5G: Stato della Standardizzazione e

Mobile (Multi-access) Edge Computing

Franco Mazzenga

Dipartimento di Ingegneria dell’Impresa «Mario Lucertini»

Università di Roma Tor Vergata

Email: mazzenga@ing.uniroma2.it

Seminario Scuola Superiore di Specializzazione in Telecomunicazioni (ISCOM)

Roma 16-04-2018

Summary

• Introduction and motivations• 5G: general design principles

• Standardization activities for 5G• 5G deployment path• Radio Interface (5G-NR)• Access Network (5G-RAN)• Core Network (5G-CN: il 5GC)• Advanced 5G features

• Network slicing

• Multiple Access (Mobile) Edge Computing for 5G• Integration of ETSI MEC in 5G network

• Conclusions

Introduction and motivations

ITU vision on new services• New communication requirements pose challenges on existing

networks in terms of technologies and business models.

• The next-generation mobile network must meet diversified demands.

• The International Telecommunication Union (ITU) has classifed 5G mobile network services into three categories: • Enhanced Mobile Broadband (eMBB),

• eMBB focuses on services that have high requirements for bandwidth, such as high defnition (HD) videos, virtual reality (VR), and augmented reality (AR)

• Ultra-reliable and Low-latency Communications (uRLLC),

• uRLLC focuses on latency-sensitive services, such as assisted and automated driving, and remote management

• Massive Machine Type Communications (mMTC)

• mMTC focuses on services that include high requirements for connection density, such as smart city and smart agriculture.

IMT: International Mobile Telecommunications

Why 5G ?

• 5G will deliver markedly increased operational performance, as well as superior user experience and better network energy efficiency.

• Mobile data traffic is rising rapidly, mostly due to video streaming.

• With multiple devices, each user has a growing number of connections.

• The emergence of the IoT means networks must handle billions more devices.

• Network operators are under pressure to reduce operational expenditure (OPEX), as users don't wish to pay more for increased services.

• Operators also need new applications for mobile technology, opening up new revenue streams.

• 5G aims at total availability. • 5G should offer a user experience near that of fixed networks with near total 5G coverage,

• cater for massive deployment of Internet of Things, while still offering acceptable levels of energy consumption, equipment cost and network deployment and operation cost to ensure the service can be provided economically.

Who is interested in using 5G ?• 5G offers network operators the potential to

offer new services to new categories of users.

• The primary beneficiaries of 5G will be consumers, but 5G presents a huge opportunity for the digitization of economies and modernization of all industry sectors.

• Several industry sectors are already engaged in the process of building 5G, and are actively shaping the technology to meet their needs through participation in the standardization process.

• Other sectors are potentially huge beneficiaries, but have yet to make signification engagement.

Potential Frequencies for 5G

• 5G frequencies include: • bands below 6 GHz • bands above 6 GHz.

• Bands < 6 GHz• For wireless communications, lower frequencies provide better coverage.

• it is necessary to guarantee wide-area coverage and outdoor-to-indoor coverage in 5G.• Currently, almost all countries are using spectrum below 6 GHz for IMT systems. • Spectrum below 6 GHz is very important for 5G.

• Bands > 6 GHz• millimeter wave (mmWave) are used for point-to-point communications in satellite systems and

microwave systems• From the perspective of public mobile communication, mmWave communication technology

provides large bandwidths.• Samsung conducted studies and tests at 13.4–14 GHz, 18.1–18.6 GHz, 27.0–29.5 GHz and 38.0–39.5 GHz.

• For indoor applications frequencies above 57 GHz have been considered

5G: general design principles

Enablers and Design Principles

• Future 5G networks are build on concepts not envisioned by the previous generation network architecture: modularization & (full) network programmability by softwarization.

• The “revolution” is based on the introduction of:• software-defined networking (SDN) and • network function concept and network function virtualization (NFV)

• 5G network has been intentionally designed to achieving:• architecture flexibility, • heterogeneous accesses and • vertical business integration.

