Need to test jitter? Complete solutions for characterization and test of jitter on high-speed digital transmission systems

Transcription

1 Need to test jitter? Complete solutions for characterization and test of jitter on high-speed digital transmission systems

2 Overview The measurement of jitter is rapidly becoming a necessity for ensuring error free communication. As data rates climb, new standards appear and development cycles shrink, you need the tools that help you keep pace with this changing environment. Whether you need to test to the requirements of jitter standards, such as SONET/SDH/OTN, or 10 Gigabit Ethernet, or whether you need to analyze the jitter as a waveform or pulse train, Agilent offers a wide range of solutions for the prediction, characterization and testing of jitter. Bathtub Eye R&D Jitter Jitter Stressed Eye Diagrams Electrical JS-1000 ParBERT 81133A/81134A 86100B Components 71612C 86130A Optical JS-1000 ParBERT 81133A/81134A 86100B Transceivers OmniBER OTN 71612C N1016A OmniBER A Line Cards OmniBER OTN 71612C 86100B OmniBER A Network Elements OmniBER OTN 71612C & Systems OmniBER A Bathtub Enterprise Jitter Stressed Eye Bathtub ParBERT (Page 6) 71612C 86130A Random 71612C & Deterministic 86130A Stressed Eye (Page 7) Electrical 81133A/81134A Optical N1016A Manufacturing Electrical 71501D ParBERT 81133A/81134A 86100B Components OmniBER OTN 71612C OmniBER A Optical 71501D ParBERT 81133A/81134A 86100B Transceivers OmniBER OTN 71612C OmniBER A Line Cards 71501D 71612C 86100B OmniBER OTN 86130A OmniBER 718 Network Elements OmniBER OTN 71612C & Systems OmniBER A SONET/SDH/OTN Generation, Transfer, Tolerance Electrical Clock 71501D (Pages 4 and 6) JS-1000 OmniBER OTN OmniBER 718 Optical and Electrical Data OmniBER OTN (Page 5) OmniBER 718 Wander OmniBER OTN (Page 4) OmniBER 718 2

3 Jitter and Its Causes Error free communications is a goal every user strives for. Unfortunately, this is difficult to achieve. Understanding the sources of error can help improve the quality of service from a communication system. Jitter is one of the major sources of these errors. Jitter can be defined as an unwanted phase modulation of a digital signal. Jitter with a phase modulation of less than 10 Hz is referred to as wander. Jitter can be due to both deterministic and random phenomenon. It can be caused by many different phenomena, including switching transients, slow turn on ramps, crosstalk, and bandwidth limitations. You need the tools that can help predict these phenomena as well as analyze them when they occur. Jitter causes eye-closure in the horizontal axis and this prevents correct sampling and ultimately results in bit errors. Using the 86107A precision time base reference module, the oscilloscope jitter can be virtually eliminated. This allows you to measure the true jitter of your signal. Jitter can be viewed in the time domain as a pulse train on the 86100B Infiniium digital communications analyzer (DCA). In order to ensure that components and systems are as error free as possible, it makes sense to run comprehensive simulation and circuit simulation before ever committing designs to a tapeout or prototype. The Advanced Design System can simulate at the IC, DUT board, module and board level. You can simulate phase noise and jitter in clock generation and PLL clock recovery circuits. You can also display eye diagram and measure eye closure. Clock phase noise jitter graph using the Advanced Design System. Pulse train representation on 86100B. A 40 Gb/s RZ signal captured using the 86107A precision timebase module. Simulate eye closure with the Advanced Design System. 3

