TIMING, TEST & MEASUREMENT 4370A DVB Sync Source The 4370A DVB Sync Source is a flexible STANDARD FEATURES GPS. The secondary 4370A synchronizes to timing system designed for Single Frequency • the primary through the fiber. All RF and 12-Channel GPS Receiver Network (SFN) synchronization for DVB/DAB pulse outputs from the two units are there- • < 50ns Accuracy to UTC applications. These applications require a fore coherently maintained at the same fre- • Flash Memory for Remote Upgrades precision time and frequency reference to quency and phase. synchronize transmitters across multiple • Modular/Hot Swap Design locations. Without synchronization, networks The input synchronization sources are • Primary and Secondary Reference are not able to reliably deliver video and audio assigned a priority order of use. For example, Inputs content to the end user. GPS could be given the highest priority. If • the GPS receiver in the primary 4370A unit Multiple 10MHz Outputs The 4370A enables Terrestrial and Mobile fails, the secondary 4370A unit assumes the • Multiple 1PPS Outputs networks to be deployed across varied land- primary role, meaning that it starts to track • Dual Hot Swap Power Supplies scapes by providing access to low cost, reli- its GPS receiver, which is still functioning able precision time and frequency reference properly. The 4370A with the failed GPS then • Low Phase Noise signals, in multiple formats ensuring a tracks the new primary 4370A. Since each • SNMP for Configuration and robust and reliable network. 4370A contains a flywheel oscillator, the Monitoring necessary switching occurs without any REDUNDANCY AND RELIABILITY • discontinuity in the phase or frequency of RoHS Compliant The 4370A receives reference-timing signals the outputs. Should both GPS receivers fail; • Output Squelching from GPS, fiber optic and E1 inputs and trans- either 4370A can begin to track one of the • Alarm Relay Contacts lates them to generate the output signals. In secondary inputs while the other 4370A con- case of a loss of GPS, the 4370A automatically tinues to track the primary. In this manner, • NTP switches to and locks to the auxiliary fiber all outputs of two interconnected 4370A can optic or 2 MHz, 2Mbit/sec input to continually be derived coherently from any one of the provide outputs that are traceable to a primary OPTIONAL FEATURES references connected to either unit. reference clock. The 4370As can be linked • 2 MHz and 2 Mbit/sec Outputs together via the optional fiber optic transceiver All of the 4370A outputs are provided on hot • 2 MHz and 2 Mbit/sec Input on the input, to provide a double redundant swappable modules so each one can be • Redundant Chassis Configuration system with no single point of failure allowing removed if needed or additional outputs can for the utmost in system reliability. In this be added without the need for powering configuration, one 4370A is designated primary down your network. and one secondary. The primary 4370A synchronizes to the primary synch source— 4370A DVB Sync Source The pre installed GUI facilitates access STANDARD CONFIGURATION DVB SYNC SOURCE GRAPHICAL The standard 4370A can be configured USER INTERFACE to status of the power supply, reference clock, GPS receiver, and plug-in modules. with AC/DC hot swap power supplies, The 4370A can be remotely configured 10MHz hot swap output modules and and monitored using SNMP. MIB defi- The status information automatically updates about every 45 seconds. Third 1PPS hot swap output modules. The nitions can be obtained from the DVB 4370A 1U chassis can support up to six Sync Source web server. Once you party SNMP management tools can alternatively be used to provide the same hot swap output modules which will download the MIB definition bundle, provide 24 total outputs in a single 1U you can extract it for import into MIB monitor and configuration capability. chassis. When fully configured, the browser applications or SNMP man- 4370A still provides dual power sup- agement software. The bundle contains plies and multiple input sources. The MIB definitions for the chassis, plug-in front panel includes a time display, module types, trap recipient registration, status and alarm indicators, and access and a MIB module that holds only textual to redundant power supply modules. It conventions used throughout the other also includes push buttons to display MIB modules. the IP address and manually set the selected input and switching mode. The rear panel provides access to all input and output modules, power supply connections, alarm connections, and Ethernet port. 2 A ROBUST DVB SYNC SOURCE REDUNDANT TIME SOURCES THAT properly. Redundant GPS receivers are also an option SFN planners may wish Robust DVB synchronization (high ARE ALSO HIGHLY ACCURATE reliability + high precision) calls for key Planners should take into account what to consider. Making devices hot swap- pable means that technicians can attributes in the SFN’s timing reference. happens if GPS reception is lost. That The DVB sync source addresses each requires a holdover clock that tracks replace modules in a chassis without powering down the system or disrupting of these key attributes within the core GPS and maintains accuracy if GPS is architecture and option modules. lost — at least for a day, or longer should the network. For example, network operators can specify dual hot swappable operators decide to protect against HIGHLY ACCURATE TIMEKEEPING outages of greater duration. Alternatively, power supplies to further enhance reliability. Direct GPS input should provide< 50 nS the sync source may also take advantage accuracy to UTC (coordinated universal of other available timing sources, such SNMP FOR CONFIGURATION time — the international standard). This as E1 networks. will