In some cases, such false reports
may incur disastrous results. For example, in sensor networks designed
for military tracking and reconnaissance surveillance, nodes are misled and
report themselves in faraway places. The false information may result in a
fatal decision-making, when sensors report that they are in a safe region [11].
Hence, it is important to assure that the received beaconing information is
true, or the resolved location is correct.
Sastryet al. [32] made the first attempt to solve the secure localization
problem in wireless sensor networks. A distance bounding protocol, ECHO,
is proposed to use both RF and ultrasound signals for secure location veri-
fication. However, such a scheme only works for in-region verification, which
means that ECHO only verifies whether or not a node is within a region of
interest. Besides, ECHO relies on the availability of both RF and ultrasound
signals.
Lazos and Poovendran propose a range-independent secure positioning
scheme, SeRLoc, in [22]. Using directional antennas, each beacon node transmits
di?®erent beacon signal at each antenna sector. Thus, if a sensor receives
a beacon from a specified antenna sector, the sensor must reside within that
sector. Based on the information received about the sector boundary lines
and the positions of the beacons, a sensor can identify the overlapping region
of all the sectors that it hears and estimate its location as the center of
gravity (CoG) of the region.
Pages:
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306