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IUH-F190-V1-*, IUT-F190-R4-V1*
Product Description
3.2.7
Frequency Hopping Spread Spectrum
With FHSS (Frequency Hopping Spread Spectrum), the information to be transmitted is
distributed successively through multiple channels. Only one frequency channel is used at any
one time. This results in a larger bandwidth for the entire signal, in spite of the fact that each
channel has a smaller bandwidth. In this section the channel assignment for China and the
USA is shown graphically. For both assignments, different parameters apply, such as channel
number and channel bandwidth. Different parameterizations apply in other countries.
China
In China, the frequency range 920 MHz ... 925 MHz is available for UHF-RFID read/write
heads. The range is split into channels, each with a bandwidth of 250 kHz. A maximum of 2
W
is permitted on 16 of the available channels. The transmission power is indicated in
ERP
W
. FHSS is used with a maximum retention time of two seconds. The UHF RFID read/write
ERP
head for China uses channel 2 to 17.
W
erp
2.0
0.1
0
920
Figure 3.2
United States
The ISM band from 902 MHz ... 928 MHz is available in the USA. The band is split into 50
channels, each with a 500 kHz bandwidth. FHSS with a maximum retention time of 0.4
seconds is used. All channels must be used. Channel restriction is not permitted.
In contrast to the read/write heads for Europe and China, the transmission power is indicated in
W
. A maximum of 4 W
eirp
W
eirp
4.0
0.2
1
902.75
Figure 3.3
16
1
2
3
4
5
6
7
920.625
is permitted on all channels.
eirp
5
10
15
20
8
9
10
11
12
13
14
25
30
35
15
16
17
18
19
Channel
924.375
925
MHz
Channel
40
45
50
927.25 MHz
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