  Devices in a beacon-enabled network use slotted CSMA/CA to contend for
channel usage. Each node in the network competes for the channels when ready to
transmit data. The slotted CSMA/CA mechanism based on the super-frame structure
fairly provides communication chance for each node and makes a reasonable usage
of the available energy in beacon-enabled Zigbee networks. When wireless
nano-sensor nodes are implanted into the target human body area for detecting
disease symptoms or virus existence, each node also requires a similar
characteristic in channel sharing and in the transmission of event-driven data
with a short length. In this paper, we suggest a wireless network model with
nano-sensor nodes for the in-body application. We propose a novel MAC protocol
derived from an existing Zigbee MAC protocol scheme and analyze the performance
of energy usage with variable super-frame durations and packet sizes.
