A method, comprising: receiving a plurality of communications signals over a plurality of different communications channels via a power line communication network, each of the communications signals having a symbol period over which a symbol is transmitted, and the plurality of communication signals including: first communications signals received over a first communications channel, the first communications signals having a first symbol period; and second communications signals received over a second communications channel, which is different than the first communications channel, the second communications signals having a second symbol period that is different than the first symbol period; for each communications channel (208a; 208b), determining respective symbol period end times (210b-1 to 210b-3; 210a) for the communications signals received over the communications channels, the symbol period end time being determined based on the respective symbol period for the communications signals received over the communications channel and a reference time; determining that a present time is coincident with an end of a sample period (206a; 206b; 206c) for the communications signals, the sample period being a period that does not exceed a minimum symbol period for the communications signals; determining that an end of the symbol period for the communications signals being received over at least one of the communications channels (208a, 208b) is coincident with the present time; and providing data representing a symbol received over each communications channel for which an end of the symbol period is coincident with the present time, the data being indicative of a measurement or a magnitude of energy accumulated from each of the communications channels for which the end of the symbol period is coincident with the present time and being accumulated at different times over a respective one or more sample periods until an end of a present sample period is coincident with an end of the respective symbol period spanning the one or more sample periods. receiving a plurality of communications signals over a plurality of different communications channels via a power line communication network, each of the communications signals having a symbol period over which a symbol is transmitted, and the plurality of communication signals including: first communications signals received over a first communications channel, the first communications signals having a first symbol period; and second communications signals received over a second communications channel, which is different than the first communications channel, the second communications signals having a second symbol period that is different than the first symbol period; first communications signals received over a first communications channel, the first communications signals having a first symbol period; and second communications signals received over a second communications channel, which is different than the first communications channel, the second communications signals having a second symbol period that is different than the first symbol period; for each communications channel (208a; 208b), determining respective symbol period end times (210b-1 to 210b-3; 210a) for the communications signals received over the communications channels, the symbol period end time being determined based on the respective symbol period for the communications signals received over the communications channel and a reference time; determining that a present time is coincident with an end of a sample period (206a; 206b; 206c) for the communications signals, the sample period being a period that does not exceed a minimum symbol period for the communications signals; determining that an end of the symbol period for the communications signals being received over at least one of the communications channels (208a, 208b) is coincident with the present time; and providing data representing a symbol received over each communications channel for which an end of the symbol period is coincident with the present time, the data being indicative of a measurement or a magnitude of energy accumulated from each of the communications channels for which the end of the symbol period is coincident with the present time and being accumulated at different times over a respective one or more sample periods until an end of a present sample period is coincident with an end of the respective symbol period spanning the one or more sample periods.