Friday, 18 July 2014 08:03




Wi-Fi is a mechanism for wirelessly connecting electronic devices. A device such as a personal computer, video game console, smart phone, or digital audio player, when enabled with Wi-Fi, can connect to the Internet via a wireless network access point.

Wi-Fi works with no physical wired connection. It uses radio frequency (RF) technology, RF being a frequency within the electromagnetic spectrum associated with radio wave propagation. When an RF current is supplied to an antenna, an electromagnetic field is created that propagates through the space. The cornerstone of any wireless network is an access point (AP). The primary job of an access point is to broadcast a wireless signal that computers can detect and "tune" into. In order to connect to an access point and join a wireless network, computers and devices must be equipped with wireless network adapters.

Wi-Fi  is supported by many applications and devices including video game consoles, home networks, PDAs, mobile phones, major operating systems, and other types of consumer electronics. The circumference, where wireless technology is present and available to the users, is known as Hot Spot.

Wi-Fi allows cheaper deployment of local Area Networks (LANs). Products designated as "Wi-Fi Certified" by the Wi-Fi Alliance are backward compatible. Unlike mobile phones, any standard Wi-Fi device will work anywhere in the world.

WiMax technology

WiMax (Worldwide Interoperability for Microwave Access) is a wireless broadband technology, which supports point to multi-point (PMP) broadband wireless access.

WiMax is a wireless digital communications system, also known as IEEE 802.16, that is intended for wireless "metropolitan area networks". WiMax can provide Broadband Wireless Access (BWA) up to 30 miles (50 km) for fixed stations, and 3 - 10 miles (5 - 15 km) for mobile stations.

Uses of WiMax technology are:

* Providing portable mobile broadband connectivity across cities and countries through a variety of devices.

* Providing a wireless alternative to cable and DSL for "last mile" broadband access.

* Providing data, telecommunications (VoIP) and IPTV services (triple play).

* Providing a source of Internet connectivity as part of a business continuity plan.

Comparison between WiMAX and Wi-Fi

• WiMAX is a long range system, covering many kilometres that uses licensed or unlicensed spectrum to deliver connection to a network whereas Wi-Fi uses unlicensed spectrum to provide access to a local network.

• Wi-Fi runs on the Media Access Control's CSMA/CA protocol, which is connectionless and contention based, whereas WiMAX runs on a connection-oriented MAC.

• WiMAX uses a QoS (Quality of Service) mechanism based on connections between the base station and the user device. Each connection is based on specific scheduling algorithms whereas Wi-Fi uses contention access in which all subscriber stations that wish to pass data through a wireless access point (AP) are competing for the AP's attention on a random interruption basis. This can cause subscriber stations distant from the AP to be repeatedly interrupted by closer stations, greatly reducing their throughput.

Although Wi-Fi and WiMAX are designed for different situations, they are complementary. WiMAX network operators typically provide a WiMAX Subscriber Unit which connects to the metropolitan WiMAX network and provides Wi-Fi within the home or business for local devices (e.g., Laptops, Wi-Fi Handsets, smart phones) for connectivity. This enables the user to place the WiMAX Subscriber Unit in the best reception area (such as a window), and still be able to use the WiMAX network from any place within their residence.