The IEEE 1588 Market Profile

Introduction

IEEE 1588 is a synchronization standard for packet based communications. It is today seen as a fundamental cornerstone for all future communication systems - wired and wireless, professional and consumer. The standard was developed to enable high accuracy time and frequency distribution via standard packet based networks.

Background

Almost all data delivery that has previously relied on proprietary or industry specific protocols is now at a high pace replaced by the all IP paradigm. The telecommunications market has had its tightly coupled infrastructure. The industrial automation has its special synchronization solutions as well as the home automation with very fragmented solutions for intra-device communications.

In the telecommunications market the Next Generation Network (NGN) is a packet-network to provide services including Telecommunication Services. It is able to make use of multiple broadband Quality of Service (QoS) -enabled transport technologies and in which service-related functions are independent from underlying transport-related technologies. It offers unrestricted access by users to different service providers. Legacy protocols such as TDM and other will be emulated over TCP/IP.
Some legacy protocols have had their own clock and thus precise time accessible to the applications. This feature is lost while moving to IP networks since packet delivery time is unpredictable. It is here the value of the standard IEEE 1588 comes to play. IEEE 1588 enables a mechanism to deliver high accuracy time and frequency information over a packet network.

IEEE 1588 is a new standard to synchronize independent clocks running on separate nodes of a distributed system. It is intended for high-accuracy, sub-microsecond, implementations on packet networks using the Internet Protocol. It was established in its first version in 2002. The standard was originally named, IEEE1588 Standard for a Precision Clock Synchronization Protocol for Networked Measurement and Control Systems. It is also called Precision Time Protocol, or just PTP. Now these two versions are simple called IEEE1588-2002 and 1588-2008 after the respective year of establishment.

As the name implies the protocol (-2002) was first used by Test & Measurement (T&M) companies and in industrial networking. The objective of the standard was synchronization of real-time clocks in components of a networked distributed measurement and control system. It still is, but now it has a much more wide spread application outside of T&M. Now the desirable time synchronization interoperability is implemented across all types of IEEE802 Local Area Networks.

PTP is a time transfer protocol, similar to the well-known Network Time Protocol (NTP). However PTP accuracy can be many orders of magnitude better than standard NTP - 1 ns versus 10 ms. Up until this moment time accuracy has been achieved by a GPS signal receiver in each node. PTP is designed for applications that cannot bear the cost of a GPS receiver, or for applications where GPS signals are inaccessible. The accuracy within the nanosecond range can be achieved with this protocol when using hardware generated timestamps, although the protocol itself has no quality requirement. The protocol revision into version 2 (-2008) was heavily influenced by the large data and telecommunication companies like Alcatel-Lucent, Cisco, Nokia, Nortel and Tellabs. We have also been a member of this effort. The new revision of the protocol has been available since March 2008.

The National Institute of Standards and Technology (NIST) in the US is the official US timekeeper and have the most precise atomic clocks in the world. NIST has been a promoter of the protocol since its inception and for example recommends the use of IEEE 1588 in robotics equipment. Another US government authority supporting 1588 is the US Department of Defense  (DoD) deploying PTP-enabled devices for use in vehicles, air crafts and vessels. China has a similar organization and interest.

The Precision Time Protocol does not per se constitute a market with the exception of grandmaster clocks as used for reference timing. It’s an enabler for future converged networked systems in all possible areas including consumer electronics as described below.

Market Analysis and Drivers

The standardization of IEEE 1588 in its second revision in 2008 meant that the increased accuracy is offered to broader market segments than the initial industrial automation markets. Since the establishment of the standard the technology has been predestined into specific telecom, power transmission and consumer applications under other standardization bodies and names, but all based on the same underlying Precise Time Protocol (PTP).

At the moment (2010) Ethernet is the dominant media, but PTP can run on every packet oriented network (IEEE 802) including the 802.1as standard. In the following we list the respective market segments implementations and our opportunities.

The general Market Analysis is based on the emergence and implementation order in key market segments:

• Industrial Automation
• Test & Measurement
• Power Transmission Industry
• Telecom:  fixed, cellular and femtocells
• Consumer Electronics.

Industrial Automation

The applications within DeviceNet (ODVA), ControlNet, and Profinet (IEC-61158) have already established respective “profiles” in the revised 1588 standard. The IEC has adopted IEEE 1588 under the name IEC 61588. The LXI Consortium has included 1588 as a subset of the LXI standard. The driving factor for 1588 is that it enables standard off-the-shelf Ethernet to be deployed. Profinet alone accounts for more than 1300 member companies and including other companies in industrial networking, adding up to several thousand companies of which many are targets for PTP.

The high requirements on precision and speed in multi-axis robotics emerge into a need for high performance synchronization solutions. The same goes for many other industrial processes where a synchronous operation settles the final performance numbers. Packaging machines, clusters of pumps or sensors are other applications.