• To this aim, 5G leverages on the advance of NFV and SDN.

• As a general principle, SDN and NFV allow the design of logical network architectures tailored to performance and functional requirements of different use cases,

Network function (NF) decomposition

• Modularization

• The principle of architecture modularization and network function decomposition was proposed at the earliest 5G research stages.

• Monolithic network functions, in 4th generation (4G) cellular to be splitted into basic modules or network functions (NFs) both for the control plane (CP) and user plane (UP)• This approach allows for the definition of different logical (network) architectures via the

interconnection of different subsets of CP and UP NFs.

• In the process of decomposing the NFs into basic modules the distinction between NFs relating tothe access network (AN) and core network (CN) emerged.

• Architecture modularization provides the support to network slicing (see after)• A network slice can be defined as an independent logical network shaped by the interconnection of a

subset of NFs, composing both CP and UP, and which can be independently instantiated and operated over physical or virtual infrastructure.

• Another 5G goal: minimizing the dependency of the 5G core on the access technology• achieve the definition of a convergent network, providing connectivity via a multitude of accesses not only including

cellular radio

5G: other building blocks (from ETSI)

• ETSI has a number of (other) component technologies that (possibly) will be integrated into the future 5G systems: • Application Programming Interfaces (API)

• Network Functions Virtualization (NFV) (i.e. modularization – see before),

• Multi-access (Mobile) Edge Computing (MEC),

• Millimetre Wave Transmission (mWT) and

• Next Generation Protocols (NGP).

Standardization activities for 5G

Standardization stages

• The core standards for 5G are being developed by 3GPP.

• 5G involves the development of a new radio interface (NR), the enhancement of current LTE Advanced Pro radio, and the development of a new core network architecture.

• The first phase of 5G specifications in Release-15 will be completed by September 2018, to accommodate early commercial deployment.

• The second phase in Release-16 will be completed by March 2020, for submission to the ITU as a candidate IMT-2020 technology.

• 3GPP has approved specifications for Non-Standalone New Radio (NR) before March 2018.

• Some key documents already available:

• Feasibility studies: TR 22.861, TR 22.862, TR 22.863 and TR 22.864, for the Massive Internet of Things, Critical Communications, Enhanced Mobile Broadband and Network Operation uses cases respectively | Architecture Study: TR 23.799 | Service Requirements: TS 22.261

…. what is being standardized ?

5GS (main) components

• 5G system: includes

• 5G radio interface (5G-NR: new radio)

• 5G radio access network (5G-RAN)

• 5G core network (5G-CN)

5G System (5GS)

5G System (3GPP TS 23.501): architettura

Access and MobilityManagement Function

Session Management Function

5G terminology: eNB, ng-eNB, gNB (2018)

5G access network (NG-RAN) (3GPP TS 38.300)

gNB

ng-eNB

NG-RAN

5GC

AMF/UPF

gNB

ng-eNB

AMF/UPF

5G deployment path

5G-NR development

• The 3GPP has completed the specification for the non-standalone 5G New Radio (NR) (3GPP RAN Plenary meeting in Lisbon, Portugal, Dec. 2017).

• The non-standalone architecture leverages the LTE and the NR air interfaces as well as the existing LTE core network. • This configuration will likely be used for early 2019 deployments.

• There is a standalone version of 5G NR that the 3GPP is still working on. • Standalone 5G NR will have full user and control plane capability (see next slide) and will

use the next-gen core network architecture.

• This specification is expected to be finished in June 2018 as part of the 3GPP Release 15.

• A little bit of history: the release of the non-standalone 5G NR spec was originally scheduled for March 2018, but that timeframe was accelerated after the 3GPP received pressure from many operators including AT&T, Sprint, Telstra, and Vodafone.

• Qualcomm was very involved in the early release of the non-standalone 5G NR spec.

