Deﬁnition: Wireless connections are network connections that transmit signals without using physical network media. Instead, signals are transmitted as electromagnetic energy, such as radio waves, satellite microwave, or infrared light. Most general office wireless implementations use radio. Wireless communication enables users to move around while remaining connected to the network.
Figure: Wireless connections.
Wireless Signal Strength
The ability to communicate via wireless network is highly dependent upon the local signal strength. Signal strength can vary in relation to a number of factors, including interference and distance from the Wireless Access Point. Most wireless devices will provide some kind of indicator regarding the strength of the current wireless signal.For example, in Windows, a wireless network card will display a message on screen when signal strength is low and connectivity is limited as a result.
802.11 Wireless Standards
The 802.11 standard is a family of speciﬁcations developed by the IEEE for wireless LAN technology.
802.11 Standard Description
802.11a: 802.11a is an approved speciﬁcation for a fast, secure, but relatively expensive wireless protocol. 802.11a supports speeds up to 54 Mbps in the 5 GHz frequency band. Unfortunately, that speed has a limited range of only 60 feet, which, depending on how you arrange your access points, could severely limit user mobility.
802.11b: 802.11b (also called Wi-Fi, short for “wireless ﬁdelity”) is probably the most common and certainly the least expensive wireless network protocol. 802.11b provides for an 11 Mbps transfer rate in the 2.4 GHz frequency. Some vendors have increased the rate on their devices. 802.11b has a range up to 1,000 feet in an open area, and a range of 200 to 400 feet in an enclosed space (where walls might hamper the signal). It is not compatible with 802.11a.
802.11e: 802.11e is a wireless standard for home and business implementations. It adds Quality of Service (QoS) features and multimedia support to 802.11a and 802.11b, and is compatible with those standards.
802.11g: 802.11g is a speciﬁcation for wireless data throughput at the rate of up to 54 Mbps in the 2.4 GHz band. It is compatible with 802.11b, and is replacing it due to its faster speed.
802.11n: 802.11n is a recent speciﬁcation for wireless data throughput. Even before approval, many “Draft N” or “Pre-N” products were already being produced and sold, compliant with the speciﬁcation. The speciﬁcation increased speeds dramatically, with data throughput up to 600 Mbps in the 2.4 GHz or 5 GHz ranges.