Atec DSAM-6000 User Manual

DSAM-6000

Digital Service Analysis Meter

Key Features

• Sweep, digital video, analog video, DOCSIS® IP, and
PacketCable™ VoIP test available in one meter

• Manages and displays sweep files via the web using
immediate data synchronized over DOCSIS RF

• Full 4 to 1000 MHz frequency range

• Forward sweep option allows sweeping of analog, digital,
and DOCSIS carriers

• Compatibility with existing JDSU Stealth Sweep™ Systems,
assuring non-interfering forward and reverse sweep
operation compatible with today’s digital carriers

• New Digital Quality Index™ (DQI) provides an easy to
understand real time digital quality history (90 seconds)

• Rugged, lightweight design withstands rain, cold, heat,
bumps, drops, and other accidental mishaps

Network maintenance is a critical element in achieving the quality of service (QoS)
necessary for cable operators to compete with alternative communications providers.

One core requirement of any cable network maintenance plan is to ensure that a
system’s broadband frequency response in both the forward path (downstream)
and the return path (upstream) performs as required.

JDSU has a long history of integrating the high-level functions and advanced
technology necessary for maintaining cable networks into scalable hardware and
software platforms. Coupling the innovative Signal Analysis Meter (SAM) with
award-winning Stealth Sweep technology (Patent No. 5,585,842), JDSU delivers
sweep meter solutions unequalled in their ability to perform advanced tests and
measurements. These capabilities were integrated into the SDA-5000 series of
products, which soon earned its current industry-lead position.

JDSU introduced the DSAM (Digital Service Activation Meter) when DOCSIS
standards pushed the industry to adopt a common technology for delivering
flawless high-speed data and IP services. This award-winning, landmark meter
integrated JDSU’s well-known Service Analysis Meter (SAM) functions with
DOCSIS cable modem and PacketCable multimedia terminal adapter (MTA)
elements and a PC-based management and file system.

Now, JDSU has introduced the next Wavetek™ Field Meter, the DSAM-6000
Digital Services Analysis Meter. Recognizing that maintaining cable networks
requires more than sweep,JDSU combined the DSAM’s video, audio, and data test
functions with the SDA’s downstream forward path and upstream return path
sweep functions and created a rugged, multitechnology handheld that performs
in the harshest environments.

Because it uses the SDA's powerful Stealth Sweep technology, the DSAM-6000 can
be used with existing SDA rackmounted sweep gear, SDA-5500 and SDA-5510,
located at headend and hub sites. Additionally, the DSAM-6000 meters can sweep
side-by-side with SDA-5000 meters. Therefore, major modifications are not
required when DSAM-6000 meters are added to a department’s pool of meters.

WEBSITE: www.jdsu.com/test

COMMUNICATIONS TEST & MEASUREMENT SOLUTIONS

Signal Level Meter (SLM)

Traditional SLM test functions for analog video and audio levels as well as JDSU’s
extremely accurate digiCheck™ digital power level measurements are supported
by the DSAM-6000. Furthermore, the ability to measure carrier-to-noise (C/N)
on analog carriers comes standard. The DSAM-6000 can measure downstream
carriers to a full 1GHz and analyze 64, 128 and 256 QAM, including deep
interleave (i=128, j=4) modulation. Also included are MER and pre- and post­FEC BER on both digital video and DOCSIS carriers, allowing technicians to
validate that digital services are received and they meet adequate margin and
quality specifications.

Miniscan and Full Scan Modes

When measuring analog and digital as well as DOCSIS signals, technicians can see
high- and low-frequency channels and verify how much level headroom remains
when limits are activated. In miniscan mode, the DSAM monitors up to 12 chan­nels at a time and in full scan mode it monitors the entire channel plan, up to 999
channels. The results of both scans are displayed either as an easy-to-see bar graph
or in an informative table.

Tilt Mode

Tilt mode is used while sweeping to check the forward tilt of the channel levels at
the low and high ends of the frequency spectrum. The variances of the levels,
which are displayed at the bottom of the DSAM-6000 screen, indicate distortion
of the frequency spectrum. Based on these results, technicians know which
equalizer pad to select that will provide optimum flatness at the end of the line.

Hum Analysis Mode

A hum measurement may be performed on a nonscrambled analog channel. Since
the instrument is battery powered, the measurement is independent of ground
loops and therefore is isolated from the line (mains). Severe hum is revealed on a
TV as either single (60/50 Hz) or double (120/100 Hz) horizontal bars across the
video screen. The DSAM-6000 hum display indicates the composit level of all
frequency components below 1000 Hz as well as the fundamental hum frequency.
The lower levels of adjacent frequencies as well as the fundamental are displayed
across a frequency graph. This is valuable in determining the source of hum
generation by displaying a telltale signature of the source (patent pending).

Constellation Mode

There are various elements in a network that compromise video quality. The
DSAM-6000 constellation mode displays patterns of data points on a graph,
which are easily interpreted, enabling technicians to detect and quickly diagnose
the source of digital video problems.

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DSAM-6000 DIGITAL SERVICE ANALYSIS METER

Features

Undesired electrical interference can appear on a
video channel as one or two horizontal bars. A Hum
measurement reveals if any electrical interference is
present on tested channel.

