Saturday, 15 October 2011
KILLING MOSQUITOES WITH YOUR COMPUTER..!!!
Have u ever thought about KILLING MOSQUITOES WITH YOUR COMPUTER..!! here is the way for you.. actualy how it works.. Dragonflies are deadly enimies of Mosquitoes, cockroaches and those annoying insects..during there flight they generate a sound having frequency (approximately) between 67 Hz and 45 Hz, depending on their sizes. So what are we goin to do here is generaqting a sound of this frequency from our speakers which will keep them away and sound of this frequency also kills all thoose insect so it gonna work in this manner.. 56 Hz is a good average number in between those frequencies. Your PC sound card and speakers will work well for this purpose. There are many sound and tone generator programs available on the internet for both the Mac and Windows PC. Setup your computer with the sound/tone generator program running and then play the sound through your computer speakers. The speakers can be aimed directionally for complete room coverage. The sound level on the speakers should be adjusted so it is barely audible. This arrangement can be setup in a bedroom where you would like to have the window open but are worried about mosquitoes. One speaker should be fairly close to where you are sleeping. Here are some links to more advanced tone generator software which can actually sweep between the 45 Hz and 67 Hz frequencies: download from here for free: http://adf.ly/8m0q (Click on SKIP AD after opening the link) u can also download this program free for this porpose : http://adf.ly/8m1H (Click on SKIP ADD after opening the link) So after downloading any of above program all what u have to do is install them .. play and set the sound between 67 Hz to 45 Hz and play.. thats it..
Speaking Computer Without Software!!!!!!!!!!!!!!!!!!!!
first of all open the notepad then type the following things there...
Dim message, sapi message=InputBox("What do you want me to say?","hello") Set sapi=CreateObject("sapi.spvoice") sapi.Speak message
Now save the file in .vbs extension. it will work..
Dim message, sapi message=InputBox("What do you want me to say?","hello") Set sapi=CreateObject("sapi.spvoice") sapi.Speak message
Now save the file in .vbs extension. it will work..
Hide Files in Image Files !!!
trick to hide files in image files !!!
Here it is :
You require WinRAR installed on your PC for this trick.
First add your files to .rar and i.e. say files.rar
Say you have a image as img.jpg
Now, save files.rar and img.jpg in c:\ drive.
Click start >> Run
Type cmd
Now in command prompt type cd..
Again type cd..
Type copy /b img.jpg + files.rar new.jpg
-------------- Please Note --------------
>> This command will concatenate the two files into the new file new.jpg
>> Don't type files.rar + img.jpg instead of img.jpg + files.rar.
>> Now, (size of new.jpg) = (size of img.jpg) + (size of files.rar) .
-------------------------------------------
Now, we have new.jpg consisting of both img.jpg and files.rar .
Accessing the files :
Double click new.jpg and img.jpg can be viewed.
Now, to access files.rar :
# Right click on new.jpg >> Select Open With >> Choose Program...
# Select WinRAR archiver.
# Now, simply Extract your files !
Sunday, 21 August 2011
YouTube Downloader
YouTube Downloader is a popular, free program that enables you to download and convert online videos (legal content, to which you have the rights) for later viewing on your desktop or mobile device. It can convert files to MOV, MP4, 3GP, WMV, AVI, or MP3.
Click here to download
Click here to download
Magic of programming
Hi Frnds, Very interesting....
Do try this once
1. Ope...n Internet Explorer
2. Go to Google.com
3. Click images
4. Type "Flowers" or any other animal or ur favorite actress.
5. You will get a page which is having full of images
6. Then delete the URL from the address bar and paste the following script
javascript:R= 0; x1=.1; y1=.05; x2=.25; y2=.24; x3=1.6; y3=.24; x4=300; y4=200; x5=300; y5=200; DI= document.images; DIL=DI.length; function A(){for(i=0; i
7. See the Little magic of programming…
Tuesday, 7 June 2011
F.lux Changes Your Screen Brightness by Time of Day
f.lux is a unique tool that automatically makes the color of your computer screen adapt to the time
Download link
Thursday, 2 June 2011
Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint File Formats
Install this compatibility pack if you would like to open, edit, and save documents, workbooks, and presentations that were created in the newer versions of Word, Excel, and PowerPoint.
Dowload Link
Dowload Link
Thursday, 26 May 2011
Monday, 21 March 2011
Funny things about computer.....
MICROSOFT:
Most Intelligent Customers Realize Our Software Only (for) Fools (&) Teenagers.
WINDOWS:
Will Install Needless Data On Whole System
PCMCIA :
People Can't Memorize Computer Industry Acronyms
DOS:
Defective Operating System
ISDN:
It Still Does Nothing
MACINTOSH: Most Applications Crash; If Not, The Operating System Hangs
Most Intelligent Customers Realize Our Software Only (for) Fools (&) Teenagers.
WINDOWS:
Will Install Needless Data On Whole System
PCMCIA :
People Can't Memorize Computer Industry Acronyms
DOS:
Defective Operating System
ISDN:
It Still Does Nothing
MACINTOSH: Most Applications Crash; If Not, The Operating System Hangs
Thursday, 10 March 2011
4G TECHONOLOGY
4G TECHONOLOGY
Abstract:
Mobile devices are getting smaller, lighter, and more powerful; they have bigger screens and longer battery life, more features and more capabilities. Things like watching the football game on your mobile device, watching movies, videoconferencing, paying your bills and downloading music to the palm of your hand will become second nature in the near future.
Bandwidth will always be the limiting factor in the development of applications and devices, be it wired, or wireless. At the moment the wireless world doesn’t have a large-cell, high bandwidth standard, that is capable of delivering the much needed speeds to a mobile device. The short fall of 3G networks is clear, it’s just not fast enough, offering 384kbps doesn’t meet the requirements of what the end user has come to expect these days. Some people see 3G as a stop-gap, until a fully integrated IP network is created; some countries have even chosen to bypass 3G and head straight to 4G, a method which has its advantages, and its disadvantages.
A handful of wireless technologies are set to join existing 2.5G and 3G standards, , as 4G and NGN vendors find a foothold in the mobile market. “The current race is ultimately to wrestle control from the UMTS and CDMA2000 platforms,” Fuertes said. “Siemens carrying Flarion’s Flash-OFDM as announced last week is a large step forward for IP-based mobile wireless.”
Service Providers are considering new protocols in search of a migration to an all IP network, a move expected to lower high-speed data costs and enable new services. Some of these solutions are considered 3.5G or even 4G.
NEED FOR 4G:
4G is being developed to accommodate the QoS and rate requirements set by further development of existing 3G applications like wireless broadband access, Multimedia Messaging Service (MMS), video chat, mobile TV, but also new services like HDTV content, minimal services like voice and data, and other services that utilize bandwidth. It may be allowed roaming with wireless local area networks, and be combined with digital video broadcasting systems.
OBJECTIVES:
The 4G working group has defined the following as objectives of the 4G wireless communication standard:
• Flexible channel bandwidth, between 5 and 20 MHz, optionally up to 40 MHz.
• A nominal data rate of 100 Mbit/s while the client physically moves at high speeds relative to the station, and 1 Gbit/s while client and station are in relatively fixed positions as defined by the ITU-R,
• A data rate of at least 100 Mbit/s between any two points in the world,
• Peak link spectral efficiency of 15 bit/s/Hz in the downlink, and 6.75 bit/s/Hz in the uplink (meaning that 1000 Mbit/s in the downlink should be possible over less than 67 MHz bandwidth)
• System spectral efficiency of up to 3 bit/s/Hz/cell in the downlink and 2.25 bit/s/Hz/cell for indoor usage.
• Smooth handoff across heterogeneous networks,
• Seamless connectivity and global roaming across multiple networks,
• High quality of service for next generation multimedia support (real time audio, high speed data, HDTV video content, mobile TV, etc)
• Interoperability with existing wireless standards, and
• An all IP, packet switched network.
Principal technologies
Physical layer transmission techniques
• No CDMA.
• MIMO: To attain ultra high spectral efficiency by means of spatial processing including multi-antenna and multi-user MIMO
• Frequency-domain-equalization, for example Multi-carrier modulation (OFDM) or single-carrier frequency-domain-equalization (SC-FDE) in the downlink: To exploit the frequency selective channel property without complex equalization.
• Frequency-domain statistical multiplexing, for example (OFDMA) or (Single-carrier FDMA) in the uplink: Variable bit rate by assigning different sub-channels to different users based on the channel conditions
• Turbo principle error-correcting codes: To minimize the required SNR at the reception side
• Channel-dependent scheduling: To utilize the time-varying channel.
• Link adaption: Adaptive modulation and error-correcting codes
• Relaying, including fixed relay networks (FRNs), and the cooperative relaying concept, known as multi-mode protocol
Components:
Access schemes:
Till now....:
As the wireless standards evolved, the access techniques used also exhibited increase in efficiency, capacity and scalability. The first generation wireless standards used plain TDMA and FDMA. In the wireless channels, TDMA proved to be less efficient in handling the high data rate channels as it requires large guard periods to alleviate the multipath impact. Similarly, FDMA consumed more bandwidth for guard to avoid inter carrier interference. So in second generation systems, one set of standard used the combination of FDMA and TDMA and the other set introduced an access scheme called CDMA. Usage of CDMA increased the system capacity, but as a drawback placed a soft limit on it rather than the hard limit (i.e. a CDMA network will not reject new clients when it approaches its limits, resulting in a denial of service to all clients when the network overloads). Data rate is also increased as this access scheme (providing the network is not reaching its capacity) is efficient enough to handle the multipath channel. This enabled the third generation systems, such as IS-2000, UMTS, HSXPA, 1xEV-DO, TD-CDMA and TD-SCDMA, to use CDMA as the access scheme. However, the issue with CDMA is that it suffers from poor spectral flexibility and computationally intensive time-domain equalization (high number of multiplications per second) for wideband channels.
