ITU-T Recommendations

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.