Mobile Plots http://mobileplots.com

The road from EPC to 5G

Alberto Diez October 2016

Alberto Diez October 2016 From EPC to 5G

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Executive Summary

The most important difference between 4G and 5G is not going to be a new modulation or

frequency band or a new technical feature, but the shift of model from business to consumer

to business to business.

The EPC has been unchanged for the last years because it supported only one use case:

Mobile Broadband, which has driven the business until now. For 5G, the use cases are

diverse and growing. IoT is predominant but is a very heterogeneous space with completely

different connectivity requirements for different IoT applications.

The requirements for 5G include higher data rates and connection density but also better

coverage and mobility. On top of that, efficiency and the millisecond latency which doesn’t

seem achievable with current paradigms.

The EPC has to be re-thought and re-architected. Today, enabling technologies like NFV,

SDN, Network Slicing, MEC and C-RAN are modelling the network of the future. The core

network for 5G will have in common with EPC some essential characteristics but it will have

more flexibility and, necessarily, a lower cost per bit and device connected.

The new EPC must support scaling down and decomposition to provide features on demand

for diverse use cases. It will have to be orchestrateable and re-configurable, supporting the

programmability paradigms and control and user plane separation that are described today in

software defined networking. New deployment models like decentralized cores will support

the requirements of the new verticals which will require massive connectivity and low

latencies.

The 5G mobile core will support industrial applications but also public safety

communications, automotive connectivity needs, not only for the connected car but also for

the self-driving autonomous car, and the SmartCity, SmartGrid and Smart-Living massive

amount of devices connected to the network. Not only reliability but security and privacy of

communications are fundamental for these verticals.

The EPC was not design for these challenges, but this report provides a roadmap to re-

architect the EPC towards the 5G future.

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Table of Contents

Motivation .............................................................................................................................. 4

The 3GPP EPC ..................................................................................................................... 5

The road to 5G ...................................................................................................................... 8

5G use cases ..................................................................................................................... 8

5G requirements ................................................................................................................ 9

2016 trends modeling first steps to 5G ............................................................................... 9

Enabling technologies .......................................................................................................11

Effects of 5G to the EPC ......................................................................................................17

Lost in the way to 5G ............................................................................................................20

Case Study: EPC roadmap to 5G .........................................................................................21

Company Landscape............................................................................................................23

Incumbents .......................................................................................................................23

Challengers ......................................................................................................................24

Alternative .........................................................................................................................25

Bibliography .........................................................................................................................26

Important Acronyms .............................................................................................................26

About the Author

Alberto Diez works as a consultant with his own business: Mobile Plots. He has been working with standard telco architectures since 2007. He started his career at Fraunhofer FOKUS where he conceived and prepared the launch of the OpenEPC project. Later he worked in the industry with Nokia Siemens Networks and in Siemens CVC with their carrier grade core network products as their AAA server and PCRF, as solution architect of the former and product manager of the latter. Alberto provides from technical to business strategy consultancy services to customers in telecommunications sector. Current topics of interest include: new services and architectures for mobile operators, NFV/SDN and 5G.

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Motivation

The introduction of LTE and 4G brought with it a new core network architecture: the Evolved

Packet Core (EPC). Since 2009, when the first carriers deployed commercially LTE, the EPC

has stayed almost the same. This situation is about to change with the introduction of 5G.

The mobile community designed 4G with the requirements of a single use case in mind:

Mobile Broadband (MBB). 3GPP introduced LTE in Release 8 as the radio interface for 4G1.

LTE required the EPC as its core network architecture handling security, mobility and quality

of service (QoS) in an All-IP flat network. The radio interface of LTE has evolved in

subsequent releases improving on bandwidth, capacity etc. but the EPC has stayed

fundamentally unchanged.

5G is the new mobile technology generation that promises to bring society a step further in a

fully connected world. Compared to 4G, 5G not only addreses the MBB use case but

introduces new use cases like those associated with the Internet of Things (IoT) that require

massive scale of communications and the low latency real-time transmissions that shall

make the autonomus cars and the tactile Internet true.

From a business perspective 5G brings new requirements in the pricing models and lower

costs for the operators to enable a massively connected society. Interestingly, there is a shift

in the business model too. 5G is a business-to-business (B2B) mobile generation while prior

ones were business-to-consumer (B2C). The operators must partner with verticals that

require 5G capabilities from now on.

5G is sometimes described as a journey with some vendors marketing 4.5G in between.

These messages usually focus in the air interface. In this journey there are evolutionary

steps as well as revolutionary ones. High order carrier aggregation is the one of those

evolutionary steps in the air interface which addresses needs for more bandwdith.

Revolutionary steps like the introduction of a new air interface in different frequency bands,

called Next generation Radio (NR) will come after 2020.

In the core network, 3GPP is also studying revolutionary visions for the next core network;

what they call the next-generation corei; but a horizon of evolutionary steps is visible today

with the surge of enabling technologies like NFV, MEC, SDN, C-RAN and network slicing.

The EPC, as it is, cannot cope with the demands of the new use cases. The result of this

evolutionary journey is a new core that slowly but steadily is detaching itself from its original

design.

This report describes briefly the status quo and the 5G vision as well as enabler technologies

from a perspective of their effect in the core network and provides an outlook to how the 5G

core network will look like as the journey advances.

1 LTE is formally not a 4G technology since it doesn’t fulfill all the requirements of ITU-T. LTE-Advanced is a 4G technology.

Alberto Diez October 2016 From EPC to 5G

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The 3GPP EPC

3GPP introduces in Release 8 the Evolved Packet Core (EPC) as the new core network

architecture for LTE. The EPC has four main components the Home Subscriber Server

(HSS), the Mobility Management Entity (MME), the Serving Gateway (SGW) and the Packet

Data Network (PDN) Gateway (PGW). These four components constitute a flat, full IP core

network which coped with the challenges of mobile networking: security, mobility and Quality

of Service (QoS).

Figure 1 The EPC highlighting fundamental components: MME, HSS, SGW and PGW

GSM was a Circuit Switching (CS) mobile network technology. In 2G and 3G the core

network included a CS part which provided the voice and short message services and the

Packet Switching (PS) part in charge of data connectivity. The CS core main function is the

Mobile Switching Center (MSC); the PS part includes the SGSN (Serving GPRS Support

Node) and GGSN (Gateway GPRS Support Node). The subscriber repository data for 2G

and 3G is the Home Location Register (HLR). 2G and 3G rely on the SS7 (Signaling System

Seven) protocols stacks, using GTP (GPRS Tunneling Protocol) for mobility in the PS

domain both for signaling (control plane) and packet tunneling (user plane).

With Release 8, 3GPP disrupts the core network design with the introduction of the EPC as

an All-IP based system. The EPC simplifies the network by eliminating the CS domain and

SS7 stacks and basing all connectivity on data and IP. The movement to the EPC is not a full

revolution since the main elements share characteristics and features with the prior ones.

The HSS was an already existing component which had been specified in the IP Multimedia

Subsystem (IMS) and for the EPC it is upgraded with HLR functionalities over Diameter

(instead of MAP/SS7). The mobility is still based on GTP which becomes fundamental to the

architecture since introduces the split between user and control plane.