First 5G NR standard complete —> toward the global 5G standard

Qualcomm – April 2018 NSA: non-standalone

Non-standalone/Standalone solutions for 5G gradual deployment and migration

Non-standalone Standalone

• In the 3GPP Release 15 standard the firstwave of networks and devices will beclassed as Non-Standalone (NSA), i.e. the5G networks will be supported by existing4G infrastructure.

• Here, 5G-enabled smartphones willconnect to 5G frequencies for data-throughput improvements but will still use4G mainly for non-data duties

• The advantage of Standalone (SA) solutionis simplification and improved efficiency,which will lower cost, and steadily improveperformance in throughput up to the edgeof the network, while also assistingdevelopment of new cellular use casessuch as ultra-low latency communications(ULLRC).

• Once the SA standard is approved this year,the eventual migration from 5G NSA to SAby operators should be invisible to theuser.

5G interworking with LTE – non standalone

5G NR – Air Interface

5G New Radio (5G-NR) (3GPP 38.xxx serie)

5G-NR – main features

5G-NR – Air interface

• The multiple access scheme/multiplexing for the NR physical layer is based on Orthogonal Frequency Division Multiplexing (OFDM) with a cyclic prefix (CP).

• Same radio interface for DownLink and UpLink• From the Standard 3GPP TS38.211: time-continuous signal on antenna port p and subcarrier m spacing

configuration for OFDM symbol in a subframe for any physical channel or signal except PRACH

• To support transmission in paired and unpaired spectrum, both Frequency Division Duplex (FDD) and Time Division Duplex (TDD) are enabled.

• The Layer 1 is defined in a bandwidth agnostic way based on resource blocks, allowing the NR Layer 1 to adapt to various spectrum allocations. • Definition: a resource block ALWAYS spans 12 sub-carriers for a given sub-carrier spacing.

• The radio frame has a duration of 10ms and consists of 10 sub-frames of 1ms.

• A sub-frame is formed by one or multiple adjacent slots.

• One slot always contains 14 OFDM symbols

Transmission frame (3GPP TS 38.211)

• Downlink and uplink transmissions are organized into frames with duration Tf=10 ms.

• Each frame consists of ten subframes of Tsf=1 ms duration each.

• Transmission of the generic uplink frame from the UE shall start TTA (time advance) before the start of the corresponding downlink frame; TTA depends on the frequency band according to (doc. 3GPP TS 38.133).

TTA

Quick refresh of OFDM (Orthogonal Frequency DivisionMultiplexing) (Qualcomm)

Sub-carrierfrequency spacing

: approx = # sub-car x Sub-car frequency spacingMain parameters:

Numerology of Scalable OFDM for 5G-NR

• Scalable OFDM: the sub-carrier frequency spacing can be changed• Main variable parameter: sub-carrier frequency spacing (Df )

• Multiple OFDM numerologies are supported as given in Table; m is thenumerology index

m [kHz] 152 D mf Cyclic prefix

0 15 Normal

1 30 Normal

2 60 Normal, Extended

3 120 Normal

4 240 Normal

Doc. 3GPP TS 38.211

Scalable OFDM – example (Qualcomm)

Transmission SubFrame organization and Scalable OFDMReference sub-carrierspacing (same as LTE)

1 slot/subframe

2 slot/subframe

4 slot/subframe

Number of OFDM symbols per slot, slots per frame, and slots per subframe for normal cyclic prefix.

m

slotsymbN

mframe,slotN

msubframe,slotN

0 14 10 1

1 14 20 2

2 14 40 4

3 14 80 8

4 14 160 16

5 14 320 32

One slot always contains 14 OFDM symbols !!!

Doc. 3GPP TS 38.211

OFDM symbols in a slot (D,X,U) (3GPP TS 38.211)

• OFDM symbols in a slot can be classified as 'downlink' (denoted 'D’), 'flexible' (denoted 'X'), or 'uplink' (denoted 'U').

