Users to benefit from higher data rates, extended reach and backward compatibility with 802.11b, plus forward compatibility to 802.11a. In 2000 the market for wireless local-area networks (WLANs) grew with the introduction of new products complying with the 802.11a and 802.11b standards. These two standards are designed to mutually coexist, allowing both wireless networks to share the same airspace in a physical location. Both types of products are in general use today. The pending ratification of a third standard, 802.11g, will combine some of the features of both its predecessors. Although all three standards are able to operate in the same physical space, certain combinations provide advantages and perform better than others, due to inevitable interference in the frequency spectrum, and the techniques designed to deal with it. At present, 802.11a/b dual band WLANs offer the best and safest implementation based on performance, network capacity, and scalability. Customers will choose standards-based, interoperable solutions that will both protect their existing investment while enabling an upgrade path to high performance WLAN connectivity.
Prior to the recent selection of the IEEE 802.11g draft standard for wireless local area networks (WLANs) operating up to54 megabits per second (Mbps) in the 2.4 gigahertz (GHz) band, the market was served by two non-compatible specifications, 802.11b and 802.11a. Faced with market availability of both products in late 2001, some end users were potentially confused about which technology would evolve to meet their future needs, and some networking manufacturers were unsure about which specification would be best to direct their developmental efforts. There is much to be understood about the new 802.11g draft standard, including its history, specifications and implications in the WLAN market, but this much is certain: it combines the best of the existing 802.11b and 802.11a standards, and promises a harmonized future that will encourage continued and rapid market development in 802.11 WLANs. In addition, users will benefit from higher data rates, extended range and compatibility with already installed Wi-Fi? devices.
As one might guess, 802.11g is a third wireless standard related to 802.11a and 802.11b. The 802.11g standard, which is nearing ratification by the IEEE, can be considered a mixture of both existing standards. It will use the same 2.4-GHzradio spectrum as current 802.11b equipment, but with the higher data rates, packet structure, and modulation technology of 802.11a. As such, 802.11g is sometimes viewed as an upgrade path for existing 802.11b networks, although certain technical limitations may not ideally suit it for this role. All three wireless network standards, 802.11a, b, and g, can be used together in the same local installation. In some cases, total network throughput will increase as more client devices come on line. However, some combinations will actually reduce throughput because of interference between these technologies. The total performance of these networks is sometimes less than the sum of their parts. In brief, 802.11g will be a compatible faster alter-native to 802.11b. It achieves this by operating in the same 2.4-GHzfrequency band as 802.11b, but with the faster data rates of 802.11a devices. That means that 802.11b and 802.11gdevices will communicate on the same network. An 802.11b client can talk to an 802.11g access point, and vice versa. New 802.11g devices can be introduced into an existing 802.11b network at any time. In such cases, the newer 802.11gdevices will reduce their speed and act just like 802.11b devices transmitting at 11 Mbps. Part of the 802.11g standard defines the complex negotiations that allow these two wireless networks to operate together, but these details are handled automatically by the hardware and software/firmware.