Process for multiple access and multiple transmission of data point to multipoint over the electricity network, comprising various user kits (A, B, . . . X) and a head-end (1) in two way communication by means of the electricity network (2), where the upstream channel is that which runs from the user kits (A, B, . . . X) to the head-end (1) and the downstream channel that which runs from the head-end (1) to the user kits (A, B, . . . X), and each one of the kits (A, B, . . . X), (1) contains a medium access controller (MAC) (3,4) to maximize the quantity of information that the user kits (A, B, . . . X) can transmit and to minimize time latency in these kits (A, B, . . . X);
- and where the electricity network is divided for the upstream and downstream channels by frequency division duplexing (FDD) and/or time division duplexing (TDD), comprising:
- Accessing the medium by various user kits (A, B, . . . X) in the upstream channel and the simultaneous sending of various information links by the head-end (1) in the downstream channel by means of multiplexing OFDMA/TDMA/CDMA, multiplexing by orthogonal frequency division, multiplexing by time division and or multiplexing by code division;
- dynamically assigning each carrier in the OFDM system, multiplexing by orthogonal frequency division, to the user, and between the users with information to send at that moment with greater transmission capacity in this carrier, more bits per carrier or better signal-to-noise ratio, so as to maximize the transmission capacity in both the upstream and downstream channels, that is, to equalize or level the response in frequency observed by the head-end in both emission and in reception;
- adjusting quality of service (QoS) depending on the type of information and the users that require the transmission, where this quality of service is adaptable according to the frequency response at different moments and to the different distances between the user kits (A, B, . . . X) and head-end kit (1);
- dynamically assigning available bandwidth between the various communication requests by constantly calculating and monitoring the signal-to-noise ratio observed by the user kits (A, B, . . . X) and by the head-end kit (1) over the whole bandwidth of the system;
- so that transmission resources, this is the combined number of carriers in the system OFDM, are distributed according to the transmission needs at each moment in time for each user, the quality of service (QoS) parameters established for this user, the criteria to maximize the total capacity of the system and the criteria to minimize transmission latency, using for this the redistribution of the carriers of one symbol between the users (OFDMA), in time (TDMA), that is symbol to symbol, and by code (CDMA), optimising said redistribution by constant monitoring of the quality parameters for the electricity line, which vary constantly.