Communication channel capacity for the
residential power lines within multiple-dwelling units (MDU's) is
evaluated to check for the potential use of power grid in shared
broadband access. Several measurements of noise and
attenuation in the HomePlug band (2 MHz-30 MHz) on actual
MDU power grids are measured. Two different grid topologies
are considered: Star and bus, which are the foremost grid
topologies of buildings in urban, suburban and rural areas. Both
in-phase and across-phase performance are measured. The
individual effect of electricity meters inherently present across
flat-to-flat path is also evaluated. An MDU emulator has been
built using meters only to measure the end-to-end frequency
response of different meter types without cables. Finally, the
obtained results are used to calculate the theoretical channel
capacity for the different configurations of MDU grid with and
without the effect of meters. The capacity of power line at all test locations selected is
found far above the targeted data rates for broadband
distribution and sharing. Capacity in the range of 300 - 400 Mbps
is common in MDU's with 2-3 floors span between transmitting
and receiving nodes, which implies a total span of 5-6 floors when
selecting the position of internet gateway carefully. It is also
proved that the decrease in link capacity due to the existence of 2
electricity meters in between sender and receiver has an average
value of 14 %, while the effect of normal cable distance within
home could reduce link capacity by more than 35%. |