The MME is a completely new entity that manages the LTE radio components (eNodeB). It is

partly an evolution of the control plane part of the SGSN.

The SGW and PGW share both control and user plane functions and already the first

designs of the EPC included the possibility of deploying them together. They are an

evolution of the GGSN with part of the features of the SGSN.

The focus of the EPC remains in the security, mobility and QoS features keeping

fundamental paradigms known from 2G and 3G. One key new aspect is that the EPC

supports heterogeneous networks from its conception. Not only backwards compatibility to

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2G and 3G but also support for the Non-3GPP accesses. Non-3GPP access were at that

time 3GPP2 accesses (i.e. HRPD), WiMAX and Wi-Fi. Today Non-3GPP is Wi-Fi. For these

access some components are added to the standard like the AAA server and ePDG (evolved

Packet Data Gateway). At the early stages of EPC standardization alternative mobility

protocols like PMIPv6 and DSMIPv6 were added to have an inclusive design.

The release 8 EPC also included as optional components the Policy and Charging Control

(PCC) components, which provide dynamic QoS control and flow based charging, and the

Access Network and Discovery Selection Function (ANDSF) aimed to helping the mobile

device to find the best network to connect by sending policies to it.

In Release 9, 3GPP completed features like emergency calls, Multimedia Broadcast and

Multicast (MBMS) and location services. Release 10 added Multi Access PDN Connectivity

(MAPCON) and IP Flow Mobility (IFOM) as well as Local IP Access (LIPA) and Selected

traffic offload (SIPTO). It also introduced GTP variants for non-3GPP access (SMOG).

Release 11 added the first standardization on Machine Type Communications (MTC) which

includes the first 3GPP work on machine to machine (M2M) communications. Other than

that, Release 11 was focused on improving and finalizing the architecture for voice over LTE

support (VoLTE) including roaming architectures (OSCAR, RAVEL), Single Radio Voice Call

Continuity (SRVCC) extensions and other enhancements for data services like Traffic

Detection. Release 12 continue finalizing features for VoLTE and added some interesting

features like Proximity Services (ProSe) which are already catering for the communications

needs of Public Safety.

Release 13 which has been frozen in March 2016 has added more features making LTE an

the EPC a possible mobile technology for Public Safety; features like Mission Critical Push

To Talk (MCPTT), network isolation and enhancements to MBMS and ProSe. Together with

that, Release 13 adds features for MTC and dedicated core networks (DeCors) and a study

con control and user plane separation (CUPS).

Figure 2 Years, 3GPP Releases, EPC features and topics influencing mobile communications

The changes to the EPC since Release 9 seem limited compared to the more relevant

advances in the radio access with LTE evolving to LTE-Advanced. The fundamental

components of the EPC have added new features but none of them has significant

modifications. Was the EPC so well design since the beginning?

The short answer would be: yes it was. Basically the EPC was designed for IP

communications and with the requirements for the use case of Mobile Broadband (MBB) in

mind. IP is obviously the correct protocol stack and MBB has been the use case which has

driven the mobile communications market in the last decade with the success of

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smartphones. Growth has been based in more devices connected for human

communications, each of them requiring more throughput; the EPC fits that scenario.

The greatest challenge for LTE and EPC design has been video consumption, increasing the

bandwidth required for each user but the radio has evolved to support higher bandwidths.

Since the main service has been video on demand, caching/Content Data Networks (CDN)

solutions outside of the EPC have been enough to improve the user experience without

changes to the EPC. An increasing challenge is the transition to more interactive and

participative ways of communication associated with mobile social networks usage. This

translates in much higher uplink bandwidth needs, but the problem is to be solved in the

radio side and not relevant in the EPC which essentially provides symmetric bandwidth.

Release 13 adds two interesting use cases which are not MBB related: Internet of Things

and Public Safety. The work on IoT had started already before but on Release 13 3GPP has

reached a consensus on three technologies for IoT: EC-EGPRS (2G), LTE-M (LTE related)

and NB-IoT (new narrowband access). There is a study2 on modifications to the core for

Cellular IoT which includes a new component as solely core network element, the C-SGN

that includes a simplified MME, SGW and PGW with connectivity to an external HSS. That is

the most significant change to the EPC.

Public Safety has been the other use case which differs from MBB in Release 13. Public

Safety organizations use mobile communications standards that are very limited in their data

transmissions capabilities (e.g. TETRA) but provide features that are not available in 3GPP

networks (e.g. device to device communications). Public Safety entities, unlike mobile

operators, manage increasing budgets and therefore there is huge interest in them moving to

3GPP related standards and deploying dedicated LTE networks. The focus in Public Safety

is resurrecting some 3GPP features with little success like eMBMS which permits to multicast

and broadcast content using radio resources efficiently.

Release 14 which will be closed in June 2017 includes several interesting items but the one

impacting the core the most is a 400 pages study3 which shall be the basis for the

standardization of the Next Generation Core network. There is summary done by Nomor

Research here, which explains the structure of the document and its most relevant

contributions. The study includes important aspects like network slicing and control and user

plane separation and new approaches to the persistent topics of cellular networks: security,

mobility, and QoS (and charging). It includes solution proposals that decompose the existing

functions and recombine them for the different use cases that are part of 5G including

enhanced MBB but also beyond MBB.

It is still early to know how much from the EPC will remain in the Next Generation Core that

will be the main system connecting to the 5G radio. Mobile operators are conducting deep

transformations moving to virtualized and software defined networks which are affecting the

EPC deployment and its integration in the overall operator systems. While it cannot be

foreseen what will be the resulting core for 5G yet, it seems that the addition of use case

diversity and the technological trends driven by other organizations beyond 3GPP (e.g. NFV

and MEC in ETSI, SDN in ONF, IETF work etc.) will influence how the new core will look like

and it will be the 5G requirements and new use cases what will model the new core network

just as MBB modelled the EPC. 2 3GPP TR 23.720 Study on architecture enhancements for cellular Internet of Things 3 3GPP TR 23.799 Study on Architecture for Next Generation System

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The road to 5G

In February 2015 NGMN Alliance published their 5G White Paper providing a comprehensive

report on 5G. It includes use cases and vision for 5G as well as a comprehensive study of

the requriements and technical considerations.

Later in 2015, ITU-T IMT-2020 group (IMT-2020 is the obscure name of 5G in ITU-T)

published a report on standard gaps for 5G. The ITU-T report covers the same topics as the

NGMN white paper but from a research perspective and provides some interesting

considerations. Other considerations as the use of Information Centric Networking (ICN) may

not be pragmatic at all.

The view of 5G that these two reports describe is still the correct one, but 5G is attracting a

lot of attention from different groups which are working in turning the vision into reality, earlier

than later. This section summarizes the use cases, requirements, trends and technologies

that the NGMN and ITU-T papers identify and that have an impact in the core network, but it

adds on top the developments which are being discussed in varios 5G symposiums,

conferences and projects.

5G use cases

NGMN, in an effort to cover all possible use cases, lists eight use case families, namely:

Broadband access in dense areas, Broadband access everywhere, Higher user mobility,

Massive Internet of Things, Extreme real-time communications, Lifeline communications,

Ultra-reliable communications and Broadcast-like services.

