Amplifier adjustments and comprehensive network management in the DOCSIS 4.0 era

Cable networks are in the process of getting a major evolutionary upgrade with introduction of 1.8 GHz amplifiers in preparation for utilization of DOCSIS 4.0 services to meet customer needs of increased network speeds. With the 1.8 GHz amplifiers the frequency bandwidths of both downstream and upstream are significantly extended from legacy networks.

In North America, where majority of coaxial cables are in aerial networks, the increased frequency bandwidths is changing how the modern amplifier needs to operate to maintain signal stability of downstream and upstream.

Maintaining downstream signal stability is not a new thing for cable networks as this has been a core functionality of amplifiers in legacy networks. However, modern 1.8 GHz amplifiers cannot fully rely on legacy methods that typically consist of measuring a single dedicated frequency, where signal stability is maintained by correcting gain of the amplifier and, in some cases, slope with approximations of cable attenuation changes based on changes of a single frequency point.

As a new challenge in aerial cable networks is maintaining upstream signal level stability between cable modems and remote PHY nodes, where already high split is pushing the cable modems’ ability to compensate the change of cable attenuations in networks, and ultra-high splits of DOCSIS 4.0 will require an ability to compensate upstream levels within the 1.8 GHz amplifiers.

Evolving AGC to ALSC

To meet the higher requirements of DOCSIS 4.0, the 1.8 GHz amplifiers need an evolutionary step from a single frequency AGC to a multi frequency ALSC to compensate downstream signal movement from gain and slope point of view, while also having a means to compensate upstream signal level movements of ultra-high split based systems.

With a multi frequency ALSC, the amplifiers can also be able to increase visibility of networks, by enhancing downstream monitoring possibilities with options like full span spectrum, TCP monitoring, and other means to introduce additional data to use for maintenance and PNM.

As upstream level compensation has not been a necessity in low-split or mid-split systems within amplifiers, the legacy amplifiers has not been required to make active compensation of upstream level changes. With the introduction of multi-frequency ALSC on downstream, upstream level changes within coaxial cables can be minimized with implementation of intelligent upstream ALSC following downstream level changes.

Join us at #SCTETechExpo24 to discover how we Teleste have successfully addressed the challenge in compensating both the downstream and upstream levels in the DOCSIS 4.0 networks. Come and connect with our experts at Teleste Intercept booth #909!

Niko Suo-Heikki

Product Manager, Access Networks, Teleste

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