Blog Date: 7/17/2013
Author: Ray Coulombe

One of the consistent trends we’ve seen in networking is the continuous increase in network speeds. In wired networks, more devices are appearing with 10 Gbps capability, while 40 Gbps and 100 Gbps equipment is on the horizon.
Wireless, too, has seen a migration in its transmission capabilities. In cellular data, most current devices are either 3G or 4G, with 5G imminent. (The “G” refers to the current generation of wireless technology employed.) Different vendors have various implementation solutions. It’s interesting to note that Samsung, in May, 2013, announced a key technical breakthrough in the use of millimeter-wave technology at 28 GHZ supporting their 5G approach, promising speeds in excess of 1 Gbps.
IEEE defines a family of wireless standards in the 802.11 family. We should all be familiar with 802.11 a, b, and g (most home routers support these) and possibly 802.11n. 802.11n upped the maximum bandwidth ante over 802.11g from 54 Mbps to 600 Mbps. It did so by providing for the use of multiple antennas using MIMO (multiple input, multiple output) technology. 802.11n operates at either 2.4 GHz or 5 GHz and provides approximate ranges of 230 ft. (indoors) and 820 ft. (Outdoors).The first generation of 802.11n devices that came to market a few years ago supported a maximum data rate of 300 Mbps by running two spatial streams. Each stream could carry 75 Mbps of data per 20 MHz of spectrum, over a double-wide 40-MHz channel. Newer devices, supporting 3 spatial streams, offer 450 Mbps capability. Common notation is a x b : c , where “a” is the maximum number of transmit antennas or TX RF chains that can be used by the radio; “b” is the radio’s maximum number of receive antennas or RX RF chains; and “c” is the maximum number of spatial streams. The maximum 600 Mbps can only be achieved with 4 spatial streams.
Fifth generation Wi-Fi, 802.11ac, can be thought of as an enhanced 802.11n, but operates only at 5 GHz. It increases the number of parallel spatial streams to 8, with the effect of significantly improved wireless network speeds. It is expected to help accommodate the need in an enterprise for increased bandwidth to deal with increasing numbers of smart devices (BYOD) and the growing use of video streaming. 802.11ac devices are expected to be dual-band, meaning that they can operate on both the 2.4GHz and 5GHz frequency bands. If such a device can’t connect at 5GHz using the 802.11ac protocol, it will attempt to drop back to 2.4GHz using 802.11n. Dual-band routers are capable of operating networks on both frequencies simultaneously, providing the ability to use different bands for different applications, e.g., 5 GHz band for media streaming and other high-performance applications. The Wi-Fi Alliance has initiated a certification program for routers, adapters, and other wireless networking gear based on the IEEE 802.11ac draft standard, where final ratification isn’t expected until February 2014. Industry analysts expect initial products to offer 433 - 1300 Mbps capability, followed by second generation products with configurations operating at up to 3.47 Gbps. Indoor distance capability will approach 300 feet.
Link to Complete Article as it appeared in Security Technology Executive Magazine

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