ITU-T is on the opposite too specific and only lists four use cases: Smart Grid, E-Health,

Autonomous car and the Internet of Things.

All use cases of ITU-T can be grouped under Massive Internet of Things which could also

include the connected car as a predecessor of the Autonomous car. On the other hand,

NGMN listing Broadband access twice may not be fully on the spot but it’s interesting that

NGMN includes use cases beyond IoT.

Both reports fail to mention explicitly Augmented Reality (AR) / Virtual Reality (VR) as a use

case although it could fall into the Extreme real-time communications of NGMN. It has

become a topic during 2016. In the Mobile World Congress 2016, VR demos attracted most

attention. The AR/VR is an interesting use case because it covers both gaming which is B2C

and other industrial/professional applications which will be B2B. When AR/VR becomes

pervasive it will require a deeper transformation in the core network than that of enhanced

MBB everywhere.

IoT is the most remarkable use case for 5G. But IoT is so diverse that there is no one IoT to

speak about, but several. Instead of wearables, gadgets and “Smart life”, the focus is again

in B2B. Healthcare, Automotive and Industrial applications are the most challenging themes

repeated in 5G conferences4.

In both, the use cases mentioned in the reports, and what are consolidating as the 5G topics

of discussion, the most relevant common characteristic is diversity of requirements. Even

4 IEEE 5G Summit Santa Clara (November 2015), IEEE 5G Summit Dresden (September 2016), Knect365 5G World Conference London (June 2016) and others

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when considering only IoT, it doesn’t seem logical that the same network can serve the

industrial AR applications and the SmartGrid sensors with total different coverage, security,

usage, mobility and traffic profiles. Add to that the connected or autonomous car and the

requirements for natural disaster communications or high speed trains and it seems the 5G

network will be able to do anything and everything.

5G requirements

There is consensus on the requirements for 5G networks to be significantly better than 4G

networks in aspects like data-rates (100x), connection density (100x), coverage, latency

(10x-50x), mobility (1.5x) and efficiency (3x spectrum, 100x energy). The requirement for

latencies of 1ms as enabler for the “tactile” internet and extreme real-time applications is

particularly challenging.

There is equally consensus that these objectives contradict each other and all of them

cannot be achieved at the same time. That is, like in the use cases the performance targets

for 5G show diversity that must be reflected in diverse mobile networks. Some of them like

the latency requirement require new technologies (like a new radio in different spectrum).

An approach is splitting requirements and pairing them to use cases, so applications that

require low latency and high-data rates but only in certain areas (low coverage) without

mobility and low density. Other massive M2M applications will require low data-rates with

high latencies and the challenge is only in the connection density and coverage required.

So it is clear that the 5G network is going to be a multi-facetted network. Therefore the 5G

network shall be flexible, integrative of heterogeneous technologies (no one technology will

fit all cases) and providing agile re-configuration capabilities.

Together with the technical requirements there are the business and operational

requirements which are less covered in the vision papers. The main shift business-wise is

the change in the business model. While mobile operators continue delivering connectivity

services, their customers for 5G networks are no longer consumers/humans but machines

and businesses. Some may think this is going to lead to increased revenue and it may be so,

but if we consider the cost per bit and cost per subscriber the prices are going to have to

decrease dramatically. The ARPUs that is realizable by the billions of machines that are part

of the IoT, even the industrial IoT (IIoT), are not going to be comparable to those of the

subscriber in the developed markets today. In the same way the new technologies will have

to realize a low-cost per bit to enable the high throughputs use cases and massive

connectivity.

2016 trends modeling first steps to 5G

5G is a trend in itself. No other mobile generation had triggered so much discussion years

before its commercial availability. The first 5G trials were announced for the next Olympic

games in Korea5 in 2018 and Japan6 in 2020, but soon those plans have been superseded

by press-releases from the north American operators with trials of 5G enabling technologies

as early as 201678. While the more distant trials possibly include new radio technologies the

5 http://www.mobileworldlive.com/featured-content/home-banner/kt-shares-plans-for-5g-at-2018-olympics/ 6 http://www.mobileworldlive.com/asia/asia-news/docomos-2020-5g-launch-not-just-for-olympics/ 7 http://about.att.com/story/unveils_5g_roadmap_including_trials.html

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ones nearer in time refer more to the application of NFV and SDN to the existing 4G core

networks to provide more efficient and flexible services.

An important trend in the industry which is clearly paving the path to 5G is the incorporation

of verticals into the multi-stakeholder technology discussions. NGMN has published in 2016

a paper about verticals and 5G9. Operators need to interact and cooperate with verticals to

implement the IoT use cases. In particular Healthcare, Automotive, SmartGrids and

SmartCity projects are on focus. While some operators do have B2B units and established

relationships with some of these industries, others need a transformation inside their

organizations to address this market and not to miss the opportunity for IoT in its different

variants. IoT is fundamental for making the business case for 5G.

The automotive industry is one of the sectors that attracts more attention within IoT and as a

use case for 5G10. Not only is an industry that moves billions in R&D yearly but it is also an

industry under pressure to produce new concepts for cleaner more efficient solutions which

connected cars help to bring. Adding to that, Google, Tesla and Uber, favorite disruptors, are

investing heavily and making announcements about self-driving car and autonomous driving

which will require also new connectivity services from the operators.

The IoT landscape is also geographically diverse. In the Middle East for example, the

government is pushing for Smart City projects and the operators are adapting to provide

solutions today for this1112. In Germany the focus is in industrial IoT under a government

initiative called Industrie 4.013 which should bring more automation and real time connectivity

into factories. The government of the USA has also programs for improvements of

manufacturing and applications of industrial IoT and bringing AR/VR to factories1415.

Application of 5G to automotive, utilities and manufacturing are very interesting since they

finally bring a real need for traffic separation and QoS support in the network. It is clear that

the sensors and cameras data of a robot which is performing a critical task in a power plant

cannot compete for bandwidth, latency and radio resources with video downloads from the

average consumer. But how will that be compatible with the net neutrality regulations

approved this year in the USA and Europe?

European net neutrality guidelines16 are particularly flexible in this regard but also FCC

regulation17 in the USA refers explicitly that net neutrality is only applicable for Internet

8 https://www.verizon.com/about/news/verizon-sets-roadmap-5g-technology-us-field-trials-start-2016 9 http://www.ngmn.org/uploads/media/160922_NGMN_-_Perspectives_on_Vertical_Industries_and_Implications_for_5G_final.pdf 10 http://europe.autonews.com/article/20160927/ANE/160929857/bmw-audi-mercedes-tech-firms-form-5g-alliance-to-accelerate-self 11 http://www.du.ae/about-us/smart-city 12 http://www.etisalat.ae/nrd/en/business/solutions/m2m-iot.jsp 13 https://www.gtai.de/GTAI/Content/EN/Invest/_SharedDocs/Downloads/GTAI/Brochures/Industries/industrie4.0-smart-manufacturing-for-the-future-en.pdf 14 https://www.whitehouse.gov/blog/2016/06/24/sharpening-our-competitive-edge-national-network-manufacturing-innovation 15 http://www.hannovermesse.de/en/news/u.s.-president-obama-to-open-hannover-messe-2016.xhtml 16 http://berec.europa.eu/eng/document_register/subject_matter/berec/download/0/6160-berec-guidelines-on-the-implementation-b_0.pdf 17 https://apps.fcc.gov/edocs_public/attachmatch/FCC-15-24A1_Rcd.pdf

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access. So a necessary trend to provide differentiated services is that those do not include

Internet access. This is perfectly aligned with 5G being a network for B2B.

