Juniper Day One+ ACX7024 User manual

Grand Master Clock Support Using External GNSS
Receiver for ACX7024
IN THIS GUIDE
About this Guide | 1
Overview | 1
Connect an ACX7024 Router to Furuno TB-1 GNSS Receiver and Install GNSS Antenna | 3
Clock Cable and Antenna Cable Specicaons | 5
ACX7024 Device GNSS Conguraon | 11
Conguraon Statements | 14
Administrave Commands | 17
Monitoring Commands | 22
About this Guide
Use this guide to learn more about the Global Navigaon Satellite System (GNSS) capabilies on a Juniper Networks®
ACX7024 Cloud Metro router. In this guide, you will learn how to connect an ACX7024 router to a FURUNO TB-1
GNSS receiver.
As a network or system administrator you can use this guide to install the FURUNO TB-1 GNSS receiver on an
ACX7024 router.
Overview
Global Navigaon Satellite System (GNSS) capability is essenal for the Grand Master (GM) clock funconality. A GNSS
receiver receives signals from a navigaon satellite constellaon. The GNSS receiver gains precise phase and me
informaon by processing these signals and delivers the informaon across the network.

Starng in Junos OS Evolved Release 23.1R1, the ACX7024 supports telecom grandmaster (T-GM) funconality using
an external GNSS receiver as a source for me informaon. The GNSS receiver obtains and processes the signals from a
navigaon satellite constellaon to deliver precise phase and me informaon across the enre packet network. The T-
GM funconality can be used, for example, to provide required synchronizaon to base staons in a data network. With
this feature, the ACX7024 devices can funcon as an edge T-GM by connecng to an external Furuno TB-1 GNSS
receiver.
The Furuno TB-1 GNSS receiver supports the following ming standards:
• IEEE standard 1588-2008, IEEE Standard for a Precision Clock Synchronizaon for Networked Measurement and
Control Systems, July 2008.
• ITU-T G.8262, G.8263, G.8265, G.8272 PRTC Class A and G.8275.
The Furuno TB-1 GNSS receiver and the Telecom Grand Master (T-GM) funconality on the ACX7024 device provides
several benets including the following:
•Mul-constellaon receiver that supports:
• GPS L1C/A
• GLONASS L1OF
• GALILEO E1B/E1C
• QZSS L1C/A
• Time traceability to GPS or UTC
• Coherent 10-MHz and 1- pulse per second (PPS) outputs
• OCXO-based receiver
•An-jamming and an-spoong support that includes mulpath spoong, jamming, interference detecon and
isolaon mechanisms.
• Supported on 10G and 25G ports.
• Transmission of Ethernet Synchronizaon Message Channel (ESMC) and enhanced ESMC packets for synchronous
Ethernet as per G.8264 standards.
For more informaon about the Furuno TB-1 GNSS receiver, see the TB-1 Operaon Manual.
2

Connect an ACX7024 Router to Furuno TB-1 GNSS
Receiver and Install GNSS Antenna
IN THIS SECTION
Connect an ACX7024 Router to Furuno TB-1 GNSS Receiver | 3
Install the GNSS Antenna | 4
Gain and Noise Figure (NF) Calculaon | 4
Before you connect an ACX7024 router to the TB-1 GNSS receiver:
• Read "Install the GNSS Antenna" on page 4.
• Ensure that the following cables are available:
• Clock cables. See "Clock Cable Specicaons" on page 5.
• Antenna cables. See "Antenna Cable Specicaons" on page 7.
• Follow the instrucons in "Cabling Guidelines" on page 10.
Connect an ACX7024 Router to Furuno TB-1 GNSS
Receiver
To connect an ACX7024 router to a Furuno TB-1 GNSS receiver:
1. Connect one end of an RG-58 cable to the PPS connector port on the TB-1 GNSS receiver (labeled PPS) and the
other end of the cable to the 1PPS connector port on the ACX7024 router (labeled 1PPS IN).
2. Connect one end of an RG-58 cable to the 10-MHz connector port on the TB-1 GNSS receiver (labeled 10MHz) and
the other end of the cable to the 10-MHz connector port on the ACX7024 router (labeled 10MHz IN).
3. Use a USB-C to USB-C cable to connect one end of the cable to the data port (labeled DATA) on the TB-1 GNSS
receiver and the other end to the USB type C port on the ACX7024 router.
3