4 SONET/SDH/OTN Test Methodologies The spectrum of jitter as defined by the SONET/SDH/OTN standards is intentionally bandlimited when verifying compliance. Elements of the baseband jitter are excluded from the measurement. For example, at 10 Gb/s these are defined as below 50 KHz and above 80 MHz. There are different filter values for different rates. Thus you need measurement equipment that can reject these frequencies, but also be flexible enough to adapt as the standards change. There are certain measurements that are defined by these standards: jitter tolerance, jitter transfer, and jitter generation. Agilent offers several jitter measurement systems: the JS-1000, the 71501D, the Omniber OTN and the OmniBER 718. The Omniber OTN and the OmniBER 718 test for wander as well. These solutions are flexible in their architecture, allowing for changes in amplitude, data rate, frequency band, and other parameters. Wander OmniBER 718 When you need to test wander, a different set of measurements is required. Wander is the longer-term phase variations ranging from 10 Hz down to micro- Hertz and below. The OmniBER OTN and OmniBER 718 measure wander in real-time. While jitter is normally measured with reference to a clock extracted from the data signal, wander is measured against an external reference clock. The fundamental measurement is Time Interval Error (TIE). This represents the time deviation of the clock signal under test relative to the reference source. Jitter Tolerance In order to ensure that your devices can operate error free in the presence of the worst case jitter from preceding sections in the network, you need a method to test SONET/SDH/OTN jitter tolerance. This requires a source of sinusoidal jitter and a method to assess bit-error-ratio. Because the OmniBER OTN and OmniBER 718 contain both, they are ideally suited for this measurement. The Omniber OTN can measure optical data jitter on the Optical Transport Network. Jitter tolerance plot on the OmniBER OTN. OmniBER OTN Time interval error plot from the OmniBER 718. Network Element 4

5 33250A Modulation Source Device Under Test Recovered Clock BPF = Bandpass Filter BPF 83752A Clock Source Block diagram for jitter transfer measurements. N1015A Modulation Test Set 71612C Error Performance Analyzer Reference Clock BPF 71501D Jitter Analyzer Jitter Transfer Jitter transfer is typically used to describe how a clock recovery module or repeater locks and tracks data as jitter is placed on it. When measuring jitter transfer, you need to be assured your device under test does not transfer more than the SONET/SDH mandated 0.1 db of peaking. A feature of the 71501D jitter analysis system is the ability to measure jitter transfer through a device where the input and output are not the same, such as with a multiplexer. The input and output rates do not need to be harmonically related because of the frequency agility of the system. Jitter Generation Jitter generation refers to the jitter present on the output of a single device (output jitter refers to that from the network). It is crucial when measuring jitter generation that the result is not affected by the intrinsic jitter of the measurement system. The JS-1000 provides you with the maximum design insight, beyond compliance, with the lowest intrinsic jitter available. JS-1000 Transfer UI (db) Jitter generation histogram plot from the JS Modulation Frequency (Hz) Jitter transfer measurement of a multiplexer from the 71501D. 5

6 Ethernet Jitter Test Methodologies Ethernet transmission standards have a different approach to characterizing jitter than the SONET/SDH/OTN test methodologies. For those engineers who need to measure jitter using the methodologies of Ethernet, Fibre Channel or other enterprise jitter transmission standards, Agilent has a number of solutions. These solutions are designed to accurately test both the deterministic and random elements of the jitter through the various required measurements. These measurements include both the bathtub curve, and the stressed receiver conformance test. ParBERT Device Under Test Bathtub Jitter Any instrument capable of performing a BER measurement can be used to create a bathtub curve, as long as the sampling point can be scanned in time. According to T11.2, Fibre Channel Methodologies for Jitter Specifications, the BERT scan method for characterizing jitter has the best jitter data efficiency of any method. There are three instruments from Agilent that can create a bathtub curve; the 71612C 12.5 Gb/s error performance analyzer, the 86130A 3.6 Gb/s BitAlyzer, both of which can show random and deterministic jitter results, and the ParBERT ParBERT has a ready-to-use measurement interface which aids with the verification and characterization of high-speed digital components and modules. The DUT output timing measurement enables the measurement of the BER of a DUTs output versus sample point delay. This can be shown graphically as a bathtub curve. Jitter can be directly equated from the bathtub curve and viewed as a histogram C Bathtub curve plot from the ParBERT Bathtub curve from the 71612C. 6