In the same direction one of the most surprising trends is the focus on security. Security has

always been an important topic in mobile networks which was often left outside of the scope

of research projects and outside of the budget of operators’ infrastructure investments.

During 2016 though, there have been mass media reports on attacks to celebrities’ mobile

phones and the lack of security of mobile networks (SS7 networks)18, as well as major hacks

to secure banking networks19 and more recently so called “cyberwar” attacks which have

made it into the press. Privacy is becoming more of a topic although still mainly concerns

Europe20. It is foreseeable though, that when considering industrial, utilities, automotive and

other IoT use cases, security and privacy of communications become of paramount

importance.

Associated with security, during 2016, 3GPP had in focus mission critical and public safety

communications in its Release 13. There are also ongoing projects like FirstNet21 in the USA

and ESN in the UK22. Other European countries are looking at the transition from TETRA

networks into LTE for Public Safety. Surely 5G will have to provide a solution for these critical

communications too.

Increasingly discussed is the role of fiber in 5G23. 5G requires fiber, a lot of it. The demands

of traffic capacity, latency, reliability and flexibility demand an underlying fiber infrastructure

that in most countries may not be there. Therefore operators are investing already today in

fiber and the first real 5G trials will occur in countries in which fiber is already available

ubiquitously.

Small Cell deployments and use of unlicensed spectrum have also been a topic. Small Cells

have been around for long but the need for better indoor coverage and enhanced MBB

requirements are impossible without them. Unlicensed spectrum usage is not only ready in

the standards but there are alternative proposals that may have a significant impact24.

Enabling technologies

This section describes the five enabling technologies that have been selected as candidates

for having the most impact in the core network architecture and design.

NFV

ETSI has been working in standardizing Network Functions Virtualization (NFV) since 2013.

They have managed to defend the applicability to mobile networks and the overall

advantages of NFV and make an architecture reference design.

The key concept for NFV is the ability to run all network functions as software which is

virtualized over a common pool of compute, storage and network resources. The system as

18 http://www.cbsnews.com/news/60-minutes-hacking-your-phone/ 19 http://www.reuters.com/article/us-usa-nyfed-bangladesh-malware-exclusiv-idUSKCN0XM0DR 20 http://europa.eu/rapid/press-release_IP-16-2461_en.htm 21 http://www.firstnet.gov/ 22 https://www.gov.uk/government/publications/the-emergency-services-mobile-communications-programme/emergency-services-network 23 http://www.rcrwireless.com/20160822/opinion/reader-forum-building-blocks-5g-fibers-role-tag10 24 http://www.multefire.org/

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a whole is managed by a Management and Orchestration (MANO) layer also defined by

ETSI.

This reference architecture is well accepted. Currently the work is in the MANO layer. The

industry has come to acknowledge that the Virtual Infrastructure Management (VIM) relies on

OpenStack, a very successful Open Source project which is used in several industries.

Companies are offering different flavors of OpenStack for Telco with support and additional

value added features. Some telco requirements are not yet completely supported by

OpenStack and there are initiatives like OPNFV25 to influence the development of Openstack

to support carrier-grade features.

Figure 3 The ETSI NFV reference architecture

Within the MANO the higher layers referred to as VNFM (Virtual Network Functions

Manager) and NFVSO (NFV Service Orchestrator) are most problematic. To avoid vendor

lock-in it is necessary to agree in information models and APIs between these functions and

this is not resulting easy. There are in parallel several Open Source initiatives262728

addressing these components and it is unclear if any consensus will be reached. The VNFM

and NFVSO components are fundamental to achieve a manageable NFV deployment and

the operational improvements that NFV promises.

Within the first use cases that ETSI referred as susceptible of NFV was EPC. The EPC of

course can be deployed as software only components and it can be virtualized. The

challenges are in the details.

The first key issue is performance. There is a performance cost of virtualization which can be

critical for user plane functions like the SGW and the PGW. Traditional vendors had functions

depending on specific hardware platforms which are not easy to virtualize. Intel’s DPDK29

helps providing optimizations for performance that can increase the amount of packets per

second processed and the overall throughput at the data-plane.

25 https://www.opnfv.org/ 26 http://openbaton.github.io/ 27 https://osm.etsi.org/ 28 https://www.open-o.org/ 29 http://dpdk.org/

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Latency is also an issue with virtualization and it affects the MME. The MME, even though

only control-plane, has tight time limitations to reply to procedures towards the radio and the

mobile device. If NFV would imply a central data-center deployment strategy it shall be

verified that the MME meets the requirements in all situations even for the most distant cells.

The HSS would be the third element of the EPC affected by NFV. In particular the HSS is

used to provide authentication vectors and profiles for all subscribers. When accessing key

material it is usually stored in specially protected hardware. Additionally HSS with distributed

database/repository may suffer from NFV if the underlying data storage technology is not

optimized for virtual deployments. Operators have decided to postpone NFV for the HSS to a

later stage to understand better the possibilities.

The benefits from NFV to the operator are the agility of deployment and scaling capabilities.

New functions and services can be rolled out quickly and functions can consume the exact

amount of resources they need; scaling when they need more. NFV is meant to decrease the

cost of deploying and operating the network and allow for new business opportunities

associated with the availability of the infrastructure and resources for new services.

Examples of new services that NFV makes possible are those associated with network

slicing and MEC, covered later in their own sections.

SDN

Software Defined Networks (SDN) is an approach to simplify and make more flexible the

management of large networks by decoupling control plane (CP) from user plane (UP). It has

become paramount to large data-center networking, providing means to dynamically modify

and administrate complex networking infrastructure. SD-WAN (Software Defined Wide Area

Networks) is a similar approach for larger networking infrastructure and transport networks.

SDN for mobile networks comes together with NFV. Virtualization decouples the software

which performs network functions from the hardware. SDN provides a flexible network which

can implement the connectivity necessary for NFV. Where NFV has its MANO layer, SDN

has the SDN Controller, an element that provides the management and operation of switches

and networking infrastructure.

In the last year, SDN is becoming more relevant for mobile operators since it’s clearly

necessary for any NFV deployment but it also provides tangible new services associated

with, for example, on demand enterprise VPN portals that simplify BSS/OSS processes.

In the EPC, control and user plane separation is not a revolutionary paradigm since its

present in the main mobility protocol (i.e. GTP) which sends control messages for the

establishment and management of data tunnels out of band. The eNodeB also sends all

control messages to the MME while sending the user plane traffic to the SGW. Nevertheless

even though GTP decouples control and user plane the Gateways (SGW and PGW)

concentrate both control and user plane functionality in one entity. 3GPP has approved for

Release 14 the “Architecture enhancements for control and user plane separation of EPC

nodes”30 (CUPS) which provides the framework for a fully SDN compliant EPC with split

gateways.

