t-berd/mts 5800 timing module overview

T-BERD/MTS 5800

Timing Module Overview

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T-BERD/MTS Timing Module Overview

Together with the T-BERD®/MTS 5800, the TEM Timing Module delivers industry leading accuracy to field portable timing and synchronization measurements.

With a T-BERD®/MTS 5800 and a TEM, you can:

➢ Perform nanosecond accurate one way delay (OWD) measurements that help you root out asymmetric network delays

➢ Perform nanosecond accurate PTP measurements (PDV, Time Error) to pre-qualify or troubleshoot a network synchronization problem

➢ Emulate a PTP Grand Master Clock (PRTC) to verify equipment configurations

➢ Qualify GNSS Antenna installations by evaluating satellite signal strength and eliminating antenna faults

➢ Troubleshoot the accuracy of equipment 1 PPS output signals with 1 PPS wander analysis

The TEM includes:

➢ A rubidium based MAC (Miniature Atomic Clock) to ensure nanosecond accurate measurements when the module is running in holdover

➢ A 72 Channel GNSS Receiver supporting multiple satellite constellations


Timing Module Product Positioning

▪ The T-BERD/MTS 5800 Timing Module (TEM) delivers the ability to accurately field test timing and synchronization.

▪ The Timing Module includes a modern 72 channel GNSS receiver that can be used internationally with different satellite constellations to receive time of day (ToD) messages and 1 PPS pulses used to frequency, phase and time

synchronize networks. In addition to GPS (US), the TEM supports GLONASS (Russian), BEIDOU (Chinese) GNSS constellations, as well as SBAS and QZSS.

▪ Included with the design is a Rubidium oscillator that enables nanosecond accurate measurements even when GNSS satellite signals are not present and the TEM is operating in holdover mode.


T-BERD/MTS-5800 Timing Expansion Module (TEM)

GPS Antenna Input

1PPS Inputs 1 & 2

10 MHz Input

10 MHz Output

1PPS Output


Workgroups Needs

➢ Mobility Technicians➢ PDV & IPDV for PTP Messages (Sync, Delay Request, etc.)➢ OWD over CWDM, dark fiber & mobility owned circuits➢ Time Error measurements to Grandmaster / Boundary Clock➢ 1 PPS Wander analysis➢ GNSS Antenna installation verification

➢ Wireline Backhaul Providers➢ OWD over EBH circuits

➢ Mobility Contractors➢ GNSS Antenna installation verification

➢ Utility Technicians➢ Time Error measurements to Grandmaster / Boundary Clock

➢ Financial Institutions Engineers/Technicians➢ OWD over CWDM, dark fiber & Ethernet circuits


Use Cases

➢ One Way Delay Measurement

➢ PTP Time Error Measurement

➢ PTP PDV & IPDV Measurement➢ Announce, Sync, Delay Request, etc.

➢ 1 PPS Wander Analysis

➢ Antenna Installation Verification

One Way Delay

Implications of Asymmetry to Timing/Sync Applications


One Way Delay Measurement Points in Mobile Networks

Fronthaul (Fiber/CPRI) Backhaul (Fiber/Ethernet)

BBU

Junction Box

RRU/RRH

Fiber Trunk Cable

SFP

Junction Box

GNSS Antenna

PTP Grandmaster

GNSS Antenna Cable

PTP Boundary Clock

1 PTP Slave - Grandmaster

31

MSC / Central Office

2

2 PTP Slave - Boundary Clock

3 Boundary Clock – Grandmaster


Why Measure OWD?

➢ To Measure OWD two test sets are required.

➢ A OWD test let’s you measure the asymmetrical delay and packet jitter of a circuit.➢ Tx and Rx fibers could be of different lengths➢ Routers and switches could have different queueing and buffering polices in the different directions.

➢ Impact to networks➢ Cellular network – the time transmitted to UTEs (User terminal equipment such as phones) will be wrong

increasing the likelihood that calls get dropped as a device goes between cell towers. It also impacts the speed and quality of a connection when a device is in the coverage area of more than one cell tower

➢ Utility Networks – relay controls will not be perfectly synchonized➢ Financial Networks – high speed trading applications will suffer from delayed trades or trade confirmations

RFC 2544 or Y.1564

RFC 2544 or Y.1564

PTP Time Error

Definitions & Impacts


PTP Time Error Measurement Points in Mobile Networks


BBU

Junction Box

RRU/RRH

Fiber Trunk Cable

SFP

Junction Box

GNSS Antenna

PTP Grandmaster

GNSS Antenna Cable

PTP Boundary Clock


31


2




Why Measure PTP Time Error?

