Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Near-Optimal Radio Use For Wireless Network Synchronization   We consider the model of communication where wireless devices can either
switch their radios off to save energy, or switch their radios on and engage in
communication. We distill a clean theoretical formulation of this problem of
minimizing radio use and present near-optimal solutions. Our base model ignores
issues of communication interference, although we also extend the model to
handle this requirement. We assume that nodes intend to communicate
periodically, or according to some time-based schedule. Clearly, perfectly
synchronized devices could switch their radios on for exactly the minimum
periods required by their joint schedules. The main challenge in the deployment
of wireless networks is to synchronize the devices' schedules, given that their
initial schedules may be offset relative to one another (even if their clocks
run at the same speed). We significantly improve previous results, and show
optimal use of the radio for two processors and near-optimal use of the radio
for synchronization of an arbitrary number of processors. In particular, for
two processors we prove deterministically matching $\Theta(\sqrt{n})$ upper and
lower bounds on the number of times the radio has to be on, where $n$ is the
discretized uncertainty period of the clock shift between the two processors.
(In contrast, all previous results for two processors are randomized.) For
$m=n^\beta$ processors (for any $\beta < 1$) we prove $\Omega(n^{(1-\beta)/2})$
is the lower bound on the number of times the radio has to be switched on (per
processor), and show a nearly matching (in terms of the radio use)
$\~{O}(n^{(1-\beta)/2})$ randomized upper bound per processor, with failure
probability exponentially close to 0. For $\beta \geq 1$ our algorithm runs
with at most $poly-log(n)$ radio invocations per processor. Our bounds also
hold in a radio-broadcast model where interference must be taken into account.

20
The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn
7
The categories of this paper are: hep-th
3
The categories of this paper are: physics
2
The categories of this paper are: math
13
The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc
16
The categories of this paper are: stat
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
36
The categories of this paper are: cmp-lg
4
The categories of this paper are: cond-mat
0
The categories of this paper are: hep-ph
8
The categories of this paper are: hep-ex