User Manual

RK-5409-5 Reference Kit User’s Guide Glossary-1
Glossary
API Application Programming Interface: A set of definitions of the ways in which
one piece of computer software communicates with another. It is a method of
achieving abstraction, usually (but not necessarily) between lower-level and
higher-level software. One of the primary purposes of an API is to provide a set
of commonly used functions-for example, to poll a wireless network for active
network nodes (mesh nodes and end nodes). Programmers can then take
advantage of the API by making use of its functionality, saving them the task of
programming everything from scratch. APIs themselves are abstract: software
that provides a certain API is often called the implementation of that API.
ad hoc network A group of wireless sensors connected as an independent wireless network,
communicating directly with each other without the use of a mesh node.
bandwidth The amount of data that can be transmitted in a fixed amount of time. For
digital devices, the bandwidth is usually expressed in bits per second (bps) or
bytes per second. For analog devices, the bandwidth is expressed in cycles per
second, or Hertz (Hz).
data model As it pertains to wireless sensor networks, the data model characterizes and
describes the way in which data flows through and is used in the network.
Common data model categories include data collection models (periodic
sampling, event driven, and store and forward) and bi-directional dialogue data
models (polling and on demand).
DSSS Direct Sequence Spread Spectrum: Spread spectrum method of spreading a
narrow band signal. This method uses special pseudo noise codes to expand the
narrow band signal out across a broad portion of the radio band. (See also FHSS
and spread spectrum.)
duty cycle The duty cycle of a module refers to the percentage of time the module is active
versus inactive.
end node The network module that provides the physical interface between the wireless
sensor network and the sensor or actuator that it is wired to. Sometimes called a
Reduced Function Device (see RFD).
endpoint See end node.
FFD Full Function Device: A term referring to a device that can act as an intermediate
mesh node, passing data from other devices. (See also RFD.)