Carrier Ethernet for Mobile Backhaul MEF Implementation Agreement Technical Review

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Carrier Ethernet for Mobile BackhaulMEF
Implementation Agreement Technical Review
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Topics

• Market Overview
• Technical Overview
• Terminology and Concepts
• Service Requirements
• Use cases
• Application Scenario
• Legacy Mobile Backhaul Migration
• Generic Interworking Function
• Traffic separation
• Synchronization
• OAM
• MEF 22 - Phase 2

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Mobile Backhaul Market Overview
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Mobile Data Traffic Growth Drivers
Source Heavy Reading, 2008
Source Analysys Mason, 2009
Source GSA, 2009
Source Heavy Reading, 2008
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MEF 22 - Technical Overview
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MEF 22 Overview

• MEF22 - Explains how to apply existing MEF
  specifications
• Provides generic specification for Ethernet
  backhaul architectures for mobile networks (2G,
  3G, 4G)
• User-Network Interface requirements
• Service Requirements
• Clock synchronization
• Common Terminology
• Offers a standardized toolset
• The Mobile Backhaul is defined as the network
  between the
• Radio Network Controllers (RNCs), and
• Radio Access Networks Base Station (RAN BS).
• MEF22 provides guidelines to architecture,
  equipment operation to that part of the network

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Terminology and Concepts (2)

• Network Elements addressed by the Specification

Terminology used in the specification and this
overview

• The RAN CE is a generic term that identifies a
  mobile network node or site, such as a RAN
  network Controller or RAN Base Station
• A RAN NC may be a single network controller or a
  site composed of several network elements
  including OSS, WCDMA Radio Network Controller or
  Synchronization Server.

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Legacy Mobile Backhaul Migration
Packet offload over Carrier Ethernet Use Case 1a
Emulation over Carrier Ethernet Use Case 1b
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When RAN nodes are equipped with Ethernet
RAN dual stack Use Case 2a
Full Ethernet Use Case 2b
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MEF22 - Application Scenario
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Application Scenario - Description

• Mobile Operator A has operates 2G and 3G mobile
  networks that utilizes TDM leased lines
• 3G base stations have both TDM-based and Ethernet
  interfaces and support IP
• Both systems are FDD (frequency sync)
• Mixed configuration sites

BSC
RNC
TDM Leased Line (1.5Mbps)
Legacy Network
3G
2G 3G
2G 3G
2G
2G 3G
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Problem

• Mobile broadband traffic generates more volume
  than can be supported cost-efficiently by legacy
  network
• Decision Mobile Operator A wants all 2G and 3G
  transport to utilize Carrier Ethernet services

• How to transport 2G non-Ethernet interfaces?
• How to define services?
• How to deliver synchronization?
• How to monitor services?

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UNI for TDM-based base stations

• The GIWF provides adaptation and interconnection
  between any legacy mobile equipments
  (TDM/ATM/HDLC based) at the BS/NC and the Carrier
  Ethernet network at the UNI.
• It enables the joint backhaul of any combination
  of 2G, 2.5G, 3G (legacy based) and Evolved-3G
  4G (Ethernet based) voice and data traffic over a
  single Carrier Ethernet RAN.
• The GIWF implementation could be based on TDM
  circuit emulation standards as well as ATM/HDLC
  pseudo-wire standards.

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MEF Mobile Backhaul and GSM

• How does the GIWF handles existing GSM based
  networks?
• GSM uses a number of T1 (1.5 Mbit/s) or E1 (2
  Mbit/s) circuits to connect the base station with
  the network controller.
• The GIWF terminates a circuit emulation service
  (CES) per such E1/T1 circuit at the cell site or
  service edge and at the network controller site
• A variety of circuit emulation services can be
  used in the implementation agreement (MEF8
  (CESoE), TDMoMPLS (MFA8), SAToP (RFC4553),
  CESoPSN (RFC5086))

CES IWF Circuit Emulation Interworking Function
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MEF Mobile Backhaul and UMTS / WCDMA

• How does the GIWF handles legacy UMTS based
  networks?
• These Technologies uses ATM over a number of
  bundled T1 (1.5 Mbit/s) or E1 (2 Mbit/s) circuits
  to connect the base station with the network
  controller.
• The GIWF terminates an ATM pseudo-wire or a TDM
  circuit emulation tunnel at the cell site or
  service edge and at the network controller site
• A variety of ATM pseudo-wire and/or TDM circuit
  emulation standards can be used in the
  implementation agreement

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Create a UNI at each site

• The GIWF provides support for Legacy circuit over
  Ethernet interface
• Single UNI towards the Network

RNC
BSC
RAN NC
GIWF
Carrier Ethernet Network
UNI
RAN BS
3G
2G 3G (GIWF)
2G 3G (GIWF)
2G (GIWF)
2G 3G (GIWF)
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Services for emulated circuits

• Assumption Emulation solution requires the
  following performance requirements
• FD 20ms, FDV 5ms, FLR10-4,
  Availability99.99
• 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

RNC
BSC
GIWF
Carrier Ethernet Network
EVPL_1
EVPL_2
EVPL_3
EVPL_4
UNI
3G
2G 3G (GIWF)
2G 3G (GIWF)
2G (GIWF)
2G 3G (GIWF)
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Service Requirements Addressed

