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Topics Covered:

• The essential technology understandings of ADSL 2+
• Terms, acronyms, measurements, and most importantly, the meaning of those measurement values
• How are max rate, attenuation, noise margin, power, and capacity calculated in each direction?
• What are the electrical effects of bridge taps, length, capacitance, resistance, etc. and how do they affect bits per tone allocations, data rates, attenuation, noise margin, power & capacity
• What do the bit per tone allocations assigned between the DSLAM and the Comtrend ADSL modem actually tell us about the wire’s integrity and electrical characteristics
• What does the noise margin reading mean - why does it drop when we increase the data rate at the DSLAM
• How do the ADSL measurement values relate to the integrity and electrical properties of the wire itself
• DSLAM configurations - profiles, interleave vs. fast, min/max rates, interleaving delay and check bytes, SNR target noise margins - how do these affect installer readings at the home
• Comtrend ADSL modem management screens and parameter values as they pertain to ADSL2+ and the wire’s integrity

ADSL Test Set Operations:

• TDR test
• Background noise test
• Bits per tone graph interpretations
• Interpreting measurements over circuits of varying lengths & electrical characteristics
• Relationship of test set readings to the Comtrend management screens and parameter values

Course Outline

This is our ADSL 2+ technology course with a special orientation toward ADSL2+ operation between the Telco distribution equipment/DSLAM and the Comtrend ADSL modem/router.

ADSL2+ is a technology that provides high speed data, video and voice over standard twisted pair copper wire. A dynamically allocated spectrum of 512 analog frequency bands (from 0 kHz to 2.2 MHz) is used. POTS remains in its original 0-4 kHz frequency; data and video are communicated using analog modem modulations over frequency bands 6-512 (25 kHz to 2.2 MHz).

ADSL 2+ relies upon DMT (Discrete MultiTone) where 4.3125 kHz wide frequency bands, and up to 15 bits per tone/frequency are modulated and aggregated. This yields a downstream bandwidth of up to 24 Mbps and an upstream rate of up to 1 Mbps.

This course provides the essential technology understandings of ADSL & the above mentioned DMT operations; the terms, acronyms, measurements and most importantly the meaning of those measurement values. How do the measurements relate to the integrity and electrical properties of the wire itself? For example, what do the bit per tone allocations assigned by the DSLAM actually tell us about the wire’s integrity and electrical characteristics? What does the noise margin reading mean? Why does it change when we increase the data rate? How does this relate to the target noise margin setting in the DSLAM? How is the Max rate actually calculated in each direction? What are the effects of bridge taps, length, capacitance, resistance, etc. and how do they affect the bits per tone allocations? What is the Fast vs. Interleave rate? How are the attenuation levels calculated in each direction? What is the capacity percentage? Lastly, ATM VPI/VCI values are explained as well as how they are used for data and video in IPTV.

This unique ADSL 2+ technology class provides the unique added benefit of relating the various ADSL 2+ operations, terms and parameters to the Comtrend management screen parameters and configurations.

This is the course we recommend for all telecom provider employees in any ADSL technical position.

Dates/Pricing

Who should attend?

Any telecom provider professional interested in gaining a crystal clear understanding of ADSL 2+ technologies from an installation and troubleshooting perspective.

• Installation and Repair, Help Desk
• Tier 1, Tier 2, Tier 3
• Engineers, Tech Support
• Network Operations Center, Data Technicians

Course Details

• ADSL Technology Components:
• The electrical properties of twisted pair copper wire circuits as they relate to ADSL
• Components of an ADSL circuit
• Acronyms, standards, terminology
• Applications - POTS, data and IPTV
• Steps for conversion of a POTS customer to ADSL - What can go wrong?
• Early DSLAM jumper block wiring at the CO, OE - potential problems
• Newer DSLAM POTS operation and wiring/operating scenarios, VOIP, GR-303
• ATU-R, ATU-C - what is the difference, which syncs with the other? Where might a Telco technician encounter this - what is the Comtrend equipment?
• A complete explanation of the various Comtrend ADSL/line oriented parameters and management screen values will be given - their specific relationship to ADSL 2+ operation in general as well as how they relate to DSLAM values, profiles and wire issues
• Outside splitters and in-line filters, inside wiring (IW) issues as they apply to the ADSL data frequencies
• DSLAM fundamentals and configurations as they relate to and affect the ADSL circuit
• How do the following affect what the Telco technician sees at installation - DSLAM profiles, Fast vs. Interleave bit rates, minimum/maximum rates, interleaving delay and check bytes, SNR margins, target noise margin, etc.
• Corrected errors vs. uncorrected errors - how does this affect data vs. IPTV
• Bit per second rates at the head end as it relates to quality
• Internet data access over the ADSL line to an ISP
• Client vs. server customer communications over ADSL
• ADSL DMT - an analog technology passing digital information
• Why do ADSL modems prefer to achieve their data rates using fewer bits per tone over more frequencies as opposed to more bits per tone over fewer frequencies
• Other DSL types - IDSL, HDSL, SDSL, VDSL
• Legacy ADSL, G.DMT
• Newer versions of ADSL (S=1/2, ADSL 2)
• ADSL 2+ (how does it differ from the other versions of ADSL)
• ATM, VPI/VCI values
• ATM based internal network delivery systems vs. Ethernet
• VPI/VCI configurations in the various Comtrend products will be demonstrated and explained

• ADSL Measurements:
• Max rate - how is it calculated and what does it indicate about the wire in each direction (interpretation of readings)
• Fast rate and Interleave rate, what do they define, delays and forward error correction variations (interpretation of readings)
• Capacity percentages and rates (interpretation of readings)
  Bits per tone, bins - what it means about the integrity of the wire pair
• Attenuation, power, etc. (interpretation of readings)
• What does the noise margin reading indicate - how does this relate to the target noise margin setting in the DSLAM?
• Bridge taps and their reflective effects on an ADSL modem
• How does the location and length of the bridge tap affect ADSL?
• Wire length, resistance and capacitance - how do they affect ADSL?
• Which frequencies are affected first?
• Can wire problems affect one direction and not the other?
• A final summary of installation and troubleshooting ADSL
• A complete explanation of the various Comtrend ADSL/line oriented parameters and management screen values will be given as they relate to ADSL2+ measurements

• ADSL Test Set Measurements and Tests:
• Running a TDR test using an ADSL test set
• Disturbers and background noise tests using an ADSL test set
• How might a T1 Line affect the bits per tone assignments on an adjacent copper wire pair running ADSL?
• Analyzing and interpreting all ADSL readings (example: max rate, fast, interleave, power, capacity, noise margin, attenuation, etc.) as well as the bit per tone readings of various ADSL lines with different lengths and electrical properties
• A comparison between the various Comtrend ADSL/line oriented parameters and management screen values will be made as they relate to ADSL2+ test set values.