Omega Vehicle Security zSeries Manuel D’Utilisation
5.5 Fine Adjustment in Performance
1. To avoid interference from WiFi / IEEE 802.11, one could consult the figure below to
1. To avoid interference from WiFi / IEEE 802.11, one could consult the figure below to
choose the best channel through the Configuration webpage. In all, channels 15, 20,
25 and 26 are not overlapping with any WiFi / IEEE 802.11 bands in the United States
while channels 15, 16, 21 and 22 can be used in Europe.
25 and 26 are not overlapping with any WiFi / IEEE 802.11 bands in the United States
while channels 15, 16, 21 and 22 can be used in Europe.
Figure 5.4 Channels
2. It is possible that IEEE 802.15.4 devices experience interference from Wi-Fi / IEEE
802.11 and Bluetooth devices and certain microwave ovens. Therefore, it is worth
locating nodes as far as possible to minimize effect. Note that international radio
regulations which govern radio equipment ensure that cell phones use their allocated
band only. It is highly unlikely that cell phones will interfere with IEEE 802.15.4
equipment.
locating nodes as far as possible to minimize effect. Note that international radio
regulations which govern radio equipment ensure that cell phones use their allocated
band only. It is highly unlikely that cell phones will interfere with IEEE 802.15.4
equipment.
3. In some cases, a short RF cable may be used to connect an antenna to your device.
Please note that RF extension cables will always add some loss to the transmitting
signal strength. The longer the cable the more signal will be lost over that cable.
Therefore, the length of the cable should be kept as short as possible. Also, note that
use of any other antenna other then what’s shipped with your device will void FCC
and CE regulatory complicance.
signal strength. The longer the cable the more signal will be lost over that cable.
Therefore, the length of the cable should be kept as short as possible. Also, note that
use of any other antenna other then what’s shipped with your device will void FCC
and CE regulatory complicance.
4. To achieve satisfactory IEEE 802.15.4 performance in the presence of WLAN
interference, a channel center-frequency offset of 7 MHz is recommended.
5. For co-channel operation, a physical separation from the WLAN Access Point (AP) of
26.2’ (8 m) is recommended to achieve a Packet Error Rate (PER) of 1%. For a
particularly saturated WLAN link, 29.5’ to 32.8’ (9 to 10 m) may be necessary.
particularly saturated WLAN link, 29.5’ to 32.8’ (9 to 10 m) may be necessary.
6. To achieve satisfactory IEEE 802.15.4 performance in the presence of Bluetooth
interference, a separation distance of 6.5 ‘ (2 m) is recommended.
US WLAN
(IEEE 802.11B)
non-overlapping
(IEEE 802.11B)
non-overlapping
European WLAN
(IEEE 802.11B)
non-overlapping
(IEEE 802.11B)
non-overlapping
IEEE 802.15.4
2400 MHz PHY
2400 MHz PHY
Channel
1
11
6
1
13
7
Channel
Channel
2400 MHz
2483.5 MHz
2412
2437
2462
2400 MHz
2483.5 MHz
2400 MHz
2483.5 MHz
2412
2442
2472
22 MHz
2 MHz
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
2405
2410
2415
2420
2425
2430
2435
2440
2445
2450
2455
2460
2465
2470
2475
2480
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