7 E4422B Signal Generator 71501D Jitter Analyzer 71612C Error Performance Analyzer N1016A Stressed Eye Test Set Device Under Test 86100B Infiniium DCA 33250A Modulation Source Simplified 10 Gigabit Ethernet stressed eye receiver conformance test with the N1016A. Stressed Eye The stressed eye test is a methodology for receiver testing that is specific to Ethernet and other 81133A enterprise standards. The stressed eye is intended to verify that a receiver is capable of operating at a given BER level when presented with the worst case allowable signal and effectively measures more than just jitter. Agilent offers two solutions that effectively provide the stressed eye signal, the 81133A/34A pulse-/pattern generator and the N1016A stressed eye test set. Device Under Test 86100B Infiniium DCA Simplified stressed eye generation with the 81133A. When you need to characterize and verify the performance of high-speed components up to 3.35 GHz, you will need test flexibility as well as superb waveform integrity. The 81133A/34A pulse-/pattern generators can provide the ability to add jitter to clock and data signals up to 3.35 GHz by controlling the eye closing over the time axis. Real world signals can be simulated, using the 33250A function/arbitrary waveform generator adding sinusoidal modulation and the 86100B Infiniium DCA for eye measurement. When you need to test the performance of 10 Gigabit Ethernet modules and linecards, the N1016A stressed eye test set is the only optical solution available that provides calibrated, adjustable, repeatable and compliant receiver testing to the 10 Gigabit Ethernet IEEE Standard 802.3ae. The 71501D jitter analyzer system generates and calibrates the sinusoidal component of the stressed eye, the E4422B economy signal generator provides the amplitude modulation, and the 71612C error performance analyzer provides the waveform pattern. A reference transmitter signal is also provided for comparison to a known good signal. Modulation jitter through the 81133A. An IEEE 802.3ae compliant optical stressed eye as described by the stressed receiver conformance test using the N1016A Stressed Eye Test Set. 7

8 Product Descriptions Jitter Systems Advanced Design System High-speed analog/digital IC design Board level design Behavioral modeling For more information contact your local Agilent EEsof sales representative about the ADS High Speed Analog Designer or visit us at B Infiniium DCA wide-bandwidth oscilloscope View optical and electrical waveforms with bandwidths to 70+ GHz electrical and 50 GHz optical. Built in measurements for high-speed digital communications and modular configurations for a test system to match your specific needs. View the true jitter of your device with ultra-low, intrinsic jitter of 200 fs. 100 Mb/s to 10 Gb/s and beyond Built-in compliance tests Integrated optical and electrical channels EN Technical Specifications EN Brochure JS-1000 Performance jitter solution Compliance to SONET/SDH standards for clock and data jitter generation, tolerance, and transfer Maximum design insight beyond compliance through the lowest intrinsic jitter of any solution in the industry Maximum ROA through flexibility to test more than SONET/SDH frequencies: 2.4 to Gb and 9.5 to 13 Gb/s The JS-1000 is a high-performance, characterization/verification solution for testing electrical components or modules in optical transport communication systems with the utmost accuracy and repeatability. The solution is a tailored phase noise system that measures clock and data jitter characteristics in the 2.5G and 10G frequency ranges. (The JS-1000 will also offer a 40G clock jitter upgrade in the fall of 2002.) JS-1000 was created for designers who want to differentiate their products on performance, time to market, or price, since the performance jitter solution impacts all three. Product Overview EN 8

