Use of Combined Synchronous Ethernet & IEEE-1588 in ... - Use of... · Use of Combined Synchronous Ethernet & IEEE-1588 in Wireless TDD applications ... Metro. Core. 2G BTS. 3G Node

VOICE & TIMING SOLUTIONS For a New Global Network

Use of Combined Synchronous Ethernet & IEEE-1588 in Wireless TDD applications

Jeremy Lewis – Product Line Manager

P.2 Confidential10/26/2009COMMUNICATION PRODUCTS

Wireless remains Strong

Backhaul investments jump by 19% in 2008, forecast to jump by 24% in 2009Increasing demand for innovative Data ServicesT1/E1 backhaul costs prove inhibitive to supporting the growth in traffic

Worldwide Average Bandwidth per Installed Connection (Mbps)

49

42

35

7 1014

2824

18

232219

5

1714

118 14131110

5 79

60

10

20

30

40

50

CY05 CY06 CY07 CY08 CY09 CY10 CY11 CY12 CY13Calendar Year

Mbp

s

New Ethernet wireline PDH and ATM over PDH SONET/SDH

Worldwide Mobile Backhaul Equipment Revenue by Technology

$0$2,000$4,000$6,000$8,000

$10,000$12,000

CY05 CY06 CY07 CY08 CY09 CY10 CY11 CY12 CY13

Calendar Year

Rev

enue

($M

)

Ethernet microwave Ethernet cell site gateways and routers PDH/SDH microwave Other SONET/SDH PDH NIU


The Move to an IPRAN

Pressure on the backhaul– Increasing data Services driving bandwidth demand– Increasing number of BTS/NodeB per Cell site driving bandwidth

demand– Increasing costs of traditional backhaul

Synchronization?

0

1,000,000

2,000,000

3,000,000

4,000,000

5,000,000

6,000,000

CY2005 CY2006 CY2007 CY2008 CY2009 CY2010 CY2011 CY2012 CY2013

Installed Cell Site Connections

Total Traditional installed connections Total IP installed connections


IPRAN Synchronization

BTS/Node B equipment have a variety of options for clock synchronization sourcesSynchronization sources may be used as a common clock for the entire node, or may only be a clock to time an individual T1/E1

PacketNetwork

CESoP (adaptive or differential)

T1/E1

Reference

or

NetworkClocks

End Node (BTS)

T1/E1

or

ServiceClocks

GPSBITS/SSU (SASE)

IEEE 1588 v2NTP v4

Synchronous Ethernet (SyncE)Packet

Network

DedicatedClocks

Leased Lines - T1/E1Circuit

Network

RadioInterface



Wireless FDD – Frequency & WanderWireless TDD – Frequency, Wander & Time Alignment

Technology FrequencyAccuracy

(ppb/ppm)

Frequency(MTIE/TDEV)

Phase/Time(Time of Day)

GPS Yes Yes Yes

Synchronous Ethernet(Physical Layer)

Yes Yes No

IEEE 1588 v2(Protocol Layer)

Yes Yes Yes

T1/E1(Leased Lines)

Yes Yes No

CESoP (e.g. PWE3 or RTP)(Protocol Layer)(Adaptive or Differential)

Yes Yes No



UMTS-FDD is the dominant technology today– WCDMA

Increasingly we will see TDD technologies be deployed– CDMA, WiMAX, LTE-TDD

TDD technologies require very accurate Time of Day alignment between basestations– This allows for efficient use of the spectrum while providing

seamless handover of the handset from one Base Station to the other

All TDD technologies use GPS today, Wireless Operators have long since sort an alternative


Frequency and Phase

Freq transfer is well suited to the physical layerPhase transfer is well suited to packet networksSyncE is a freq transfer mechanism while 1588 is a phase transfer mechanismBoth can be used independently and in combination to address the synchronization needs of the networkOperators would like to see the widespread use of SyncEbecause of its accuracy and Management capabilities1588 is a technology used in existing networks and for Time Synchronization


Access Metro Core

PSN

DWDM

SyncE

DWDM

Frequency Synchronization Using SyncE

SyncE allows operators to offer synchronous services over upgraded or new packet network infrastructureSyncE applies a simple, reliable, and well understood method of distributing synchronization over the physical layer of a packetnetworksSyncE is based on a well established SONET/SDH synchronization distribution models, it’s highly accurate over 10 nodes and more

Legacy FAX

SOHO/ Residential

PON ONT/ONU

IAD

ACCESS DLC or OLT


Phase Synchronization Using IEEE 1588

1588 allows operators to offer synchronous services over an existing packet network infrastructure1588 provides a method of distributing frequency synchronization and time of day alignment over packet switched network1588 functionality is only required at both ends of the connection

RAN Metro Core

2G BTS

3G Node B

Basestation Controller

PSN

DWDM

ToP Client ToP Server

DWDM

Server to Client1588 packet flow

3G Node B

Basestation Controller


Time of Day Alignment

Two main Parameters affect the quality of phase alignment1. Recovered clock wander