Tomorrow....:
Recently, new access schemes like Orthogonal FDMA (OFDMA), Single Carrier FDMA (SC-FDMA), Interleaved FDMA and Multi-carrier CDMA (MC-CDMA) are gaining more importance for the next generation systems. These are based on efficient FFT algorithm and frequency domain equalization, resulting lower number of multiplications per second. They also make it possible to control the bandwidth and form the spectrum in a flexible way. However, they require advanced dynamic channel allocation and traffic adaptive scheduling.WiMax is using OFDMA in the downlink and in the uplink. For the next generation UMTS, OFDMA is used for the downlink. By contrast, IFDMA is being considered for the uplink since OFDMA contributes more to the PAPR related issues and results in nonlinear operation of amplifiers. IFDMA provides less power fluctuation and thus avoids amplifier issues. Similarly, MC-CDMA is in the proposal for the IEEE 802.20 standard. These access schemes offer the same efficiencies as older technologies like CDMA. Apart from this, scalability and higher data rates can be achieved.
The other important advantage of the above mentioned access techniques is that they require less complexity for equalization at the receiver. This is an added advantage especially in the MIMO environments since the spatial multiplexing transmission of MIMO systems inherently requires high complexity equalization at the receiver.In addition to improvements in these multiplexing systems, improved modulation techniques are being used. Whereas earlier standards largely used Phase-shift keying, more efficient systems such as 64QAM are being proposed for use with the 3GPP Long Term Evolution standards.
How OFDM works
First of all the FDM part - Frequency division multiplexing is a technology that transmits several signals at the same time over a single transmission path, in a medium such as a cable or wireless system. Each signal is transmitted inside its own unique frequency range (the carrier frequency), which is then modulated by the data that is needing to be transmitted.
Orthogonal FDM's spread spectrum technique spreads the data over a lot of carriers that are spaced apart at precise frequencies. This spacing provides the "orthogonality" in this method which prevents the receivers/demodulators from seeing frequencies other than their own specific one. The main benefit of OFDM is high spectral efficiency, but with OFDM you also get; high resiliency to RF interference and the multi-path distortion is lower.
When OFDM was first implemented, it was by using banks of sinusoidal generators, e.g. just placing up a whole lot of single carriers in parallel. The use of the discrete Fourier transform (DFT) was originally proposed in 1971 by Weinstein and Ebert, which greatly reduces the implementation complexity of OFDM systems. This was further reduced by the development of the fast Fourier transform (FFT). Shortly after an equalization algorithm was implemented in order to help suppress both ISI and intersubcarrier interference, which is caused by the channel impulse response and timing and frequency errors.
In OFDM the sub carrier pulse which is used for transmission is rectangular. This is why the capability of pulse forming and modulation can be performed by an IDFT, which can be generated very efficiently as an IFFT. Because of this, the receiver only needs a FFT to reverse this process. Taking into account the theories of the Fourier Transform the rectangular pulse shape will end up as a sin(x)/x style of spectrum of the subcarriers. In traditional FDM the sub-channels aren’t orthogonal therefore need to be separated by guard bands which obviously wastes much needed spectrum.
Because an IIFT is used for modulation in OFDM, this spacing of the sub carriers is done in such a way the frequency where we evaluate the received signal all other signals are zero thus allowing the sub channels to overlap. But because of this, for an OFDM system to work using this method, the receiver and the transmitter must be in perfect synch, and there can’t be any multipath fading, which is unusual since finding a fix to this is one of the main goals of OFDM.
Luckily there is an easy way to solve this problem. If a guard interval is used, which is larger than the expected delay spread, which is done by artificially extending the symbol time and then removing this extension at the receiver, the problem is solved but with only a minimal loss in bandwidth.
IPv6 support
Unlike 3G, which is based on two parallel infrastructures consisting of circuit switched and packet switched network nodes respectively, 4G will be based on packet switching only. This will require low-latency data transmission.By the time that 4G is deployed, the process of IPv4 address exhaustion is expected to be in its final stages. Therefore, in the context of 4G, IPv6 support is essential in order to support a large number of wireless-enabled devices. By increasing the number of IP addresses, IPv6 removes the need for Network Address Translation (NAT), a method of sharing a limited number of addresses among a larger group of devices, although NAT will still be required to communicate with devices that are on existing IPv4 networks.As of June 2009, Verizon has posted specifications that require any 4G devices on its network to support IPv6.
Advanced Antenna Systems:
MIMO and MU-MIMO
The performance of radio communications depends on an antenna system, refer to smart or intelligent antenna. Recently, multiple antenna technologies are emerging to achieve the goal of 4G systems such as high rate, high reliability, and long range communications. In the early 90s, to cater the growing data rate needs of data communication, many transmission schemes were proposed. One technology, spatial multiplexing, gained importance for its bandwidth conservation and power efficiency. Spatial multiplexing involves deploying multiple antennas at the transmitter and at the receiver. Independent streams can then be transmitted simultaneously from all the antennas. This increases the data rate into multiple folds with the number equal to minimum of the number of transmit and receive antennas. This is called MIMO (as a branch of intelligent antenna). Apart from this, the reliability in transmitting high speed data in the fading channel can be improved by using more antennas at the transmitter or at the receiver. This is called transmit or receive diversity. Both transmit/receive diversity and transmit spatial multiplexing are categorized into the space-time coding techniques, which does not necessarily require the channel knowledge at the transmit. The other category is closed-loop multiple antenna technologies which use the channel knowledge at the transmitter..
4G wireless standards:
In September 2009 the technology proposals have been submitted to ITU-R as 4G candidates. Basically all proposals are based on two technologies:
* LTE Advanced standardized by the 3GPP;
* 802.16m standardized by the IEEE.
Considering the huge industry support for 3GPP based technologies such as LTE the vision of an almost unified global 4G standard might not be out of reach anymore. A first set of 3GPP requirements on LTE Advanced has been approved in June 2008. LTE Advanced will be standardized in 2010 as part of the Release 10 of the 3GPP specification. LTE Advanced will be fully built on the existing LTE specification Release 10 and not be defined as a new specification series.
Towards4G...
For 1 and 2G standards, bandwidth maximum is 9.6 kbit/sec, This is approximately 6 times slower than an ISDN (Integrated services digital network). Rates did increase by a factor of 3 with newer handsets to 28.8kbps. This is rarely the speed though, as in crowded areas, when the network is busy, rates do drop dramatically.
Third generation mobile, data rates are 384 kbps (download) maximum, typically around 200kbps, and 64kbps upload. These are comparable to home broadband connections.
Fourth generation mobile communications will have higher data transmission rates than 3G. 4G mobile data transmission rates are planned to be up to 100 megabits per second on the move and 1000gigbits per second stationary, this is a phenomenal amount of bandwidth, only comparable to the bandwidth workstations get connected directly to a LAN.
4G SYSTEMS:
There are major three types of systems in 4G technology, they are listed below as follows
1. 1. WiMAX
2. 2. LTE
3. UMB
WiMAX:
WiMAX stands for Worldwide interoperability for Microwave 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. In contrast, the WiFi/802.11 wireless local area network standard is limited in most cases to only 100 - 300 feet (30 - 100m).With 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.
The IEEE 802.16 standard defines the technical features of the communications protocol. The WiMAX forum offers a means of testing manufacturer's equipment for compatibility, as well as an industry group dedicated to fostering the development and commercialization of the technology.
The carriers want 'evolution rather than revolution' with each advance in system design. That has already been seen in current 3G systems but still not to the extent that carriers would like.That is why 802.16 has core requirements that are adaptable to many types of applications and ability to extend the platform in several ways, such as higher order MIMO-AAS, without breaking core compatibility. Like LTE, WiMAX strives to be a 'long term evolution' framework platform. So both because these systems use a set of core and optional technologies and because they are fully expected to evolve over time, it is misleading to call WiMAX or LTE 'a technology'
LTE:
Long Term Evolution, the 4th generation mobile broadband standard, successor to UMTS (which is a 3G cellular technology) Increased spectrum efficiency for larger carriers and therefore increase capacity.It consists of lower cost per bit and lower prices for end-users.It has Simplified protocol stack & all-IP network architecture.
It provides reduced latency,easier network management.Has high Flexibilities and scalability in deployment depending on spectrum availability.Operating in various frequency bands from 1.4 to 20MHz and therefore can be deployed in lower frequencies.
Operators can start with smaller deployment and increase bandwidth as users increase and
supports resource aggregation for radio band resources
UMB:
UMB (Ultra Mobile Broadband) was the brand name for a project within 3GPP2 to improve the CDMA2000 mobile phone standard for next generation applications and requirements. In November 2008, Qualcomm, UMB's lead sponsor, announced it was ending development of the technology, favoring LTE instead.