9 Eye Test Solution Jitter Solutions Bathtub Jitter Solutions Stressed Eye Diagrams OmniBER OmniBER 81133A Data Rate 71501D JS-1000 OTN 718 ParBERT 71612C 86130A 81134A N1016A 86100B PDH/T-carrier Mb/s Mb/s Mb/s Gb/s Gb/s Gb/s Gb/s Gb/s Gb/s Gb/s Gb/s Gb/s Gb/s D Jitter analyzer system Compliant to SONET/SDH standards for clock jitter Cost effective solution Frequency agile from 50 Mb/s to 12.5 Gb/s Provides an easy upgrade path from the 71501C The 71501D Jitter analysis system is the lowest cost measurement solution available that provides clock jitter compliant measurements to the SONET/SDH standards. The low intrinsic noise floor is less than half that required by the standards. This is provided by the new N1015A modulation test set, which, along with the new software, provides an easy upgrade path from the 71501C. The 71501D also allows for differential I/O rate jitter analysis for mux/demux. A set of test templates is provided for standard SONET/SDH testing. New test templates can easily be created for emerging standards such as 10 Gigabit Ethernet EN Product Overview EN Application Note 1267 or see OmniBER OTN High-accuracy jitter testing on all optical rates from 52 Mb/s to 10 Gb/s, plus OTU-2 (10.71 Gb/s) Significantly exceeds test-equipment specification ITU-T O.172 Enabling network-equipment manufacturers to reliably demonstrate compliance to ITU-T and Telcordia standards The OmniBER OTN analyzer is a powerful SONET/SDH tester and is ideal for testing the optical transport network (OTN). The analyzer covers all jitter rates from 52 Mb/s up to 10 Gb/s, and supports optical channel functionality at Gb/s (OTU-2) to ITU-T G.709. For in-depth testing at all line rates, the OmniBER OTN also offers both framed and unframed operation EN Brochure OmniBER 718 Communication performance analyzer The OmniBER 718 Communications performance analyzer provides the benchmark in SONET, SDH, PDH and ATM, BER and jitter testing from 1.5 Mb/s to 2.5 Gb/s. Traditional capabilities of this instrument include: Best-in-class SONET/SDH and PDH jitter capability Real-time MTIE, MRTIE and TDEV wander measurements Through-mode jitter testing Improvements in the jitter noise floor, providing even lower intrinsic levels EN Technical Specifications EN Brochure 9

10 Bathtub Jitter ParBERT ParBERT provides parallel BER testing up to 10.8 Gb/s for multiplexers/de-multiplexers, high-speed digital and optoelectronic components. The modular design lets you mix and match analyzer channels, generator channels (electrical and optical) and speed classes (675 MHz, 1.65 Gb/s, 2.7 Gb/s, 3.35 Gb/s, 10.8 Gb/s and 45 Gb/s) to create a system that matches your unique needs. Test up to OC-768 electrical devices with ParBERT 45 Gb/s. Key features include: Generate pseudo random word sequences (PRWS) and standard PRBS up to Jitter modulation (with 3.35 Gb/s modules) Independent programmable control of voltage levels and timing delay Automatic synchronization E ParBERT Product Overview EN ParBERT Gb/s Product Overview or see A BitAlyzer error performance analyzer Operating over the data range of 50 Mb/s to 3.6 Gb/s, this integrated pattern generator and error detector is designed to quickly solve your design and manufacturing problems. The 86130A brings a new level of insight into your testing toolbox. Powerful analysis, easy set up and use, together in a small, expandable package makes digital testing easy. This instrument includes Synthesis Research error analysis capability. These powerful and innovative features provide insight into the underlying causes behind the error conditions that you may encounter. Ethernet Fibre Channel jitter compliance testing and analysis 50 Mb/s to 3.0 Gb/s bit error ratio (BER) with internal clock source Up to 3.6 Gb/s measurements with optional external clock Powerful error analysis built in E Product Brochure E Technical Specifications EN Bathtub Jitter Analysis or see C Error performance analyzer The 71612C Error performance analyzer is the ideal solution for the research, development and manufacturing test of Gbit lightwave and digital components, devices and subsystems from 100 Mb/s to 12.5 Gb/s. With this high performance serial pattern generator and error detector, you can perform error analysis to verify the operation and quality of lightwave submarine cable systems, SONET/SDH telecom and datacom transceivers, Gbit datacom serial links, high-speed logic devices, and optical amplifiers and modulators. The analyzer can be used to test 10.6 Gbit Ethernet and forward error correction (FEC) rates. The four sub-rate outputs of the 71612C are suitable for the generation of Gb/s test patterns required to test the XAUI interface of 10 Gigabit Ethernet devices EN Product Brochure EN Technical Specifications EN Bathtub Jitter Analysis 10

