M68: Managed Timing Engine Module Gateway Clock



  • Small cells, macro-cells (eNodeBs) etc.
  • Mobile Backhaul Carrier Ethernet Equipment
  • Power smart grid time synchronization
  • Sensor network slave device
  • Internet of Things and industrial automation precision timing


  • Gateway Clock (using IEEE-1588-2008 PTP)
  • Supports GPS and PTP input
  • Physical Layer Sync (SyncE)
  • Support one-step and two-step clock
  • Support both P2P and E2E modes
  • Support multicast and unicast
  • Support 8 slaves @16 packets per second
  • Low power, small form factor
  • Telecom, power and default profiles
  • Fully transparent, low latency, pass through traffic
  • Industry leading algorithms for G.8261 test suite

As mobile networkarchitectures evolve from 3G to 4G LTE and beyond, to offer higher capacity amidst constraints of bandwidth, spectrum and interference management, innovative synchronization solutions are needed for both indoor and outdoor coverage.

Synchronization requirements are getting more stringent in the next generation 4G LTE-TDD and LTE-A infrastructure. Qulsar’s Managed Timing Engine (MTE) Module M68 series, is a full packet network based synchronization engine, designed for applications that require distribution of frequency and phase synchronization from edge nodes such as a Carrier Ethernet demarcation point, or macro base station that is aggregating traffic from small cells or substation clocks in power utility smart grids. the M68 series can also be used to build Time Servers or Edgemaster clocks to synchronize a small cell cluster.

A key innovation is that the M68 is much more than a boundary clock. It is a Gateway Clock that can take 1PPS and Time of the Day (ToD) from a GNSS receiver, as well as IEEE1588 PTP or SyncE input from the network, and deliver PTP, Time of the Day and Frequency as output.

The key differences between a boundary clock and a gateway clock is that in a boundary clock the master side gets its reference from the slave side; whereas in a gateway clock, the master side uses an external (primary) time reference such as 1PPS and ToD (from a GNSS receiver) and is thus essentially a Grand Master. In addition to GNSS, a gateway clock can use PTP or any other frequency source that is capable of being a reference. Examples include SyncE or macro sniff, also known as Network Listen (NL).

Design & Integration

The M68 is a boundary clock module that provides a simple and cost effective option to integrate precision timing by replacing standard generic parts in host systems such as femtocells, small cells and carrier Ethernet equipment. The M68 can replace the PHY in the host system, supporting line-rate traffic.

For rapid ‘turnkey’ integration, the M68 should be prepackaged in a subsystem (such as a P68 board or a Local Gateway Master such as the QLGM) that can be fairly quickly used as a synchronization "system", enabling a rapid design cycle while allowing for deeper integration at a later time. The first step towards integration is the purchase of an Evaluation & Developer’s Kit that includes all the interface details, licenses and tools necessary for enabling the design effort.

Multi-sync & Algorithms

The M68 series module has industry leading algorithms. These enable it to extract precise time signals from packets impeded over the network by traffic load, congestion and packet delay variation (PDV).

In addition, the M68 series has cutting edge patented technology that enables it to manage multiple clock domains from multiple inputs. The ability to use multiple synchronization inputs is particularly powerful in today’s applications, where a host system may need to be versatile and deployable in multiple environments.

System Features

  • Assisted Partial Timing Support Clock (APTSC) G.8273.4
  • Fully compliant to telecom, power and default profiles
  • Multi-sync handling support
  • Frequency accuracy better than 1ppb under ITU-T G.8261 test conditions 1
  • Phase accuracy better than ±1µs accuracy under G.8261 testing conditions 1
  • Enhances synchronization and network performance metrics

Network Interface

  • Upstream 1GbW magnetics
  • Downstream 1 RGMII Port
  • Wirespeed low latency pass through
  • Integrated TCP/IP Stack
  • IPv4 and IPv6 (PTP)

1 ITU-T G.8261 tests conducted at both Qulsar internal labs and 3rd party labs – details available on request and under NDA

Technical Specifications

  • Wire speed 1GbE pass-through
PTP Master
  • Accuracy with GPS as reference better than ±25ns
  • Support 8/32/64/128+ slaves
  • Support 1 step and 2 step
  • Output Sync rate: up to 128 sync packet per second (individually programmable per slave)
PTP Slave
  • Time alignment, better than ±1 μs on a managed 10-switch GbE network under G.8261 test conditions 2
  • Frequency alignment, better than ±10 ppb on a managed switch GbE network under G.8261 test conditions 2
  • Supports 1-step and 2-step
  • Input sync rate: up to 128 sync packets per second
Other Features
  • DHCP client
  • FTP server
  • TELNET server
  • SSH server
  • Serial terminal
  • Remote firmware upgrade
  • Command line interface configuration (Telnet, SSH or serial port terminal)
Input Synchronization Interfaces
  • PTP: Ethernet (L2) or UDP IPv4/IPv6 (L3)
  • 1PPS
  • ToD in: TTL, 4800/9600 bps, via dedicated pin port up to 115200 bps via serial port
  • Output Synchronization Interfaces
    • Freq. out: 5/10/20/25 MHz
    • PPS out: up to 2 kHz with 1 μs resolution
    • ToD out: TTL 4800/9600 bps on dedicated pin. Up to 115200 bps on serial port
    • PTP: Ethernet (L2) or UDP IPv4/IPv6 (L3)
    ToD Format (output)
    • NMEA & China Mobile binary format
    Physical Interfaces
    • GPIO, Asynchronous serial, SPI RGMII, MDIO, LVTTL Operating Specifications
    Operating Specifications
    • Supply: 3.3V, 1.8V, 1.2V +/- 10%
    • Operating temperature: -40°C to 85°C
    • RoHS compliant
    • Low power processor module: 1.1W (typical)
    Physical Specifications
    • Package: LCC84
    • Size: 29.2x29.2x2.8 mm
    Ordering Information
    • 83-800-00 MTE Module M68 Gateway Clock 8 slaves @16pps

    2 With industry standard PDV profiles of switches and network conditions.

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    Qulsar_M6x Series MTE Product Brief

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