We present the \emph{discrete beeping} communication model, which assumes
nodes have minimal knowledge about their environment and severely limited
communication capabilities. Specifically, nodes have no information regarding
the local or global structure of the network, don't have access to synchronized
clocks and are woken up by an adversary. Moreover, instead on communicating
through messages they rely solely on carrier sensing to exchange information.
We study the problem of \emph{interval coloring}, a variant of vertex coloring
specially suited for the studied beeping model. Given a set of resources, the
goal of interval coloring is to assign every node a large contiguous fraction
of the resources, such that neighboring nodes share no resources. To highlight
the importance of the discreteness of the model, we contrast it against a
continuous variant described in [17]. We present an O(1timealgorithmthatterminateswithprobability1andassignsanintervalofsize\Omega(T/\Delta)thatrepeatseveryTtimeunitstoeverynodeofthenetwork.ThisimprovesanO(\log n)timealgorithmwiththesameguaranteespresentedin\citeinfocom09,andaccentuatestheunrealisticassumptionsofthecontinuousmodel.Underthemorerealisticdiscretemodel,wepresentaLasVegasalgorithmthatsolves\Omega(T/\Delta)−intervalcoloringinO(\log n)timewithhighprobabilityanddescribehowtoadaptthealgorithmfordynamicnetworkswherenodesmayjoinorleave.Forconstantdegreegraphsweprovealowerboundof\Omega(\log n)onthetimerequiredtosolveintervalcoloringforthismodelagainstrandomizedalgorithms.Thislowerboundimpliesthatouralgorithmisasymptoticallyoptimalforconstantdegreegraphs.