At a recent open workshop hosted by the Small Cell Forum, Mark Grayson (Distinguished Engineer, Cisco) set out plans for a new work stream for the organisation. Focusing on the demand and development of Virtualization, this presentation also outlines the operator needs and a full work plan for the Forum. The aim of the Small Cell Forum is to provide leadership in creating a unified view of the evolving role of virtualized architectures for dense HetNet.

1. New SCF work stream:
Virtualisation of the Small Cell
RAN: Business, Technology,
Architecture
Small Cell Forum
June, 2014

2. • Virtualization technology has emerged as a cornerstone of the IT
industries as it has transformed the way the IT infrastructure is
deployed
• Virtualization is the foundation of cloud computing and forms the
base for offering cloud services
• Essential for every organization to be aware of the virtualization
technology and its benefit
Source: A Survey on Virtualization Service Providers, Security Issues,
Tools and Future Trends, IJCA, May 2013
• “I often get questions from analysts regarding how small cells fits
together with Cloud RAN, so I believe that SCF tackling
virtualisation and small cells is well timed and definitely needed.”
–
Source: Gordon Mansfield
Recognized trend of accelerating
adoption of virtualization
13/06/2014 © Small Cell Forum Ltd 2013

3. • Is there any divergence between how virtualization is viewed from a
macro RAN perspective versus a small cell perspective?
• What are the real business benefits of virtualization in the RAN? Do
benefits apply equally to macro and small cell deployment use cases?
• Can virtualization be used to dynamically optimize costs versus
performance?
• Are current small cell architectures well suited to
virtualization/cloudification?
• Are there unique attributes of small cell transport that impact
fronthaul considerations? (e.g., synchronization, latency, sharing)
• Will virtualization enable enhanced flexibility in the small cell RAN,
e.g., physical layer characteristics (bands, waveforms, …)
• Can virtualization deliver a phased roadmap, e.g., aligned with longer-
term 5G directions
• How do we ensure virtualization supports innovation across a multi-
vendor ecosystem?
Key Questions that the Operator Group
would like the forum to consider
13/06/2014 © Small Cell Forum Ltd 2013

4. 1. Work Stream Rationale
2. Virtualized RAN investigations
3. Proposal
Agenda
13/06/2014 © Small Cell Forum Ltd 2013

5. 1. Work Stream Rationale
13/06/2014 © Small Cell Forum Ltd 2013

6. • Our observation is that vocabulary is currently ambiguous
• Centralization versus Cloudification
• Virtualization versus Resource Sharing
• Decomposition versus hardware-software separation
• We plan to re-use the use-case definition approach leveraged in
earlier releases to align understanding across all SCF working
groups, refine the problem statement(s) and drive prioritization of
these different use-cases
• Q. What lessons can we learn from you and the wider
industry?
A quick disclaimer on terminology
13/06/2014 © Small Cell Forum Ltd 2013

7. • SCF and NET WG already
scoping out re-use of
Network Function
Virtualization to address scale
down use case of
rural/remote in Release 5
timeframe
• Q. Does this address
sufficiently the business
rationale for
virtualization?
Virtualized/Cloudified Small Cell
Infrastructure
13/06/2014 © Small Cell Forum Ltd 2013
Small
Cell
Small
Cell
Small
Gateway
Small
Gateway
Small Cell
Management
System
Small Cell
Management
System
Scope of NET
WG Release 5
Virtualization
Discussions for
rural and
remote
Virtualization
scope not
currently being
addressed

8. • Virtualization no longer just about compute resources, but
virtualization of transmission networks, network functions, network
management, spectrum, radio access technologies
• Recognize that virtualization/cloudification techniques now being
reapplied to eNB base station functionality
• Increased drive towards virtualization to address a number of use
cases, including
• Scalability (scale up/down)
• Improved resource utilization/sharing (lower peak-to-mean)
• Multi-tenancy (Multi-carrier, carrier/enterprise)
• Enhanced resource co-ordination (between small cell and macro
and between small cells)
• Multi-point capability
• Co-located core network virtualized functions
• Q. How is broader industry handling this level of divergence?
Virtualization trends impacting Small
Cell (and other) RAN Solutions
13/06/2014 © Small Cell Forum Ltd 2013

9. RPH
BKH
DEP
NET
MKT
IOT
Small Cell Virtualization – a complex
issue requiring key competencies
13/06/2014 © Small Cell Forum Ltd 2013
• RPH: Analysis of different
virtualization decompositions
(versus small cell radio
performance)
• BKH: Small Cell backhaul
constraints impacting
virtualization
• DEP: Deployment benefits of
small cell virtualization, data
center hosting options
• MKT: Small cell virtualization
business cases
• NET: Network Function
Virtualization aspects
• IOT: Multi-vendor virtualized
environments

