Mobile communications for industrial applications - CERN

Wireless technologiesWireless networksBluetoothBluetooth is a Personal Area Network(PAN) and operates in the 2.4 GHz bandwith a data transfer rate of 1 Mbit/s.The range is limited to 10 m. This range,together with the limited data transferrate, mean that Bluetooth is currentlyonly suitable for industrial wirelessLANs to a very limited extent.Wireless LANWireless LAN (WLAN) is a local radionetwork operating in the 2.4 GHz frequencyband. WLAN products are basedon the IEEE 802.11b standard with datatransfer rates from 1 Mbit/s to 11 Mbit/s.The radio network is connected to alocal Ethernet network using WLANaccess points.The access points transmit informationwithin a radius of 30-300 m dependingon the building properties.Outside buildings, the transmissionranges can be significantly increasedusing dimensional antennae. WLANdoes not require a direct visible linkbetween the devices. Communicationslinks can be passed on from one accesspoint to the next (roaming). This meansthat even large ranges can be coveredusing WLAN.GSM, HSCSD, GPRS and UMTSThese networks were primarily developedfor mobile telephones. These networkstherefore enable connectionsextending beyond countries and continents.The differences to wireless LANs are thelower data transfer rate, and thatcharges are made for connections or thetransmitted data quantity.Fig. 14: Comparison between wired LAN and wireless LAN12