30 https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=3077

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When separating the control and user plane the “traditional” approach is to do it with an

OpenFlow interface between them. Using OpenFlow for GTP and the EPC Gateways is not

straightforward since it requires extensions, has issues with scalability and implementation

constrains when using the same networking infrastructure for several multi-tenant EPCs. It

also would proof difficult to implement all policy and charging functions in a meaningful way

using only OpenFlow to the switches. Instead SDN Controllers shall be used31.

The SDN controllers provide a NorthBound Interface (NBI) which provides a higher level API

in which SDN Applications require resources and networking capabilities to the network.

Ideally the NBI is a very high level API that abstracts all network specific and infrastructure

related parameters. There is still a lot of research on SDN NBI but an interesting paradigm is

Intent networking32 although may not be applicable when implementing the EPC NBI.

A topic tightly related to SDN, at least in the research, and which affects the core network is

that of Service Function Chaining (SFC). SFC refers to the possibility of configuring

dynamically user plane traffic to be routed through a chain of network components which

provide value added services. The typical example is deciding that all traffic of a certain type

for a certain customer has to pass through a protocol optimization (e.g. video) component or

a security function (e.g. parental controller). SFC has been present in EPC deployments prior

to SDN and it was called the Gi-LAN. The difference comes that Gi-LAN are usually quite

static, in the sense that all traffic for all users is sent through the Gi-LAN which may include

several services and it’s the service itself the one deciding whether a particular traffic flow is

susceptible of its control or not. SDN brings dynamicity and better use of resources to this.

Gi-LAN is a practical concept deployment in most mobile operators that benefits from SDN.

On the business perspective what SDN is bringing to the mobile operator is the on demand

model. With SDN it’s possible to permit business customers, to buy, provision and manage

their networking resources on demand33. It is indeed relevant because operators leading the

SDN transformation of their networks are able to not only optimize their existing procedures

but also provide new services that were not available to customers. Again the main SDN

advantages are business to business.

Considering the EPC and mobile core, SDN is together with NFV fundamental for network

slicing (see next section). There are initiatives of providing EPC as a Service for specific

applications which highlight the overall softwarization of the EPC; turning management of the

mobile network into something similar to managing IT infrastructure of a data-center using

SDN and NFV.

Network slicing

Slicing is about separating different use cases in the network. Slicing is not only enabled by

NFV/SDN but it’s an extreme application of the concepts behind NFV and SDN. The

resources whether they are radio heads and baseband radio units, computing nodes,

switching capabilities, transport resources or EPC functions are completely managed as a

pool of elements that can be grouped for specific use cases.

31 http://conferences.sigcomm.org/sigcomm/2014/doc/slides/127.pdf 32 https://www.sdxcentral.com/articles/contributed/intent-based-networking-seeks-network-effect-david-lenrow/2015/09/ 33 https://www.wirelessweek.com/news/2016/07/t-expands-enterprise-sdn-offerings-network-functions-demand

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Network slicing permits offering within the same mobile networks complete different services,

as those necessary for the 5G use cases described before. In the current EPC, service

separation is based on Access Point Name (APN) but that typically limits to a selection of a

different PDN-Gw or PDN-Gw configuration. APN provides some differentiation but it doesn’t

provide an end to end separation. With network slicing for example a slice of the network,

which includes access, transport and core, can provide highly reliable and secure low latency

industrial robotics connectivity in an area while another slice of the network provides a low

bandwidth high latency sensor connectivity service.

Figure 4 Representation of an operators network before and after slicing. Slicing can be end to end including the Radio Access Network (with radio units shared and other dedicated to certain slices). The core can be instantiated with different configurations per slice.

Network slicing requires orchestration. It requires management and control of all resources

available in the network and dynamic re-configuration and programmability capabilities.

Especially when considering end to end slicing it may require a hierarchical architecture of

orchestrators and controllers.

Technically there are a couple of challenges associated with slicing the core network. 3GPP

had a study about use case specific dedicated core networks34 that results in a suboptimal

implementation that preserves the mobile device without any impact. Basically the

mechanism implies that the initial MME selected by the eNodeB acts as a slice selection

function. Together with the profile from the HSS that initial MME redirects to a slice specific

MME which will then select slice specific SGW, PGW etc35. The implementation of this slice

selection function at the current MME is the first step towards a more complex slice selection

for the 5G core.

Slice selection is not the only challenge. From the core perspective network slicing will also

require not only full NFV MANO capabilities to instantiate and manage slices but also

programmability of the core and ability to configure dynamically all parameters associated

with service provisioning and policies which will be essentially different in each slice.

34 https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=868 35 https://www.nttdocomo.co.jp/english/binary/pdf/corporate/technology/rd/technical_journal/bn/vol17_4/vol17_4_006en.pdf

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Network slicing must provide traffic isolation and security. This can use SDN capabilities.

Another gap is the inclusion of different reliability requirements as part of the slicing criteria. If

at the end all slices are implemented with the same pool of infrastructure resources and

VNFs the allocation of resources must consider all requirements and constrains.

From regulation perspective network slicing can be compliant with net neutrality if there is a

common slice for Internet services and network slicing is done not based on the subscriber

category or similar but on non-Internet services (e.g. enterprise, IoT).

Initial interest in slicing is focused on IoT. With network slicing it shall not only be possible to

provide a high capabilities slice for the Automotive or Industrial but also a very low cost and

low features core and transport network for non-critical sensor networks. Networks for

enterprise services and private LTE networks (e.g. possibly including Public Safety networks)

will also benefit from slicing.

The business opportunity is immense and demonstrations in MWC, 5G conferences are

difficult to avoid. This year those demonstrations are focused in the MANO capabilities which

is a huge gap to solve for slicing. The EPC is a passive VNF that needs to scale down and

be instantiable and configurable easily. In the future network slicing demonstrations will

include different re-configurations of EPC for different services as well as end to end slicing

with the radio, backhaul and switching in between also sliced.

MEC

Since 2014 ETSI has been working on Mobile Edge Computing (MEC) as a deployment

paradigm for mobile networks that enable better services in particular for content caching,

gaming, AR/VR, location, big data, protocol optimizations and enterprise. MEC is necessary

for achieving the latency reduction that 5G aims for.

While the principle of MEC is simple: bring the service nearer to the edge of the network; its

application requires some particular solutions. First MEC requires of a platform to host

services near the edge. Such platform must support NFV since there is no question that

virtualized is the way of deploying services. Second MEC requires a way to route traffic to

the edge service instead of the centralized one. SDN can help here but there are also 3GPP

standards (LIPA, SIPTO) that can be leveraged; it is widely accepted that at least part of the

EPC or a new gateway will have to be deployed at the edge, for edge applications to work.

An important challenge for MEC is that porting apps to be optimized for running on the edge

is not seamless. ETSI is working on APIs that should be standardized but collaboration

between telco and applications for optimizations doesn’t have many succesful references.

While deploying applications at the edge does require at least the Serving-Gw to be

deployed also at the edge it can also mean deploying the complete EPC at the edge (except

the HSS). This option is interesting for some scenarios like enterprise connectivity associated

with industrial IoT, private LTE networks and remote/rural connectivity. EPC at the edge is an

approach that is being already offered by several vendors as LTE in a Box and that brings

some interesting advantages considering 5G. It reduces backhaul and latency if traffic

remains local between the locally connected devices and the MEC applications deployed at

the edge but it also adds privacy and security. In this regard this is an important requirement

for the industrial IoT which may see in MEC a solution.