4. Connect one end of the LMR400 cable to the GNSS connector port (labeled GNSS) on the TB-1 GNSS receiver and
the other end to the GNSS antenna.
Install the GNSS Antenna
You must install a Global Navigaon Satellite System (GNSS) antenna to ensure opmal signal recepon. For informaon
about antenna installaon guidelines, see GNSS Antenna Installaon in the TB-1 Operaon Manual.
To enable the Furuno TB-1 GNSS receiver, connect to the Furuno AU-217 antenna. For informaon about installing the
AU-217 antenna, see GNSS Antenna AU-217 Installaon Procedure.
Gain and Noise Figure (NF) Calculaon
To calculate the total gain and NF, see GNSS Antenna Installaon Appendix on the Furuno data download page.
RELATED DOCUMENTATION
No Link Title
4

Clock Cable and Antenna Cable Specicaons
IN THIS SECTION
Clock Cable Specicaons | 5
Antenna Cable Specicaons | 7
Cabling Guidelines | 10
Clock Cable Specicaons
IN THIS SECTION
TE Cable Specicaons | 6
Samtec Cable Specicaons | 7
The ACX7024 router supports an RG-58 clock cable that has an SMA male connector at one end and a DIN 1.0/2.3
connector at the other end.
We recommend the following Juniper-qualied clock cables:
• RG-58 cable from TE Connecvity (Part number: 2423629-4). For more informaon, see "TE Cable Specicaons"
on page 6.
• RG-58 cable from Samtec (Part number: RSP-228559-01). For more informaon, see "Samtec Cable Specicaons"
on page 7.
5

TE Cable Specicaons
Electrical Characteriscs
Impedance 50 Ω
Frequency DC-3GHz
Voltage Rang 170 Vrms
Dielectric Withstanding Voltage 750 V min
Insulaon Resistance 500 MΩ
Inseron Loss 4 dB max
V.S.W.R 1.2 max
6

Samtec Cable Specicaons
Electrical Characteriscs
Impedance 50 Ω
Frequency 3GHz
Dielectric Withstanding Voltage 750 V
V.S.W.R 1.3 max
Antenna Cable Specicaons
IN THIS SECTION
LMR400 (10-m Segment) Cable Specicaons | 8
LMR400 (95-m Segment) Cable Specicaons | 9
LMR400 (5-m Segment) Cable Specicaons | 10
The following topology (Figure 1 on page 8) depicts the antenna cable connecons with connector types. Use this
topology as an example to install the antenna cables.
7

Figure 1: LMR400 Cable Connecons
Juniper has tested this topology with the following LMR400 cables:
• LMR400 (10-m segment) from TE Connecvity (Part number: CD-2430293). For more informaon, see "LMR400
(10-m Segment) Cable Specicaons" on page 8.
• LMR400 (95-m segment) from TE Connecvity (Part number: CD-2430295). For more informaon, see "LMR400
(95-m Segment) Cable Specicaons" on page 9.
• LMR400 (5-m segment) from TE Connecvity (Part number: CD-2430297). For more informaon, see "LMR400 (5-
m Segment) Cable Specicaons" on page 10.
You must ensure that you install a surge protector to protect the GNSS receiver from lightning surges. This topology
uses TVA-03C and TVA-03V surge protectors. For more informaon about the surge protectors, see Coaxial lightning
arrestor TVA-03.
The following secons describe the antenna cable specicaons:
LMR400 (10-m Segment) Cable Specicaons
8

Electrical Characteriscs
Impedance 50 Ω
Frequency DC-3GHz
Voltage Rang 335 Vrms
Dielectric Withstanding Voltage > 1000 V
Insulaon Resistance > 5000 MΩ
LMR400 (95-m Segment) Cable Specicaons
Electrical Characteriscs
Impedance 50 Ω
Frequency DC-3GHz
Voltage Rang 335 Vrms
Dielectric Withstanding Voltage > 1000 V
Insulaon Resistance > 5000 MΩ
9

