Fujitsu Read More... NGMobile Backhaulwp

User Manual: Fujitsu Read More... FNC Resources - White Papers - Fujitsu United States

Open the PDF directly: View PDF .
Page Count: 6

Achieving Smooth Migration to a

Next-Generation Mobile Backhaul Network

FUJITSU NETWORK COMMUNICATIONS INC.

2801 Telecom Parkway, Richardson, Texas 75082-3515

Telephone: (972) 690-6000

(800) 777-FAST (U.S.)

us.fujitsu.com/telecom

1

Current 2G and 3G fiber-fed mobile backhaul networks use highly reliable SONET network elements to

transport DS1 services from cell towers to MSCs effectively. Service providers are using OC-3 and OC-12

circuits to interconnect multiple cell towers in a UPSR, providing non-service-affecting site scalability and

survivability.

Network element hardware and power sources are fully redundant. Network element power supplies

are distributed on individual cards and fed over redundant power buses to eliminate any single point of

failure, yielding 99.999% availability. Scaling the cell tower access capacity adds DS1s until an economical

breakpoint is reached relative to DS3 tariff pricing. Based on DS3 tariffs, a crossover point of five to seven

DS1s justifies a DS3 lease. To facilitate DS3 service access, service providers will add M13 multiplexer

functionality to the optical multiplexer using an external M13 network element or, if using an advanced

MSPP, will install a transmux card emulating the M13.

MSPP

DS1

OC-n

MxDS3 or

NxDS1

MxDS3 NxDS1

TMUX

Figure 1: Transmux DS1 Grooming to DS3 Over OC-n

The transmux card grooms the DS1s into a DS3 at the access point, satisfying the DS3 tariff while providing

an economic advantage of 28 DS1 capacity for the price of five to seven. Once groomed, an advanced MSPP

will transport the DS3 directly over the system bus to the OC-n optics, further saving capital expense and

additional equipment to break out and remultiplex the DS3.

As 4G technology becomes available, wireless service providers will upgrade their network for WiMAX and

LTE. Use of 4G radios at cell tower sites requires a transition from DS1 to Ethernet interfaces for backhaul.

OC-n rates at cell sites typically scale to OC-48 once Ethernet traffic is added. Wireless service providers will

transition their equipment over the course of the next several years. Therefore, the wireline service providers

must offer both DS1service for legacy providers and service-aware Ethernet for WiMAX/LTE upgraded

providers.

For your convenience, a list of acronyms can be found at the end of this document.

FUJITSU NETWORK COMMUNICATIONS INC.

2801 Telecom Parkway, Richardson, Texas 75082-3515

Telephone: (972) 690-6000

(800) 777-FAST (U.S.)

us.fujitsu.com/telecom

2

Ethernet

Ethernet

DS1

LAG

Cell Site MSPP

4G Wireless

Service Providers

Legacy Wireless

Service Providers

Figure 2: MSPP at Cell Site with LAG and DS1

Over time, DS1 demand will convert to Ethernet, but that transition period is unclear. To reduce risk, provide

flexibility and maintain installed base investment, wireline service providers will implement a platform

capable of supporting both traditional TDM and service-aware Ethernet through scaling, using GFP-F [1]

plug-in cards as needed. Otherwise, wireline service providers must install new Ethernet-centric equipment

at cell towers where footprint is at a premium, increasing both capital and operational expenses. The 4G

cell site contains a mix of CIR and EIR services and signals to be transported to the MSC. These services may

include VoIP, streaming video, Internet data and telemetry signals. Wireless service providers may use an

L2A [2] to efficiently consolidate these signals at the cell site using various classes of service and statistical

multiplexing. The consolidated L2A is the service port to be backhauled. Since Ethernet traffic at the cell site

is policed using the L2A, the MSPP service port will be all CIR service and transported over an EVC. The EVC

may be duplicated by the wireless service provider at the L2A. The duplicated EVCs are diversely mapped

across the WAN facility by the wireline service provider and service multiplexed at the MSC.

