ABS and
AQS achieve good performance compared with other protocols because they can take
advantage of the identi?¬?cation information of the previous stage.
25
Zhen
Vogt1
Vogt2
Zhen
DFSA
QT
BT
AQS
ABS
DFSA
Zhen (quiet)
DFSA (quiet)
QT
BT
AQS
ABS
30 40
0
1
2
3
4
5
6
7
8
9
104
45 50 55 60 65
Interval (ms)
70 75 80 85 90 5 10 15
Interval (ms)
Number of identified tags
Number of identified tags
(a) (b)
20
5000
4000
3000
2000
1000
0
FIGURE 9.11
The number of identi?¬?ed tags and readable slots. (a) The number of identi?¬?ed tags. (b) The number of
readable slots.
Comparative Performance Analysis of Anticollision Protocols in RFID Networks 177
9.7 Discussions and Summary
RFID applications have various requirements. Mobility of tags is a key factor for branching
properties of RFID applications. Mobility of tags varies accordingly as what kinds of RFID
applications are employed. We divide RFID applications into two cases. The ?¬?rst one is the
case that has little mobility of tags. In these kinds of applications, the time for identifying
all tags in reader??™s range is a critical factor for evaluating performance of RFID tag
anticollision protocols. We ?¬?nd out that probabilistic and tree-based tag anticollision
protocols show similar ability in identifying tags. The second one is the case in which we
have to consider mobility of tags for performing identi?¬?cation operation.
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