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MEF 22Ethernet Based Mobile Backhaul

MEF Ambassador to the Americas

Rami Yaron

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• MEF Introduction

• Mobile Backhaul – The Market View

• MEF specifications for Mobile Backhaul

• Multi Physical Transport

• Use Case: Legacy Network Migration

• Phase 2: Preparing for LTE and Beyond

Today’s Webinar Agenda

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MEF 22Mobile Backhaul Implementation

Agreement - Phase I

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MEF 22: Overview

• MEF22 Explains how to apply existing MEF specifications to Mobile Backhaul

• Provides generic specification for Ethernet backhaul

• Includes guidelines to architecture, equipment & operation of the RAN

• Offers a standardized toolset

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MEF 22: Standardization Process

TDM to IP/Eth

Industry trends

Other SDOs

MEFs own work as the foundation

Standardizedreference

points

ServiceRequirements

(Service Types,CoS, Eth OAM, etc)

SynchronizationRecommendations

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MEF Terminology and Concepts

• Network Elements as defined in MEF 22 Specification

Service requirements:• Connectivity - From a few to thousands of sites• Assurance - Capacity, quality and availability• Operations - Provisioning, SLA monitoring, fault-finding

GIWF Generic Inter-working Function

PCP Priority Code Point

PEC Packet based Equipment Clocks

PTP Precision Time Protocol

RAN Radio Access Network

RAN BS RAN Base Station

RAN CE RAN Customer Edge –Mobile network node/site

RAN NC RAN Network Controller –Single or multiple network elements

RNC Radio Network Controller

Terminology used in the specification and this overview

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Legacy RAN Mobile Backhaul Migration

Emulation over Carrier Ethernet – Use Case 1b

Packet offload over Carrier Ethernet – Use Case 1a

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Ethernet RAN Mobile Backhaul Migration

RAN dual stack – Use Case 2a

Full Ethernet – Use Case 2b

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Legacy RAN Mobile Backhaul MigrationUse Case

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Use Case Background

• Mobile Operator operates 2G and 3G mobile networks that utilizes TDM leased lines

• 3G base stations Supports both TDM and Ethernet interfaces• Both systems are FDD (frequency sync)• Mixed configuration sites

Legacy Network

TDM Leased Line (1.5 / 2 Mbps)

3G

2G 2G + 3G2G + 3G

2G + 3G

BSC RNC

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Migration Challenges

– 2G transport– Service definition – Timing delivery– Service monitoring

Problem:• Capacity increase not cost-efficiently sustainable on legacy

network

Solution:• 2G and 3G networks should transport Carrier Ethernet

services

Challenges:

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UNI for TDM-based Base Stations

• Generic Interworking Function (GIWF)– Adaptation and interconnection between legacy mobile equipment

at the BS/NC and the Carrier Ethernet network at the UNI– Enables backhaul of any combination of 2G/3G legacy and

Evolved-3G & 4G voice and data traffic over a single Carrier Ethernet RAN

– Implementation based on TDM circuit emulation standards as well as ATM/HDLC pseudo-wire standards

Carrier Ethernet Network

UNI-NUNI-C

Eth Access Link

EFT

GIWFRAN BS

Non-EthernetI/F

UNI-CUNI-N

Eth Access Link

EFT

GIWF RAN NC

Non-EthernetI/F

Ethernet I/F Ethernet I/F

EVC

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2G(GIWF)

2G + 3G(GIWF)

2G + 3G(GIWF)

3G2G + 3G(GIWF)

Services for Emulated Circuits

EVPL_1

EVPL_2

EVPL_3

EVPL_4

UNI

Carrier EthernetNetwork

BSC

• The GIWF Provides support for legacy circuits over Ethernet• Assumption: Emulation solution requires the following:

– FD = 20ms, FDV = 4ms, FLR=10-5, Availability=99.999%– CIR = 2Mbps, EIR = 0Mbps (per emulated leased line)

• EVCs is defined with the same performance requirements• Bandwidth allocated depends on the number of leased lines

that are emulated, n. CIR = n * 2Mbps

GIWF

RNC

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Services for 3G

EVPL_1

EVPL_2

EVPL_3

EVPL_4

UNI

Carrier EthernetNetwork

• 3G service utilizes the Node B Ethernet interface• Assumptions:

– 3G solution requires 3 CoS

– 3G, BWP for each RAN BS: CIR = 6Mbps, EIR = 4Mbps– Ingress BWP for RAN NC UNI: CIR = 24Mbps, EIR = 12Mbps