LMR400 (5-m Segment) Cable Specicaons
Electrical Characteriscs
Impedance 50 Ω
Frequency DC-3GHz
Voltage Rang 335 Vrms
Dielectric Withstanding Voltage > 1000 V
Insulaon Resistance > 5000 MΩ
Cabling Guidelines
Follow these guidelines when you install cables:
• Ensure that the GNSS dongle can track the satellites and can acquire a lock.
• Examine the cable end points and connectors for any bends or damage.
• Check the electrical connuity of the cable for both inner and outer conductors.
• Check for any electrical short in cables.
• Inspect the cable outer sheath for any damage.
10

ACX7024 Device GNSS Conguraon
SUMMARY IN THIS SECTION
Congure GNSS Receiver | 12
The ACX7024 device supports the G.8275.1 prole, Telecom Grand Master (T-GM) me management funconality for
all devices on the network on 10G and 25G ports. Addionally, the system supports the following funconalies:
– Compliance to ITU-T G.8272 (Unied funconal architecture for transport networks) PRTC Class A.
– Support for mulple constellaons such as GPS, GLONAS, QZSS and Galileo.
– Support for mulpath spoong, jamming, interference detecon and isolaon mechanisms.
Use the following commands to congure the T-GM funconality:
– set chassis synchronization gnss-receiver
<(0|1)> receiver-type <name>
– set chassis synchronization gnss-receiver <(0|1)> interface
Use the following commands to enable GM funconality:
– set protocols ptp clock-mode ordinary
– set protocols ptp profile-type g.8275.1
– set protocols ptp master interface
<interface-name> multicast-mode transport ieee-802.3
– ptp-mode
– gnss-receiver
– show chassis synchronization gnss-receiver extensive
– show chassis synchronization extensive
– show ptp lock-status detail
In T-GM mode router funcons as an ordinary clock and all PTP congured ports are in "Master only" state. Up to 512
master ports are supported on ACX7024.
NOTE: A synchronous Ethernet (SyncE) input is not allowed when system is funconing as a T-GM. Use the
following command to congure a wait-to-restore check for SyncE input:
set chassis synchronization source interfaces et-0/0/4 quality-level prc wait-to-restore 0
11

Congure GNSS Receiver
The Furuno TB-1 GNSS receiver is designed to operate with mulple constellaons. When connected to an external
GNSS antenna, the receiver contains all the circuitry necessary to automacally acquire GNSS satellite signals, track
GNSS satellites, and acquire precise posion and ming soluons. It provides 1 pulse-per-second (PPS) precision ming
and stable 10-MHz frequency output.
To opmize the GNSS capability, establish a common me scale and coordinated system between all the systems. This
coordinated system simplies network synchronizaon, provides exibility and resiliency.
Table 1 describes the steps to congure GNSS receiver on ACX7024 router.
Table 1: GNSS Receiver Conguraon
Conguraon Step Command
Step 1: (Mandatory) Enable GNSS receiver and grandmaster clock
funconality.
Enable the GNSS receiver by using the gnss-receiver 0 interface
statement at the edit chassis synchronization hierarchy level. By
enabling the GNSS receiver, you establish communicaon
between the ACX7024 router and the GNSS receiver.
Congure the satellite constellaon by using the gnss-receiver 0
constellation statement at the edit chassis synchronization
hierarchy level. Various constellaons are available. Through this
conguraon, you can congure the GNSS receiver to explicitly
use a specic constellaon or combinaon of constellaons.
For more informaon, see clock-mode, prole-type, transport-
ieee-802.3, gnss-receiver, and ptp-mode.
1. Set clock mode.
[edit protocols ptp]
user@host# set clock-mode ordinary
2. Set G.8275.1 prole type.
[edit protocols ptp]
user@host# set profile-type g.8275.1
3. Set transport protocol as IEEE 802.3.
[edit protocols ptp master interface
interface name multicast-
mode]
user@host# set transport ieee-802.3
4. Set the GNSS receiver interface.
[edit chassis synchronization gnss-receiver number ]
user@host# set interface
5. Congure the GNSS receiver type as TB-1.
[edit chassis synchronization gnss-receiver number ]
user@host# set receiver-type tb-1
6. Set the GNSS receiver constellaon.
[edit chassis synchronization gnss-receiver number ]
user@host# set constellation
7.Set PTP mode for FPC and PIC.
[edit chassis fpc 0 pic 0]
user@host# set ptp-mode
12

