ITU-T Recommendations

ITU-T Recommendation G.9954 defines the PHY, MAC, LINK and CONVERGENCE protocol stack layers for the G.9954v2 system providing the following features:
• Operation over phoneline and/or over coax;
• PHY-layer payload transmission rates of 4 to 320 Mbit/s;
• Rate adaptive transceivers that optimize data rates and packet error rates for dynamically varying channel conditions on a per-packet basis;
• QAM modulation technique for communication over phone wire or coaxial cabling;
• Spectrum notching over phoneline for compatibility with amateur radio services;
• Synchronous MAC protocol controlled by a dynamically elected master employing a collision avoidance media access strategy;
• Support for constant and variable bit-rate data services;
• Peer-to-peer communication within a master-controlled network;
• Packet aggregation (packetization) performed within the G.9954v2 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/G.9952 in mode A over phoneline using G.9951/G.9952 asynchronous MAC protocol;
• Coexistence and interoperability between G.9954v1 and G.9954v2 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;
• Compatibility with other coaxial services such as VDSL, VDSL2 and cable-TV channels;
• Interoperability between phone and coax PHY layers using spectral modes A and B, thus allowing a mixed phoneline/coaxial network;
• Local and remote management of G.9954v2 devices;
• Provisions for future security extensions.