Cable
operators globally acknowledge that tight networks merely work higher, and sign leakage is one of the best ways to detect, discover, and repair the shielding weaknesses which let undesirable upstream ingress into networks. Leakage monitoring has tailored with the evolving HFC to stay possible and maximize effectiveness, however the migration to a 204MHz upstream with high-split networks presents essentially the most daunting problem that leakage instruments have confronted thus far.
Excessive-Break up Leakage Problem
Plant leakage programs actually took off in recognition after, as legend has it, leakage from a cable system interfered with Air Power One navigation – driving the FCC to crack down on networks leaking sign into the aeronautical band. 138MHz has been the default monitoring frequency close to the aero band,
That is the place excessive splits throw a wrench into present instruments/strategies. By shifting the upstream break up as much as 204Mhz, the standard 138MHz aero band monitoring frequency shifts from the downstream to the upstream. Now not can sign taggers transmit tags to be mixed into the downstream for detection by area meters – instruments and strategies should adapt.
The Resolution – OUDP Take a look at Burst Detection
Leakage detection has usually consisted of detecting sign tags mixed into HFC downstreams or OFDM pilots escaping from shielding weaknesses in cable crops. With the transfer of the aeronautical band to the upstream, the one sensible resolution to allow continued monitoring of this band is to make use of alerts transmitted within the upstream. Utilizing cable modems to transmit conventional sign tags is theoretically potential, however this strategy would end in lack of upstream spectrum obtainable for revenue-generating site visitors, would degrade CPE bandwidth capability, and would require intensive R&D and specification modifications to operationalize.
The intelligent different that the trade is gravitating towards is the usage of present upstream take a look at alerts referred to as OFDMA Upstream Knowledge Pilot (OUDP) take a look at bursts as sign tags. These bursts are typically used to find out the utmost Interval Utilization Code (IUC) that modems can assist, however the OUDP bursts with the very best pilot density have been confirmed to be detectable by superior leakage meters. OUDP utilization is already specified within the DOCSIS 3.1 specification, so all deployed DOCSIS 3.1 {hardware} ought to assist these bursts – no spec modifications and intensive R&D required!
How To Put together for and Launch Excessive-Break up Leakage
From a Tech Ops perspective, the objective of any know-how migration plan is to make it as clear as potential to the parents and reuse present instruments and processes each time potential. Swapping out take a look at gear each time community know-how modifications is pricey and a logistical nightmare. Because of this software-defined radio-based leakage detectors with full-frequency agility are taking off in recognition. Operators should buy these detectors as we speak and clear up their nodes focused for future excessive break up upgrades, specializing in FM ingress which is way simpler to seek out/repair as a downstream challenge vs within the high-split upstream. When the time involves migrate nodes to excessive break up, these meters can then have a license key and new frequency plan deployed to them through a cellular app and start OUDP monitoring additionally with out the meters ever leaving technicians vans.
Abstract
Excessive break up architectures are coming whether or not we’re prepared or not, the five hundred% improve in usable spectrum vs 42MHz crops is simply too highly effective of a price proposition to cross up. Whereas switching from downstream tag of OFDM pilot detection to upstream OUDP take a look at burst detection sounds difficult, the change might be seamless with the fitting preparation and gear choice. Whether or not you wish to monitor leakage in high-split upstreams to take care of FCC compliance or simply to stop ingress points, you possibly can relaxation assured that options shall be prepared when you’re to make this transition.
Need to study extra? Hearken to the Broadband Lounge Podcast Collection or go to the VIAVI Sign Leakage Web page or Excessive Break up Leakage Web page for extra data.
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