A wireless local area network is computer network that requires no physical links, in the forms of cables, to bring together a number of connected devices. Using a wireless distribution method, such as WiFi, they are designed for local installations only, for example within the limited area of an office, home, school or assembly line. In industrial communications, WLAN is frequently used as a communication medium for machinery and telemetry devices as well as connecting things such as computer terminals. For example, robots using a consumable can use it to report to operatives elsewhere on a production line that they require replenishing, given the right sort of software. The majority of today's WLAN set ups are based on IEEE 802.11 standards and many of them can connect to one another, if required via the internet through router technology. All sorts of WLAN products now exist to provide this sort of wireless communication. For instance, WLAN modules are produced which can be fitted to computerised equipment, thus allowing it to talk to a server or central database without a wired connection. In addition, WLAN aerials, such as WiFi antennae, are produced which offer improved ranges for modules and base units. The amplification offered by a WLAN module is an important factor when choosing one for a given location and this is commonly rated by manufacturers as its dBi level.