Like LTE, the UMB system was to be based upon Internet (TCP/IP) networking technologies running over a next generation radio system, with peak rates of up to 280 Mbit/s. Its designers intended for the system to be more efficient and capable of providing more services than the technologies it was intended to replace. To provide compatibility with the systems it was intended to replace, UMB was to support handoffs with other technologies including existing CDMA2000 1X and 1xEV-DO systems. However 3GPP added this functionality to LTE, allowing LTE to become the single upgrade path for all wireless networks. No carrier had announced plans to adopt UMB, and most CDMA carriers in Australia, USA, Canada, China, Japan and Korea have already announced plans to adopt either WiMAX or LTE as their 4G technology.
UMB was intended to be a so-called fourth-generation technology. These technologies use a high bandwidth, low latency, underlying TCP/IP network with high level services such as voice built on top. Widespread deployment of 4G networks promises to make applications that were previously not feasible not only possible but ubiquitous. Examples of such applications include mobile high definition video streaming and mobile online gaming.UMB's use of OFDMA would have eliminated many of the disadvantages of the CDMA technology used by its predecessor, including the "breathing" phenomenon, the difficulty of adding capacity via microcells, and the fixed bandwidth sizes that limit the total bandwidth available to handsets.Data speeds over 275 Mbit/s downstream and over 75 Mbit/s upstream Scalable bandwidth between 1.25-20 MHz (OFDMA systems are especially well suited for wider bandwidths larger than 5 MHz)
Current research:
Pervasive networks are an amorphous and at present entirely hypothetical concept where the user can be simultaneously connected to several wireless access technologies and can seamlessly move between them (See vertical handoff, IEEE 802.21). These access technologies can be Wi-Fi, UMTS, EDGE, or any other future access technology. Included in this concept is also smart-radio (also known as cognitive radio technology) to efficiently manage spectrum use and transmission power as well as the use of mesh routing protocols to create a pervasive network.
Future development plans:
Digiweb, an Irish fixed and wireless broadband company, announced that they have received a mobile communications license from the Irish Telecoms regulator, ComReg. This service will be issued the mobile code 088 in Ireland and will be used for the provision of 4G Mobile communications.Aruond 2011 Digiweb will launch a mobile broadband network using FLASH-OFDM technology at 872 Mhz.
On September 20, 2007, Verizon Wireless announced that it plans a joint effort with the Vodafone Group to transition its networks to the 4G standard LTE. On December 9, 2008, Verizon Wireless announced that they intend to build and begin to roll out an LTE network by the end of 2013.
Telus and Bell Canada, the major Canadian cdmaOne and EV-DO carriers, have announced that they will be cooperating towards building a fourth generation (4G) LTE wireless broadband network in Canada. As a transitional measure, they are implementing 3G UMTS to go live by early 2010.Sprint offers a 3G/4G connection plan, currently available in select cities in the United States. It delivers rates up to 36 Mbit/s.
O2 is to use Slough as a guinea pig in testing the 4G network and has called upon Huawei to install LTE technology in six masts across the town to allow people to talk to each other via HD video conferencing and play PlayStation games while on the move.
Conclusion:
4G will change the way we work, live and play. Cheap end user costs, fast, always on, reliable connectivity, where ever you are, what ever your doing. Some people view 3G as a stop gap until the real 4G network arrives, something which is due around 2010, and will impact every one, every where.
This technology will overcome the disadvantages of the past technologies.World with this will become very fast & furious .Thus we conclude that the upcoming world will be fulfilled by 4g technology……,
Abstract:
Mobile devices are getting smaller, lighter, and more powerful; they have bigger screens and longer battery life, more features and more capabilities. Things like watching the football game on your mobile device, watching movies, videoconferencing, paying your bills and downloading music to the palm of your hand will become second nature in the near future.
Bandwidth will always be the limiting factor in the development of applications and devices, be it wired, or wireless. At the moment the wireless world doesn’t have a large-cell, high bandwidth standard, that is capable of delivering the much needed speeds to a mobile device. The short fall of 3G networks is clear, it’s just not fast enough, offering 384kbps doesn’t meet the requirements of what the end user has come to expect these days. Some people see 3G as a stop-gap, until a fully integrated IP network is created; some countries have even chosen to bypass 3G and head straight to 4G, a method which has its advantages, and its disadvantages.
A handful of wireless technologies are set to join existing 2.5G and 3G standards, , as 4G and NGN vendors find a foothold in the mobile market. “The current race is ultimately to wrestle control from the UMTS and CDMA2000 platforms,” Fuertes said. “Siemens carrying Flarion’s Flash-OFDM as announced last week is a large step forward for IP-based mobile wireless.”
Service Providers are considering new protocols in search of a migration to an all IP network, a move expected to lower high-speed data costs and enable new services. Some of these solutions are considered 3.5G or even 4G.
NEED FOR 4G:
4G is being developed to accommodate the QoS and rate requirements set by further development of existing 3G applications like wireless broadband access, Multimedia Messaging Service (MMS), video chat, mobile TV, but also new services like HDTV content, minimal services like voice and data, and other services that utilize bandwidth. It may be allowed roaming with wireless local area networks, and be combined with digital video broadcasting systems.
OBJECTIVES:
The 4G working group has defined the following as objectives of the 4G wireless communication standard:
• Flexible channel bandwidth, between 5 and 20 MHz, optionally up to 40 MHz.
• A nominal data rate of 100 Mbit/s while the client physically moves at high speeds relative to the station, and 1 Gbit/s while client and station are in relatively fixed positions as defined by the ITU-R,
• A data rate of at least 100 Mbit/s between any two points in the world,
• Peak link spectral efficiency of 15 bit/s/Hz in the downlink, and 6.75 bit/s/Hz in the uplink (meaning that 1000 Mbit/s in the downlink should be possible over less than 67 MHz bandwidth)
• System spectral efficiency of up to 3 bit/s/Hz/cell in the downlink and 2.25 bit/s/Hz/cell for indoor usage.
• Smooth handoff across heterogeneous networks,
• Seamless connectivity and global roaming across multiple networks,
• High quality of service for next generation multimedia support (real time audio, high speed data, HDTV video content, mobile TV, etc)
• Interoperability with existing wireless standards, and
• An all IP, packet switched network.
Principal technologies
Physical layer transmission techniques
• No CDMA.
• MIMO: To attain ultra high spectral efficiency by means of spatial processing including multi-antenna and multi-user MIMO
• Frequency-domain-equalization, for example Multi-carrier modulation (OFDM) or single-carrier frequency-domain-equalization (SC-FDE) in the downlink: To exploit the frequency selective channel property without complex equalization.
• Frequency-domain statistical multiplexing, for example (OFDMA) or (Single-carrier FDMA) in the uplink: Variable bit rate by assigning different sub-channels to different users based on the channel conditions
• Turbo principle error-correcting codes: To minimize the required SNR at the reception side
• Channel-dependent scheduling: To utilize the time-varying channel.
• Link adaption: Adaptive modulation and error-correcting codes
• Relaying, including fixed relay networks (FRNs), and the cooperative relaying concept, known as multi-mode protocol
Components:
Access schemes:
Till now....:
As the wireless standards evolved, the access techniques used also exhibited increase in efficiency, capacity and scalability. The first generation wireless standards used plain TDMA and FDMA. In the wireless channels, TDMA proved to be less efficient in handling the high data rate channels as it requires large guard periods to alleviate the multipath impact. Similarly, FDMA consumed more bandwidth for guard to avoid inter carrier interference. So in second generation systems, one set of standard used the combination of FDMA and TDMA and the other set introduced an access scheme called CDMA. Usage of CDMA increased the system capacity, but as a drawback placed a soft limit on it rather than the hard limit (i.e. a CDMA network will not reject new clients when it approaches its limits, resulting in a denial of service to all clients when the network overloads). Data rate is also increased as this access scheme (providing the network is not reaching its capacity) is efficient enough to handle the multipath channel. This enabled the third generation systems, such as IS-2000, UMTS, HSXPA, 1xEV-DO, TD-CDMA and TD-SCDMA, to use CDMA as the access scheme. However, the issue with CDMA is that it suffers from poor spectral flexibility and computationally intensive time-domain equalization (high number of multiplications per second) for wideband channels.
Tomorrow....:
Recently, new access schemes like Orthogonal FDMA (OFDMA), Single Carrier FDMA (SC-FDMA), Interleaved FDMA and Multi-carrier CDMA (MC-CDMA) are gaining more importance for the next generation systems. These are based on efficient FFT algorithm and frequency domain equalization, resulting lower number of multiplications per second. They also make it possible to control the bandwidth and form the spectrum in a flexible way. However, they require advanced dynamic channel allocation and traffic adaptive scheduling.WiMax is using OFDMA in the downlink and in the uplink. For the next generation UMTS, OFDMA is used for the downlink. By contrast, IFDMA is being considered for the uplink since OFDMA contributes more to the PAPR related issues and results in nonlinear operation of amplifiers. IFDMA provides less power fluctuation and thus avoids amplifier issues. Similarly, MC-CDMA is in the proposal for the IEEE 802.20 standard. These access schemes offer the same efficiencies as older technologies like CDMA. Apart from this, scalability and higher data rates can be achieved.