– Network Packet Delay Variation: size and loading of a given network

– Client oscillator stability: cost performance trade off2. Link delay asymmetry

– Path Asymmetry: forward and reverse path are different – Load Asymmetry: forward and reverse path asymmetry,

this varies as network condition varyUse of physical layer synchronization techniques. For example the clock can be extracted from the physical layer using SyncE– Less than 100nsec TIE over 100,000 sec test period


Hybrid Mode

Hybrid mode combines SyncE and IEEE 1588– An accurate frequency is obtained through SyncE– An accurate Time of Day alignment is obtained through 1588

Timing Distribution Using ToP + Synchronous Ethernet1PPS (Time of Day)

ZL30106ZL30106

1GbEPHY

PRS

TimingPackets

DataPackets

ZL30106ZL30106

1GbEPHY

SyncEDPLL +

Server TopEngineSSU/BITS

ZL30106ZL30106

1GbEPHYZL30106ZL30106

1GbEPHY

SyncEDPLL

TimingPackets

ZL30106ZL30106

1GbEPHYZL30106ZL30106

1GbEPHY

SyncEDPLL

SyncEDPLL +

Slave ToPEngine

TimingPackets


Test results for SyncE Only


SyncE, 10 Node MTIE Results

100nsec


SyncE, 10 Node TDEV Results


Test results for IEEE 1588 only


Test Results

The following are Time of Day plots for various traffic Test Cases for a 5 node network– All nodes are GbE Routers– Link Delay asymmetry will be small

Numerous G.8261 Test Cases have been usedMany will cause traffic asymmetryTDD technologies require less than +/-1us


Network Setup

Forward Timing Over PacketReverse Timing Over PacketForward TrafficReverse Traffic

Notes:1. R - GE (1 Gbps) Gigabit Routers (L3 Cisco 7600)2. T - Traffic Generator (R is reverse path, F is forward path)3. ToP protocol is IPV4 UDP Port 3194. Traffic Generators are GE (1 Gbps); IXIA 1600 or similar

T5R

R1

T1F

T4R

R2

T2F

T3R

R3

T3F

T2R

R4

T4F

T1R

R5

T5F

ClientServer


G.8261 TC12 Constant Traffic

1PPS Start -50ns1pps Delay 870ns/-50ns from Start


G.8261 TC13 Square

1PPS Start 195ns1pps Delay 730 ns/-75ns from Start


G.8261 TC14 Ramp

1PPS Start 318ns1pps Delay 630ns/-90ns from Start


G.8261 TC16 Congestion

1PPS Start 260 ns1pps Delay 320 ns/40 ns from Start


Test results for Hybrid Mode


Test Results

The following are Time of Day plots for various traffic Test Cases for a 10 node network– All nodes are GbE Routers– Link Delay asymmetry will be small

Numerous G.8261 Test Cases have been usedMany will cause traffic asymmetryTDD technologies require less than +/-1us


Network Setup

K1

A2B2

C2D2

E2F2

G2H2

J2K2

A1B1

C1D1

J1H1

G1F1E1

IXIA 1600T Traffic Generator / Performance Analyzer

IXIA 1600T Traffic Generator / Performance Analyzer

1/12 3

14 5 6 7 8 9

1/2

1/1

1/2

1/1

1/2

1/1

1/2

1/1

1/2

1/1

1/2

1/1

1/2

1/1

1/2

1/1

2/2

1/3

1/4

1/3

1/4

1/3

1/42/4

1/3

1/4

1/3

1/4

1/3

1/4

1/3

1/4

1/3

1/4

1/3

1/11/2

1/31/4

2/12/2

2/3 2/4 3/13/2

3/33/4

4/14/2

4/34/4 5/1 5/3

5/2 5/4

2/3

GPS Feed E1 PRC to ANT20

ANT-20

E1 recovered clock to ANT20

1/20 1/201/20

IXIA #1

IXIA #1

2/5 2/62/7

1588 GM

1/6

1/7

1/5

Recovered Phase to AnalyzerPhase to Analyzer

Phase Analyzer

SynchE


G.8261 TC12 Constant Traffic

50.0nsec/div


G.8261 TC13 Square

50.0nsec/div


G.8261 TC14 Ramp

50.0nsec/div


G.8261 TC16 Congestion

50.0nsec/div


Conclusion

Traffic Density is increasingMove to an IPRAN is happening nowSynchronization is key to allowing this migration3G & 4G technologies are increasingly requiring Time of Day Synchronization– CDMA, LTE-TDD, WiMax . .

IEEE 1588 offers both Phase and Frequency synchronization– But SyncE offers better performance Frequency synchronization

Combined 1588 and SyncE can offer better performance than 1588 alone

Documents

Use of Combined Synchronous Ethernet & IEEE-1588 in ... - Use of... · Use of Combined Synchronous Ethernet & IEEE-1588 in Wireless TDD applications ... Metro. Core. 2G BTS. 3G Node