The right handheld test tool for the job at hand

The access network is growing in complexity. More intelligence, more circuits, and more services are moving to the network edge. FTTx deployments push the fiber plant closer to the home and require higher performance copper plant and home wiring technologies to deliver new broadband services. This new level of complexity in the field puts increased pressure on those in the outside plant who must install, provision, turn-up, and maintain new types of circuits and services.

Field engineers and technicians need to be equipped with the right tools to stay on top of new technologies. JDSU’s SmartClass portfolio of test tools provides the triple-play of intelligence, power and portability to help deliver the triple-play of voice, video, and data services.

SmartClass consists of a set of tools targeted at specific network technologies and designed to reduce testing time and complexity. These tools provide the outside plant engineer or technician unparalleled ease of use, helping them to quickly perform the tests that are necessary to validate circuits for delivery of triple-play services.

Included in the portfolio are handheld testers for optical power and loss measurement, optical laser sources and attenuators, ADSL2+ testing, and more. Combined with JDSU’s modular field test platforms, SmartClass completes the industry’s most comprehensive portfolio of access network test tools.

Optical loss testing
When installing fiber, network topology and equipment specifications have to be taken into consideration. One of the major parameters to measure is optical loss budget or end-to-end optical link loss. Optical loss budgets should take into account the cable and equipment margins, which cover the allowances for time and environmental factors such as launched power, receiver sensitivity, connector or splice degradation, etc. Typical values of attenuation for different fiber components include:

• 0.2 dB/km for singlemode fiber loss at 1550 nm
• 0.35 dB/km for singlemode fiber loss at 1310 nm
• 1 dB/km for multimode fiber loss at 1300 nm
• 3 dB/km for multimode fiber loss at 850 nm
• 0.05 dB for a fusion splice
  - 0.4 dB for a mechanical splice
  - 0.5 dB for a connector pair
•  3.5 dB for a 1 to 2 splitter (3 dB splitting loss plus 0.5 dB excess loss)

Power meter/light source combinations (also defined as loss test sets) measure cable continuity and cable attenuation. Light sources and power meters are the main instruments recommended by the ITU-T (G651) and the IEC 61350 to measure insertion loss.

The SmartClass optical loss test set measures loss for up to three wavelengths simultaneously and provides a laser source with output level adjustment to ensure correct power for individual applications.

JDSU’s SmartClass optical level controller offers more than the typical combination of an optical attenuator and optical power meter. Its five instrument modes include:

• Optical level controller for direct output power setting
• Optical level stabilizer for automatic output power control
• Optical power meter with 80 dB dynamic range
• Optical in-line power meter with built-in coupler for in-service measurements
• Optical attenuator to manually adjust power levels

Optical power testing
Power testing is a fundamental task performed during fiber installation and restoration. The main function is to measure the incident power with a photodiode, but meters with more sophisticated functions also have the ability to calibrate to different wavelengths, display power relative to "reference" input, and introduce attenuation. Meters must be able to accommodate enough power to measure the output of the transmitter being used, but be sensitive enough to measure the received power at the far (receive) end of the link.

Typical dynamic range requirements for power meters are:

• +13 dBm to -70 dB for telephony applications
• +26 dB to -50 dB for CATV applications
• + 5 dB to -60 dB for LAN applications

The JDSU SmartClass power meter is wavelength-selective, capable of simultaneous power measurement of different channels. To support the increasing number of optical channels and the use of Raman amplifiers, JDSU’s SmartClass power meter can measure extremely high optical power (-60 to +30 dBm) and can simultaneously detect and test multiple wavelengths.

ADSL testing
ADSL2 technology improves the rate and reach of ADSL by improving modulation efficiency, reducing framing overhead, achieving higher coding gain, improving the initialization state machine, and providing enhanced signal processing algorithms. ADSL2+ further improves on the ADSL2 standard by allocating additional spectrum for downstream data, dramatically improving the data rate.

JDSU’s SmartClass ADSL2+ tester verifies that synch can be achieved and service delivered at the desired bit rate. Placing this tester at various points in the network (ATU-R, NID, splice case, cross box, MDF, DSLAM) can isolate a problem’s location and provide measurements of key physical parameters such as actual upstream and downstream bit rates, noise margin, attenuation, and capacity.

Click for more information on the SmartClass Portfolio.