• In a downlink slot, the UE shall assume downlink transmissions to occur in 'downlink' or 'flexible' symbols only.

• In an uplink slot, the UE shall transmit in 'uplink' or 'flexible' symbols only.

• Questions: why we need so many different types of slot formats ?

• It is to make NR scheduling flexible especially for TDD operations.

• By applying a slot format or combining different slot formats in sequence, we can implement various different types of scheduling

Table 4.3.2-3: Slot formats.

Format Symbol number in a slot

0 1 2 3 4 5 6 7 8 9 10 11 12 13

0 D D D D D D D D D D D D D D

1 U U U U U U U U U U U U U U

2 X X X X X X X X X X X X X X

3 D D D D D D D D D D D D D X

4 D D D D D D D D D D D D X X

5 D D D D D D D D D D D X X X

6 D D D D D D D D D D X X X X

7 D D D D D D D D D X X X X X

8 X X X X X X X X X X X X X U

9 X X X X X X X X X X X X U U

10 X U U U U U U U U U U U U U

11 X X U U U U U U U U U U U U

12 X X X U U U U U U U U U U U

13 X X X X U U U U U U U U U U

14 X X X X X U U U U U U U U U

15 X X X X X X U U U U U U U U

16 D X X X X X X X X X X X X X

17 D D X X X X X X X X X X X X

18 D D D X X X X X X X X X X X

19 D X X X X X X X X X X X X U

57 D D D D X X U D D D D X X U

58 D D X X U U U D D X X U U U

59 D X X U U U U D X X U U U U

60 D X X X X X U D X X X X X U

61 D D X X X X U D D X X X X U

62 – 255 Reserved

NOTE: Even though all the slot format looks like a TDD structure, these can be deployed in FDD mode as well

Self-contained integrated sub-frame

• It is a key enabler for low latency, forward compatibility, and many new 5G NR features.

• The lower latency is achieved by having the data transmission and its acknowledgement all contained in the same subframe.

• The figure shows an example of a TDD downlink centric subframe, where data transmission is from the network to the device and the acknowledgement is sent by the device back to the network in the same subframe.

• With the 5G NR self-contained integrated subframe, each TTI is now a modular transaction (e.g., DL grant -> DL data -> Guard Period -> UL ACK) that gets completed within that time period.

Note: a subframe always include CRTL and User Data

Carrier bandwidth part (CBWP)

• It is a part of the DL or UL channel bandwidth configured by the network

• Configuration per UE• Up to 4 CBWPs for UL and DL carriers per UE

• Each CBWP may have different SCS, location, and bandwidth

• UE transmit/receive channels and signals on one of CBWPs indicated by control channel

• Formal definition (from 3GPP TS 38.211 doc): a carrier bandwidth part is a contiguous set of physical resource blocks, selected from a contiguous subset of the common resource blocks for a given numerology (m) on a given carrier.

Example

Carrier bandwidth part (cont.)

Flexible slot-based 5G NR framework

Carrier Aggregation for 5G

• The detailed mechanism of Carrier Aggregation in 5G/NR is not specified yet (as of Sep 2017), but the overall mechanism should be similar to LTE Carrier Aggregation.

• At least, these followings has been determined :• Carrier Aggregation is specified from the first specification of NR (i.e, Release 15)

• Maximum number of Secondary Component Carrier in addition to Primary Carrier is 15 (3GPP TS 38.211 – Par. 4.5)

• Transmissions in multiple cells can be aggregated where up to fifteen secondary cells can be used in addition to the primary cell.

5G RAN

5G-RAN architecture (3GPP TS 38.300)

• Includes NG-RAN nodes.

• An NG-RAN node is either:

• A gNB, providing NR user plane and control plane protocol terminations towards the UE;

• an ng-eNB, providing E-UTRA user plane and control plane protocol terminations towards the UE.

• The gNBs and ng-eNBs are interconnected with each other by means of the Xn interface.

