Appeal No. 1998-0219 Page 10
Application No. 08/265,000
We appreciate the examiner’s observation that even a
slight difference in the propagation delays seen by the second
interrogation unit 16 and the additional interrogation units
16a could allow the units to begin their respective
transmissions at different times. The examiner does not show,
however, that beginning transmissions at different times
ensures that each of
the interrogation units would be allowed to complete its
transmission without any of the other units beginning to
transmit.
To the contrary, the carrier sense multiple access (CSMA)
protocol, used by the interrogator units and referenced by the
examiner, is subject to simultaneous transmissions.
Specifically, “it may happen that two or more stations attempt
to transmit at about the same time. If this happens, there
will be a collision.” William Stallings, Data and Computer
Communications 303 (2d ed. 1988) (copy attached). The 1
1The ALOHA protocol is also subject to simultaneous
transmissions. See Stallings at 296 (copy attached)(“The
packet may be invalid ... because another station transmitted
a frame at about the same time.”)
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