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Saturday, December 12, 2015

What is Li-Fi?


Yes, it's time to shift from Wi-Fi to Li-Fi , an alternative technology that is 100 times faster than the average speeds of Wi-Fi. Scientists have just field-tested the new wireless technology called Li-Fi [Light Fidelity] for the first time and achieved marvelous wireless speeds that are 100 times faster than current Wi-Fi speeds.
      This technology is a ground-breaking light-based (LEDs)
 [light-emitting diodes] communication technology, which makes use of light waves instead of radio technology to deliver data.
Li-Fi technology will in future enable faster, more reliable internet connections, even when the demand for data usage has outgrown the available supply from existing technologies such as 4G, LTE and Wi-Fi. It will not replace these technologies, but will work seamlessly alongside them.
Using light to deliver wireless internet will also allow connectivity in environments that do not currently readily support Wi-Fi, such as aircraft cabins, hospitals and hazardous environments.
Light is already used for data transmission in fiber-optic cables and for point to
point links, but Li-Fi bulbs are outfitted with a chip that modulates the light imperceptibly for optical data transmission. Li-Fi data is transmitted by the LED bulbs and received by photoreceptors. Li-Fi's early developmental models were capable of 150 megabits-per-second (Mbps). Some commercial kits enabling that speed have been released. In the lab, with stronger LEDs and different technology, researchers have enabled 10 gigabits-per-second (Gbps), which is faster than 802.11ad.
 Benefits of Li-Fi:
  • Higher speeds than Wi-Fi.
  • 10000 times the frequency spectrum of radio.
  • More secure because data cannot be intercepted without a clear line of sight.
  • Prevents piggybacking.
  • Eliminates neighboring network interference.
  • Unimpeded by radio interference.
  • Does not create interference in sensitive electronics, making it better for use in environments like hospitals and aircraft. 
what about the drawbacks?
  • currently in the development stage of Li-Fi so it’s unlikely to be in your home anytime in the near future.
  •  Another issue is with light itself, although an advantage for security, as light cannot pass through walls, it’s a disadvantage for practicality.  You’ll need to have all the rooms in a building kitted out with Li-Fi distributors if you want full coverage like WiFi. 
  • Light pollution could also prove to be an issue with Li-Fi with other light sources interfering with the signal, this could also be the same for outdoor connectivity.




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

12. LTE (Long-Term Evolution)

13.Li-Fi [Light Fidelity]

 


                                 

Tuesday, July 28, 2015

Remembering the Missile Man of India, Dr APJ Abdul Kalam


League of Nations Failures...

While the League of Nations could celebrate its successes, the League had every reason to examine its failures and where it went wrong. These failures, especially in the 1930’s, cruelly exposed the weaknesses of the League of Nations and played a part in the outbreak of World War Two in 1939. During the 1920’s the failures of the League of Nations were essentially small-scale and did not threaten world peace. However they did set a marker – that the League of Nations could not solve problems if the protagonists did not ‘play the game’.


Article 11 of the League’s Covenant stated: "Any war or threat of war is a matter of concern to the whole League and the League shall take action that may safeguard peace."


Therefore, any conflict between nations, which ended in war and the victory of one state over another, had to be viewed as a failure by the League.


The first crisis the League had to face was in north Italy In 1919, Italian

Monday, July 27, 2015

What is LTE?

 Wireless World

Long-Term Evolution, commonly marketed as 4G LTE, is a standard for wireless communication of high-speed data for mobile phones and data terminals. It is based on the GSM/EDGE and UMTS/HSPA network technologies, increasing the capacity and speed using a different radio interface together with core network improvements.

This technology is the most efficient mobile broadband technology for providing an excellent user experience. It offers the highest data rates and shortest latency times.
  Over 600 operators in more than 180 countries are investing in LTE networks.  As it stands, most of the time when your phone displays the “4G” symbol in the upper right corner, it doesn’t really mean it. When the ITU-R set the minimum speeds for 4G, they were a bit unreachable, despite the amount of money tech manufacturers put into achieving them. In response, the regulating body decided that LTE, the name given to the technology used in pursuit of those standards, could be labeled as 4G if it provided a substantial improvement over the 3G technology.

