Bench Talk

Wi-Fi, short for wireless fidelity, is a means by which computers, peripherals, mobile devices, and smart phones may connect to a local area network (LAN), enabling connection to the World Wide Web. The heart of a wireless network is the router, a hub to which all devices connect. Devices communicate with the wireless router by transmitting and receiving data via radio signals through one or more antennas. 

The radios used in wireless networks are like two-way communication devices, such as walkie-talkies or cell phones. Wi-Fi networks operate at frequencies of 2.4GHz or 5GHz, which are considerably higher than frequencies used by walkie-talkies or cell phones. The higher frequencies enable them to transmit and receive more data, although at a significantly shorter range. The lower frequency 2.4GHz routers have a range of about 46m indoors and 92m outdoors. The higher frequency 5GHz routers have a range that is one third that of the 2.4GHz routers; however, the 5GHz band is less cluttered and has a greater capacity to carry more data at a faster rate. Some wireless modems, termed “dual-band modems,” offer communications in both the 2.4GHz and 5GHz bands, which offer advantages of range and speed at both frequencies.

Wi-Fi networks operate in accordance with a family of IEEE 802.11 standards, which are created and managed by an organization known as the Wi-Fi^® Alliance, a worldwide network of companies that promote common standards for wireless Internet communications. These standards determine the range, speed, and communication protocols of a Wi-Fi network. Over the years, as wireless technology has evolved, so have the standards, hence the different letters after the 802.11 designation. A brief overview of these standards is provided below:

• 802.11a was the original Wi-Fi standard introduced in 1999, which transmits at 5GHz and can move data at rates up to 54Mbps. 802.11a was not widely adopted in consumer products because manufacturing delays in producing router components allowed the less-expensive 802.11b routers and devices to become widely adopted.
   
• 802.11b was created about the same time as 802.11a and is the slowest and least expensive standard. It was initially popular due to its low cost; however, it is now becoming less common because faster standards have become less expensive. 802.11b transmits in the 2.4GHz frequency band and can handle up to 11Mbps of data. In 2003, 802.11g was introduced, increasing data transfer rates up to 54Mbps. 802.11n was introduced in 2009, enabling operation at both 2.4GHz and 5GHz, with a maximum speed of 150Mbps. 802.11n allows the use of multiple-input multiple-output (MIMO) antennas for parallel throughput, which theoretically enables data transfer up to 450Mbps, depending on the number of antenna connections.
   
• 802.11ac was designed to dramatically increase the speed of data transfers, enabling speeds that can reach 7Gbps. This is accomplished by operating only within the 5GHz band, allowing the use of up to 32 MIMO antennas, and using beamforming technology. Beamforming minimizes phase errors in radio signals that may bounce off different surfaces, thereby enabling a stronger, more concentrated, and more stable signal. 802.11ac routers are backward compatible to older 802.11a and 802.11n Wi-Fi devices that operate at 5GHz. They can also connect to older 802.11b/g/n devices by incorporating dual-band radios capable of switching to 2.4GHz. 
   
• 802.11ad was developed to significantly increase speed by transmitting the signal at 60GHz, enabling speeds of about 7Gbps, which would permit them to be used with wireless hard drives. At the higher frequency, however, its range is limited to about 30ft (10m). 802.11ad devices would therefore be limited to use in a single room and would not be applicable for a whole house or office. 
   
• 802.11ax is an emerging standard that will allow routers and devices to transfer data at a rate that is from four to 10 times faster than existing Wi-Fi standards, using wider and multiple channels to greatly increase throughput. The difference between 802.11ax and previous Wi-Fi generations may not be very noticeable for a single user on a residential Wi-Fi, as the goal of 802.11ax was to increase the data rate in congested environments by a factor of four or more. The 802.11ax standard is expected to be available sometime during the 2019 calendar year.

The current trend is that more and more devices are becoming Wi-Fi compatible, going beyond computers, cell phones, and peripherals, toward appliances, home entertainment, automation and security systems, cloud-based computing, automobiles, and more. To meet these demands, we expect Wi-Fi technology to continue evolving, enabling faster transfer of larger amounts of data between an ever-increasing number of wireless devices.