• The gNBs and ng-eNBs are also connected by means of the NG interfaces to the 5GC, more specifically to the:

• AMF (Access and Mobility Management Function) by means of the NG-C interface and to

• UPF (User Plane Function) by means of the NG-U interface (see 3GPP TS 23.501)

Functional Split between NG-RAN and 5GC

NG-RAN protocol architecture: guidelines

• The general principles guiding the definition of NG-RAN architecture and interfaces are:• Logical separation of signalling and data transport networks.

• Protocols over Uu (LTE, UMTS) and NG interfaces are divided into two parts:• User plane protocols

• These protocols are used to carrying user data through the access stratum.

• Control plane protocols• These are the protocols for controlling the PDU Sessions and the connection between the UE and

the network (requesting the service, controlling different transmission resources, handover etc.).

• Also a mechanism for transparent transfer of NAS messages is included.

• Mobility for an RRC connection is fully controlled by the NG-RAN.

Protocol architectures (3GPP TS 38.401)

• User plane • Control plane

NOTE 1: The radio interface protocols are defined in

3GPP TS 38.2xx and TS 38.3xx.

NOTE 2: The NG interface protocols are defined in

3GPP TS 38.41x.

NOTE 1: The radio interface protocols are defined in 3GPP TS 38.2xx and TS 38.3xx.

NOTE 2: The protocol is defined in 3GPP TS 38.41x. (Description of NG interface).

NOTE 3: CM, SM: This exemplifies a set of NAS control protocols between UE and 5GC.

Both the Radio protocols and the NG protocols contain a mechanism to transparently transfer NAS messages.

Radio protocols stack(s) – Access Stratum(3GPP TS 38.300)• User plane • Control plane

Network interfaces (NG interfaces) - (3GPP TS 38.300)

• User plane • Control plane

The NG control plane interface (NG-C) is defined between the NG-RAN node and the AMF. The transport network layer is built on IP transport. For the reliable transport of signalling messages, SCTP is added on top of IP. The application layer signalling protocol is referred to as NGAP (NG Application Protocol). The SCTP layer provides guaranteed delivery of application layer messages. In the transport, IP layer point-to-point transmission is used to deliver the signalling PDUs.

The NG user plane interface (NG-U) is defined between the NG-RAN node and the UPF.

The transport network layer is built on IP transport and GTP-U is used on top of UDP/IP to carry the user plane PDUs between the NG-RAN node and the UPF.

5G CORE (5GC)

Core Network Evolution

Service based architecture (SBA): concepts

• Compared to previous generations the 3GPP 5G system architecture is service based. • This means the architecture elements are defined as network functions (NF) that offer their

services via interfaces of a common framework to any network functions that are permitted to make use of these provided services.

• Network repository functions (NRF) allow every network function to discover the services offered by other network functions.

• This architecture model, further adopts principles like:• modularity, • reusability • self-containment of network functions,

• SBA has been chosen to take advantage of the latest virtualization and software technologies.

Service based architecture (3GPP TS 23.501)

Network functions (NF)

Service basedinterfaces (SBI)

Service Based Architecture (Control Plane)

• The 5G System architecture consists of network functions (NF) (mainly for the CP) and entities.

• Legend:• Authentication Server Function (AUSF), Access and Mobility Management Function (AMF), Data Network (DN), e.g. operator services, Internet access or 3rd

party services, Unstructured Data Storage Function (UDSF) – not shown, • Network Exposure Function (NEF), NF Repository Function (NRF), Network Slice Selection Function (NSSF), Policy Control Function (PCF), Session

Management Function (SMF), Unified Data Management (UDM), Unified Data Repository (UDR) – not shown, User Plane Function (UPF), • Application Function (AF), User Equipment (UE), (Radio) Access Network ((R)AN), 5G-Equipment Identity Register (5G-EIR), Security Edge Protection Proxy

(SEPP)

Service BUS ?

The Application Function (AF): some words

• AF is powerful element in mobile data networks.

