Title: 3.1 History, Organizations, & Standards
Course: Information and Communication Technology: Module B > Section: Section 3 - Wireless Technology Basics

3.1.1 History

Wireless communications were used by the U.S. military during World War II with encryption. This gave field units the ability to update their status and receive new orders securely. Spread spectrum technology used today (patented in the 1940s by the actress Hedy Lamar) was not actually implemented until the 1960s by the U.S. military. It required the invention of the digital computer.

Wireless local area networks were conceived as early as the 1970s. The first one was developed in 1970 at the University of Hawaii. Named ALOHA-NET, it was used to wirelessly communicate between islands. The network implemented an OSI layer 2 protocol called ALOHA. ALOHA-NET used a shared wireless medium transmitting in the 400 MHz frequency range. It is considered a precursor of 802.3 Ethernet’s Carrier Sensed Multi-Access with Collision Detection (CSMA/CD) and 802.11’s Carrier Sensed Multi-Access with Collision Avoidance (CSMA/CA).

Various manufacturers began to create low-speed wireless networking products in the 1990s. These products operated in the 900 MHz frequency band. They were not successful due to a lack of standardization. In 1991, the Institute of Electrical and Electronics Engineers (IEEE) began to discuss the need to standardize these technologies so they could be used more reliably.

It took until 1997 for the IEEE to ratify the original 802.11 standard. This standard was low-speed, 1-2 Mbps, and was not widely adopted. An amendment to the standard known as 802.11b was ratified in 1999. The 802.11b standard has a maximum data rate of 11 Mbps and operates in the 2.4 GHz band. The typical indoor range is 30 m (100 ft) at 11 Mbit/s. This is the standard that launched the modern WLAN. Many of these early wireless products were sold for home networking applications. The technology then began to make its way into businesses and corporations.

3.1.2 History

The 802.11a amendment to the original standard was ratified in 1999. This standard uses the same core protocol as the original standard, but IT operates in the 5 GHz band and has a data rate of up to 54 Mbps. The actual throughput is closer to 22 Mbps.

Using the 5 GHz band gave 802.11a a significant advantage over 802.11b since its 2.4 GHz band was and is heavily used. The near absence of other interfering systems, like microwave ovens and cordless phones, gave 802.11a more bandwidth and reliability over 802.11b. The disadvantage is that the overall range of 802.11a is significantly less.

The 802.11g amendment came to consumers in 2003, but it was not ratified until 2007. Its raw throughput is closer to a true maximum of 54 Mbps but went back to using the 2.4 GHz band that was used by 802.11b. It also provides greater range than 802.11a. This specification, under the marketing name of Wi-Fi, has been implemented all over the world. It is backward compatible with 802.11b.

The 802.11n amendment standard improved network throughput over the two previous standards. It significantly increased the maximum data rate from 54 Mbps to 540 Mbps via wider channel bandwidth. It uses the 2.4 GHz band and the 5 GHz band. Using both is known as Dual Band. 802.11n standardized support for multiple-input multiple-output (MIMO), frame aggregation, and security improvement features.

The 802.11ac amendment is expected to become a standard in 2013. It will provide a maximum data rate of 1 gigabit per second (Gbps) and will work in the 5 GHz band. Devices will extend the concepts of 802.11n: wider RF bandwidth, more MIMO spatial streams, multi-user MIMO, and high-density modulation.

The 802.11ad standard is currently being developed and will be available soon. It will use a new 60 GHz band and will achieve a theoretical maximum throughput of up to 7 Gbps.

3.1.3 Organizations

In the United States, the Federal Communications Commission (FCC) is responsible for regulating licensed and unlicensed communications, including wireless communications. Regulations typically cover topics like frequency, bandwidth, maximum power, indoor and outdoor usage.

Globally, the International Telecommunication Union (ITU) is an organization tasked by the United Nations with managing the global radio frequency spectrum. Even with this international management, each region has different RF regulations. The allocation of RF spectrum varies from the United States, Europe, and Asia.

The Industry of Electronic and Electrical Engineers (IEEE) is a global professional society whose mission is to “foster technological innovation and excellence for the benefit of humanity.” The IEEE has created a variety of communication standards, including the IEEE 802 LAN standards and the IEEE 802.11 wireless standards.

The International Organization for Standardization (ISO) is a global, non-governmental organization focused on identifying business, government, and societal needs and then developing standards that adequately address those needs. The ISO is responsible for the creation of the widely-used Open System Interconnection (OSI) 7-layer model we have already discussed.

Most people associate the term WiFi with WLANs and incorrectly attribute it to mean "wireless fidelity." Wi-Fi is a brand name developed by the Wi-Fi Alliance as a means of standardizing 802.11 devices and ensuring interoperability between vendors. The Wi-Fi Alliance tests and certifies products. Products that are Wi-Fi certified are interoperable.