Table 1: GNSS Receiver Conguraon (Connued)
Conguraon Step Command
Step 2: (Oponal) Specify the posion mode. TB-1 as ming
receiver has two dierent posion modes— posion-x-mode
and survey-mode. The default posion mode is survey-mode if no
specic mode is congured.
•posion-x-mode: Use this mode when you know the
accurate antenna locaon.
•survey-mode: Use this mode when you do not know the xed
locaon of the antenna.
For more informaon about posion mode, see gnss-receiver.
[edit chassis synchronization gnss-receiver number ]
user@host# set position-mode
Step 3: (Oponal) Specify the cable delay compensaon value.
This conguraon is used to compensate the delay introduced
due to RF cable which is routed from Antenna to TB-1 RF input.
You can also use this command to compensate the PPS cable
delay by adding both RF cable and PPS cable delays.
For long cable runs, this delay can be signicant. The range is
from -1000000 to 1000000 nanoseconds.
For more informaon about cable delay compensaon, see gnss-
receiver.
[edit chassis synchronization gnss-receiver number ]
user@host# set cable-delay-compensation value
Step 4: (Oponal) Specify the Signal-to-Noise Rao (SNR)
threshold value.
The SNR is the rao of the signal power to the noise power.
GNSS receiver measures SNR value to indicate the signal strength
of the received satellite signal and the noise density. You can
congure the SNR threshold value. Satellites with the signal level
equal to or above the threshold value can only be used for
posioning.
•range: 0 - 99 dBHz
For more informaon about SNR threshold, see gnss-receiver.
[edit chassis synchronization gnss-receiver number ]
user@host# set snr-threshold value
Step 5: Commit the conguraon.
[edit]
user@host# commit
13

Table 1: GNSS Receiver Conguraon (Connued)
Conguraon Step Command
Step 6: Verify the conguraon.
For more informaon about the operaonal commands, see show
chassis synchronizaon gnss-receiver extensive, show chassis
synchronizaon extensive, and show ptp lock-status detail.
[edit]
user@host# run show chassis synchronization gnss-receiver
extensive
[edit]
user@host# run show chassis synchronization extensive
[edit]
user@host# run show ptp lock-status detail
[edit]
user@host# run show ptp clock detail
Conguraon Statements
SUMMARY IN THIS SECTION
clock-mode | 14
prole-type | 15
clock-mode
IN THIS SECTION
Syntax | 15
Hierarchy Level | 15
Descripon | 15
Opons | 15
Required Privilege Level | 15
14

Syntax
clock-mode (ordinary);
Hierarchy Level
[edit protocols ptp]
Descripon
Congure the clock mode as ordinary clock with GNSS conguraon. The clock mode determines whether the node
behaves as a client or primary node. This aribute is mandatory and has no default value.
Opons
ordinary—The clock mode of the node is a system clock that acts either as a primary node or as a client node.
Required Privilege Level
roung—To view this statement in the conguraon.
roung-control—To add this statement to the conguraon.
prole-type
IN THIS SECTION
Syntax | 16
Hierarchy Level | 16
Descripon | 16
15

Opons | 16
Required Privilege Level | 16
Syntax
profile-type (g.8275.1);
Hierarchy Level
[edit protocols ptp]
Descripon
On ACX7024 router, congure the G.8275.1 prole for GNSS conguraon that require accurate phase and me
synchronizaon. This prole supports the architecture dened in ITU-T G.8271.1 specicaon to enable the distribuon
of phase and me with full ming support. This prole requires all devices in the network to operate in combined or
hybrid modes. To fulll this requirement, you must enable Precision Time Protocol (PTP) and Synchronous Ethernet on
all devices.
Opons
g.8275.1—Enable the G.8275.1 PTP prole.
Required Privilege Level
roung—To view this statement in the conguraon.
roung-control—To add this statement to the conguraon.
16

