AT&T Monitors Remote Sites Using LabVIEW System

Author(s):
Corey Miller - Microsys Technologies

Industry:
Telecommunications

Products:
LabVIEW,

The Challenge:
Remote monitoring of telecommunications transmission for quality assurance, troubleshooting and research for future systems.

The Solution:
Developing a PC-based virtual instrumentation system using GPIB and DAQ boards controlled by LabVIEW.

Imagine being on an important long-distance business call when the phone line gets cut by a construction crew. Although you might expect the line to be disconnected, the conversation continues, unhindered by the break.
At the AT&T facility in Holmdel, NJ, this break, or "event," is recorded in subsecond detail by a LabVIEW-based DS-3 Remote Monitoring System designed by Microsys Technologies Inc. later on that same day, AT&T engineers and scientists study reports and graphs generated by this system. AT&T will study this event as they design the long-distance network of the 21st century.

System Features
Developed using LabVIEW graphical programming software, the DS-3 Remote Monitoring System monitors an unlimited number of AT&T sites from their New Jersey office. Each remote site contains a PC running LabVIEW under Windows, a modem, a GPIB board and PC-DIO-24 board from National Instruments, an Anritsu DS-3 network analyzer, and a Baranti bit-error event monitor.
The remote site software continuously polls the local instrumentation and stores events and other performance data to its hard drive. Meanwhile, at AT&T in New Jersey, the headquarters computer periodically dials each remote site and retrieves all new data. The software automatically extracts the most important data and generates performance reports.
To help the engineer further understand the nature of an event, on-screen graphical controls give him/her views of related performance data and manipulate the presentation. To prepare for the next event, the engineer may reconfigure the remote DS-3 network analyzer from the site set-up screen of the headquarters computer. Engineers can add, modify, or remove remote sites without performing programming changes, giving them the freedom to design new experiments quickly in response to interesting or unusual events.

System Operation
The DS-3 Remote Monitoring System has six main screens:
• Menu screen
• Headquarters Monitor screen
• View Report screen
• Monthly Report screen
• Bit-Error Event Report screen
• Remote Site Configuration screen

The AT&T engineer uses the Headquarters Monitor screen to select a remote site, select a DS-3 receiver within a remote site, and view its data. It is particularly valuable to have the headquarters computer immediately poll the remote site - for example, when the engineer receives notice about an interesting event that might require further investigation.
To generate a report automatically, the engineer uses the View Report screen to select a remote site, a DS-3 receiver within the remote site, a month and year, and the report type. Using the Monthly Report screen, AT&T engineers can generate reports on a variety of events.
One of the most interesting reports is the Bit-Error Subseconds Event report. Using this report, the engineer can view bit-error events with high resolution, where an event is defined as a specific time window following the occurrence of a single bit error. In the example of the long-distance phone call, the engineer would see the impact of the breakage as the line was touched, stretched, and finally severed completely. This may sound like an instantaneous event, but the DS-3 Remote Monitoring System can resolve the break to a distinct error signature. This is the first time that AT&T engineers have had the ability to view bit-error signatures graphically, thus making the signatures easy to evaluate visually.
The Remote Site Configuration screen demonstrates the flexibility of the system. When a new site is installed, the engineer uses this screen to set up system parameters, such as telephone number and baud rate, and configure the Anritsu DS-3 network analyzer. The site installer can choose all operating parameters of the Anritsu instrument, giving the engineer the flexibility to change test parameters without traveling to the location of the remote site.

A Success Story
Since the initial system was delivered in 1995, engineers at AT&T have used the DS-3 Remote Monitoring System for several three to four-month experiments. In addition to gaining a better understanding of the nature of random bit errors, they are also studying the cause and effect of transport switching errors.
Microsys has developed several similar remote monitoring systems for monitoring of SDH, PDH, and SONET networks. Test systems designed by Microsys Technologies are used worldwide to ensure the quality of telecommunications, RF/microwave, wireless, and optical products. The company has standardized on LabVIEW as the programming language for all its test systems.

For more information, contact:

Corey Miller

Microsys Technologies Inc.

3100 Steeles Avenue West

Concord, ON L4K 3R1

Tel: (905) 761-5250

Fax: (905) 761-5244

E-mail: sales@micro-sys.com

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