The other important advantage of the above mentioned access techniques is that they require less complexity for equalization at the receiver. This is an added advantage especially in the MIMO environments since the spatial multiplexing transmission of MIMO systems inherently requires high complexity equalization at the receiver.In addition to improvements in these multiplexing systems, improved modulation techniques are being used. Whereas earlier standards largely used Phase-shift keying, more efficient systems such as 64QAM are being proposed for use with the 3GPP Long Term Evolution standards.
How OFDM works
First of all the FDM part - Frequency division multiplexing is a technology that transmits several signals at the same time over a single transmission path, in a medium such as a cable or wireless system. Each signal is transmitted inside its own unique frequency range (the carrier frequency), which is then modulated by the data that is needing to be transmitted.
Orthogonal FDM's spread spectrum technique spreads the data over a lot of carriers that are spaced apart at precise frequencies. This spacing provides the "orthogonality" in this method which prevents the receivers/demodulators from seeing frequencies other than their own specific one. The main benefit of OFDM is high spectral efficiency, but with OFDM you also get; high resiliency to RF interference and the multi-path distortion is lower.
When OFDM was first implemented, it was by using banks of sinusoidal generators, e.g. just placing up a whole lot of single carriers in parallel. The use of the discrete Fourier transform (DFT) was originally proposed in 1971 by Weinstein and Ebert, which greatly reduces the implementation complexity of OFDM systems. This was further reduced by the development of the fast Fourier transform (FFT). Shortly after an equalization algorithm was implemented in order to help suppress both ISI and intersubcarrier interference, which is caused by the channel impulse response and timing and frequency errors.
In OFDM the sub carrier pulse which is used for transmission is rectangular. This is why the capability of pulse forming and modulation can be performed by an IDFT, which can be generated very efficiently as an IFFT. Because of this, the receiver only needs a FFT to reverse this process. Taking into account the theories of the Fourier Transform the rectangular pulse shape will end up as a sin(x)/x style of spectrum of the subcarriers. In traditional FDM the sub-channels aren’t orthogonal therefore need to be separated by guard bands which obviously wastes much needed spectrum.
Because an IIFT is used for modulation in OFDM, this spacing of the sub carriers is done in such a way the frequency where we evaluate the received signal all other signals are zero thus allowing the sub channels to overlap. But because of this, for an OFDM system to work using this method, the receiver and the transmitter must be in perfect synch, and there can’t be any multipath fading, which is unusual since finding a fix to this is one of the main goals of OFDM.
Luckily there is an easy way to solve this problem. If a guard interval is used, which is larger than the expected delay spread, which is done by artificially extending the symbol time and then removing this extension at the receiver, the problem is solved but with only a minimal loss in bandwidth.
IPv6 support
Unlike 3G, which is based on two parallel infrastructures consisting of circuit switched and packet switched network nodes respectively, 4G will be based on packet switching only. This will require low-latency data transmission.By the time that 4G is deployed, the process of IPv4 address exhaustion is expected to be in its final stages. Therefore, in the context of 4G, IPv6 support is essential in order to support a large number of wireless-enabled devices. By increasing the number of IP addresses, IPv6 removes the need for Network Address Translation (NAT), a method of sharing a limited number of addresses among a larger group of devices, although NAT will still be required to communicate with devices that are on existing IPv4 networks.As of June 2009, Verizon has posted specifications that require any 4G devices on its network to support IPv6.
Advanced Antenna Systems:
MIMO and MU-MIMO
The performance of radio communications depends on an antenna system, refer to smart or intelligent antenna. Recently, multiple antenna technologies are emerging to achieve the goal of 4G systems such as high rate, high reliability, and long range communications. In the early 90s, to cater the growing data rate needs of data communication, many transmission schemes were proposed. One technology, spatial multiplexing, gained importance for its bandwidth conservation and power efficiency. Spatial multiplexing involves deploying multiple antennas at the transmitter and at the receiver. Independent streams can then be transmitted simultaneously from all the antennas. This increases the data rate into multiple folds with the number equal to minimum of the number of transmit and receive antennas. This is called MIMO (as a branch of intelligent antenna). Apart from this, the reliability in transmitting high speed data in the fading channel can be improved by using more antennas at the transmitter or at the receiver. This is called transmit or receive diversity. Both transmit/receive diversity and transmit spatial multiplexing are categorized into the space-time coding techniques, which does not necessarily require the channel knowledge at the transmit. The other category is closed-loop multiple antenna technologies which use the channel knowledge at the transmitter..
4G wireless standards:
In September 2009 the technology proposals have been submitted to ITU-R as 4G candidates. Basically all proposals are based on two technologies:
* LTE Advanced standardized by the 3GPP;
* 802.16m standardized by the IEEE.
Considering the huge industry support for 3GPP based technologies such as LTE the vision of an almost unified global 4G standard might not be out of reach anymore. A first set of 3GPP requirements on LTE Advanced has been approved in June 2008. LTE Advanced will be standardized in 2010 as part of the Release 10 of the 3GPP specification. LTE Advanced will be fully built on the existing LTE specification Release 10 and not be defined as a new specification series.
Towards4G...
For 1 and 2G standards, bandwidth maximum is 9.6 kbit/sec, This is approximately 6 times slower than an ISDN (Integrated services digital network). Rates did increase by a factor of 3 with newer handsets to 28.8kbps. This is rarely the speed though, as in crowded areas, when the network is busy, rates do drop dramatically.
Third generation mobile, data rates are 384 kbps (download) maximum, typically around 200kbps, and 64kbps upload. These are comparable to home broadband connections.
Fourth generation mobile communications will have higher data transmission rates than 3G. 4G mobile data transmission rates are planned to be up to 100 megabits per second on the move and 1000gigbits per second stationary, this is a phenomenal amount of bandwidth, only comparable to the bandwidth workstations get connected directly to a LAN.
4G SYSTEMS:
There are major three types of systems in 4G technology, they are listed below as follows
1. 1. WiMAX
2. 2. LTE
3. UMB
WiMAX:
WiMAX stands for Worldwide interoperability for Microwave 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. In contrast, the WiFi/802.11 wireless local area network standard is limited in most cases to only 100 - 300 feet (30 - 100m).With 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.
The IEEE 802.16 standard defines the technical features of the communications protocol. The WiMAX forum offers a means of testing manufacturer's equipment for compatibility, as well as an industry group dedicated to fostering the development and commercialization of the technology.
The carriers want 'evolution rather than revolution' with each advance in system design. That has already been seen in current 3G systems but still not to the extent that carriers would like.That is why 802.16 has core requirements that are adaptable to many types of applications and ability to extend the platform in several ways, such as higher order MIMO-AAS, without breaking core compatibility. Like LTE, WiMAX strives to be a 'long term evolution' framework platform. So both because these systems use a set of core and optional technologies and because they are fully expected to evolve over time, it is misleading to call WiMAX or LTE 'a technology'
LTE:
Long Term Evolution, the 4th generation mobile broadband standard, successor to UMTS (which is a 3G cellular technology) Increased spectrum efficiency for larger carriers and therefore increase capacity.It consists of lower cost per bit and lower prices for end-users.It has Simplified protocol stack & all-IP network architecture.
It provides reduced latency,easier network management.Has high Flexibilities and scalability in deployment depending on spectrum availability.Operating in various frequency bands from 1.4 to 20MHz and therefore can be deployed in lower frequencies.
Operators can start with smaller deployment and increase bandwidth as users increase and
supports resource aggregation for radio band resources
UMB:
UMB (Ultra Mobile Broadband) was the brand name for a project within 3GPP2 to improve the CDMA2000 mobile phone standard for next generation applications and requirements. In November 2008, Qualcomm, UMB's lead sponsor, announced it was ending development of the technology, favoring LTE instead.
Like LTE, the UMB system was to be based upon Internet (TCP/IP) networking technologies running over a next generation radio system, with peak rates of up to 280 Mbit/s. Its designers intended for the system to be more efficient and capable of providing more services than the technologies it was intended to replace. To provide compatibility with the systems it was intended to replace, UMB was to support handoffs with other technologies including existing CDMA2000 1X and 1xEV-DO systems. However 3GPP added this functionality to LTE, allowing LTE to become the single upgrade path for all wireless networks. No carrier had announced plans to adopt UMB, and most CDMA carriers in Australia, USA, Canada, China, Japan and Korea have already announced plans to adopt either WiMAX or LTE as their 4G technology.
UMB was intended to be a so-called fourth-generation technology. These technologies use a high bandwidth, low latency, underlying TCP/IP network with high level services such as voice built on top. Widespread deployment of 4G networks promises to make applications that were previously not feasible not only possible but ubiquitous. Examples of such applications include mobile high definition video streaming and mobile online gaming.UMB's use of OFDMA would have eliminated many of the disadvantages of the CDMA technology used by its predecessor, including the "breathing" phenomenon, the difficulty of adding capacity via microcells, and the fixed bandwidth sizes that limit the total bandwidth available to handsets.Data speeds over 275 Mbit/s downstream and over 75 Mbit/s upstream Scalable bandwidth between 1.25-20 MHz (OFDMA systems are especially well suited for wider bandwidths larger than 5 MHz)
Current research:
Pervasive networks are an amorphous and at present entirely hypothetical concept where the user can be simultaneously connected to several wireless access technologies and can seamlessly move between them (See vertical handoff, IEEE 802.21). These access technologies can be Wi-Fi, UMTS, EDGE, or any other future access technology. Included in this concept is also smart-radio (also known as cognitive radio technology) to efficiently manage spectrum use and transmission power as well as the use of mesh routing protocols to create a pervasive network.
