CSCE 121 Culture Report 5

Gigabit Wi-Fi

Most of today's hottest electronic devices operate wirelessly: phones, laptops, home entertainment systems, video games, computer accessories, and even charging stations. However, wired connections have always been preferred over wireless connections because of their unmatched dependability and data transfer rate . . . until now.

IEEE Computer writer Steven Vaughan-Nichols explains that the IEEE has been working hard to improve the current Wi-Fi standards to support faster, more reliable, and farther-reaching wireless devices . The current, most widely supported wireless local area network (WLAN) protocol is 802.11. 802.11 has been updated three times since its first ratification in 1997: 802.11a, 802.11b, 802.11g, and—just ratified in 2009—802.11n. Previously, 802.11 only worked on a 2.4 GHz frequency (20 MHz bandwidth), which provided a maximum throughput of 54 Mbps. Although optionally available for previous versions, 802.11n has been modified to work better on a 5 GHz frequency (40 MHz bandwidth) and allow for a data rate up to 150 Mbps. This was not fast enough for some people, so IEEE entered the race to develop the first 1+ Gbps Wi-Fi standard.

When dealing with wireless transmissions, several problems arise that can corrupt data streams such as interference, resonance and echoes, and obstructions between transmitting and receiving antennae. Higher frequencies typically have shorter indoor ranges because they cannot easily transmit through walls. Even humidity droplets play a factor in wireless network stability.

802.11ac, 802.11ad, and WiGig, the projected candidates for gigabit standardization address all of the problems associated with wireless transmission and even have a few surprises: 802.11ac might include multiple-user, multiple-input, multiple-output (MU-MIMO) to boost its data rate. MU-MIMO is an improvement on the existing MIMO (currently used on 802.11n) that allows for simultaneous streams on one channel. MIMO exploits the problem with echoes and resonance to transmit different streams of data from different antennae that are slightly off-phase with each other. For example, without MIMO, a wireless device could transfer one packet of data at a time over a given channel; with MIMO, the same device could transfer several packets of data simultaneously over the same channel. The new gigabit standards will provide backward compatibility for legacy devices that do not have gigabit-capable chipsets.

802.11ad and WiGig would utilize a 60 GHz frequency instead of 5 GHz like 802.11ac and 802.11n. 60 GHz would have less interference with other devices, but would have an even shorter indoor range. To counter this side effect, 802.11ad and WiGig (and even 802.11ac) will attempt to focus their data stream onto the receiving antenna and prevent signal degradation.

I have mixed feelings about a faster Wi-Fi protocol: wireless technology is fascinating and has a lot of room for discovery and improvement, but 802.11n has only recently had time to propagate through the market and into people's homes and businesses. A new standard would not seem very practical at this point since most 802.11n devices are less than a year old. On the other hand, the newer technology has added perks such as HD audio/video streaming. A gigabit wireless network seems almost paradoxical: the speed of a wireless network would surpass the widely-accepted 100 Mbps wired ethernet network.