Ethernet

Ethernet

DS1

LAG

Cell Site MSPP

VoIP

High Priority HS Data

Second Priority HS Data

Telemetry

Legacy Wireless

Service Providers

L2A

Figure 3: Cell Site MSPP with L2A Interconnect

FUJITSU NETWORK COMMUNICATIONS INC.

2801 Telecom Parkway, Richardson, Texas 75082-3515

Telephone: (972) 690-6000

(800) 777-FAST (U.S.)

us.fujitsu.com/telecom

3

The MSPP service port interface should offer rate-limiting CIR to backhaul the L2A traffic efficiently.

Maintaining 99.999% reliability for Ethernet service at the cell site requires a similar level of redundancy to

the DS1 hardware method. Use of 802.3ad [3] LAG between the L2A and two service cards within the micro

packet-OTN ensures Ethernet resiliency, effectively providing a 1:1 hardware redundancy, as illustrated in

Figure 3. To ensure maximum end-to-end performance over the WAN, Connection-Oriented Ethernet (COE)

techniques are used within the MSPP or Micro Packet ONP. COE offers deterministic operation, consistently

delivering Ethernet services with the lowest latency, jitter and frame loss. Ethernet service delivered

using COE provides the same performance whether the network has few or many network elements and

regardless of WAN facility fault protection switching.

Maintaining SONET performance at brownfield sites provides carrier-class service capabilities in the access

network. Legacy TDM services are undisturbed, whereas circuit emulation using current techniques over

Layer 2/Layer 3 facilities oversubscribes network bandwidth and has unpredictably high latency and jitter.

Ethernet CIR traffic over SONET provides COE operation using GFP-F, and realizes one-way latency in the

order of 1.3 milliseconds (worst case) using jumbo frames, as shown in Figure 4. Jitter and frame loss are less

than 125 microseconds and are therefore nonexistent, due to the predictable time-based nature of SONET.

I nt er f a c e F r ame S i z e

A v e r ag e

L a t enc y ( ms )

10 /10 0B ase-T 64 0.0 4

10 /10 0B ase-T 19 2 0.0 6

10 /10 0B ase-T 320 0.0 8

10 /10 0B ase-T 16 0 0 0.2 5

10 /10 0B ase-T 960 0 1.3 2

10 0 B ase-X 64 0.0 4

10 0 B ase-X 19 2 0.0 6

10 0 B ase-X 320 0.0 7

10 0 B ase-X 16 0 0 0.2 4

10 0 B ase-X 960 0 1.31

GigE 64 0.0 4

GigE 19 2 0.0 4

GigE 320 0.0 4

GigE 16 00 0.0 6

GigE 960 0 0 .19

Figure 4: Table of Latency Rates for Ethernet CIR Traffic over SONET using GFP-F

Greenfield networks used for 4G service use micro Packet ONPs at the cell site to transport data services

using COE over OC-48, point-to-point LAG or G.8031 VLAN protected ring topologies up to 10 GbE WAN

facilities. COE over OC-48 offers almost a 2.5 bandwidth increase over GbE access multiplexers.

FUJITSU NETWORK COMMUNICATIONS INC.

2801 Telecom Parkway, Richardson, Texas 75082-3515

Telephone: (972) 690-6000

(800) 777-FAST (U.S.)

us.fujitsu.com/telecom

4

At the MSC, the MSPP TDM traffic is aggregated to a DCS using DS3 or OC-n interconnects. Ethernet traffic

is service-multiplexed [3] providing EVPL [4] connectivity as per MEF-9 from the cell towers. Maintaining

multi-customer service separation and preventing multi-tag duplication in mixed in- and out-of-franchise

networks is solved using 802.1Q [4] VLAN tagging offering pushed, popped or swapped tag treatment.

