Compare different Link Systems
To compare different system means to search the most suitable solution. Each system has its advantages and disadvantages. To find the right solution, the following question should be asked.
|Different Wireless Technologies||Range|
|Bluetooth class 1 (100mW)||~100m|
|Bluetooth class 2 (2.5mW)||~20m|
|Bluetooth class 3 (1mW)||~10m|
|Ultra Low Power Bluetooth||< 10m|
|RFID||0cm - 10m|
|NFC||< 10 cm|
|Nanotron (10mW)||900 m (Outdoor), 60m (Indoor)|
|Cypress WirelessUSB||10m - 50m|
|ANT Networks||< 30m|
Data Transmission Rate
|Different Wireless Technologies||Data Transmission Rate (Brutto)|
|Bluetooth 1.1 und 1.2||723.2 kBit/s|
|Bluetooth 2.0||2.1 MBit/s|
|Bluetooth 3.0||480 MBit/s|
|Ultra Low Power Bluetooth||1 MBit/s|
|RFID Tag||10-100 Byte|
|RFID active Transponder||several kBit|
|WLAN a/h||54 MBit/s|
|WLAN b||11 MBit/s|
|WLAN g||54 MBit/s|
|Cypress WirelessUSB||62.5 kBit/s|
The table should only give a smart overview of the power consumptions. The highest in the table needs the most and the lowest the few energy.
|Hierarchy||Different Wireless Technologies||Example|
|5||ZigBee||Jennic JN5121 50mA, 400m|
|8, 9, 10||ANT, NFC, Ultra-Low-Power Bluetooth|
More and more companies produce products that use the 2.4-GHz portion of the radio spectrum. This leads to interferences under the devices. Different technologies like Bluetooth, ZigBee and WLAN are used. Each of them has its own range of application with its advantages and disadvantages.
The aim is to show how Bluetooth, ZigBee and WLAN minimize the interferences from other sources. This should only give a small overview. For more information look at the Link-List.
|Data Rate||Number of channels||Interference-Avoidance-Method||Minimum quiet Bandwidth required|
|WLAN 802.11||11 Mbps||13||Fixed channel collision avoidance (DSSS)||22 MHz (Static)|
|Bluetooth||723 Kbps||79||Adaptive frequency hoping (FHSS)||15 MHz (Dynamic)|
|WirelessUSB||62.5 Kbps||79||Frequency Agility||1 MHz (Dynamic)|
|ZigBee||250 Kbps||16||Frequency Agility||3 MHz (Dynamic)|
Fixed channel collision avoidance (DSSS)
(DSSS, direct-sequence spread spectrum)
The transmission is made on a selected channel. Collision are avoided by the CSMA/CA - Methode. The devices measure the radio-channel if there are some other transmissions. If not they send the data.
Adaptive frequency hopping (FHSS)
(FHSS, frequency-hopping spread spectrum)
The transmission is implemented on several frequencies. The different channels are selected randomly from the devices.
WirelessUSB and ZigBee uses DSSS instead of FHSS as Bluetooth. The devices are frequency agile, in other words, they use a “fixed” channel, but dynamically change channels if the link quality of the original channel becomes suboptimal.