➢ Time Error measures the time difference between two clocks➢ Time reference required (5800+TEM) – only 1 tester is required➢ Phase synchronization relies on time synchronization

➢ Impact to Networks➢ Cellular networks – Need time / phase sync within 1μs

➢ LTE time-division duplex (LTE-TDD) systems – avoid interference between uplink and downlink on neighboring eNodeBs

➢ enhanced Inter-cell Interference Coordination (eICIC) – avoid call drops & low throughput at cell edge

➢ coordinated multipoint (CoMP) – improved call reception, cell utilization & reduce interference➢ multi-broadcast single frequency network (MBSFN) – required for coordinated mobile TV broadcast

➢ Utility networks ➢ Replacement of IGIR-B by PTP requires 10μs accuracy➢ Replacement of 1 PPS satellite signal by PTP

ClockPTP

PTP PDV Message Measurements

Definitions & Impacts


PDV Measurement Points in Mobile Networks


BBU

Junction Box

RRU/RRH

Fiber Trunk Cable

SFP

Junction Box

GNSS Antenna

PTP Grandmaster

GNSS Antenna Cable

PTP Boundary Clock


31


2




Why Measure PTP PDV?

➢ Sync, Announce and Delay Request are used to establish and adjust clock offsets between clocks.

➢ Cellular and utility networks can use different PTP architectures based on what is available.➢ In a PTP aware network transparent clocks adjust time for transit delays,

thereby adjusting the end to end delay of the messages without regenerating them.

➢ In a PTP unaware network there are no transparent clocks and PTP messages are not adjusted for transit delays.

➢ In this scenario, measuring PDV is crucial because the intermediate elements can add significant delays and delay variation if the network is not optimized to transport PTP traffic.

PTP PDV

PTP PDV

PTPUnaware

1 PPS Wander Analysis

Troubleshooting boundary and grandmaster phase accuracy


1PPS Measurement Points in Mobile Networks


BBU

Junction Box

RRU/RRH

Fiber Trunk Cable

SFP

Junction Box

GNSS Antenna

PTP Grandmaster

GNSS Antenna Cable

PTP Boundary Clock

1 PTP Boundary Clock

21


2 PTP Grandmaster


Why Perform a 1 PPS measurement?

➢ Use 1 PPS Wander measurements to troubleshoot & calibrate boundary clocks➢ Ideally the 1 PPS signals should be phase aligned with minimal variations in the < 10ns range

ClockPTP traffic

1 PPS Clock Output

Grandmaster Emulation 1 PPS from GNSS signal


GNSS Antenna Installation Verification Test Point in Mobile Networks


BBU

Junction Box

RRU/RRH

Fiber Trunk Cable

SFP

Junction Box

GNSS Antenna

PTP Grandmaster

GNSS Antenna Cable 1

PTP Boundary Clock

1 Antenna Installation Verification

PTPUnaware


Use Case: GNSS Antenna Installation Verification Overview

➢ Set tester for automatic reports➢ Review reports for obstructions, signal strength &

number of satellite signals acquired

➢ Check Sky Plot for obstructions➢ Observe where the satellites are located. If you see

satellites in a portion of the plot with “No Signal”, you could have a partial obstruction

➢ Verify Satellite Signal Strength➢ For best performance look for CNR* values greater

than 35

➢ Verify Number of Satellites Acquired

Partial obstruction:Satellites present – No signal

*CNR: the carrier-to-noise ratio, is a measure of the received carrier strength relative to the strength of the received noise. High values indicate better quality of reception.


Timing Module Features and Specs

▪ Discipline the frequency of the rubidium oscillator from BITS, SETS, external 10MHz, or external PPS in addition to GNSS.

▪ Delivers GPS (GNSS) related status

▫ Satellite constellations, signal to noise indicators etc.

▫ TEM application provides report generation capability to show all setups/results/actions as single application including the graphics like sky plot, bar graph.

▪ TEM application can be combined as dual view with another BERT application. Dual view reports that include TEM information are supported.

▪ Ability to recall surveyed positions for static timing mode.

▪ Can provide accurate time with only a single satellite visible when in static timing mode.

▪ In addition to GPS (US), the TEM supports GLONASS (Russian), and BEIDOU (Chinese) GNSS constellations, and SBAS.

▪ Provides open/short detection on antenna

▪ Supports both 5V and 3.3V antennas (TM-4M required 5V antenna)

▪ Modern 72 channel receiver, 32 for satellite tracking, 40 for acquisition aiding and noise estimation

▪ Provides two PPS inputs and the ability to measure phase between them < 5ns accuracy.

▪ Outputs:

▫ Disciplined 1PPS output.

▫ Disciplined 10Mhz clock

▪ The accuracy in holdover after stabilization

▫ minimum of 7 microseconds over 24 hours

▪ Supported Applications

▫ One Way Delay measurement

▫ 1588v2 accurate PDV and Master/Slave Delay measurement

▫ Wander measurements

t-berd/mts 5800 timing module overview

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