The DSP, then, makes sure that
the appropriate demodulation scheme is available to demodulate the incoming signal. If
it does not have the appropriate demodulation scheme then, it raises an alarm, notifying
the operator. Or alternatively it can send a request to the host computer asking for the
latest demodulation scheme.
5.1.4.2 Peer to Peer Component Sharing
Tuttlebee (1998) describes Over-The-Air Recon?¬?guration (OTAR) for a software radio.
Using this concept, a remote device can be reprogrammed by the transfer of new software
into the device. Up to now, hardware restrictions have meant that OTAR has only been
used for one-off projects such as satellites.
Now, advances in hardware allow OTAR to be used in ad hoc networks. An ad hoc
network can be a connected set of RFID readers without any centralized or hierarchical
structure. In an ad hoc environment, readers might be communicating with tags using
many different protocols, modulation schemes, and location-speci?¬?c parameters. The
ability of nodes to share information about network conditions would be of key importance
to ensure reliable communication is happening.
In such a situation, readers can go beyond just sharing information by sharing their
network layer component as downloads. These network layers, for example, a new
demodulation scheme, can also be downloaded from a central computer.
Pages:
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202