Odd and even EVCs are service multiplexed on separate ports in dual EVC architectures. These separate

service multiplexed EVC ports presented from the wireline service provides Packet ONP to the wireless

service provider using 802.3ad LAG between two cards of the Packet ONP maintaining high service reliability

just as is used at cell sites.

SONET

Switch

Fabric

Packet

Switch

Fabric

Mapper

Advanced MSPP

SONET IOF

10G Packet

SONET to Cell Sites

LAG

Figure 5: Advanced MSPP Dual Fabric and Mapper

Packet ONPs at the hub and MSC sites have both TDM and packet switch fabric to optimize traffic treatment

with mapping processors to translate between the two. The mapping processor provides a smooth transition

for brownfield sites using SONET to and from packet facilities. This smooth transition allows Packet ONPs to

operate in a SONET network and terminate packet traffic, as well as forwarding to higher-order networks

using 10 Gbps facilities. The higher-order network provision enables gateway operation for future packet-

based network applications.

SONET

Switch

Fabric

Packet

Switch

Fabric

Mapper

Advanced MSPP

SONET IOF

SONET 10G Packet

LAG

Ethernet

Ethernet

DS1

LAG

Cell Site MSPP

4G

Services

Legacy Wireless

Service Providers

L2A

Figure 6: Next-Generation Mobile Backhaul Network

FUJITSU NETWORK COMMUNICATIONS INC.

2801 Telecom Parkway, Richardson, Texas 75082-3515

Telephone: (972) 690-6000

(800) 777-FAST (U.S.)

us.fujitsu.com/telecom

5

Summary

Packet ONPs offer multiservice operation to achieve 99.999% service availability for COE and TDM traffic

backhauling, while providing solutions for greenfield and brownfield backhaul applications. Smooth

transition from legacy SONET to packet functionality enables service providers to reuse legacy networks

to offer advanced data and maintain original TDM services. Packet ONPs with multiple switch fabrics

optimize operations for SONET and packet with mapping translation between them. These architectures

offer seamless migration from present-mode SONET to packet while preserving installed-base investments.

Access networks using Packet ONPs using GbE, OC-48 or 10 GbE for point-to-point or ring protection offer

in-service scaling to higher speed rates in an all industrial grade, temperature-hardened “five-nines” platform.

COE service delivery offers easy provisioning and deterministic low latency/jitter/frame loss performance

regardless of the number of network elements or whether a protection switch occurred. Finally, centralized

network management of the backhaul network simplifies operation and expedites fault mitigation.

References:

[1] GFP-F Generic Framing Procedure (GFP), ITU-T G.7041

[2] IEEE 802.3ad; Layer 2 aggregator

[3] IEEE 802.3ad Link Aggregation

[4] Metro Ethernet Forum; MEF-9; EVPL Ethernet Virtual Private Line; service multiplexed virtual connection

Term Definition

4G Fourth-generation wireless technology

CIR Committed Information Rate

DCS Digital Cross-connect System

EIR Excess Information Rate

EVPL Ethernet Virtual Private Line

GFP-F Frame-based Generic Framing Procedure

GigE Gigabit Ethernet

IEEE Institute of Electrical and Electronic Engineers

IOF Interoffice Facility

L2A Layer 2 Aggregation

LAG Link Aggregation

Term Definition

LTE Long-Term Evolution

MEF Metro Ethernet Forum

MSC Mobile Switching Center

MSPP Multiservice Provisioning Platform

SLA Service Level Agreement

SONET Synchronous Optical Networking

TDM Time-Division Multiplexing

UPSR Unidirectional Path Switched Ring

VLAN Virtual Local Area Network

VoIP Voice over IP

© Copyright 2010 Fujitsu Network Communications Inc.

FUJITSU (and design)® are trademarks of Fujitsu Limited.

All Rights Reserved. All other trademarks are the property of their respective owners.

Configuration requirements for certain uses are described in the product documentation.