SummaryThis 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. |