Future development plans:
Digiweb, an Irish fixed and wireless broadband company, announced that they have received a mobile communications license from the Irish Telecoms regulator, ComReg. This service will be issued the mobile code 088 in Ireland and will be used for the provision of 4G Mobile communications.Aruond 2011 Digiweb will launch a mobile broadband network using FLASH-OFDM technology at 872 Mhz.
On September 20, 2007, Verizon Wireless announced that it plans a joint effort with the Vodafone Group to transition its networks to the 4G standard LTE. On December 9, 2008, Verizon Wireless announced that they intend to build and begin to roll out an LTE network by the end of 2013.
Telus and Bell Canada, the major Canadian cdmaOne and EV-DO carriers, have announced that they will be cooperating towards building a fourth generation (4G) LTE wireless broadband network in Canada. As a transitional measure, they are implementing 3G UMTS to go live by early 2010.Sprint offers a 3G/4G connection plan, currently available in select cities in the United States. It delivers rates up to 36 Mbit/s.
O2 is to use Slough as a guinea pig in testing the 4G network and has called upon Huawei to install LTE technology in six masts across the town to allow people to talk to each other via HD video conferencing and play PlayStation games while on the move.
Conclusion:
4G will change the way we work, live and play. Cheap end user costs, fast, always on, reliable connectivity, where ever you are, what ever your doing. Some people view 3G as a stop gap until the real 4G network arrives, something which is due around 2010, and will impact every one, every where.
This technology will overcome the disadvantages of the past technologies.World with this will become very fast & furious .Thus we conclude that the upcoming world will be fulfilled by 4g technology……,
3G NETWORKING
3G NETWORKING
INTRODUCTION:
There are evolutionary standards that are backwards-compatible extensions to pre-existing 2G networks as well as revolutionary standards that require all-new networks and frequency allocations.[3] The later group is the UMTS family, which consists of standards developed for IMT-2000, as well as the independently-developed standards DECT and WiMAX, which were included because they fit the IMT-2000 definitionONLINE EXAMINATIONS
History
The first pre-commercial 3G network was launched by NTT DoCoMo in Japan branded FOMA, in May 2001 on a pre-release of W-CDMA technology.[7] The first commercial launch of 3G was also by NTT DoCoMo in Japan on 1 October 2001, although it was initially somewhat limited in scope;[8][9] broader availability was delayed by apparent concerns over reliability.[10] The second network to go commercially live was by SK Telecom in South Korea on the 1xEV-DO technology in January 2002. By May 2002 the second South Korean 3G network was by KT on EV-DO and thus the Koreans were the first to see competition among 3G operators.
The first European pre-commercial network was at the Isle of Man by Manx Telecom, the operator then owned by British Telecom, and the first commercial network in Europe was opened for business by Telenor in December 2001 with no commercial handsets and thus no paying customers. These were both on the W-CDMA technology.
The first commercial United States 3G network was by Monet Mobile Networks, on CDMA2000 1x EV-DO technology, but this network provider later shut down operations. The second 3G network operator in the USA was Verizon Wireless in October 2003 also on CDMA2000 1x EV-DO. AT&T Mobility is also a true 3G network, having completed its upgrade of the 3G network to HSUPA.
The first pre-commercial demonstration network in the southern hemisphere was built in Adelaide, South Australia by m.Net Corporation in February 2002 using UMTS on 2100 MHz. This was a demonstration network for the 2002 IT World Congress. The first commercial 3G network was launched by Hutchison Telecommunications branded as Three in March 2003.
In December 2007, 190 3G networks were operating in 40 countries and 154 HSDPA networks were operating in 71 countries, according to the Global Mobile Suppliers Association (GSA). In Asia, Europe, Canada and the USA, telecommunication companies use W-CDMA technology with the support of around 100 terminal designs to operate 3G mobile networks.
In Europe, mass market commercial 3G services were introduced starting in March 2003 by 3 (Part of Hutchison Whampoa) in the UK and Italy. The European Union Council suggested that the 3G operators should cover 80% of the European national populations by the end of 2005.
Roll-out of 3G networks was delayed in some countries by the enormous costs of additional spectrum licensing fees. (See Telecoms crash.) In many countries, 3G networks do not use the same radio frequencies as 2G, so mobile operators must build entirely new networks and license entirely new frequencies; an exception is the United States where carriers operate 3G service in the same frequencies as other services. The license fees in some European countries were particularly high, bolstered by government auctions of a limited number of licenses and sealed bid auctions, and initial excitement over 3G's potential. Other delays were due to the expenses of upgrading equipment for the new systems.
By June 2007 the 200 millionth 3G subscriber had been connected. Out of 3 billion mobile phone subscriptions worldwide this is only 6.7%. In the countries where 3G was launched first - Japan and South Korea - 3G penetration is over 70%.[11] In Europe the leading country is Italy with a third of its subscribers migrated to 3G. Other leading countries by 3G migration include UK, Austria, Australia and Singapore at the 20% migration level. A confusing statistic is counting CDMA2000 1x RTT customers as if they were 3G customers. If using this definition, then the total 3G subscriber base would be 475 million at June 2007 and 15.8% of all subscribers worldwide.
In Canada, Rogers Wireless was the first to implement 3G technology, with HSDPA services in eastern Canada in early 2007. Their subsidiary Fido Solutions offers 3G as well. Because they were the only incumbent carrier (out of 3) with UMTS/HSDPA capability. Realizing they would miss out on roaming revenue from the 2010 Winter Olympics, Bell and Telus formed a joint venture and rolled out a shared HSDPA network using Nokia Siemens technology. Bell launched their 3G wireless lineup on 4 November 2009, and Telus followed suit a day later on 5 November 2009.
Mobitel Iraq is the first mobile 3G operator in Iraq. It was launched commercially on February 2007.
China announced in May 2008, that the telecoms sector was re-organized and three 3G networks would be allocated so that the largest mobile operator, China Mobile, would retain its GSM customer base. China Unicom would retain its GSM customer base but relinquish its CDMA2000 customer base, and launch 3G on the globally leading WCDMA (UMTS) standard. The CDMA2000 customers of China Unicom would go to China Telecom, which would then launch 3G on the CDMA2000 1x EV-DO standard. This meant that China would have all three main cellular technology 3G standards in commercial use. Finally in January 2009, Ministry of industry and Information Technology of China has awarded licenses of all three standards,TD-SCDMA to China Mobile, WCDMA to China Unicom and CDMA2000 to China Telecom. The launch of 3G occurred on 1 October 2009, to coincide with the 60th Anniversary of the Founding of the People's Republic of China.
In November 2008, Turkey has auctioned four IMT 2000/UMTS standard 3G licenses with 45, 40, 35 and 25 MHz top frequencies. Turkcell has won the 45 MHz band with its €358 million offer followed by Vodafone and Avea leasing the 40 and 35 MHz frequencies respectively for 20 years. The 25 MHz top frequency license remains to be auctioned.
The first African use of 3G technology was a 3G videocall made in Johannesburg on the Vodacom network in November 2004. The first commercial launch of 3G in Africa was by EMTEL in Mauritius on the W-CDMA standard. In north African Morocco in late March 2006, a 3G service was provided by the new company Wana.
T-Mobile, a major Telecommunication services provider has recently rolled out a list of over 120 U.S. cities which will be provided with 3G Network coverage in the year 2009.[12]
In 2008, India entered into 3G Mobile arena with the launch of 3G enabled Mobile services by Mahanagar Telephone Nigam Limited (MTNL). MTNL is the first Mobile operator in India to launch 3G services.Government owned BSNL has already been provided with a 3G license and has been operating its services in many cities. Nation wide auction of 3G wireless spectrum in April 2010 has been announced, and 3G services by private service providers are expected by the end of 2010.
Features
Data rates
ITU has not provided a clear definition of the data rate users can expect from 3G equipment or providers. Thus users sold 3G service may not be able to point to a standard and say that the rates it specifies are not being met. While stating in commentary that "it is expected that IMT-2000 will provide higher transmission rates: a minimum data rate of 2 Mbit/s for stationary or walking users, and 348 kbit/s in a moving vehicle,"[13] the ITU does not actually clearly specify minimum or average rates or what modes of the interfaces qualify as 3G, so various rates are sold as 3G intended to meet customers expectations of broadband data.
Security
3G networks greater security than their predecessors the 2G. By allowing the UE (User Equipment) to authenticate the network it is attaching to, the user can be sure the network is the intended one and not an impersonator. 3G networks use the KASUMI block crypto instead of the older A5/1 stream cipher. However, a number of serious weaknesses in the KASUMI cipher have been identified [14].
In addition to the 3G network infrastructure security, end-to-end security is offered when application frameworks such as IMS are accessed, although this is not strictly a 3G property.
Applications
The bandwidth and location information available to 3G devices gives rise to applications not previously available to mobile phone users. Some of the applications are:
• Mobile TV - a provider redirects a TV channel directly to the subscriber's phone where it can be watched.
