Distribution networks are usually made of a variety of conductor types, and terminating into loads of different impedances, which also vary over time.
Such infrastructure results in a communication channel which has a time dependent amplitude and phase response that varies with frequency.
Interference and impulsive noise produced by motors, switching power supplies and halogen lamps reduces the reliability of communication signals.
[1] The PRIME physical layer is based on OFDM (Orthogonal Frequency Division Multiplexing) and Differential Phase Shift Keying (BPSK, DQPSK and D8PSK) as carrier modulation.
To address averse power line channel properties, robustness mechanism convolutional encoding (optional), scrambling and interleaving are used.
Originally, PRIME uses carrier frequencies (42 – 89 kHz) within the CENELEC A band and offers raw data rates between 5.4 kbit/s (Robust mode: DBPSK with convolutional encoding and repetition code) and 128.6 kbit/s (D8PSK).
Base nodes and switches announce their presence with beacon messages in well specified intervals.
PRIME makes use of address structure for packet routing, which reduces state information needed by service nodes.
The PRIME MAC layer includes control mechanism/messages to open and close unicast, multicast and broadcast connections.