Summary

This Recommendation defines the PHY, MAC, LINK and CONVERGENCE protocol stack layers for the G.9954 system providing the following features:

������������ PHY-layer payload transmission rates of 4 to 240 Mbit/s;

������������ Rate adaptive transceivers that optimize data rates and packet error rates for dynamically varying channel conditions on a per-packet basis;

������������ Frequency Diverse QAM for robust communication over highly frequency-selective channels;

������������ Spectrum notching for compatibility with Amateur Radio services;

������������ Synchronous MAC protocol controlled by a dynamically elected master employing a combination of collision avoidance and controlled contention-based access strategies;

������������ Support for isochronous and asynchronous data services;

������������ Peer-to-peer communication within a master-controlled network;

������������ Master-less mode of operation using G.9951/2-like asynchronous MAC protocol;

������������ Packet aggregation (packetization) performed within the G.9954 protocol stack layer up to latency limits of the service flow and available transmission bandwidth;

������������ Quality of Service guarantees for bandwidth, jitter, latency and BER;

������������ QoS support for services with explicit traffic and rate specifications providing a link layer that is well suited for streaming audio and video;

������������ Protocol-specific convergence layers;

������������ Backward Compatible with G.9951/2, allowing transmissions at G.9951/2 compatibility mode rates;

������������ Coexistence and interoperability between G.9951/2 and G.9954 devices in a mixed network;

������������ Compatibility with other phoneline services such as POTS, V.90, ISDN and G.992.1, G.992.2, G.992.3, and G.992.4;

������������ Local and remote management of G.9954 devices;

������������ Provisions for future security extensions.