maintain to the sub-millisecond AND MONITORING Technicians in the network operations level the spacing between bits traveling REDUNDANT HOT SWAPPABLE through the air — so bit echoes do not DESIGN center will want network-wide visibility to anywhere an out-of-spec condition interfere with each other. Planners may also want the option to configure two sync sources — one as may occur so they can take immediate action. The ability to monitor alarms LOW PHASE NOISE primary and one as backup — for auto- The timing source utilized to generate matic switchover if the primary fails. and be able to diagnose errors at a glance ensures robust network operation. a signal on a channel can contribute to Designation of “primary” should depend noise on that channel — which can interfere on which has GPS reception. Even if the with clear reception of information. primary source goes down, the secondary Low phase noise in the timing source should still track the primary’s GPS reduces the likelihood of that occurring. receiver if that receiver still functions 3 4370A DVB SYNC SOURCE MODULES Symmetricom makes it easy to configure the 4370A DVB Sync Source to meet varying time and frequency requirements. Below is a description of available modules. 10MHz Output Module 1PPS Output Module The 10MHz output card provides four low phase noise sine The 1PPS output card provides pulse outputs through four wave outputs through four BNC connectors. These outputs BNC connectors. These outputs are phase locked to the host are phase locked to the host receiver's disciplined reference receiver’s disciplined reference oscillator. They are automati- oscillator. They are automatically enabled upon initialization cally enabled upon initialization and are independently and are independently selectable by the user with no selectable by the user with no configuration setup required. configuration setup required. This option is a hot swap module that can be added or This option is a hot swap module that can be added or removed from the 4370A without hardware or software removed from the 4370A without hardware or software modification and without disturbance to the main system. modification and without disturbance to the main system. Outputs are preconfigured at the factory but can be configured Outputs are preconfigured at the factory but can be configured by the user via the network SNMP interface. by the user via the network SNMP interface. 10MHz OUTPUT SPECIFICATIONS 1PPS OUTPUT SPECIFICATIONS • Amplitude: 1Vrms into 50 ohms • Level: >2.4V High <0.8V Low • Harmonic distortion: <-40dBc • Pulse width: <100uS ±10µS • Accuracy: Function of input synchronization source • Rise time: <15nS • Squelch: When signal accuracy out of specification • Jitter: <200pS • Connector: BNC • Squelch When signal accuracy out of specification • Connector: BNC 4 4370A DVB SYNC SOURCE Telecommunications Power Supply Module Output Module The 4370A can be configured with dual redundant AC or DC The E1 Output provides 2 MHz and 2 Mbit/sec outputs meeting the requirements of ITU-TG.703.10 and ITU-T G.703.6 hot swap power supply modules. Each module is inserted in the front of the 4370A for easy access. Oscillator Specifications The below tables describe the Allan deviation and phase noise performance of the internal OCXO. POWER SUPPLY MODULE SPECIFICATIONS • AC Power supply module 100 - 240VAC, 45-65Hz OSCILLATOR SPECIFICATIONS Hot swap module Status LED • Allan Deviation (σ(T)) OCXO • DC Power supply module 1s 2E-11 40.5 - 70VDC 10s 2E-11 Hot swap module 100s 2E-11 Status LED Holdover 1E-10/day • Phase Noise (dBc/Hz) OCXO 1Hz -95 10Hz -125 100Hz -125 1kHz -130 10kHz -140 5 4370A SPECIFICATIONS MECHANICAL/ENVIRONMENTAL • Power GPS RECEIVER Dual redundant supplies • TNC Connector Receiver input: 1575.42MHz L1 C/A code 100 - 240VAC, 50-60Hz • Tracking: 12 parallel channels 40.5 - 70VDC 40W (full loaded chassis) • Acquisition time: Cold start<20 min • Size • 1PPS output accuracy: UTC(USNO) ±50ns RMS 100ns peak when in fixed Height: 1.75” position mode,<500ns, 2sigma in 3D mode Width: 17.00” • Frequency output accuracy: 1E-11 @ 1 day Depth: 19.00” • Allan deviation (Locked to GPS) • Weight: Approximately 8.4 kg (18.5 pounds) with two Averaging time power supplies and six plug-in modules 100s <1E-11 • Operating temperature: 0°C - 50°C • Holdover • Humidity: 0 - 90% non-condensing OCXO 1E-10/day • Display: Year, Day, Hour, Minute, Second Loss of input signal STANDARD INPUT/OUTPUT SIGNALS Unlock • Network Interface: Standard 10/100Base-T RJ-45, 8 pin connector • Optional antenna • Protocols: TCP/IP and SNMP Size: 3” dia x 3” H • 1PPS Input: N Female to GPS receiver Level >2.4V High Power: 5VDC <0.8V Low Operating temperature: -55°C to +85°C Pulse width <100uS ±10μS Storage temperature: -55°C to +85°C Rise time <15nS Humidity: 95% non-condensing Jitter <200pS Certification: CE Connector BNC Squelch When signal accuracy out of specification OPTIONS • 10MHz • Telecommunications interface (2MHz & 2Mb/s outputs) Level 13dBm ±2dBm • Fiber optic interface Format Sine wave Harmonic <-40dBc Impedance 50Ω Connector BNC Squelch When signal accuracy out of specification • Phase noise (dBc/Hz) Offset (Hz) OCXO 1 -95 Rear View Fully Loaded Chassis 10 -125 100 -125 1kHz -130 10kHz -140 • E1 Format 2MHz per ITU-T Rec. G.703 §10 2Mb/s per ITU-T Rec. G.703 §6 Connector BNC Impedance 75Ω Squelch When signal accuracy out of specification SYMMETRICOM, INC. 2300 Orchard Parkway San Jose, California 95131-1017 tel: 408.433.0910 fax: 408.428.7896 info@symmetricom.com ©2009 Symmetricom. Symmetricom and the Symmetricom logo are registered trademarks of Symmetricom, Inc. All other trademarks are the www.symmetricom.com property of their respective companies. All specifications subject to change without notice. DS/4370A/D/1009/PDF