• The AF could improve the quality of experience for mobile data and revolutionize how operators engage with their subscribers.

• Concept of AF:• It was introduced in IP media subsystem (IMS) architecture

• The AF is a logical element of the 3GPP framework and usually sits in the control plane

• It establishes the quality of service and (potentially) some charging aspects for a service.

• Simply put, the AF acts a quality controller for specific applications which resides on the network and interconnects with a policy charging and rules function element.

• An AF sitting in a modern mobile data network could be vital for service quality.

• it understands the application traffic that a subscriber is using and could request that necessary QoS and charging resources be made available to the end-user.

• It could apply bandwidth parameters for video streaming to ensure a positive experience, provided the network resources were there.

• AF can be used to interface/integrate MEC with 5G core network (see after)

(Very !) basic example of SBA working

NFs: Service Consumer & Service Producer (provider ?)

Service registrationby the Service Provider

Service discoveryService utilization

Protocols over the Service Based Interface (SBI)• 5G SBI Protocols

• HTTP/2 adopted as the application layer protocol for the service based interfaces

• TCP adopted as the transport layer protocol; • Use of QUIC, binary encoding (e.g. CBOR) and

other aspects are left for possible support in future releases

• JSON adopted as the serialization protocol;

• REST-style service design whenever possible and custom (RPC based) methods otherwise.

Advanced 5G features

Network Slicing

• General concept:• Network (slice) = combination of NFs -> if we use virtualization -> obtain NFVs

-> combination of NFVs = create more Network Slices on the same physicalinfrastructure (Network IaaS - Network infrastructure as a service)

• A network slice can be defined as an independent logical network shaped by the interconnection of a subset of NFs (or NFVs), composing both CP and UP, and which can be independently instantiated and operated over physical or virtual infrastructure.

Network slice: main characteristics

• As said before, a network slice is a logical network providing specific network capabilities and network characteristics.

• The network slice comprises NF(V)s, computing and networking resources to meet the performance requirements of the tenants (e.g. verticals).

• A network slice comprises: • Radio access network (RAN) NF(V)s and • Core Network (CN) NF(V)s and, • depending on the degree of freedom that a tenant may have, also the management and orchestration

NF(V)s.

• A network slice may be:• dedicated to a specific tenant or • partially shared by several tenants that have the same performance requirements but different security or

policy settings.

• The decoupling between the virtualized and the physical infrastructure allows for the efficient scaling of the slices, hence suggesting the economic viability of this approach that can adapt the used resources on demand.

Network slice: examples and deployment

In the figure: network slice #3 is a straightforward deployment - all network functions serve a single network slice only.The figure also shows how a UE receives service from multiple network slices, #1 and #2.In such deployments slices #1 and #2 have network functions in common including the AMF and the related policy control (PCF) and network function servicesrepository (NRF). In fact, there is a single access control and mobility management instance per UE and this is responsible for all services of a UE.The user plane services, specifically the data services, can be obtained via multiple, separate network slices. In the figure, slice #1 provides the UE with dataservices for Data Network #1, and slice #2 for Data Network #2. Those slices and the data services are independent of each other apart from interaction withcommon access and mobility control that applies for all services of the user/UE.Thus each slice can be tailored for e.g. different QoS data services or different application functions, all determined by means of the policy control framework.

Mobile Edge Compuntingnow

Multi-Access Edge Computing

Motivations for MEC inside 5G• 5G is also about an end-to-end converged network and cloud infrastructure for not only traditional human

based services but also for emerging Internet of Things (IoT) services. • It is envisioned that billions of heterogeneous IoT devices will be connected to the 5G network, enabling a wide variety of

applications in different vertical industries such as automotive, energy, media and entertainment, e-health and factories of the future

• Thus, at the cloud level, 5G requires massive distributed computing and storage infrastructures in order to perform IoT analytics (e.g. Bigdata) from the data collected of sensors and actuators (e.g., temperature monitoring, energy consumption measurement, etc.,)