Test & Measurement

Introduced in 2005 the LXI consortium is a group of T&M companies having 50 members including Agilent, National Instruments and Rohde and Schwartz. The LXI Consortium (http://www.lxistandard.org) is a not-for-profit corporation initially established by Agilent Technologies and VXI Technology, Inc. Its primary purpose is to promote the development and adoption of the LXI Standard, an open, accessible standard identifying specifications and solutions relating to the functional test, measurement and data acquisition industry.

In March 2010 there were already more than 1300 LXI-compliant products shipping. Again, the 1588 technology enables the use of standard Ethernet with an overlay protocol and acts as a driver. The LXI consortium is the LAN-based successor to GPIB (IEEE 488). LXI has adopted the 1588 synchronization technology as a subset of the LXI standard (LXI 1588 Profile).

Power Transmission industry

Similar to industrial automation, the power industry has created a power-specific IEEE 1588 profile within the IEEE Power Engineering Society. The main intention is to control power nodes, synchrophasors and substations in the power transmission network. Smart grids and Micro grids are now very interesting applications for the synchronization. The emergence of energy sources like wind mill and solar panel parks connected to the power grid have emphazised the need for synchronization.

China is a large market for power distribution grids. Today this is controlled largely by GPS or other costly time source technologies. Decisions are taken to distribute timing in packet networks. A low cost solution can drive this market in its granularity, not only as substation gateways, but also as field deployed grand masters and onto each high power switch in a station.

Telecommunications

The revised standard has been influenced of the needs from the telecommunications companies for very high time and frequency accuracy as specified in the e.g. ITU-T G.8261 and G.823. The market driver for IEEE 1588 in the telecommunications industry is the target of carrier class Ethernet, and IEEE 1588-2008 is a key technology for this.

The G.8261 recommendation defines synchronization aspects in packet networks and specifies the maximum network limits of jitter and wander that shall not be exceeded and the minimum equipment tolerance to jitter and wander that shall be provided at the boundary of these packet networks. It also outlines the minimum requirements for the synchronization function of network elements. The G.823 covers the same in the 2048 kbit/s telecom hierarchy. The requirements for the jitter and wander characteristics that are specified in ITU-T recommendations must be adhered to in order to ensure interoperability of equipment produced by different manufacturers and a satisfactory network performance.

Femtocells

One special area within telecommunications where IEEE 1588 is increasingly important is the small cellular base station. The market driver for femtocell access points is that they offer cellular carriers the opportunity to address fixed-mobile convergence markets with a attractive and efficient solution. A femtocell is a radio base station, typically for home and office use and serves only a few lines/channels. As the infrastructure grows, more and more of the backbone is IP based, and a large share of it is in homes and offices - the network is owned and operated by the user. The new setting provides savings on backhaul costs, improves in-building coverage, reduces churn, promotes migration and provide a platform for operators to build an effective delivery system for triple play services.

The shift towards picocell and femtocell base stations means that the performance/cost trade off for achieving synchronization is increasingly important. The femtocell products will be consumer like products, but owned or sold by the operators in the beginning. And just like the cellular phone, compliance with the service network is a must.

The distribution of exact time to enable seamless handovers, ensure quality of service and reuse of frequencies is a great challenge. More or less proprietary and vendor specific ways to distribute time are today offered. However the operators of these local cell units require a standardized way to achieve synchronization, and IEEE 1588-2008 has now been tested in the field (VF, ITSF 2007 and 2008) and has emerged as a low cost standardized technology. Except from proprietary solutions evolved from NTP services and a high stability, but expensive, local oscillator, the alternatives are to use a local GPS, or some other means of transmitting synchronization via air. Reliability and cost exclude these from becoming viable alternatives.

The femtocell market is expected to grow to 40 million units in 2013, according to research institute Isuppli (March 2010). Femtocells are very cost sensitive and our indication is that they must have a bill of material of well under US$ 100. Acheiving synchronization at low cost is crucial for this equation.

Consumer

As digital consumer electronics evolve, networking is today becoming an integral feature, increasing the value of both the device itself and the content stored on or played by the device. The standardization community has set up work for a standard for Local and Metropolitan Area Networks - Timing and Synchronization for Time-Sensitive Applications in Bridged Local Area Networks – the IEEE 802.1as and recently (March 2010) released a draft standard (see 802.1AS, Draft 7.0). This work is intended for the consumer electronics as well as professional AV networks and has recently . It deals with AV streaming and content control, and the technologies for bridging in the network. This standard is largely based on the native IEEE1588 profile for its time synchronization and there are setup box and media gateways for consumer usage. To ensure quality of the experience in these products synchronization is again seen as a driver and a key enabling technology. Audio and Video (AV) time synchronization technologies require in the range of 100 ns of accuracy, location technologies in the single digit ns accuracy range. Both will require hardware time stamping technology to achieve this.