• Video on demand - a provider sends a movie to the subscriber's phone.
• Video conferencing - subscribers can see as well as talk to each other.
• Tele-medicine - a medical provider monitors or provides advice to the potentially isolated subscriber.
• Location-based services - a provider sends localized weather or traffic conditions to the phone, or the phone allows the subscriber to find nearby businesses or friends.
Evolution
Both 3GPP and 3GPP2 are currently working on extensions to 3G standard that are based on an all-IP network infrastructure and using advanced wireless technologies such as MIMO, these specifications already display features characteristic for IMT-Advanced (4G), the successor of 3G. However, falling short of the bandwidth requirements for 4G (which is 1 Gbit/s for stationary and 100 Mbit/s for mobile operation), these standards are classified as 3.9G or Pre-4G.
CONCLUSION:
3GPP plans to meet the 4G goals with LTE Advanced, whereas Qualcomm has halted development of UMB in favour of the LTE family.[5]
On 14 December 2009, Telia Sonera announced in an official press release that "We are very proud to be the first operator in the world to offer our customers 4G services."[15] With the launch of their LTE network, initially they are offering pre-4G (or beyond 3G) services in Stockholm, Sweden and Oslo, Norway.
INTRODUCTION:
There are evolutionary standards that are backwards-compatible extensions to pre-existing 2G networks as well as revolutionary standards that require all-new networks and frequency allocations.[3] The later group is the UMTS family, which consists of standards developed for IMT-2000, as well as the independently-developed standards DECT and WiMAX, which were included because they fit the IMT-2000 definitionONLINE EXAMINATIONS
History
The first pre-commercial 3G network was launched by NTT DoCoMo in Japan branded FOMA, in May 2001 on a pre-release of W-CDMA technology.[7] The first commercial launch of 3G was also by NTT DoCoMo in Japan on 1 October 2001, although it was initially somewhat limited in scope;[8][9] broader availability was delayed by apparent concerns over reliability.[10] The second network to go commercially live was by SK Telecom in South Korea on the 1xEV-DO technology in January 2002. By May 2002 the second South Korean 3G network was by KT on EV-DO and thus the Koreans were the first to see competition among 3G operators.
The first European pre-commercial network was at the Isle of Man by Manx Telecom, the operator then owned by British Telecom, and the first commercial network in Europe was opened for business by Telenor in December 2001 with no commercial handsets and thus no paying customers. These were both on the W-CDMA technology.
The first commercial United States 3G network was by Monet Mobile Networks, on CDMA2000 1x EV-DO technology, but this network provider later shut down operations. The second 3G network operator in the USA was Verizon Wireless in October 2003 also on CDMA2000 1x EV-DO. AT&T Mobility is also a true 3G network, having completed its upgrade of the 3G network to HSUPA.
The first pre-commercial demonstration network in the southern hemisphere was built in Adelaide, South Australia by m.Net Corporation in February 2002 using UMTS on 2100 MHz. This was a demonstration network for the 2002 IT World Congress. The first commercial 3G network was launched by Hutchison Telecommunications branded as Three in March 2003.
In December 2007, 190 3G networks were operating in 40 countries and 154 HSDPA networks were operating in 71 countries, according to the Global Mobile Suppliers Association (GSA). In Asia, Europe, Canada and the USA, telecommunication companies use W-CDMA technology with the support of around 100 terminal designs to operate 3G mobile networks.
In Europe, mass market commercial 3G services were introduced starting in March 2003 by 3 (Part of Hutchison Whampoa) in the UK and Italy. The European Union Council suggested that the 3G operators should cover 80% of the European national populations by the end of 2005.
Roll-out of 3G networks was delayed in some countries by the enormous costs of additional spectrum licensing fees. (See Telecoms crash.) In many countries, 3G networks do not use the same radio frequencies as 2G, so mobile operators must build entirely new networks and license entirely new frequencies; an exception is the United States where carriers operate 3G service in the same frequencies as other services. The license fees in some European countries were particularly high, bolstered by government auctions of a limited number of licenses and sealed bid auctions, and initial excitement over 3G's potential. Other delays were due to the expenses of upgrading equipment for the new systems.
By June 2007 the 200 millionth 3G subscriber had been connected. Out of 3 billion mobile phone subscriptions worldwide this is only 6.7%. In the countries where 3G was launched first - Japan and South Korea - 3G penetration is over 70%.[11] In Europe the leading country is Italy with a third of its subscribers migrated to 3G. Other leading countries by 3G migration include UK, Austria, Australia and Singapore at the 20% migration level. A confusing statistic is counting CDMA2000 1x RTT customers as if they were 3G customers. If using this definition, then the total 3G subscriber base would be 475 million at June 2007 and 15.8% of all subscribers worldwide.
In Canada, Rogers Wireless was the first to implement 3G technology, with HSDPA services in eastern Canada in early 2007. Their subsidiary Fido Solutions offers 3G as well. Because they were the only incumbent carrier (out of 3) with UMTS/HSDPA capability. Realizing they would miss out on roaming revenue from the 2010 Winter Olympics, Bell and Telus formed a joint venture and rolled out a shared HSDPA network using Nokia Siemens technology. Bell launched their 3G wireless lineup on 4 November 2009, and Telus followed suit a day later on 5 November 2009.
Mobitel Iraq is the first mobile 3G operator in Iraq. It was launched commercially on February 2007.
China announced in May 2008, that the telecoms sector was re-organized and three 3G networks would be allocated so that the largest mobile operator, China Mobile, would retain its GSM customer base. China Unicom would retain its GSM customer base but relinquish its CDMA2000 customer base, and launch 3G on the globally leading WCDMA (UMTS) standard. The CDMA2000 customers of China Unicom would go to China Telecom, which would then launch 3G on the CDMA2000 1x EV-DO standard. This meant that China would have all three main cellular technology 3G standards in commercial use. Finally in January 2009, Ministry of industry and Information Technology of China has awarded licenses of all three standards,TD-SCDMA to China Mobile, WCDMA to China Unicom and CDMA2000 to China Telecom. The launch of 3G occurred on 1 October 2009, to coincide with the 60th Anniversary of the Founding of the People's Republic of China.
In November 2008, Turkey has auctioned four IMT 2000/UMTS standard 3G licenses with 45, 40, 35 and 25 MHz top frequencies. Turkcell has won the 45 MHz band with its €358 million offer followed by Vodafone and Avea leasing the 40 and 35 MHz frequencies respectively for 20 years. The 25 MHz top frequency license remains to be auctioned.
The first African use of 3G technology was a 3G videocall made in Johannesburg on the Vodacom network in November 2004. The first commercial launch of 3G in Africa was by EMTEL in Mauritius on the W-CDMA standard. In north African Morocco in late March 2006, a 3G service was provided by the new company Wana.
T-Mobile, a major Telecommunication services provider has recently rolled out a list of over 120 U.S. cities which will be provided with 3G Network coverage in the year 2009.[12]
In 2008, India entered into 3G Mobile arena with the launch of 3G enabled Mobile services by Mahanagar Telephone Nigam Limited (MTNL). MTNL is the first Mobile operator in India to launch 3G services.Government owned BSNL has already been provided with a 3G license and has been operating its services in many cities. Nation wide auction of 3G wireless spectrum in April 2010 has been announced, and 3G services by private service providers are expected by the end of 2010.
Features
Data rates
ITU has not provided a clear definition of the data rate users can expect from 3G equipment or providers. Thus users sold 3G service may not be able to point to a standard and say that the rates it specifies are not being met. While stating in commentary that "it is expected that IMT-2000 will provide higher transmission rates: a minimum data rate of 2 Mbit/s for stationary or walking users, and 348 kbit/s in a moving vehicle,"[13] the ITU does not actually clearly specify minimum or average rates or what modes of the interfaces qualify as 3G, so various rates are sold as 3G intended to meet customers expectations of broadband data.
Security
3G networks greater security than their predecessors the 2G. By allowing the UE (User Equipment) to authenticate the network it is attaching to, the user can be sure the network is the intended one and not an impersonator. 3G networks use the KASUMI block crypto instead of the older A5/1 stream cipher. However, a number of serious weaknesses in the KASUMI cipher have been identified [14].
In addition to the 3G network infrastructure security, end-to-end security is offered when application frameworks such as IMS are accessed, although this is not strictly a 3G property.
Applications
The bandwidth and location information available to 3G devices gives rise to applications not previously available to mobile phone users. Some of the applications are:
• Mobile TV - a provider redirects a TV channel directly to the subscriber's phone where it can be watched.
• Video on demand - a provider sends a movie to the subscriber's phone.
• Video conferencing - subscribers can see as well as talk to each other.
• Tele-medicine - a medical provider monitors or provides advice to the potentially isolated subscriber.
• Location-based services - a provider sends localized weather or traffic conditions to the phone, or the phone allows the subscriber to find nearby businesses or friends.
Evolution
Both 3GPP and 3GPP2 are currently working on extensions to 3G standard that are based on an all-IP network infrastructure and using advanced wireless technologies such as MIMO, these specifications already display features characteristic for IMT-Advanced (4G), the successor of 3G. However, falling short of the bandwidth requirements for 4G (which is 1 Gbit/s for stationary and 100 Mbit/s for mobile operation), these standards are classified as 3.9G or Pre-4G.