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C-RAN

Cloud RAN (C-RAN) is a new deployment concept for the Radio Access Network (RAN)

which takes advantage of the general softwarization of telecommunications infrastructure

and NFV. Basically the eNodeB can be divided in two elements: the radio unit that requires

hardware (i.e. the antenna and radio chipsets) and the Base Band Unit (BBU) that is only

software. The BBU, being only software, can be deployed virtualized at a central location.

The main aim of C-RAN is to reduce costs of operating the network. An important cost for the

operators is having to access the radio sites for any operation, being maintenance

modification or upgrade. Most of those operations do not affect the radio unit but instead the

software components. When developing the BBU centralized or at least concentrated in one

point for a metro area it has significant costs reduction effects for operators.

In the practice the radio unit includes some software to avoid sending radio samples over a

link to the BBU which would require that the interface between radio unit and BBU, called the

fronthaul, supports huge bandwidth and strict timing and latency requirements only

achievable with dark fiber and short distances. The higher the split in the protocol layers the

less bandwidth and strict requirements but also the less benefits there are from C-RAN.

Strictly speaking C-RAN does not have any effect to the EPC. The radio network will

continue to backhaul towards the core network. But C-RAN requires a new location in the

deployment of operators that supports NFV to deploy those BBUs. That same location could

be leveraged to deploy a virtual EPC or at least parts of it and it is at this location the C-RAN

and MEC converge decentralizing the EPC.

Effects of 5G to the EPC

The 5G network cannot be a straight-forward evolution of the 4G one because the difference

in requirements and most importantly in use cases is too large. In particular with 5G

extending its use cases beyond the MBB, the requirements for the network, overflow a

simple increase on capacity or features. Still the EPC as the core network of 4G was well

designed and a transition from the EPC to the 5G core is possible not just a revolutionary

clean slate approach.

The NGMN paper addresses this topic in section 5.3.2 dedicating two paragraphs to the core

network. It explicitly says “In this regard, a rethink of models such as bearers, APNs,

extensive tunnel aggregation and gateways is needed.” That re-think of models is happening

stepwise through the incorporation into the EPC of the 5G enabling technologies: NFV/SDN,

network slicing, MEC and C-RAN. The EPC is being re-architected. The drivers are lowering

cost and increasing flexibility and efficiency.

The cost topic is not an explicit requirement but if with 2G/3G the cost of a core network was

in the dozens of dollars per connected device, today it is in the dollar range and to support

massive amount of devices it must decrease to cents and alternative pricings are necessary.

Flexibility is fundamental to accommodate the different use cases and technologies which

will be part of 5G. The EPC today is not flexible enough and is being deployed as a

monolithic centralized component that can only cater one use case. If the EPC is going to be

part of the future it cannot remain so.

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With the massive capacity needs, efficiency has to be considered with every component,

function and feature in the network. Everything not necessary shall be removed.

NFV deployment of the EPC permits to scale the functions to the exact needs of the operator

increasing efficiency. NFV also makes the EPC easier to deploy, operate and manage and

adds flexibility supporting new scenarios. NFV also lowers the cost by instantiating functions

only when needed and scaling them adequately.

With SDN and the separation of UP and CP in the EPC gateways it is possible to scale

separated control and user plane. It also permits to reduce cost by implementing UP in cost

effective white-labelled switches or alternatively in virtualized functions with optimizations.

NFV/SDN enable network slicing, which is key for having different core networks for each

different use case and set of requirements. Ultimately slicing can be extended to the radio.

Cost can be reduced with slicing since some of these EPC slices will not need to have all of

the functions and features36.

To increase flexibility decomposition of functionality must extend to all the features of the

EPC. NFV/SDN shall enable this since not all services require all functions. For example a

slice that only servers fixed sensors doesn’t need all the signaling overhead for mobility. If

already current EPC supports optional features and functions this has to be extended to

provide feature separation and possibility of re-configurable deployments with the right

amount of features. It will have a positive impact in cost and efficiency and it will make the

networks more targeted providing a better service experience.

The EPC must focus on the essentials. The essentials are charging, identity and security

(although there could be communication services that may not need security or identity).

QoS and mobility should not be included in the essential features of mobile networks but

instead added on demand and as a service when required. Some operators are considering

pushing the MME out of the core network into the LTE radio leaving the EPC solely with the

gateways, authentication and charging functions and optionally QoS.

This decomposition and focus on essential combines with turning the EPC into a cloud native

application. It shall also enable scaling down the EPC. Scaling down is necessary to support

the smaller slices for private LTE networks, enterprise services and IoT core networks.

All this flexibility and cloud capabilities comes with a requirement and that is the need of

better orchestration and management tools. The EPC has to become easier to manage,

more programmable and deployable. The tools for NFV MANO and SDN control have to

improve. Ideally the new core network supports orchestration and programmability permitting

flexible on demand creation and re-configuration of slices for the diverse use cases and

scenarios necessary for 5G.

Beyond this changes, the support for extreme data transmission rates and low latencies is

not compatible with the current deployment model of a central core network. Decentralization

is mandatory37. It is also aligned with Industrial applications that require on-premises

connectivity with additional privacy, security and control. The operators will own the spectrum

at those sites but will partner with the industrial verticals to deploy complete slices with radio

36 Section 5.1 of the NGMN white paper shortly addresses this issue 37 http://www.lightreading.com/mobile/5g/atandt-virtualized-mobile-core-key-to-5g/d/d-id/721124

Alberto Diez October 2016 From EPC to 5G

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and core virtualized managing the local traffic which will not be backhauled to any operator

controlled data-centers.

Decentralization may not mean fully autonomous smaller core networks, although in some

cases it will be so. It can also mean the capacity of deploying parts of core slices nearer to

the edge on demand. Again more orchestration complexity, SDN integration and software

flexibility.

MEC and C-RAN are going to be the enablers for de-centralization but it will come combined

with slicing and over a generic edge infrastructure which is assigned and administered by

hierarchical controllers.

For some IoT use cases new radios are more adequate. 3GPP has standardized LTE-M and

NB-IOT. These may be connected to a new core network. Other non-3GPP options like

LoRA and SigFox may also be susceptible of becoming connected. There is no one

technology that covers all IoT use cases that the operators are confronted with. The 5G core

has to integrate both 3GPP accesses and non-3GPP access for IoT as it does today with

2G/3G and Wi-Fi. The challenge is that some of these technologies require totally different

features and may not be IP based. The EPC shall be decomposed and offer the features

required for these technologies avoiding the overheads of all not needed functions.

Figure 5 5 requirements, use cases, technologies and effects to the EPC of 5G

As a summary of effects, 5G is turning the EPC into a low cost fully programmable and

cloud-native core with decomposed functionality to provide on Demand essential and per-

slice value added services, scaling to the right size, supporting decentralized deployment

models and integrating new radios.

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Lost in the way to 5G

3GPP in particular but also other standard bodies have researched during the last 7-8 years

the future of the core network and the evolution of the EPC. This process has added several

features to the EPC that although well standardized have not made it to the market, and may

never do. Quite often there was simply no requirement or business need for the feature. In

other cases the feature not only affects the core but also the user equipment (UE) and the

feature was not accepted by UE manufacturers.

