Cisco Headend System Release 2.7 Design Guide
Chapter 1 Introducing Switched Digital Video
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Traditional Linear Broadcasting
Overview
The following diagram illustrates the traditional method of "linear" broadcasting
over HFC. Some "narrowcasting" is done in that not all hubs need to carry all the
same content. However, any broadcast content that is selected for that hub is
transmitted continuously to all subscribers.
over HFC. Some "narrowcasting" is done in that not all hubs need to carry all the
same content. However, any broadcast content that is selected for that hub is
transmitted continuously to all subscribers.
This method of linear broadcasting is extremely simple and has worked reliably and
cost-effectively for both cable service providers and consumers. However, increases
in channel offerings and higher-bandwidth programming content, such as high-
definition (HD) programming, have resulted in a greater demand for bandwidth.
This bandwidth demand cannot be readily satisfied by continuous access network
upgrades and rebuilds. It is no longer cost-effective to continuously increase
bandwidth for services with low viewership. Cable service providers have a need for
a new architecture that will reclaim wasted bandwidth and improve the subscriber's
experience without requiring endless bandwidth expansion. SDV represents that
new architecture.
cost-effectively for both cable service providers and consumers. However, increases
in channel offerings and higher-bandwidth programming content, such as high-
definition (HD) programming, have resulted in a greater demand for bandwidth.
This bandwidth demand cannot be readily satisfied by continuous access network
upgrades and rebuilds. It is no longer cost-effective to continuously increase
bandwidth for services with low viewership. Cable service providers have a need for
a new architecture that will reclaim wasted bandwidth and improve the subscriber's
experience without requiring endless bandwidth expansion. SDV represents that
new architecture.