  We propose a protocol (called RBO) for broadcasting long streams of
single-packet messages over radio channel for tiny, battery powered, receivers.
The messages are labeled by the keys from some linearly ordered set. The sender
repeatedly broadcasts a sequence of many (possibly millions) of messages, while
each receiver is interested in reception of a message with a specified key
within this sequence. The transmission is arranged so that the receiver can
wake up in arbitrary moment and find the nearest transmission of its searched
message. Even if it does not know the position of the message in the sequence,
it needs only to receive a small number of (the headers of) other messages to
locate it properly. Thus it can save energy by keeping the radio switched off
most of the time. We show that bit-reversal permutation has "recursive
bisection properties" and, as a consequence, RBO can be implemented very
efficiently with only constant number of $\log_2 n$-bit variables, where $n$ is
the total number of messages in the sequence. The total number of the required
receptions is at most $2\log_2 n +2$ in the model with perfect synchronization.
The basic procedure of RBO (computation of the time slot for the next required
reception) requires only $O(\log^3 n)$ bit-wise operations. We propose
implementation mechanisms for realistic model (with imperfect synchronization),
for operating systems (such as e.g. TinyOS).
