On the Performance Modelling and Optimisation of DOCSIS HFC Networks
نویسندگان
چکیده
The DOCSIS protocol defines the MAC and physical layer operations governing two-way transmission of voice, video and multimedia data over HFC cable networks, thus constituting a complex system with many interdependent parameters. This tutorial employs simulation and analytic methodologies for the performance modelling and optimisation of DOCSIS 1.1/2.0 HFC networks with particular focus on the contention resolution algorithm, upstream bandwidth allocation strategies, flow-priority scheduling disciplines, QoS provisioning and TCP applications. In this context two performance evaluation case studies are reviewed in detail based respectively on two open queueing network models of DOCSIS 1.1/2.0 HFC networks. The first study evaluates, via ‘ns’ simulation, the effect of carrying TCP/IP traffic on network performance whilst the second optimises analytically the upstream network bandwidth allocation. It is expected that many of the performance affecting operational behaviours exhibited by former releases of DOCSIS-based HFC networks will also exist under the latest DOCSIS 3.0 protocol and future extensions.
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