Digital Signal Analyzers Questions & Answers

Digital Signal Analyzers Questions & Answers A circularly rotating pattern in a constellation indicates - CORRECT ANSWER - phase noise BER is degraded (increased) by a variety of issues that can occur in the HFC network and customer location, among which are: - CORRECT ANSWER - Excessive attenuation in the path which leads to low C/N and/or low MER In-band interference from radio signals such as HAM or CB radios Burst or impulse interference from power supplies and motors Non-linear amplification effects in the HFC plant resulting in excessive CTB and CSO Other Non-linear effects such as common path distortion or CPD Cable modem termination system (CMTS) - CORRECT ANSWER - Cable modem termination system (CMTS) is a router with Ethernet interfaces on one side and coax RF signal interfaces on the other side typically found in a cable company's headend to provide DOCSIS services for HSD. can a SLM measure AC powering voltage? - CORRECT ANSWER - no Channel Maps can be used to relate channel frequencies to channel numbers displayed on a STB. - CORRECT ANSWER - true consumer electronics association (CEA) - CORRECT ANSWER - Consumer electronics association (CEA) is a standards and trade organization that manages the cable downstream channel frequencies. Customer Premises Equipment (CPE) - CORRECT ANSWER - Customer premises equipment (CPE) is located at the end-user or customer's premises, for example, any converter (set-top box), satellite dish and receiver, television, home theater amplifier, remote control device, cable modem, MTA, eMTA, tuner, terminal, router, telephone, PBX switch, fax machine, etc. The term is usually used to refer to devices supplied by the cable operator, but sometimes the term is used to refer to consumer electronics regardless of who owns the equipment. digital cliff - CORRECT ANSWER - where a digital transmission goes from working to showing some signs of issues to complete loss of function. ie 33 MER, things are good. 32 MER, everything is off. Dots that fall as a round blob around each ideal constellation point indicate thermal or Gaussian noise. The more "blurry" the plot of received symbols in the constellation diagram, the worse (that is, LOWER) the MER. If significant phase noise is also present, the constellation diagram will appear as if it is rotating in a circular pattern - CORRECT ANSWER - true For a digital channel what portion of the signal will it use for the RF power level measurement? - CORRECT ANSWER - the center frequency of the channel