10. 2. Virtualized RAN investigations
13/06/2014 © Small Cell Forum Ltd 2013

11. Alternative Virtualized RAN
Decompositions (NGMN)
13/06/2014 © Small Cell Forum Ltd 2013
PDCP
RLC
MAC
PDCP
RLC
MAC
QAM+
Antenna
mapping
QAM+
Antenna
mapping
Resource
Mapping
Resource
Mapping
FECFEC
MAC-PHY
Fronthaul
Split I:
Soft Bit
Fronthaul
Split II:
Subframe data
Fronthaul
User ProcessingUser Processing
IFFT +
Cyclic
Prefix
IFFT +
Cyclic
Prefix Split III:
Subframe
Symbol
Fronthaul
P/S
CPRI
encode
P/S
CPRI
encodeSplit IV:
CPRI or Split IV’:
Compressed CPRI
Fronthaul
Cell ProcessingCell Processing
S1
Backhaul
←Xn→

12. • Cloud-RAN is based on CPRI or Compressed CPRI
• Requires lambda or OTN service with very tight bounds on latency
• Incompatible with current GbE packet switched “last mile” networks
that are preferred approach for deploying today’s small cells
• Q. How interoperable will the systems be, e.g., compared to
SCF plugfest success?
• Q. Will current C-RAN conclusion deliver on aims of Small Cell
Forum?
• Accelerate small cell adoption - seems requirement for Lambda/OTN
service to each small cell site will likely hinder mass adoption; or
• Change the shape of mobile networks – seems there is no revolution
as the innovation in the small cell ecosystem will be have to
continually address the centralization versus distribution issue (and
which may consequently hinder small cell adoption)
Current observations regarding Cloud
RAN investigations
13/06/2014 © Small Cell Forum Ltd 2013

13. • Is there any divergence between how virtualization is viewed from a
macro RAN perspective versus a small cell perspective?
• What are the real business benefits of virtualization in the RAN? Do
benefits apply equally to macro and small cell deployment use cases?
• Can virtualization be used to dynamically optimize costs versus
performance?
• Are current small cell architectures well suited to
virtualization/cloudification?
• Are there unique attributes of small cell transport that impact
fronthaul considerations? (e.g., synchronization, latency, sharing)
• Will virtualization enable enhanced flexibility in the small cell RAN,
e.g., physical layer characteristics (bands, waveforms, …)
• Can virtualization deliver a phased roadmap, e.g., aligned with longer-
term 5G directions
• How do we ensure virtualization supports innovation across a multi-
vendor ecosystem?
Key Questions that the Operator Group
would like the forum to consider
13/06/2014 © Small Cell Forum Ltd 2013

14. 3. Proposal
13/06/2014 © Small Cell Forum Ltd 2013

15. MKT
RPH
DEPBKH
NET
Small Cell Virtualization – a complex
issue
13/06/2014 © Small Cell Forum Ltd 2013
1. Business Case
depends on
2. Enhanced radio
performances
which needs to
be
3. Offset by
deployment costs
5. Which need to
be supported by
system
architecture
4. Which will
likely be driven
by fronthaul
considerations

16. STUDY PHASESTUDY PHASE EXECUTION PHASEEXECUTION PHASE
Virtualization Work Plan
13/06/2014 © Small Cell Forum Ltd 2013
Kick off, Option Analysis
Small Cell Virtualization
Definition
Backhaul/Fronthaul constraints
Backhaul Recommendations for
virtualized Small Cells
Data Center Hosting Options
Deployment Recommendations
for virtualized Small Cells
(Parallel R5 NFV Aspects of SC
Gateway and Management)
Architectural aspects of
virtualized small cell infra
Business case analysis Finalized Business case
Multi-vendor aspects for
virtualized small cells
RPH
BKH
DEP
NET
MKT
IOT
OG Requirements capture Phasing and prioritization

17. Virtualization Work Stream Kick-Off
• Accelerate scope definition leveraging use cases:
centralization, virtualization, resource sharing, ….
• Capturing common aspects and different characteristics
• What is out of scope (or potentially out of scope)
• Residential, 3G, ….?
• Timelines – what is achievable? Market relevance?
• Do timelines drive a preference towards MAC-PHY?
• Eventual target or step on roadmap towards 5G?
• Terminology/nomenclature – need to quickly align on
common understandings
• Q. What feedback on timing and relevance do we
need to consider?

18. www.smallcellforum.org