• Furthermore, the adoption of Cloud Radio Access Network (C-RAN), Network Function Virtualization (NFV), network slicing etc. requires cloud services for the deployment of virtualized network functions (VNFs)

• Cloud services include core cloud (e.g., in core/metro data centers) for high-computational capability but:

• Core cloud only based solution cannot solve all problems related to capacity, flexibility and latency etc., • Evolved mobile cloud computing and future 5G services will be directly accessible from mobile devices (smartphone,

tablets etc.). Due to low processing power, mobile devices rely on cloud resources to perform their computational tasks hereby saving processing power and energy.

• Important facts:• high network load, and growing demand of network bandwidth since data are transmitted/received to and from mobile

devices and cloud data centers. It is estimated that demand of bandwidth is expected to be doubled each year.

• Offloading device computation to core cloud only may involve long latency for data exchange between the public cloud and edge devices through the Internet.

• To overcome the above challenging issues, EDGE CLOUD (based on micro-data centers) is closer to the end-users (e.g. in Central Offices) with lower capabilities but PROVIDES fast response time.

MEC: Key concepts• The European Telecommunications Standards Institute (ETSI) is

the body that started the standardization of MEC, and it has issued a MEC architecture and framework in March 2016

• It has already been introduced in LTE, and it will become more essential and will require native support in the 5G system, is that of multi‐access edge computing (MEC), previously known as mobile edge computing.

• Key concepts and advantages of MEC:

• move cloud close to the radio (i.e. the Edge Cloud), for instance, physically co‐located with base stations for the benefit of:

• reduce E2E latency for, e.g., URLLC use cases; for instance, the communication between a device and an application server can be kept in local proximity and need not involve a long‐distance transport network or cloud environment;

• increased networking efficiency, as application data which is only needed locally can also be kept locally, and need not be unnecessarily routed over a large‐scale communications infrastructure;

• increased security, because application data can be confined within areas where it is actually needed;

• providing applications access to local context and communications‐related information (for instance, an application may make use of proximity information among devices).

Strategic relevance of MEC

• MEC provides a new ecosystem and value chain. • Operators can open their Radio Access Network (RAN) edge to authorized third-parties, allowing them to flexibly and

rapidly deploy innovative applications and services towards mobile subscribers, enterprises and vertical segments.

• MEC will enable new vertical business segments and services for consumers and enterprise customers. Use cases include:

• video analytics

• location services

• Internet-of-Things (IoT)

• augmented reality

• optimized local content distribution and

• data caching

• MEC allows software applications to tap into local content and real-time information about local-access network conditions.

The MEC serverThe key element of MEC is its Commercial-Off-The-Shelf (COTS) application server, which is integrated with the base station (or in the BBU or in the backhaul etc.).

The MEC server provides:

• computing resources,

• storage capacity and

• connectivity

Additionally, it provides access to user traffic and radio network information that can be used by application providers to tailor their applications and services for enhanced user experience.

Offline or batch processing, data intensive and high latency tasks are relegated to larger clouds.

Deploying MEC in the 5G system architecture

• The 5G Service Based Architecture (SBA) contains:

• multiple control plane functional entities, (Policy Control Function (PCF), Session Management Function (SMF) and the Application Function (AF), etc., and

• data plane functional entities like the User Plane Function (UPF).

• The 5G system has been conceived to allow a more flexible deployment of the data plane, aiming to natively support edge computing.

• As a consequence, the MEC architecture can easily be integrated into that defined for 5G as for example in Figure.

• The MEC host’s data plane is mapped to 5G’s UPF element to perform the traffic routing and steering function in the UPF. For example, a UL Classifier of UPF is used to divert to thelocal data plane the user traffic matching traffic filters controlled by the SMF, and further steer to the application.

• The PCF and the SMF can set the policy in CP to influence such traffic routing in the UPF. Also the AF via the PCF can influence the traffic routing and steering.