CONCLUSION:
3GPP plans to meet the 4G goals with LTE Advanced, whereas Qualcomm has halted development of UMB in favour of the LTE family.[5]
On 14 December 2009, Telia Sonera announced in an official press release that "We are very proud to be the first operator in the world to offer our customers 4G services."[15] With the launch of their LTE network, initially they are offering pre-4G (or beyond 3G) services in Stockholm, Sweden and Oslo, Norway.
WIFI
WIRELESS FIDELITY
INTRODUCTION:
Wi: Wirless Fi: Fidelity.
The name itself indicates that wireless data carrying capacity so it is called wireless Fidelity. WiFi is the way to connect devices together without wires.
HOW DOES IT WORK:
Wireless Internet Access has four components that form its structure. The four components are,
1)High-speed access which is also known as broadband is an internet connection which is generally faster than dial up service. Example: satellite service.
2) Network Gateway is between your high-speed access connection and the wireless network, it acts like a gate. This gate will prevent people from accessing your wireless network unless you know about it, the gateway also allows managing tools as well.
3) Wireless network is a system of connecting PC's and otherdevices within the same physical proximity using high frequency radiowaves instead of wires.
4) Wireless customers are people who have a PC and a wireless adapter . The wireless adapter can be built in or it can be an external device plugged into your computer.
The radio waves are transmitted from antennas and routers and are picked up by WiFi receivers s. When these devices receive a signal, the WiFi card then reads the signals and produces an internet connection.
HOT SPOTS:
Hot spots are connection points for WiFi networks; areas where wireless internet is available for those who have internet ready devices. Hot spots are becoming available everywhere, in airports, hotels, etc.
HOW SECURE IS WiFi:
wireless LANs are more vulnerable due to the fact that the data travels over radio waves which are much easier to intercept. In 2002 the wireless LANs security was upgraded when WiFi Protected Access (WPA) was introduced. WPA had several improvements like better encryption, and it also used the RADIUS-based 802.1X, which authorizes the user to gain access to the ISP provider.
In 2004 802.11i was completed and became the new and current standard for WiFi. 802.11i is also nown as WPA2. WPA2 upgraded its encryption of data with the Advanced Encryption Standard
Many corporations today use a Virtual Private Network (VPN) to send and receive important information by creating a tunnel connecting the two end users. VPN encrypts the data to keep any hackers from stealing the information while it is being sent
FUTURE WiFi ADVANCEMENTS:
BLUETOOTH:
It is a wireless technology that allows computers, phones and other devices to talk to each other over short distances. In non-discoverable mode of devices all your information and data are safe. However, in order to receive business contacts wirelessly you will need to place the phone in discoverable mode.
ULTRA WIDEBAND MODULATIONS(UWB): one of the most leading technologies is Ultra-wideband (UWB) modulations. UWB usually refers to a radio modulation technique based on transmitting very-short-duration pulses . UWB operates at such low power, it has very little interference impact on other systems.
RADIO FREQUENCY IDENTIFICATION TAG (RFID):
It is a small silicon microchip attached to an antenna that emits a unique serial number via radio over short distances. And, just as a bar code or magnetic strip must be scanned to get the information, the RFID device must be scanned to retrieve the information. . RFID tags can also be placed in living organisms to help track or identify them within short distances. RFID tags can be read without your knowledge which enables others to view information about you.
ADVANTAGES:
Reduces the costs of network deployment and expansion.
The price of chipsets for Wi-Fi continues to drop.
Unlike mobile telephones, any standard Wi-Fi device will work anywhere in the world.
The current version WPA2 is not easily defeated, provided strong passwords are used.
LIMITATIONS:
Wi-Fi signal actually occupies five channels in the 2.4 GHz band resulting in only three non-overlapped channels in the U.S.and three or four in Europe.
Security problems.
WAYS TO PROTECT YOUR WIRELESS COMPUTER:
You should have strong passwords on your wireless.
Another way to protect yourself is to download firewalls onto your computer.
Downloading anti-virus software onto your computer is another way to protect your computer. You should update your anti-virus software often .
Also when you are not on your computer, you should turn it off.
CONCLUSION:
WIFI has a lot of advantages over its disadvantages, hence we must understand that we have to take the proper precautions to make the WIFI technology more secure .
INTRODUCTION:
Wi: Wirless Fi: Fidelity.
The name itself indicates that wireless data carrying capacity so it is called wireless Fidelity. WiFi is the way to connect devices together without wires.
HOW DOES IT WORK:
Wireless Internet Access has four components that form its structure. The four components are,
1)High-speed access which is also known as broadband is an internet connection which is generally faster than dial up service. Example: satellite service.
2) Network Gateway is between your high-speed access connection and the wireless network, it acts like a gate. This gate will prevent people from accessing your wireless network unless you know about it, the gateway also allows managing tools as well.
3) Wireless network is a system of connecting PC's and otherdevices within the same physical proximity using high frequency radiowaves instead of wires.
4) Wireless customers are people who have a PC and a wireless adapter . The wireless adapter can be built in or it can be an external device plugged into your computer.
The radio waves are transmitted from antennas and routers and are picked up by WiFi receivers s. When these devices receive a signal, the WiFi card then reads the signals and produces an internet connection.
HOT SPOTS:
Hot spots are connection points for WiFi networks; areas where wireless internet is available for those who have internet ready devices. Hot spots are becoming available everywhere, in airports, hotels, etc.
HOW SECURE IS WiFi:
wireless LANs are more vulnerable due to the fact that the data travels over radio waves which are much easier to intercept. In 2002 the wireless LANs security was upgraded when WiFi Protected Access (WPA) was introduced. WPA had several improvements like better encryption, and it also used the RADIUS-based 802.1X, which authorizes the user to gain access to the ISP provider.
In 2004 802.11i was completed and became the new and current standard for WiFi. 802.11i is also nown as WPA2. WPA2 upgraded its encryption of data with the Advanced Encryption Standard
Many corporations today use a Virtual Private Network (VPN) to send and receive important information by creating a tunnel connecting the two end users. VPN encrypts the data to keep any hackers from stealing the information while it is being sent
FUTURE WiFi ADVANCEMENTS:
BLUETOOTH:
It is a wireless technology that allows computers, phones and other devices to talk to each other over short distances. In non-discoverable mode of devices all your information and data are safe. However, in order to receive business contacts wirelessly you will need to place the phone in discoverable mode.
ULTRA WIDEBAND MODULATIONS(UWB): one of the most leading technologies is Ultra-wideband (UWB) modulations. UWB usually refers to a radio modulation technique based on transmitting very-short-duration pulses . UWB operates at such low power, it has very little interference impact on other systems.
RADIO FREQUENCY IDENTIFICATION TAG (RFID):
It is a small silicon microchip attached to an antenna that emits a unique serial number via radio over short distances. And, just as a bar code or magnetic strip must be scanned to get the information, the RFID device must be scanned to retrieve the information. . RFID tags can also be placed in living organisms to help track or identify them within short distances. RFID tags can be read without your knowledge which enables others to view information about you.
ADVANTAGES:
Reduces the costs of network deployment and expansion.
The price of chipsets for Wi-Fi continues to drop.
Unlike mobile telephones, any standard Wi-Fi device will work anywhere in the world.
The current version WPA2 is not easily defeated, provided strong passwords are used.
LIMITATIONS:
Wi-Fi signal actually occupies five channels in the 2.4 GHz band resulting in only three non-overlapped channels in the U.S.and three or four in Europe.
Security problems.
WAYS TO PROTECT YOUR WIRELESS COMPUTER:
You should have strong passwords on your wireless.
Another way to protect yourself is to download firewalls onto your computer.
Downloading anti-virus software onto your computer is another way to protect your computer. You should update your anti-virus software often .
Also when you are not on your computer, you should turn it off.
CONCLUSION:
WIFI has a lot of advantages over its disadvantages, hence we must understand that we have to take the proper precautions to make the WIFI technology more secure .
SATELLITE COMMUNICATION
SATELLITE COMMUNICATION
A communications satellite (sometimes abbreviated to SATCOM) is an artificial satellite stationed in space for the purposes of telecommunication.
In telecommunication, the use of artificial satellites to provide communications links between various points on Earth. Communications satellites relay voice, video, and data signals between widely separated fixed locations (e.g., between the switching offices of two different national telephone networks), between a fixed location and numerous small fixed or mobile receivers in a designated area (e.g., direct satellite broadcasting of television programming), and between individual mobile users (e.g., aircraft, ships, motor vehicles, and personal handheld units). The technique involves transmitting signals from an Earth station to a satellite. Equipment onboard the satellite receives the signals, amplifies them, and retransmits them to a region of Earth. Receiving stations within this region pick up the signals, thus completing the link.
Satellites provide communications links via microwave radio, most commonly in the superhigh-frequency band of 3 to 30 gigahertz (3 billion to 30 billion hertz, or cycles per second). These frequencies correspond to wavelengths ranging from 10 cm to 1 cm (4 inches to 0.4 inch). On land this can be achieved by using towers or hilltop locations, but microwave communication across oceans is impossible without the use of satellites.
