GSM (Global System for Mobile communication)

Wireless World

GSM (Global System for Mobile communication)

GSM (Global System for Mobile communication) is a digital mobile telephony system that is widely used in Europe and other parts of the world. GSM uses a variation of time division multiple access (TDMA) and is the most widely used of the three digital wireless telephony technologies (TDMA, GSM, and CDMA). GSM digitizes and compresses data, then sends it down a channel with two other streams of user data, each in its own time slot. It operates at either the 900 MHz or 1800 MHz frequency band.Where these bands were already allocated, the 850 MHz and 1900 MHz bands were used instead (for example in Canada and the United States). In rare cases the 400 and 450 MHz frequency bands are assigned in some countries because they were previously used for first-generation systems.The transmission power in the handset is limited to a maximum of 2 watts in GSM 850/900 and 1 watt in GSM 1800/1900.

 

wireless-world

                                    1.Bluetooth

                                     2.Wi-Fi (Wireless Fidelity)

                                      3.Infrared

                                       4.Wi-max, WLANS, WPANS, WMANS, WWMANS

                                        5.GSM

                                         6.3g

                                          7.4g

                                           8.GPRS

                                            9.CDMA

                                            10.EVDO

                                             11.UMTS and HSDP

WHAT IS WiMAX?(Worldwide Interoperability for Microwave Access), WLANS, WPANS, WMANS, WWMAS.

           Wireless World 
WHAT IS WiMAX?(Worldwide Interoperability for Microwave Access), WLANS, WPANS, WMANS, WWMAS. 

WiMAX is an IP based, wireless broadband access technology that provides performance similar to 802.11/Wi-Fi networks with the coverage and QOS (quality of service) of cellular networks. WiMAX is also an acronym meaning "Worldwide Interoperability for Microwave Access (WiMAX).  

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. In contrast, the WiFi/802.11 wireless local area network standard is limited in most cases to only 100 - 300 feet (30 - 100m).
WiMAX would operate similar to WiFi but at higher speeds over greater distances and for a greater number of users. WiMAX has the ability to provide service even in areas that are difficult for wired infrastructure to reach and the ability to overcome the physical limitations of traditional wired infrastructure.
WiMAX was formed in April 2001, in anticipation of the publication of the original 10-66 GHz IEEE 802.16 specifications. WiMAX is to 802.16 as the WiFi Alliance is to 802.11.
 WiMAX, WiFi-like data rates are easily supported, but the issue of interference is lessened. WiMAX operates on both licensed and non-licensed frequencies, providing a regulated environment and viable economic model for wireless carriers. 
At its heart, however, WiMAX is a standards initiative. Its purpose is to ensure that the broadband wireless radios manufactured for customer use interoperate from vendor to vendor. The primary advantages of the WiMAX standard are to enable the adoption of advanced radio features in a uniform fashion and reduce costs for all of the radios made by companies, who are part of the WiMAX Forum - a standards body formed to ensure interoperability via testing. The more recent Long Term Evolution (LTE) standard is a similar term describing a parallel technology to WiMAX that is being developed by vendors and carriers as a counterpoint to WiMAX.

WiMAX is:

• Acronym for Worldwide Interoperability for Microwave Access.
• Based on Wireless MAN technology.
• A wireless technology optimized for the delivery of IP centric services over a wide area.
• A scaleable wireless platform for constructing alternative and complementary broadband networks.
• A certification that denotes interoperability of equipment built to the IEEE 802.16 or compatible standard. The IEEE 802.16 Working Group develops standards that address two types of usage models:
  
  • A fixed usage model (IEEE 802.16-2004).
  • A portable usage model (IEEE 802.16e).
  WLANS: Wireless Local Area NetworksWLANS allow users in a local area, such as a university campus or library, to form a network or gain access to the internet. A temporary network can be formed by a small number of users without the need of an access point; given that they do not need access to network resources.
  WPANS: Wireless Personal Area Networks
  The two current technologies for wireless personal area networks are Infra Red (IR) and Bluetooth (IEEE 802.15). These will allow the connectivity of personal devices within an area of about 30 feet. However, IR requires a direct line of site and the range is less.
  WMANS: Wireless Metropolitan Area Networks
  This technology allows the connection of multiple networks in a metropolitan area such as different buildings in a city, which can be an alternative or backup to laying copper or fiber cabling.
  WWANS: Wireless Wide Area Networks
  These types of networks can be maintained over large areas, such as cities or countries, via multiple satellite systems or antenna sites looked after by an ISP. These types of systems are referred to as 2G (2nd Generation) systems.
  

      Wireless World

  1.Bluetooth

    2.Wi-Fi (Wireless Fidelity)

     3.Infrared

      4.Wi-max, WLANS, WPANS, WMANS, WWMANS

          5.GSM

            6.3g

             7.4g

              8.GPRS

                9.CDMA

                   10.EVDO

                     11.UMTS and HSDPA