There are examples of functions and features of 3GPP standardization work which have

made it to the market long after they had been standardized when there was actually a need

for them. The most prominent example is the IP Multimedia Subsystem (IMS) which

appeared in the standards in Release 6 (approximately 2005) and although vendors made

solutions and products available it only become fundamental for mobile operators with Voice

over LTE (VoLTE) between 2013 and 2015.

Between Release 8 and Release 13 features have been added to the EPC that have not

made it to the market yet. Most of these features focus on improving the MBB experience but

may still play a role in the 5G core.

Both Local IP Access (LIPA) and Selective IP Traffic Offload (SIPTO) are Release 10

features that permit routing traffic more efficiently when connected to small cells. LIPA allows

the device to connect with other devices in the local network without forwarding to the core

network and SIPTO allows selective offload to the Internet. LIPA can be interesting because

it provides solutions to MEC issues (e.g. paging device when IDLE).

The Access Network Discovery and Selection Function (ANDSF) was already part of the

EPC in Release 8. It adds a new function and an interface to the UE (i.e. S14). The problem

the ANDSF resolves is that in the presence of several accesses, including 3GPP and non-

3GPP, an UE may not have sufficient information to take the best decision to which network

to connect. The ANDSF provides policies to the UE that help in this decision. It requires UE

support and it is unclear whether the user wants to permit the operator to select the network.

IP Flow Mobility (IFOM) is a very complex feature that permits since Release 10 to move

concrete IP Flows between different access networks. It presumes a device which can be

connected to several accesses at the same time and permits splitting an IP connection

between the accesses. It requires DSMIPv2 which is a mobility protocol supported but

unused in the EPC. It even affects the ANDSF and PCRF over-complicating their already

complex interfaces. 5G will be multi-technology and multi-access but it doesn’t seem obvious

that there is a use case which justifies the complexity of IFOM.

Machine Type Communications (MTC) has been in 3GPP since Release 10-11. It didn’t

include the standardization of a new category of device which came later (CAT-0 and CAT-

M) or of a new type of access of Release 13 (NB-IOT). Instead it was providing core network

elements like the MTC-AAA and the MTC-IWF that standardize access from M2M devices to

the LTE core network and permit the operator to provide an API for M2M applications to hook

into the network and control M2M devices. It is an interesting attempt of opening a new

business which is fundamental for 5G way ahead of time. It failed in that it didn’t incorporate

the view of the most relevant stakeholders (i.e. M2M applications) and tries to resolve their

needs from the telco operators and vendors perspective.

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Case Study: EPC roadmap to 5G

From an operator perspective the core network that it has today is probably a proprietary

hardware based EPC with no signs of being able to support 5G scenarios. The roadmap for

the operator to 5G also describes the features that EPC vendors need to provide in time

before 5G is there.

Figure 6 Roadmap from EPC to 5G

The start phase is definitely virtualizing. A vendor which today does not offer a virtual EPC

(vEPC) is not a core vendor anymore but a legacy vendor. Operators need an EPC which

they can scale down and deploy separated from its existing EPC.

These advanced operators even before deploying a separate EPC they are exploring SDN

because it has direct impact by itself with new services, for example for enterprise. EPC and

SDN infrastructure permit the operator start slicing. At the beginning, network slicing may

only include the core and IoT use cases which are not connected to the Internet, for

regulatory issues avoidance.

Many of these stages will happen in parallel and for some operators network slices are

already there for some time. The next step is making it more dynamic and introduce a

powerful orchestrator architecture. The EPC has to be manageable and operated by the

VNFM and NFVSO.

Probably prior to the next level of NFV/SDN improvements the operator experiments with

MEC and C-RAN. This brings the need for new features in the EPC but also opportunities for

decentralization. MEC for example may require a lightweight Serving-Gw deployable at the

edge or even a complete P-GW. Some operators may consider LTE in a box solutions for

remote areas and EPC vendors shall support those scenarios.

MEC and decentralized deployments will also cater for the needs of security and privacy of

communications of some verticals. The industrial and manufacturing sector will need that

internal communications will not be routed to a central core and instead are handled locally

at the factory. Application of MEC will also improve latencies critical in industrial AR/VR

applications.

Sooner than later the EPC has to support Public Safety features described in Release 13

and the deployment models associated with Public Safety. These can be slice based but

must guarantee resiliency and high availability features which in NFV/SDN deployments

require new approaches.

The next stage of NFV/SDN requires the EPC to support performance optimizations for the

user plane processing. That may imply a UP/CP separation and using OpenFlow enabled

hardware for the UP or it may be enough with DPDK extensions. What is necessary is that

control and user plane scale independently and support for higher throughputs and lower

Alberto Diez October 2016 From EPC to 5G

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latencies. At this point the operator can consider new slices with EPC for enterprise and

generic usage.

Support for the new radios in the EPC requires additional functions but guarantees that the

operator can serve all use cases and provide its connectivity services beyond its current limit.

Those new radios can be non-3GPP and require non-IP features.

Further decomposition of the EPC is fundamental; charging and QoS shall be the first targets

for separation. Some slices do not require the standardized charging control mechanisms

and QoS at the gateways and the user plane (e.g. sensor networks and smart grids) but

instead massive connectivity. The EPC scales better providing only what is needed for each

use case and all these features must be turned off in these cases.

Mobility is the next stage of decomposition to support IoT cases for fixed devices. The EPC

may not need to support GTP anymore but instead lower overhead alternatives from SDN

and IETF.

At this stage there should be data models defining all EPC functions and dynamic

programmatic configuration from the orchestrator and controller which makes slice

composition more flexible; resulting slices are more efficient and targeted. The EPC is no

longer recognizable although the fundamental principles are still respected and the MBB use

case is still available and serviced through a similar core as the one today overall the core

network it is not a monolithic architecture anymore.

Figure 7 The resulting core network doesn't look like the EPC anymore

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Company Landscape

This section describes a reduced set of companies actively promoting products in the EPC

and 5G core technologies covered in this report. It does not provide a comprehensive list, the

information included is highly subjective and based on presentations, webinars, whitepapers,

blogs and demonstrations during MWC 2016 and other shows by the listed companies.

Three categories and three representatives of each category have been selected for this

listing.

Incumbents

Nokia

! The author has worked for Nokia when it was called Nokia Siemens Networks

Nokia is struggling after its acquisition of Alcatel-Lucent to consolidate its product portfolio. In

the core neither former NSN nor ALU were particularly strong with their EPC gateways and

MME propositions although of course they have together hundreds of reference customers

world-wide. ALU brings interesting additions to the portfolio for NFV like CloudBand38. During

2016 Nokia has contracted EANTC to test its virtual gateways39 getting this way an

independent certification of their vEPC capabilities. Nokia is promoting MEC as a way to not

only reduce latency but also enable new services.

Beyond gateways and MME, both Nokia and ALU have good footprint for their HSS but

difficulties with its virtualization. It remains to be seen how consolidation affects this area.

For Public Safety and small scale solutions Nokia partners with Athonet.

