAN
components. ”

Self-organising
networks: Self- Femtocells are the
planning…, Self- first commercial
Configuration…, Self-
optimisation and self-
instance of a true
tuning…, Self-testing SON
and self-healing…

Femto Forum is working with NGMN Alliance to create the conditions to comply
with these recommendations

LTE Femtocell Standards
• In 3GPP terminology, LTE femtocell = Home eNode-B
• Femtocells have been included from the beginning of LTE
standards, supported by close partnership between 3GPP
and Femto Forum
• The first LTE standards release (3GPP Release 8, completed
April 2009) included support in user equipment for
femtocell-specific features such as Closed User Groups
• 3GPP Release 9 (completed April 2010) added full definition
of the RF and OAM aspects, thereby providing full end-to-
end support for LTE femtocells


Option 1: No HeNB
Architecture Gateway

• Femto/ HeNB fits well with flat
Enhanced Packet Core architecture
• HeNB Gateway is optional and
transparent, delivering concentration
Option 2: HeNB
and scalability without sacrificing
Gateway aggregates all
architectural simplicity traffic
• Reusing standardised open
management approach
• Femtocells form an essential element
in the heterogeneous network
„toolkit‟ for LTE operators (no more Option 3: HeNB VPLMN HPLMN

Gateway aggregates
one-size-fits-all approach) CSG HSS
control traffic only ListSrv

C1(OMA DM /OTA) S6a

S1-MME MME
S1-MME
HeNB
U GW S11
HeNB
E LTE
-Uu
S-GW
S1-U


The Case for LTE Femtocells

Performance Business Case

LTE Femtocells

Deployment
Services
Approaches


Business Case
Business Case

Revenue impact Time-to-market Cost savings

• New revenue • Rapid deployment • Optimised macro
streams from value- of NGN roll-out
added services • Operational savings –
• Rapid provisioning
• Location-specific especially
tariffs without
of new services power, backhaul, site
leakage rental
• Family contracts • Churn reduction –
contract extension

Substantial value to be created, challenging
preconceptions of cellular economics

Business Case
Business Case
• New business case analysis
completed by Signals Research
Group, accounting for the
continued and forecasted growth in
mobile broadband
• Includes two major studies of the
business case for LTE and
LTE/HSPA femtocells


Business Case
Dual Mode Femtocell Business Case
• Add dual mode HSPA/LTE femtocells to existing network:
• Macro-offload savings easily exceed the femtocell cost
• Customer lifetime value increases by 2-10 times in representative scenarios
• Operator with 10 million subscribers deploying to 10% of their base gains a
return on investment of more than 10x

+232% Increase in Household
~ € 500 million network cost saving
Lifetime Value

Business Case

New LTE network business case
• Modest delay to small proportion of macrocell build: 4-10% of sites, by few years
depending on scenario
• Opex savings sufficient to fully fund subsidized offer: free femtocells plus superior
indoor user experience


Performance

Capacity – Reaching Limits?
• Next-generation system performance is • Cooper‟s Law suggests that increasing
close to the Shannon bound the number of cells has always been
the main means of adding capacity

Approaching
the limit

Most gain
from
frequency
re-use

• Need more cells and tighter interference control
to continue to increase capacity


Performance

Higher Rates from Lower Interference
• High SNR and low contention deliver near-peak rate
performance throughout coverage area
50
Throughput
45
(Mbps) Typical femtocell geometry
40 factor in this range
35

LTE Throughput (DL, 4x4, 10 MHz) 30
Substantial
25 increase in
20 throughput
15
Typical macrocell geometry
10 factor in this
5 range, depending on loading
0
-15 -10 -5 0 5 10 15 20

Signal-to-noise plus interference ratio (SINR)


Performance

LTE Femtocell Performance
• Detailed study of the most challenging
scenarios for LTE femtocell deployment:
closed user groups, co-channel with macrocell
etc.
• Addition of femtocells to the network allows
femtocell users to consistently receive much
closer to the headline LTE/WiMAX data rates
than those connected to macrocells.
• Femtocells can achieve this even when using
the same channel as the macro network when
suitable mitigation techniques are adopted.
• Addresses a significant spectrum challenge for
LTE deployment
See www.femtoforum.org


Performance

LTE in femtocell environments
• Propagation environment:
• Home provides site shielding from macrocell
• Rich angular multipath and high SNR, maximising gains available from
MIMO
• Delivers high geometry factor (own : other cell interference)
• Allows LTE to work at its highest modulation rates and
spectral efficiency, delivering great services to a large
number of high-usage customers


Performance
Backhaul Availability & Bit Rates Growing Rapidly
• In all regions, progressive evolution to higher rates is predicted, with major growth in the
period for LTE introduction
• This will differentially favour early adopters of LTE
• Air interface rates exceeding backhaul rates are important to deliver responsive user
experience (cf demand for 11n Wi-Fi)
• Increasing proportions of traffic expected on home LAN, not involving backhaul


Services
Femto Enabling Customer Propositions

With full operator management, in existing
spectrum, at reduced cost-per-bit


Services
Enabling Next-Generation Services
• Femtocell acts as a portal to in-home services and
automation
• High-bandwidth connected-home services
• Femtocells deliver presence, context & location
• A powerful operator opportunity for mobile presence in the
home


Deployment
Femtocells beyond the home
• Not only for the home!
• Femtocell economies of scale can deliver cost-effective deployments in
offices and in high-traffic or low coverage locations
• Femtos in the enterprise and metrozone
• Scope for cost-effective access to rural and developing markets via
appropriate backhaul solutions


Deployment
Self-Organizing Networks
• Self-organizing network capability is crucial to meet the
economics of mobile broadband demand growth with
realistic revenue growth
• Femtocells deliver SON capabilities with 3G today:
• Open interfaces
• Standardised management protocol
• No need for site-specific radio planning or optimisation – but
always within operator-set limits and with full control in
extreme situations
• Enables delivery of many more cells in the network without
increasing operational overhead


Deployment
New Deployment Approaches

Femto-centric NGN femto quick- Match costs to
NGN Introduction start package revenues
• Build femto first • Provide NGN • Avoid „build it
user device and and they will
femto to early come‟
adopters
Revenue

Costs
+
Time


Femto Forum LTE Special Interest Group
• Chaired by Vodafone
• Mission: To ensure that the LTE femtocell requirements, specifications,
product recommendations, and guidelines are delivered to allow
operators to offer compelling new LTE services
• Some goals in 2011:
• Provide clarity on choice of architectures according to operating
environment
• LTE femtocell service requirements and concepts
• Use of spectrum bands for LTE femtocells
• Assessment of LTE multiradio combinations
• High level LTE femtocell product specification
• LTE femtocell deployment guidelines

27

Conclusions
• There is a compelling case for LTE femtocells
• Femtocells have a key role in LTE services:
• Speed-up launch
• Enabling services to encourage adoption
• Delivering performance
• The key launch pad for new services, building demand
beyond the home and supporting business case for wider
roll-out
• Enabling factors being addressed via co-operation in
standards bodies and the Femto Forum
• Femtocells used in harmony with macrocell networks
represent the best that LTE mobile networks can be!

The Best That LTE Can Be

More Related Content

What's hot

Similar to The Best That LTE Can Be

More from Continuous Computing

Recently uploaded

The Best That LTE Can Be