GPS World

Tag: network clock

  • Schweitzer Labs Adds PTP Support to Network Clock

    Schweitzer Labs Adds PTP Support to Network Clock

    Graphic: Schweitzer Labs

    Schweitzer Engineering Laboratories, Inc. (SEL) has added support for the Precision Time Protocol (PTP) to its SEL-2488 Satellite-Synchronized Network Clock. In a single clock, users can now synchronize end devices with sub-microsecond accuracy using demodulated IRIG-B and/or PTP. The SEL-2488 can meet all the timing needs of industrial and utility applications.

    The SEL-2488 offers security features, including Satellite Signal Verification in which the clock uses two satellite constellations to validate time signals, providing a layer of protection from GPS spoofing attacks. For fault tolerance, customers can opt for a second, redundant hot-swappable power supply, which can be connected to a second power input source. If GPS is lost, the clock switches to a standard TCXO holdover with 36-microsecond-per-day accuracy or an optional OCXO holdover with 5 microsecond average accuracy. The clock operates over a wide temperature range of –40° to +85°C (–40° to +185°F) and is backed by SEL’s 10-year, no-questions-asked worldwide warranty.

    In addition to providing IRIG-B and NTP outputs, the SEL-2488 can now serve as a PTP grandmaster clock, supporting both the default profile (IEEE 1588-2008) and the power system profile (IEEE C37.238). The SEL-2488 is capable of synchronizing time for up to four independent networks with a time-stamp accuracy of 100 nanoseconds. Existing users of the SEL-2488 can purchase this as a firmware upgrade.

    “Now there’s a choice,” said Shankar Achanta, R&D manager for precise time and wireless networks at SEL. “You can use different timing protocols based on your infrastructure and application needs. The SEL-2488 is the one network clock that can meet all our customers’ timing needs.”

    The SEL-2488 was first released in September 2014. SEL included several security features such as Syslog, the Ethernet standard for event messaging, which allows the SEL-2488 to integrate smoothly into a customer’s existing event system; role-based accounts and Lightweight Directory Access Protocol (LDAP) for user authentication; and a secure HTTPS web interface, which provides a graphical SkyView display for troubleshooting signal or antenna issues. The SEL-2488 also meets and exceeds IEEE 1613 Class 1, an electric transient and interference standard for communications products.

    Designed, tested and manufactured in Pullman, Wash., a standard SEL-2488 configuration, including a dual-constellation, high-gain GNSS antenna, retails for $2,700. The PTP firmware upgrade option for existing users costs $1,750. To learn more about the PTP enhancement in the SEL-2488, visit www.selinc.com/p222.

  • MWC 2015: RAD Demonstrates IEEE 1588 Grandmaster

    RAD-grandmaster-MiCLK
    Photo: RAD

    Telecom company RAD will be expanding the timing synchronization capabilities of its Service Assured Access (SAA) solution when it introduces MiCLK, an IEEE 1588 grandmaster clock with a built-in GNSS receiver.The grandmaster clock is SFP-based (small form-factor pluggable).

    RAD is demonstrating the MiCLK at Mobile World Congress 2015, being held this week in Barcelona, Spain.

    “LTE and LTE-A’s stringent synchronization requirements and the growing use of small cells in 4G networks create synchronization challenges in the backhaul segment, but existing solutions are either too expensive or do not provide full network coverage,” said Ulik Broida, RAD’s vice president of marketing and business development. “With the revolutionary MiCLK, RAD makes it easy to upgrade existing backhaul networks to support LTE-A at an affordable price.”

    Many network operators prefer to use IEEE 1588-2008 (also known as Precision Time Protocol, or PTP) and synchronous ethernet to deliver accurate frequency and time throughout 4G backhaul networks. They are reluctant to install GNSS at every cell site because of practical and cost reasons, as well as concern about possible GNSS jamming and spoofing. However, accurate time distribution requires every network element between the time reference — the grandmaster — and the cell site to support IEEE 1588. This could be an expensive and complex endeavor when the grandmaster is located in a central PoP. “MiCLK allows network operators to avoid costly upgrades by bringing the grandmaster to the base station,” said Broida.

    RAD’s patent-pending MiCLK is a miniature pluggable device that responds to the needs of next-generation cellular backhaul networks, the company said. Its SFP design allows simple installation to upgrades any network device with a fully featured IEEE 1588 grandmaster, including a GNSS receiver and various redundancy options to sustain its operation in case of GNSS failure, RAD said.

    “Easily installed with minimal technical intervention, MiCLK is a versatile add-on anywhere in the network,” Broida concludes. “It is a valuable addition to mobile equipment vendor portfolios, and an ideal solution for 4G service providers in search of a quick, cost-effective way to bring accurate synchronization to small cell backhaul.”

    RAD  is exhibiting at Hall 2, Stand 2D50 at Mobile World Congress.

     

  • Satellite-Synchronized Network Clock Released by SEL

    Satellite-Synchronized Network Clock Released by SEL

    The SEL-2488 satellite-synchronized network clock. Photo: SEL
    The SEL-2488 satellite-synchronized network clock. Photo: SEL

    SEL has released a new network clock designed for critical infrastructure and harsh environments. Model SEL-2488 receives GNSS time signals and distributes precise time via multiple output protocols, including IRIG-B and NTP.

    The SEL-2488 provides time-delay compensation for antenna cables and output cables on per-port basis to further optimize time distribution accuracy. For security, the clock features the Syslog Ethernet standard for event messaging, role-based accounts and LDAP for user authentication, and secure HTTPS web interface.

    The clock synchronizes with precise time accuracy to within ±40 nanoseconds to UTC for power protection applications. The standard TCXO holdover accuracy is 36 µs/day and the optional OCXO holdover accuracy is5 μs/day.

    Time can be distributed from eight time outputs configurable for IRIG-B or time pulse outputs. The SEL-2488 also includes four standard Ethernet ports, which provide NTPv4 and are available in copper as well as single- or multimode fiber.

    With Satellite Signal Verification, the SEL-2488 uses signals from a second satellite constellation to validate the GPS time signals, providing a layer of protection from GPS spoofing attacks. The SEL-2488 also provides an option for a second, redundant power supply and operates in a temperature range of –40° to +85°C (–40° to +185°F).

    The SEL-2488 supports DHCP with a captive portal, LDAP, an HTTPS device webpage, and acSELerator QuickSet SEL-5030 software for easy and secure configuration.