FREQUENCY BANDS
The specific frequency bands open to civilian satellite communication are assigned by the International Telecommunication Union, based in Geneva. Each band consists of an uplink (Earth-to-satellite) frequency and a downlink (satellite-to-Earth) frequency .The two bands that have been in use longest, and still carry the most traffic, are the C band, with uplink frequencies centred on 6 gigahertz and downlink frequencies centred on 4 gigahertz, and the Ku band, with uplink/downlink frequencies centred on 14/11 gigahertz.
TYPES
There are three different types of satellite systems.
1. International satellite communication system INTELSAT.
2. Domestic satellite system DOMSAT.
3. Search and rescue system SARSAT.
INTELSAT
The INTELSAT Organization was established in 1964 to handle the myriad of technical and administrative problems associated with a world wide telecommunication system. The international regions served by INTELSAT are divided in to the Atlantic Ocean region (AOR), the Pacific Ocean Region (POR) and the Indian Ocean region (IOR). For each region , satellites are positioned in geo-stationary orbit above the particular Ocean, where they provide a transoceanic telecommunication route. In addition to providing trans oceanic routes, the INTELSAT satellites are used for domestic services within any given country and regional services between countries. Two such services are vista for telephony and Intelnet for data exchange.
DOMSAT
Domestic satellites are used to provide various telecommunication services, such as voice, data, and video transmission (T.V channels), with in a country.
SARSAT
SARSAT is one type of Polar orbiting satellites.
Polar-orbiting satellites orbit the earth in such a way as to cover the north and south polar-regions. Infinite number of polar polar satellite orbits are possible
Polar satellites are used to provide environmental data , and to help locate ships and aircrafts in distress .This service known as SARSAT, for search and rescue satellite.
ADVANTAGES
o HIGH CAPACITY
o LONG RANGE
o GOOD QUALITY
o COVERAGE
o REALIABLITY
APPLICATIONS
AIR TRAFFIC CONTROL(ATC)
Satellites can provide two types of communication services to support air traffic control functions. Air traffic control satellites collect navigation data from ground monitoring systems and broadcasts it to aircraft aloft, greatly increasing the navigational accuracy and reliability of the global positioning system (GPS) for aircraft location and safe take-offs and landings. These satellites also provide a highly reliable digital communications path for air traffic controllers and pilots to share vital flight information.
BROAD BAND DIGITAL COMMUNICATIONS
Broadband satellites transmit high-speed data and video directly to consumers and businesses. Markets for broadband services also include interactive TV, wholesale telecommunications, telephony, and point-of-sale communications, such as credit card transactions and inventory control.
DIRECT BROADCAST SATELLITES
Direct-broadcast satellites (DBS) transmit signals for direct reception by the general public, such as satellite television and radio. Satellite signals are sent directly to users through their own receiving antennas or satellite dishes, in contrast to satellite/cable systems in which signals are received by a ground station, and re-broadcast to users by cable.
ENVIRONMENTAL MONITORING
Environmental monitoring satellites carry highly sensitive imagers and sounders to monitor the Earth's environment, including the vertical thermal structure of the atmosphere; the movement and formation of clouds; ocean temperatures; snow levels; glacial movement; and volcanic activity. Large-scale computers use this data to model the entire earth's atmosphere and create weather forecasts such as those provided by national weather services in the U.S. and abroad
FIXED SATELLITES SERVICES
Satellites providing Fixed-Satellite Services (FSS) transmit radio communications between ground Earth stations at fixed locations. Satellite-transmitted information is carried in the form of radio-frequency signals. Any number of satellites may be used to link these stations. Earth stations that are part of fixed-satellite services networks also use satellite news gathering vehicles to broadcast from media events, such as sporting events or news conferences. In addition, FSS satellites provide a wide variety of services including paging networks and point-of-sale support, such as credit card transactions and inventory control.
MILTARY APPLICATIONS
RADAR(Radio Detection And Ranging) is used to detect the targets such as submarines and air craft along with its distance.
CONCLUSION
Thus satellite communication provides the basis of the different types of communication in today’s world.
A communications satellite (sometimes abbreviated to SATCOM) is an artificial satellite stationed in space for the purposes of telecommunication.
In telecommunication, the use of artificial satellites to provide communications links between various points on Earth. Communications satellites relay voice, video, and data signals between widely separated fixed locations (e.g., between the switching offices of two different national telephone networks), between a fixed location and numerous small fixed or mobile receivers in a designated area (e.g., direct satellite broadcasting of television programming), and between individual mobile users (e.g., aircraft, ships, motor vehicles, and personal handheld units). The technique involves transmitting signals from an Earth station to a satellite. Equipment onboard the satellite receives the signals, amplifies them, and retransmits them to a region of Earth. Receiving stations within this region pick up the signals, thus completing the link.
Satellites provide communications links via microwave radio, most commonly in the superhigh-frequency band of 3 to 30 gigahertz (3 billion to 30 billion hertz, or cycles per second). These frequencies correspond to wavelengths ranging from 10 cm to 1 cm (4 inches to 0.4 inch). On land this can be achieved by using towers or hilltop locations, but microwave communication across oceans is impossible without the use of satellites.
FREQUENCY BANDS
The specific frequency bands open to civilian satellite communication are assigned by the International Telecommunication Union, based in Geneva. Each band consists of an uplink (Earth-to-satellite) frequency and a downlink (satellite-to-Earth) frequency .The two bands that have been in use longest, and still carry the most traffic, are the C band, with uplink frequencies centred on 6 gigahertz and downlink frequencies centred on 4 gigahertz, and the Ku band, with uplink/downlink frequencies centred on 14/11 gigahertz.
TYPES
There are three different types of satellite systems.
1. International satellite communication system INTELSAT.
2. Domestic satellite system DOMSAT.
3. Search and rescue system SARSAT.
INTELSAT
The INTELSAT Organization was established in 1964 to handle the myriad of technical and administrative problems associated with a world wide telecommunication system. The international regions served by INTELSAT are divided in to the Atlantic Ocean region (AOR), the Pacific Ocean Region (POR) and the Indian Ocean region (IOR). For each region , satellites are positioned in geo-stationary orbit above the particular Ocean, where they provide a transoceanic telecommunication route. In addition to providing trans oceanic routes, the INTELSAT satellites are used for domestic services within any given country and regional services between countries. Two such services are vista for telephony and Intelnet for data exchange.
DOMSAT
Domestic satellites are used to provide various telecommunication services, such as voice, data, and video transmission (T.V channels), with in a country.
SARSAT
SARSAT is one type of Polar orbiting satellites.
Polar-orbiting satellites orbit the earth in such a way as to cover the north and south polar-regions. Infinite number of polar polar satellite orbits are possible
Polar satellites are used to provide environmental data , and to help locate ships and aircrafts in distress .This service known as SARSAT, for search and rescue satellite.
ADVANTAGES
o HIGH CAPACITY
o LONG RANGE
o GOOD QUALITY
o COVERAGE
o REALIABLITY
APPLICATIONS
AIR TRAFFIC CONTROL(ATC)
Satellites can provide two types of communication services to support air traffic control functions. Air traffic control satellites collect navigation data from ground monitoring systems and broadcasts it to aircraft aloft, greatly increasing the navigational accuracy and reliability of the global positioning system (GPS) for aircraft location and safe take-offs and landings. These satellites also provide a highly reliable digital communications path for air traffic controllers and pilots to share vital flight information.
BROAD BAND DIGITAL COMMUNICATIONS
Broadband satellites transmit high-speed data and video directly to consumers and businesses. Markets for broadband services also include interactive TV, wholesale telecommunications, telephony, and point-of-sale communications, such as credit card transactions and inventory control.
DIRECT BROADCAST SATELLITES
Direct-broadcast satellites (DBS) transmit signals for direct reception by the general public, such as satellite television and radio. Satellite signals are sent directly to users through their own receiving antennas or satellite dishes, in contrast to satellite/cable systems in which signals are received by a ground station, and re-broadcast to users by cable.
ENVIRONMENTAL MONITORING
Environmental monitoring satellites carry highly sensitive imagers and sounders to monitor the Earth's environment, including the vertical thermal structure of the atmosphere; the movement and formation of clouds; ocean temperatures; snow levels; glacial movement; and volcanic activity. Large-scale computers use this data to model the entire earth's atmosphere and create weather forecasts such as those provided by national weather services in the U.S. and abroad
FIXED SATELLITES SERVICES
Satellites providing Fixed-Satellite Services (FSS) transmit radio communications between ground Earth stations at fixed locations. Satellite-transmitted information is carried in the form of radio-frequency signals. Any number of satellites may be used to link these stations. Earth stations that are part of fixed-satellite services networks also use satellite news gathering vehicles to broadcast from media events, such as sporting events or news conferences. In addition, FSS satellites provide a wide variety of services including paging networks and point-of-sale support, such as credit card transactions and inventory control.
MILTARY APPLICATIONS
RADAR(Radio Detection And Ranging) is used to detect the targets such as submarines and air craft along with its distance.
CONCLUSION
Thus satellite communication provides the basis of the different types of communication in today’s world.
Simple way to find your OS(WINDOWS) version..........
SOLUTION:
* Get run dialog box (Start->Run).
* Type WINVER.
* Press Enter, Now you can find a window on the screen that tell about your OS.
* Get run dialog box (Start->Run).
* Type WINVER.
* Press Enter, Now you can find a window on the screen that tell about your OS.
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