  Direct detection of the Dark Ages and the Epoch of Reionization
  (EOR) is among the main scientific objectives of all current and future
low-frequency radio facilities. In this paper we summarize and discuss recent
results, based on state-of-the-art numerical simulations, regarding the
fundamental EOR properties and its observability with current and future radio
arrays, like the Giant Metrewave Radio Telescope (GMRT), the Low Frequency
Array (LOFAR), the 21-CM Array (21CMA), the Murchison Widefield Array (MWA) and
the Square Kilometre Array (SKA). Results show that the optimal observational
frequencies for statistical detection are 140-160 MHz. The signals are strongly
non-Gaussian at late times. The correlation widths between 21-cm maps at
neighbouring frequencies are short, of order 300-800 kHz, which should help
with the cleaning of the strong foregrounds. Direct comparison of the
resolutions and expected sensitivities of GMRT and MWA indicate that their
optimal sensitivity ranges are similar, at scales k~0.2-0.4 h/Mpc, however, all
else being equal the former should require shorter integration times due to its
significantly larger collecting area.