A Constellation graph shows impairments on the
network with patterns in the display.By identifying
the pattern technicians can figure out what is the
probable cause of the impairment.

Level mode on an analog channel displays video
and audio signal levels and their delta value.
Carrier-to-Noise (C/N) ratio is also displayed.

Miniscan measures signal strength of up to 12
channels simultaneously.

Digital Quality Index™ (DQI) Mode

DQI is an indicator of the overall health of a QAM stream. This measurement
does a great job tracking intermittent problems and is unique only to JDSU. It is
represented by an easy to understand Index rating from "1" to "10" with ten being
the highest quality. DQI also catches errors sometimes missed by BER and Errored
Seconds measurements. It also displays a 90 second graphical history.

MER Mode

Modulation error ratio (MER) is the earliest indication of transmission quality
degradation resulting from noise, ingress, and composite distortions. An expres­sion of signal-to-noise ratio plus all other non-transient distortion signals, MER
also shows phase and amplitude distortions that may have been passed from the
headend. MER is the best overall quality measurement that can be performed on a
digital QAM carrier. JDSU has perfected this valuable measurement by optimizing
both custom hardware and proprietary software algorithms (Patent Nos. 6,061,393;
6,233,274; 6,278,730 and 6,385,237). The result is accurate readings that far exceed
those reported from customer premise equipment such as digital settops.

BER Mode

Bit error ratio (BER) helps to quickly detect impulse changes in the system by
revealing when information is lost or corrupted at the bit layer. The DSAM-6000
measures BER by tracking the number of errored bits that are seen before forward
error correction (FEC), known as pre-BER, and the number of bits that cannot be
fixed by FEC, known as post-BER.

Errored Seconds and Severely Errored Seconds Measurement

For troubleshooting connections that are suspected of intermittent bit errors, the
technician needs a means of capturing the presence of errors that have occurred
over a period of time. If an error has occurred during any second of elapsed time,
the errored second field increments by one. One error or multiple errors in the
same second is counted as one errored second. If more than 1 bit in 1 million bits
has errors occurring in the same second, the severely errored second register in­crements by one. The errored seconds fields are conveniently included in the
digital level display.

QAM Ingress Mode

Detecting the presence of ingress within the digital tier of carriers on the
downstream path is nearly impossible without turning off the service. The tightly
spaced QAM carriers hide any visual presence of unwanted forward ingress such
as CSO and CTB. An MER test will indicate that an issue exists but with the
DSAM-6000 and the patented JDSU QAM Ingress mode the technician can
inspect what is actually going on beneath the digital “haystack” while still
remaining in service.

Return QAM Generator

Standard on the DSAM-6000, the Return QAM Generator is a mobile 16 QAM
transmitter. The ability to transmit a QAM-16 modulated signal back to the
headend is helpful for proving line capabilities for future data and voice channels
and for troubleshooting return path issues in the network.

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DSAM-6000 DIGITAL SERVICE ANALYSIS METER

QAM Ingress test allows the technician to see what is
going on underneath a live digital carrier which is
usually not viewable due to the presence of the
“haystack”.

In the level mode on a digital channel, the signal’s
level and MER are measured and the channel’s BER
and errored seconds are tracked.

The Return QAM Generator eanables operators to test
and prove upstream network performance.

DQI will display intermittent, short duration impair­ments missed by MER and BER as well as steady state
issues typically captured by MER and BER.

Comprehensive Analog and Digital Testing on the Forward Path

The DSAM architecture incorporates analog and digital testing into a single user
interface. This allows the technician to select a specific channel or a scan of
channels without having to differentiate between analog or digital video, DOCSIS
high-speed data, or voice.

The active channel plan functions as a meter configuration file as well as a channel
lineup. An extensive selection of configuration elements establishes the type of
tests that can be performed on a particular channel for each channel in the plan.

Also inherent within a given channel plan are autotest configurations for analog,
digital, and DOCSIS services. Most configurations can be entered into the meter
directly or through the JDSU Test Productivity Pack (TPP) client/server appli­cation software. Accessed via a PC, TPP manages channel plans and measurement
files for a collection of DSAM meters.

Networks with a history of multiple ownerships and diverse hardware arch­itectures are not a problem for the DSAM-6000. Supervisors can create multiple
channel plans for a specified group of meters or one channel plan for the whole
network. The channel plans can be deployed with plan parameters locked when
needed. Specific plans are easily selected from Configure mode, or in many cases,
directly from within a measurement mode. After selecting an active plan, a
technician can check the top of the measurement screen to confirm that it is the
correct plan. The channel plan name is included any saved measurement file for
reference. Using the channel plan to configure an Autotest, multiple tests can be
run in a short period of time with only two button presses.

Return and Forward Path Testing and Maintenance

A cable plant is a two-way path of information, enabling communication between
equipment. As a vital link between the CPE and the CMTS, the return path must
be aligned and kept free of ingress and noise. With digital services, limiting noise
and ingress becomes even more important because their effect may not be noticed
until service has significantly degraded.

The DSAM-6000 is designed to test and maintain both the downstream forward
path and upstream return path. Its ability to sweep, along with conducting signal
level and quality measurements; ingress testing; verifying forward path signals;
and testing the level of ingress and noise provide the optimal approach to
maintaining the return path.

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DSAM-6000 DIGITAL SERVICE ANALYSIS METER

Applications