• Carrier Ethernet Services for Mobile Backhaul
• Typically there are 1-2 RNC sites and between
  hundreds to thousands of RAN BS sites
• Bandwidth requirements for a base station site
  will vary and may range from a few Mbps to over a
  Gbps
• MEF services
• Generally, the requirement is to follow one of
  the following MEF services
• Ethernet Private Line Service
• Ethernet Virtual Private Line Service
• Ethernet Private LAN Service
• Ethernet Virtual Private LAN service
• Ethernet Private Tree Service
• Ethernet Virtual Private Tree Service

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Services for 3G

• 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

RNC
BSC
GIWF
Carrier Ethernet Network
EVPL_1
EVPL_2
EVPL_3
EVPL_4
EVP-Tree
UNI
3G
2G 3G (GIWF)
2G 3G (GIWF)
2G (GIWF)
2G 3G (GIWF)
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Protection at RAN NC
RAN NC UNI
UNI-C
Link Aggregation Group
UNI-N
RNC
BSC
GIWF
Carrier Ethernet Network
EVPL_1
EVPL_2
EVPL_3
EVPL_4
EVP-Tree
UNI
3G
2G 3G (GIWF)
2G 3G (GIWF)
2G (GIWF)
2G 3G (GIWF)
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CoS configuration

• Guidelines for the number of CoS classes to use
• Bundling traffic types into limited number of CoS
  classes
• CoS class performance requirements

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CoS configuration
Example values!
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Synchronization

• Components of sync
• Frequency (2G, 3G, 3.5G)
• Phase (4G in some cases)
• Time of Day
• Legacy TDM delivers only Frequency
  Synchronization
• Migration to all packet networks means loss of
  TDM clock source

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Mobile Wireless Requirements
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Synchronization

• Packet based Synchronization is a challenge
• No end-to-end physical layer clock
  synchronization
• Packet delay variation caused by queuing
  delays, routing changes, network technology
• Packet loss
• Symmetric/asymmetric network
• MEF22 Approach to Synchronization
• Packet based methods are in scope for Phase 1
• Synchronization quality requirements reference
  the ITU G.8261 standard
• The IA is agnostic to specific methods/implementat
  ions like Adaptive Clock Recovery (ACR), Extended
  ACR (RTP Header), IEEE1588, NTPv4, etc.
• Synchronous Ethernet - in scope for phase 2
• Out-of-band sync (GPS, legacy E1 clocking) is
  outside of scope

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Delivering Synchronization

• Options sync over a separate EVC or sent over
  the services in a different CoS class
• Note Not all sites have an emulated service!

UNI
UNI
EVPL_1
EVPL_1 (CES)
CoS 1 (CES)
CoS 2 (Sync)
EVPL_Sync
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OAM in MBH Migration

• Ethernet OAM
• Provides Ethernet with management features
  similar to legacy services
• Features
• Connectivity Fault Management
• Performance Management
• Link Management
• Deployment
• Ethernet can start at the Base Station or the
  legacy traffic can be converged onto a Carrier
  Ethernet Network
• The following slide provides a picture of where
  Ethernet OAM is performed from the Wireless
  Providers perspective and from the Backhaul
  Operators perspective

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Carrier Ethernet enhanced with OAM
Cell Site
MSC
NC (4G)
2G
RNC (3G)
Ethernet
T1/E1
3G
Ethernet
Carrier Ethernet
N x GigE
ATM
T1/E1 (TDM ATM)
Ch-OC3 or T1/E1
T1/E1
BSC (2G)
LTE
Service Provider
RAN BS UNI
RAN NC UNI
Wireless Provider Maintenance Entity
Operator Maintenance Entity
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Application Scenario Summary

• Illustrated how to apply MEF 22 toolset
• Combined Use Case 1b and Use Case 2b
• Several other viable combinations

2G
3G
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MEF 22 - Phase 2
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LTE Reference Architecture

• Basic principles in MEF 22 still apply!
• Whats new with LTE?
• IP from the start
• New logical interfaces
• New pooling concept
• Greater throughput

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MEF 22 - Phase 2 Scope

• Primary items
• New Mobile Technologies
• Performance recommendations
• Resiliency
• Synchronization
• Secondary items
• Detailed SOAM recommendations
• Multi-MEN
• Security

So far, on track!
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Summary

• RAN is going IP
• MEF 22 specifies a toolset for defining Carrier
  Ethernet services
• There are many solutions to the same problem
• Phase 2 will provide additional recommendations
  and include LTE requirements

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Thank You
http//www.metroethernetforum.org (Carrier
Ethernet in Action Carrier Ethernet for Mobile
Backhaul)
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Backup slide
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Relationship between the MEF and BBF

• The MEF MBH IA describes a superset of potential
  implementations
• The Broadband Forum provides a specific network
  implementation reference based on MPLS
• MEF and Broadband Forum will continue to align
  future activities

Carrier Ethernet Network
MPLS Network
Ethernet
Ethernet
E-Line Service
RAN BS
RAN NC
Pseudo-wire Service
UNI
UNI
MPLS Service Termination
MPLS Service Termination