11 Stressed Eye Generation 81133A/81134A Pulse-/pattern generators The 81133A (1 channel) and the 81134A (2 channels) are high performance sources for square waves, pulses, data patterns and pseudorandom data sequences (PRBS) up to 3.35 GHz. The hardware PRBS generation from to and 8kB pattern memory make the 81133A/81134A ideal sources for eye diagram measurements. Timing and levels can be individually programmed. The fast rise times of less than 50 ps and low jitter of less than 2 ps ensure the highest signal integrity when timing is critical. The ability to add jitter to clock and data signals, starting at jitter levels of less than 2 ps up to 500 ps, allow the performance characterization and verification of high speed components and the simulation of real world signals EN Product Overview N1016A Stressed eye test set The N1016A Stressed eye test set is a unique optical solution for the design, verification and manufacturing of 10 Gigabit Ethernet modules and linecards. As part of a complete system, the N1016A is designed to provide an optical stressed eye at Gb/s for testing stressed receiver conformance to the IEEE standard 802.3ae. The N1016A is Calibrated Adjustable Repeatable Compliant Beyond compliance, the N1016A also allows for adjustability of the level of stress, providing the design or verification engineer the ability to determine the breaking point of the receiver, or to determine where and how a particular device is failing. The test set also operates as a reference transmitter, providing a clean eye at 1310 nm EN Product Flyer or see 11

12 Agilent Technologies Test and Measurement Support, Services, and Assistance Agilent Technologies aims to maximize the value you receive, while minimizing your risk and problems. We strive to ensure that you get the test and measurement capabilities you paid for and obtain the support you need. Our extensive support resources and services can help you choose the right Agilent products for your applications and apply them successfully. Every instrument and system we sell has a global warranty. Support is available for at least five years beyond the production life of the product. Two concepts underlie Agilent s overall support policy: Our Promise and Your Advantage Get the latest information on the products and applications you select. Our Promise Our Promise means your Agilent test and measurement equipment will meet its advertised performance and functionality. When you are choosing new equipment, we will help you with product information, including realistic performance specifications and practical recommendations from experienced test engineers. When you use Agilent equipment, we can verify that it works properly, help with product operation, and provide basic measurement assistance for the use of specified capabilities, at no extra cost upon request. Many self-help tools are available. Your Advantage Your Advantage means that Agilent offers a wide range of additional expert test and measurement services, which you can purchase according to your unique technical and business needs. Solve problems efficiently and gain a competitive edge by contracting with us for calibration, extra-cost upgrades, out-of-warranty repairs, and on-site education and training, as well as design, system integration, project management, and other professional engineering services. Experienced Agilent engineers and technicians worldwide can help you maximize your productivity, optimize the return on investment of your Agilent instruments and systems, and obtain dependable measurement accuracy for the life of those products. By internet, phone, or fax, get assistance with all your test & measurement needs. Online assistance: Phone or Fax United States: (tel) Canada: (tel) (fax) (905) China: (tel) (fax) Europe: (tel) (31 20) (fax) (31 20) Japan: (tel) (81) (fax) (81) Korea: (tel) (82-2) (fax)(82-2) Latin America: (tel) (305) (fax) (305) Taiwan: (tel) (fax) (886-2) Other Asia Pacific Countries: (tel) (65) (fax) (65) tm_asia@agilent.com Product specifications and descriptions in this document subject to change without notice Agilent Technologies, Inc. Printed in USA August 1, EN BitAlyzer is a register trademark of SyntheSys Research, Inc.