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Wi Fi (Wireless Fidelity)

WiFi stands for “wireless fidelity” and is a popular technology being used by homes, workplaces, mobiles and computer systems world-wide.

The unique feature of WiFi is that it uses two technologies simultaneously:

  • Single carrier direct-sequence spread spectrum radio technology
  • Multi-carrier OFDM (Orthogonal Frequency Division Multiplexing) radio technology

Why do We Need WiFi?

  • To facilitate convenient access to information
  • To eliminate the need for wires and cables in order to access data and media.
  • To aid compatibility and connectivity between different systems in the network
  • To eliminate the need for other paraphernalia like switchboards, adapters and plugs that clutter up the work station.

What can WiFi do?

Access to internet is possible with any WiFi enabled device such as:

  • Personal Computer
  • Laptop
  • Cellular Phone
  • PDA
  • Game Console
  • MP3 Player

“Hot Spots” or wireless access points may be:

  • Limited to a single small area
  • Cover a large area as a mesh network made up of several overlapping access points
  • Provide free internet access
  • Require a paid membership

Where can WiFi be used?

WiFi Hot Spots can be made available in the following set-ups:

  • Home
  • Office
  • Airports
  • Hotels
  • Railway stations
  • Restaurants

Benefits of WiFi

  • In wireless ad-hoc network mode, devices like consumer electronics and gaming applications can directly connect and exchange data with each other.
  • Digital images can be transferred wirelessly from cameras and other devices.
  • All connected devices within the range have access to internet and inter-networking.
  • Wi-Fi enables wireless voice-applications (VoWLAN or WVOIP)
  • WiFi provides a secure computer networking gateway, firewall, DHCP server and an intrusion detection system among many other features.
  • Cost of cabling and network deployment of Local Area Networks is significantly reduced.
  • Can be used at placed where wiring and cable lay-out is not feasible.
  • Due to its cost effective nature, it can be used widely in corporate set-ups and university campuses.
  • A standard WiFi (wireless fidelity)device can function in any geographical location.
  • Latest service protocols like WPA2 encryption and WMM enhance the security parameters and make WiFi more adaptable to latency-sensitive applications.
  • WMM also enhances the battery efficiency and optimizes power consumption.

Limitations

Like any othet piece of technology, WiFi (wireless fidelity) too has its set of drawbacks that are listed as follows:

  • Global inconsistency of spectrum assignments and operational limitations.
  • Overlapping of channels.
  • Limited range of Equivalent Isotropically radiated power in some areas.
  • Greater power consumption compared to lower bandwidth standards.
  • Limited battery life due to range and reach requirements.
  • WiFi network range is also limited.
  • At constant radiation levels, the signal strength decreases with range expansion.

Security and Privacy

  • WiFi networks are typically “open” or un-encrypted as a default setting.
  • In order to secure a WiFi, network, the device must be configured using a Graphical User Interface or GUI.
  • Un-encrypted networks are freely accessible and any data can be accessed through these.

Parts of a Standard WiFi device

  • Wireless access points: establishes a link between wireless devices and LAN and facilitates relaying of information.
  • Wireless adapters allow devices to connect to a wireless network mediums like PCI, miniPCI, USB, ExpressCard, Cardbus and PC card. They may be external or internal..
  • Wireless routers establish a connection between wired and wireless ethernet LAN and a WAN device such as cable modem or DSL modem.
  • Wireless network bridges connect a wired network to a wireless network or use a wireless link to connect two wired networks.
  • Wireless range extenders or wireless repeaters enhance the range of an existing wireless network by expanding a signal area or maneuvering signals around physical obstacles.

Scope of WiFi

  • Can be implemented in remote monitoring systems like telemedicine and security systems.
  • Latest embedded WiFi  models are equipped with real time operating systems that enable communication via serial ports.
  • Facilitates transfer of real time data over the internet to anywhere in the world- a facility that can have a vast utility in the medical and research field.
  • Simplicity of design make the devices user-friendly
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