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1588 Certification Program Offers Mobile Network Operators Time and Cost Savings in Product Selection

March 2, 2015 by Ixia Blog Team

As Mobile Network Operators (MNOs) upgrade their networks to deploy LTE, they are also migrating the network infrastructure from TDM to IP/Ethernet for mobile backhaul. Ethernet is a natural selection since it is the lowest-cost transport to address the growing mobile data traffic. However, one important feature Ethernet lacks is that it is not a synchronous technology (as opposed to TDM), which means synchronization must be added to Ethernet to address the gap. Mobile network technologies such as GSM, LTE-FDD, LTE-TDD, and others have requirements for frequency synchronization and Time-of-day/Phase Synchronization.

Reference diagram providing Timing over Ethernet from the MEF

The Precision Timing Protocol (PTP), IEEE 1588-2008 is the predominant technology of choice for adding timing to IP/Ethernet networks. If the timing and synchronization are not working correctly, this will result in call setup failures, call drops, and failures in handover from one base station to another as a subscriber moves. It is critical for carriers to test and select vendors who properly implement the IEEE 1588 protocol. For operators this means extensive testing is required to ensure each vendor implementation is standards-based, interoperable, and performs at the necessary scale. Due to the complexity of 1588, operators are running into fundamental issues prior to performance testing—extending the testing phases.

To help address this challenge and increase the chance of interoperable implementations, the IEEE has started a new program called the IEEE Conformance Assessment Program (ICAP). This program is directed under the IEEE Standards Association (IEEE-SA). The first certification kicked off in the program is for IEEE 1588, and will be focused on the Telecom Profile for Frequency Transfer (ITU-T G8265.1).

As outlined by the IEEE 1588-2008 specification, “The purpose of a PTP profile is to allow organizations to specify specific selections of attribute values and optional features of PTP that, when using the same transport protocol, inter-work and achieve a performance that meets the requirements of a particular application. A PTP profile is a set of required options, prohibited options, and the ranges and defaults of configurable attributes.” Different profiles specify particular combinations of options and attribute values to support for a given application, and adaptations of the Best Master Clock Algorithm (BMCA).

The IEEE 1588 standard itself only defines one profile, referred to as the “default profile.” Other profiles for other problems are defined by other standards organizations as they try to solve the issue.

ITU-T Recommendation G.8265.1 [2] defines a profile, colloquially known as the “Telecom Profile,” that is aimed at distribution of accurate frequency over packet networks. This is primarily intended for use with synchronization of cellular base stations, where the main requirement is to operate the radio interface at a frequency accuracy of within 50 parts per billion.

For the IEEE 1588 certification program, the ICAP has selected Iometrix as the authorized test laboratory. Iometrix worked in close collaboration with the Committee of Experts in the development of the Test Suites, covering IEEE 1588-2008 and the specific requirements for frequency distribution in telecommunications networks recently adopted by the ITU-T in G.8265.1. This program offers testing and certification for Packet Master Clock devices as well as Packet Slave Clock devices. Certified product listing can be found on the ICAP web site.

Ixia has worked very closely with Iometrix to provide a test solution to execute the required test suites. This solution leverages IxNetwork PTP emulation, along with automation from Test Conductor. This suite is available for customers preparing for the certification as well as operators looking to extend the testing into performance and scale test cases. Ixia also offers clock quality testing with the Ixia Anue 3500.

The IEEE-ICAP is continuing its work and is expected to announce the kick-off of the pilot for the next profile, G.8275.1, very soon. This profile is very important to operators since most want to leverage boundary clocks in the network.

To learn more about the IEEE-ICAP certification programs for 1588 offered by Iometrix, check out the upcoming WSTS 2015 event next week, and also stop by the Ixia booth to learn about the testing solutions.

Event Location and Time

Location: Double Tree Hotel, San Jose, CA

Cedar/Pine Ballroom, Second Floor

Dates: Exhibition March 10 – 12, 2015

Time: 8:00 am – 6:00 pm

**exhibits close at noon on Thursday, March 12th

Speaking sessions of note:

Tuesday March 10th

5:10 – 5:35pm The Care and Feeding of a Network Sync Test Lab
Steve Jackson, Senior FAE, Ixia

5:35 – 6:00PM IEEE 1588 Telecommunications Certification Program
Sebastien Jobert, Director of Engineering, Iometrix
Rudi Schubert, Director, New Initiatives, IEEE

Additional Resources:

IxNetwork PTP emulation

Test Conductor

WSTS 2015 event