February 2018

5G, network slicing and MEC

The 5G network infrastructure allows

network slicing involving

• shared network,

• cloud and virtualized functions

resources to exist in parallel

Core Cloud and Edge cloud cooperate for

(optimally) creating slices over the 5G

network infrastructure

Conclusions

• Standardization of 5G-NR (non-standalone) interface has been finalized• OFDM wins again !!!

• This is an important step because it enables the manufacturing of 5G terminals

• Non-standalone solution for first field trials with 5G-NR for 5G gradual deployment

• 5G design and development concepts are based on modularization, softwarization and network programmability at every level: access and core• Enables flexible management of network resources

• NF and NFV are the main enablers for 5G networks

• Network slicing is a distinctive feature of 5G

• Service based (SBA) architecture of the 5G network using standard and well established Information Technologies (IT)

• ETSI Multi-access Edge Computing keeps pace with 5G• Possible solutions for MEC integration in 5G network architecture have been presented (Feb. 2018)

Performance and economical advantages of MEC deployment in 4G/5G networks are analyzed in the last presentation !!

Main references

1. 3GPP TS 38.xx document serie, 2018

2. Qualcomm: “Making 5G NR a commercial reality”, available online, Dec. 2017

3. Qualcomm: “ Making 5G-NR a reality”, available online, Dec. 2016

4. Ericsson: “Designing for the future: the 5G NR physical layer”, Ericsson Review, 2017-07-24

5. ETSI, “Mobile-Edge Computing – Introductory Technical White Paper”, available online, Feb. 2018

WebSites

1. http://www.3gpp.org

2. https://blog.3g4g.co.uk/ (blog)

Backup

Some gNB and ng-eNB functionalities• Functions for Radio Resource Management:

• Radio Bearer Control, Radio Admission Control, Connection, Mobility Control, Dynamic allocation of resources to UEs in both uplink and downlink (scheduling);

• IP header compression, encryption and integrity protection of data;

• Selection of an AMF at UE attachment

• Routing of User Plane data towards UPF(s);

• Routing of Control Plane information towards AMF;

• Connection setup and release; Scheduling and transmission of paging messages (originated from the AMF); Scheduling and transmission of system broadcast information (originated from the AMF or O&M); Measurement and measurement reporting configuration for mobility and scheduling; Transport level packet marking in the uplink;

• Session Management

• Support of Network Slicing;

• QoS Flow management and mapping to data radio bearers;

• Support of UEs in RRC_INACTIVE state;

• Distribution function for NAS messages;

• Radio access network sharing;

• Dual Connectivity;

• Tight interworking between NR and E-UTRA.

AMF functions (see 3GPP TS 23.501)

• NAS signalling termination;

• NAS signalling security;

• AS Security control;

• Inter CN node signalling for mobility between 3GPP access networks;

• Idle mode UE Reachability (including control and execution of paging retransmission);

• Registration Area management;

• Support of intra-system and inter-system mobility;

• Access Authentication;

• Access Authorization including check of roaming rights;

• Mobility management control (subscription and policies);

• Support of Network Slicing;

• SMF (Session Management function) selection.

UPF functions (3GPP TS 23.501)

• Anchor point for Intra-/Inter-RAT mobility (when applicable);• External PDU session point of interconnect to Data Network;• Packet routing & forwarding;• Packet inspection and User plane part of Policy rule enforcement;• Traffic usage reporting;• Uplink classifier to support routing traffic flows to a data network;• Branching point to support multi-homed PDU session;• QoS handling for user plane, e.g. packet filtering, gating, UL/DL rate

enforcement;• Uplink Traffic verification (SDF to QoS flow mapping);• Downlink packet buffering and downlink data notification triggering.

SMF functions

• Session Management;

• UE IP address allocation and management;

• Selection and control of UP function;

• Configures traffic steering at UPF to route traffic to proper destination;

• Control part of policy enforcement and QoS;

• Downlink Data Notification.