  This paper proposes and investigates the concept of a safe carrier-sensing
range that can guarantee interference safe (also termed hidden-node-free)
transmissions in CSMA networks under the cumulative interference model.
Compared with the safe carrier-sensing range under the commonly assumed but
less realistic pairwise interference model, we show that the safe
carrier-sensing range required under the cumulative interference model is
larger by a constant multiplicative factor. The concept of a safe
carrier-sensing range, although amenable to elegant analytical results, is
inherently not compatible with the conventional power threshold carrier-sensing
mechanism (e.g., that used in IEEE 802.11). Specifically, the absolute power
sensed by a node in the conventional mechanism does not contain enough
information for it to derive its distances from other concurrent transmitter
nodes. We show that, fortunately, a carrier-sensing mechanism called
Incremental-Power Carrier-Sensing (IPCS) can realize the carrier-sensing range
concept in a simple way. Instead of monitoring the absolute detected power, the
IPCS mechanism monitors every increment in the detected power. This means that
IPCS can separate the detected power of every concurrent transmitter, and map
the power profile to the required distance information.