Administrave Commands
SUMMARY IN THIS SECTION
ptp-mode | 17
gnss-receiver | 18
transport-ieee-802.3 | 21
ptp-mode
IN THIS SECTION
Syntax (ACX7024) | 17
Hierarchy Level | 17
Descripon | 18
Required Privilege Level | 18
Syntax (ACX7024)
ptp-mode;
Hierarchy Level
[edit chassis fpc name pic name ]
17

Descripon
The PTP mode conguraon is mandatory to enable the PTP ordinary clock feature in ACX7024.
When you enable PTP mode, the system disables one of the ports that are used for data trac. For example, on
ACX7024, when you enable PTP mode, port 27 is disabled.
For more informaon about valid port conguraons on ACX7024 router, see Port Speed on ACX7024 Router.
Required Privilege Level
interface—To view this statement in the conguraon.
interface-control—To add this statement to the conguraon.
gnss-receiver
IN THIS SECTION
Syntax (ACX7024) | 18
Hierarchy Level | 19
Descripon | 19
Opons | 19
Required Privilege Level | 20
Syntax (ACX7024)
gnss-receiver {
cable-delay-compensation;
constellation {
galileo (e1);
glonass (l1of);
gps (l1ca);
qzss (l1ca);
}
interface;
18

position-mode {
position-fix-mode (latitude | longitude | altitude);
survey-mode (survey-length);
}
receiver-type;
snr-threshold
}
Hierarchy Level
[edit chassis synchronization]
Descripon
Congure GNSS receiver with ACX7024 router. The GNSS receiver receives signals from a navigaon satellite
constellaon. The receiver gains precise phase and me informaon by processing these signals and delivers the
informaon across the packet network.
Opons
cable-delay-compensation—GNSS receiver unit to router RF cable delay compensaon in nanoseconds. You can specify a
value in nanoseconds to compensate the delay that the cable introduces.
• Range: -1000000 through 1000000 nanoseconds
constellation—Various constellaons are available. You can congure the GNSS receiver to explicitly use a specic
constellaon or combinaon of constellaons.
The following constellaons are available:
•gps: Enables detecon and locking to the GPS constellaon.
GPS signals enable you to determine the posion of the receiver on earth and maintain a high level of me accuracy.
The GPS L1CA receiver with 10MHz clock frequency output synchronized to a GPS satellite.
NOTE: You can use only GPS L1CA to congure the GNSS receiver.
•galileo: Enables detecon and locking to the GALILEO constellaon.
19

•glonass: Enables detecon and locking to the GLONASS constellaon.
•qzss: Enables detecon and locking to the QZSS constellaon.
interface—Enable/Disable GNSS port/slot communicaon.
NOTE: For ACX7024 router, only one port of GNSS receiver is supported.
position-mode—GNSS receiver's posion modes. You can congure two posion modes of GNSS receiver— position-fix-
mode and survey-mode.
•position-fix-mode: Use this mode when you know the accurate antenna locaon.
•Latitude— Latude in degrees.
• Range: -90.0000000 to 90.0000000 degrees
•Longitude— Longitude in degrees.
• Range: -180.0000000 to 180.0000000 degrees
•Altitude— Altude in meters.
• Range: -1000 to 18000 meters
NOTE: Be cauous when you use this mode. Ensure that you congure the correct posion. Conguring the
wrong posion might cause erroneous receiver funcon and faulty grandmaster clock performance.
•survey-mode: Use this mode when you do not know the xed locaon of the antenna.
GNSS receiver does a self survey of its own posion for a period menoned in survey length and then moves to
posion x mode. This is the default mode and the default survey length is 120 minutes.
receiver-type— Only TB-1 is supported as the GNSS receiver.
snr-threshold— GNSS receiver measures the Signal-to-Noise Rao (SNR) value to indicate the signal strength of the
received satellite signal and the noise density. You can congure the SNR threshold value. You can perform posioning
by using only those satellites that have signal level equal to or above the threshold value with a range of 0 to 99 dBHz.
Required Privilege Level
interface—To view this statement in the conguraon.
interface-control—To add this statement to the conguraon.
20