Delivery: Online
Estimated Length: 12 seat hours
Price: $485.00
Course Assessment/Equivalency Exam: $110.00
The return path in today’s broadband cable network is integral to the successful and reliable operation of cable modems, video-on-demand (VOD), telephony, and other revenue sources. NCTI’s Return Path Operations course introduces the basic concepts of return path functions, and outlines procedures for testing, repairing, and maintaining a viable return path. The course provides details on how ingress, noise, system alignment, optical operations, and installation of equipment at the customer premises can jeopardize return path performance. It then guides the student with instructions on how to mitigate related problems that can occur inside and outside the customer premises, and in the outside network back to the headend over coaxial and fiber-optic cable. Any technician that works in these functional areas of the network will find valuable answers to questions about the return path that they may have been hesitant to ask.
Completion Time:
The estimated completion time for this course is 12 hours. The maximum allotted time is four months from enrollment.
Benefits:
- use this course to help prepare for SCTE’s Broadband Distribution Specialist (BDS) and Broadband Transportation Specialist (BTS) certifications
- receive credit towards NCTI Master Technician certification
- receive an industry-recognized NCTI certificate of graduation
Upon completing this course, students will be able to:
- describe the return path signal flow and major transmission elements
- explain the concept of long-loop automatic gain control (ACG)and how it is used to establish and maintain RF levels from cable modems, embedded multimedia terminal adapters (EMTA), and set-top boxes (STB)
- explain the concept of funneling on the return path
- discuss procedures for improving overall return path performance, including use of high-pass filters and step attenuators
- explain how test equipment for return path alignment measures and reports levels measured in the headend to devices in the field
- discuss the differences, advantages and disadvantages of single carrier, multicarrier and return sweep testing
- define and discuss upstream transmit level and path attenuation
- explain how to measure the amplitude of transient signals and noise measurements on the return path
- describe why optimization of the optical portion of the return path is critical to reliable operations of the services that use the return path
Outline:
Return Path Operations Overview
Generating return path signals, identifying nonresponding set-top boxes, examining forward and return path frequencies, introducing the funneling effect, adjusting return path signal levels in the drop system, examining attenuation characteristics, calculating the signal loss in the drop system, following signal flow in the hybrid fiber coax network.
Addressing Return Path Challenges
Identifying ingress, impulse noise, thermal noise, characterizing common path distortion, explaining micro-reflections, listing causes of hum, describing laser clipping, checking drop system integrity, searching for the presence of ingress/egress, employing mitigation filters, examining house amplifiers, summarizing PNM operations, diagnosing upstream ingress: case study 1 and repairing micro-reflections: case study 2
Troubleshooting the Return Path
Observing operational considerations, examining test equipment for the drop system, examining test equipment for the HFC network, introducing return path monitoring systems, utilizing proactive network maintenance, quantifying impairment severity, adjusting the drop system attenuation, resolving return path attenuation issues, describing test points and test probes, exploring spectrum analyzer considerations, characterizing laser clipping on a spectrum analyzer and discussing return path troubleshooting techniques
Maintaining Return Path Signals
Examining return amplifier input levels, examining return amplifier output levels, examining the fiber node, adjusting upstream channel levels from the headend, injecting test carriers, describing equipment test points, injecting test carriers without interference, injecting return sweep pulses, explaining measurement methodology, considering test carrier injection, observing the balancing sequence, balancing the node, balancing a distribution amplifier and balancing the return path in a line extender
Examining Return Path Signals
Reviewing basic types of digital modulation, citing quadrature phase shift keying, detailing quadrature amplitude modulation, explaining bit rate, symbol rate, bandwidth, conceptualizing orthogonal frequency division multiplexing, controlling access to the media, delving into time division multiple access, achieving higher data throughput, employing ingress cancellation, discussing S-CDMA, reviewing set-top box return carriers, examining DOCSIS 1.0 and 1.1 return carriers, discussing DOCSIS 2.0 return carriers, analyzing DOCSIS 3.0 return carriers and assessing DOCSIS 3.1 return carriers
Examining the Optical Return Path
Defining electromagnetic spectrum and wavelength, identifying the common wavelengths used in fiber-optic transmissions, understanding return lasers, understanding optical detectors, exploring the traditional analog return, characterizing the upstream signal path, controlling the signal level, working with real-world numbers, explaining the power-to bandwidth relationship, converting the optical return path to digital, aligning the optical return path and exploring a new architecture