• E-LINE/E-LAN may be used as well

EVP-Tree

2G(GIWF)

2G + 3G(GIWF)

2G + 3G(GIWF)

3G

BSC RNC

2G + 3G(GIWF)

GIWF

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CoS Configuration

Service Class Name

Example of Generic Traffic Classes mapping into CoS

4 CoS Model 3 CoS Model 2 CoS Model

Very High (H+) Synchronization - -

High (H) Conversational,Signaling and Control

Conversational and Synchronization,

Signaling and Control

Conversational and Synchronization,Signaling and Control,

Streaming

Medium (M) Streaming Streaming -

Low (L) Interactive and Background

Interactive and Background

Interactive and Background

Very High (H+) High (H) Medium (M) Low (L)

-

FD = 20msFDV=4msFLR=10-5

Availability=99.999%

FD=50msFDV=10msFLR=10-4

Availability=99.99%

FD=100msFDV=10msFLR=10-4

Availability=99.99%

Examples:

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MEF22 Approach to Synchronization

– Packet based methods (in scope Phase 1)• Synchronization quality requirements reference the ITU G.8261 standard• Agnostic to specific methods/implementations like Adaptive Clock

Recovery (ACR), Extended ACR (RTP Header), IEEE1588v2, NTPv4, etc.

– Synchronous Ethernet (in scope phase 2)

– Non Ethernet sync (outside IA scope)

F1+ f2

F1

T1 T2

+/- 50ppb

+/- 50ppb

Time

Mobile cannot lock to BTS2

and call is dropped

BTS2 drifts outside 50ppb window

BTS 2

BTS 1

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Delivering Packet Synchronization

• In-band: Within the mobile data stream– Use packet rate based adaptive clock recovery (ACR) – no additional

bandwidth is needed, must have constant packet rate (MEF8)

– Use CES RTP optional header for synchronization timestamps

• Out of band: Separate from the mobile data stream– For packet based synchronization methods like IEEE1588 and NTPv4

– Map synchronization information to separate EVPL or

– Map synchronization information to a different Class of Service (CoS)

Note: Not all sites use circuit emulation services

UNI

EVPLEVPLCoS Data

CoS Sync

UNI

EVPL_Sync

EVPL DataEVPL Data

UNI

EVPL Data & Sync

EVPL Data & Sync

Sync in separate EVPL Sync uses different Class of ServiceSync within the data EVPL

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OAM in MBH Migration

• Ethernet OAM– Provides Ethernet

management

• Features– Connectivity Fault

Management

– Performance Management

– Link Management

• Deployment– Ethernet starts from Base

Station

– or legacy traffic “converged” onto a Carrier Ethernet Network

2G

T1/E1

T1/E1(TDM + ATM)

Ethernet

3G

LTE

EthernetCarrier

Ethernet

N x GigE

Ethernet

ATM

Ch-OC3 or T1/E1

BSC (2G)

RNC (3G)

NC (4G)

Cell Site MSC

Wireless Provider and Backhaul Operator each have visibility of their own Ethernet performance and fault data

Service ProviderRAN BS UNI RAN NC UNI

Wireless Provider Maintenance Entity

Operator Maintenance Entity

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Preparing Ethernet Services for LTEMEF 22 - Phase 2

ApprovedSpecification

ApprovedDraft

LetterBallot

Working Document

StrawBallots

NewProject

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Current Focus Areas

• LTE– Understand LTE and requirements for Ethernet services

• Synchronization– Frequency synchronization requirements and timing methods

• Resiliency– Discuss how resiliency applies to MBH Ethernet services

• Performance monitoring– What needs to be monitored, establish reference model

• Service performance– Common MBH Ethernet service performance recommendations

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MEF 22 Scope Comparison

ITEM PHASE 1 PHASE 2UNI Service Types Link OAM Service OAM FM Service OAM PM CoS Performance recommendations Packet based sync SyncE Resiliency GSM, WCDMA, CDMA2000, WiMAX 802.16e

LTE

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Summary

• RAN is going IP

• MEF 22 specifies a toolset for defining Carrier Ethernet services

• Carrier Ethernet provides solutions for wireless providers and backhaul operators

• MEF22 Phase 2 underway, preparing Ethernet services for LTE

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Thank YouFor details on Carrier Ethernet for Mobile Backhaul visit: http://www.metroethernetforum.org/mobile-backhaul

rami@axerra.com+1 203 554-1522

Rami Yaron