Immediately networks began advertising their connections as 4G LTE, a marketing technique that allowed them to claim next-gen connectivity without having to reach the actual required number first; it would be like the U.S. claiming they had landed on the moon because they got pretty close and the spaceship that got them there was a lot better than the previous ship. It’s not entirely trickery though, despite inconsistent speeds depending on location and network, the difference between 3G and 4G is immediately noticeable.
So the real question is, can you feel a difference between 4G and LTE networks? Is the speed of loading a page or downloading an app on your handheld a lot faster if you have LTE technology built in? Probably not. While the difference between slower 3G networks and new 4G or LTE networks is certainly noticeably faster, most of the 4G and “true 4G” networks have upload and download speeds that are almost identical. For now, LTE is the fastest connection available for wireless networks.
     Creating 4G connectivity requires two components: a network that can support the necessary speeds, and a device that is able to connect to that network and download information at high enough speed. Just because a phone has 4G LTE connectivity inside doesn’t mean you can get the speeds you want, in the same way that buying a car that can drive 200 MPH doesn’t mean you can go that fast on a 55 MPH freeway.
Before carriers were able to truly offer LTE speeds in major areas, they were selling phones that had the capabilities they would need to reach the desired speeds, and afterwards started rolling out the service on a limited scale. Now that LTE service is fairly widespread, this isn’t as much of a problem, but if you don’t live in a major metropolitan area it’s worth checking to make sure you actually need LTE service where you live and work. With the rise in popularity, it’s uncommon for a provider to charge less if you aren’t utilizing the LTE speeds on a regular basis, but you can save money by picking up an older generation smartphone with only 3G or 4G connectivity.
         No matter what the data is or how fast it’s being transferred, it needs to be packaged and sent so that other points on the network can interpret it. Older networks use circuit-switching technology, a term that refers to the method of communicating. In a circuit-switching system, a connection is established directly to the target through the network, and the entirety of the connection, whether it’s a phone call or a file transfer, happens through that connection.

A lot of the technology used to create 4G speeds doesn’t have anything to do with voice communication. Because voice networks still use circuit-switching technology, it became necessary to reconcile the difference between older and newer network structures. A few different methods have been enacted that deal with the issue, and most carriers chose to deploy one of two options that preserved their control over the minutes used.They do this by either allowing the phone to fall back to circuit-switching standards when used to make or receive a call, or by using packet-switching communication for data and circuit-switching for voice at the same time. The third option is to simply run the voice audio as data over the new LTE networks, a method that most companies have avoided, most likely because it takes away their power to easily charge for voice minutes. Voice over LTE is basically what happens already when you make a Skype call or a Face time Audio connection to another user, with higher-resolution audio and faster connection speeds.
benefits
  • Delivers extremely fast broadband for people and things (LTE-M)
  • Operates on a global standard on licensed and unlicensed spectrum (LTE-U)
  • Offers efficient delivery and smooth implementation
  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

                     12. LTE (Long-Term Evolution)


Tuesday, July 21, 2015

3G (third generation of mobile telephony)

  Wireless World

 3G (third generation of mobile telephony)

 

3G refers to the third generation of mobile telephony (that is, cellular) technology. The third generation, as the name suggests, follows two earlier generations.


The first generation (1G) began in the early 80's with commercial deployment of Advanced Mobile Phone Service (AMPS) cellular networks. Early AMPS networks used Frequency Division Multiplexing Access (FDMA) to carry analog voice over channels in the 800 MHz frequency band.

The second generation (2G) emerged in the 90's when mobile operators deployed two competing digital voice standards. In North America, some operators adopted IS-95, which used Code Division Multiple Access (CDMA) to multiplex up to 64 calls per channel in the 800 MHz band. Across the world, many operators adopted the Global System for Mobile communication (GSM) standard, which used Time Division Multiple Access (TDMA) to multiplex up to 8 calls per channel in the 900 and 1800 MHz bands.

The International Telecommunications Union (ITU) defined the third generation (3G) of mobile telephony standards IMT-2000 to facilitate growth, increase bandwidth, and support more diverse applications. For example, GSM could deliver not only voice, but also circuit-switched data at speeds up to 14.4 Kbps. But to support mobile multimedia applications, 3G had to deliver packet-switched data with better spectral efficiency, at far greater speeds.

However, to get from 2G to 3G, mobile operators had make "evolutionary" upgrades to existing networks while simultaneously planning their "revolutionary" new mobile broadband networks. This lead to the establishment of two distinct 3G families: 3GPP and 3GPP2.The speed of data transmission on a 3G network ranges between 384KBPS to 2MBPS. This means a 3G network actually allows for more data transmission and therefore the network enables voice and video calling, file transmission, internet surfing, online TV, view high definition videos, play games and much more.  3G is the best option for users who need to always stay connected to Internet.
Contributor Technologies of 3G
The 3G technology is comprised of basically three technologies, but it is not the reason for its nomenclature as 3G. The technologies are:
·         CDMA2000        -       Code Division Multiple Access.
TD-SCDMA       -       Time-division Synchronous Code-division Multiple Access.
·         W-CDMA (UMTS)      -      Wideband Code Division Multiple Access.

   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

Friday, July 10, 2015

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