Ericsson

Ericsson EPC offering has not been up to the expectations. While it is claimed that virtual

EPC is available since end of 201440 there have not been any significant announcements or

breakthroughs other than proof of concepts41 and smaller network deployments with LTE-in-

a-box42.

Ericsson has been lagging behind in NFV for its complete portfolio, but it has shown some

R&D leadership on 5G in which it seems to be investing in heavily. Ericsson also contributes

significantly to SDN projects in areas like SFC and demonstrated network slicing43.

Huawei

Huawei has been actively marketing 4.5G as an intermediary step for operators on the road

to 5G but that has referred to optimizations for the radio including more carrier aggregation

and radio enhancements.

Huawei is showing R&D leadership in several areas in particular antennas and radio related

features. Within the core there hasn’t been much promotion beyond network slicing44 and

38 https://networks.nokia.com/solutions/cloudband 39 http://resources.alcatel-lucent.com/asset/192725 40 https://www.ericsson.com/ourportfolio/telecom-operators/virtual-evolved-packet-core 41 https://www.ericsson.com/news/151228-network_functions_virtualization_244069644_c 42 https://www.ericsson.com/news/160920-tampnet-ericsson-lt-core_244039854_c 43 https://www.ericsson.com/news/151029-ericsson-and-sk-telecom_244069644_c

Alberto Diez October 2016 From EPC to 5G

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their NFV/SDN marketing activities in all possible projects and initiatives (e.g. OPNFV,

ONOS/CORD). Huawei also has in portfolio IoT and Public Safety. Huawei has a MEC

solution: CloudEdge, which has been actively marketed during 2016.

Challengers

Affirmed

Affirmed Networks is the newest and most important player in the EPC space. Affirmed was

funded in 2010 as a startup which focuses on providing the virtual gateways of the EPC.

Affirmed has won a lot of attention after AT&T selected them for their IoT virtual core as part

of the Domain2.0 initiative45. That movement may have been a tactical move from AT&T to

challenge its mainstream EPC vendors but backed up Affirmed to sell itself as the vEPC of

AT&T.

Affirmed has won a lot of references for vEPC IoT cores after AT&T including Etisalat and

Vodafone, the latter not surprisingly as its VC is an investor in Affirmed. It has to be noted

though, that Affirmed only has gateways in its portfolio and other key functions like MME,

HSS, PCRF and IMS have to be selected from partners, also Affirmed is winning for service

specific cores (IoT mainly) which may be the smaller deals but an excellent starting point for

NFV and 5G with a large potential to scale. This is one of the impacts of NFV that an

operator can select best of breed for each function and that is for the advantage of Affirmed.

Samsung

Samsung is not only the largest manufacturer of SmartPhones world-wide but also one of the

large vendors challenging the incumbent telco vendors. Samsung has won some important

LTE radio network contracts and its eNodeBs are widely considered of top quality and

features. Samsung’s EPC core is called AdaptiV Core46 and is a virtualized EPC that has got

some attention after PoC in South Korea with SK Telecom47. AdaptiV includes the MME and

Gateway components and claims to provide all the advantages of a fully NFV designed EPC.

Whether it will have success outside of Korea is still to be seen.

NEC

NEC has had for some time in its portfolio a virtual only EPC48 including MME and Gateways.

NEC has a very solid position in the NFV area due to its acquisition of NetCracker which it

can leverage with its vEPC as VNFs. NEC has have some success in APAC region4950 and it

has allegedly some presence in the MEA region.

44 http://www.huawei.com/en/news/2016/2/Demonstrate-5G-E2E-Network-Slicing-Technology 45 http://www.fiercewireless.com/tech/at-t-s-virtualization-play-makes-a-star-out-affirmed-networks 46 http://www.samsung.com/global/business/networks/core-network/core-network/virtualized-epc 47 https://news.samsung.com/global/samsung-completes-sdn-enabled-epc-proof-of-concept-with-sk-telecom 48 http://www.nec.com/en/global/solutions/tcs/pdf/vEPC_WP.pdf 49 http://www.fiercewireless.com/tech/ntt-docomo-uses-nfv-gear-from-cisco-nec 50 http://www.capacitymedia.com/Article/3576261/NEC-and-Netcracker-provide-virtualized-LTE-core-network-to-Taiwan.html

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Alternative

Core Network Dynamics

! The author started the OpenEPC project and has a relationship to CND

Core Network Dynamics is a spin-off a german research institute that has been

commercializing OpenEPC for test-labs and R&D usage since 2009. In 2016, with OpenEPC

7, they are addressing also commercial deployments for markets like Public Safety, IoT and

NFV/SDN51.

Since 2013 they have been demonstrating their SGW and PGW with CP/UP spilt using

OpenFlow before 3GPP started studying the topic. During 2016 they have shown OpenEPC

deployed in a RaspBerry Pi 2 controlling a commercial LTE SmallCell at the MWC, VoLTE

calls using OpenEPC together with an Open Source IMS at the Kamailio World conference

and a C-RAN prototype with an Ethernet based split above MAC layer at the OPNFV

Summit.

Athonet

Athonet is an Italian small company founded by ex- Ericsson employees that provides a

compact EPC used by Nokia in their LTE in a box solution52. Athonet is active in the Public

Safety and Critical communications, private LTE networks as well as in the IoT area. Athonet

has shown their support of e-MBMS at the 5G World Conference in London.

Quortus

Quortus is a British company that delivers small core networks for special use cases like

remote/rural connectivity, private LTE networks and tactical communications. Quortus has

been providing core networks for 2G and 3G as well and evolved to the EPC. Quortus is

marketing the applicability of its EPC for MEC with large presence in the MEC Congress

201653.

Quortus has announced collaboration with Expeto54 that delivers EPC as a service based on

their NFV platform which is targeting remote and rural operators in North America.

51 http://www.corenetdynamics.com/2016/02/15/cnd-unveils-openepc-7-ramps-up-for-carrier-grade-deployments/ 52 http://www.athonet.com/athonet/nokia-partners-with-athonet-for-network-in-a-box-solution-3/ 53 https://www.quortus.com/news-and-events/events/mec-congress- 54 http://www.realwire.com/releases/Quortus-and-Expeto-co-operate-to-deliver-advanced-wireless-networks

Alberto Diez October 2016 From EPC to 5G

26

Bibliography

Most relevant sources of information about evolution of EPC and 5G mobile core

[1] NGMN 5G vision whitepaper

[2] 3GPP TR 23.799 Technical Study on Architecture for Next Generation System

[3] ITU-T 5G standardization gaps report

[4] 5G-PPP Architecture document

Important Acronyms

API – Application Programming Interface NBI – Northbound Interface AR – Augmented Reality NFV – Network Functions Virtualization B2B – Business to Business SDN – Software Defined Network B2C – Business to Consumer SFC – Service Functions Chaining C-RAN – Cloud Radio Access Network UP – User Plane CP – Control Plane VNF – Virtual Network Function EPC – Evolved Packet Core VoLTE – Voice over LTE IMS – IP Multimedia Subsystem VR – Virtual Reality IIoT – Industrial IoT IoT – Internet of Things LTE – Long Term Evolution QoS – Quality of Service MANO – Management and Orchestration MBB – Mobile Broadband MBMS – Multimedia Broadcast and Multicast System

MEC – Mobile Edge Computing

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