A Basic Comparison between GSM and CDMA 2000

GSM is the most popular standard for mobile phones in the world. GSM as elaborated Global System for Mobile communications is largely dominate the share of telecommunication network worldwide. Its promoter, the GSM Association, estimates that 80% of the global mobile market uses the standard. GSM is used by over 3 billion people across more than 212 countries and territories. Its ubiquity makes international roaming very common between mobile phone operators, enabling subscribers to use their phones in many parts of the world. GSM differs from its predecessors in that both signaling and speech channels are digital, and thus is considered a second generation (2G) mobile phone system. This has also meant that data communication was easy to build into the system.

CDMA, Code Division Multiple Access, on the other hand, uses a special type of digital modulation called spread spectrum which spreads the voice data over a very wide channel in pseudorandom fashion. The receiver undoes the randomization to collect the bits together and produce the sound.

For comparison, imagine a cocktail party, where couples are talking to each other in a single room. The room represents the available bandwidth. In GSM, a speaker takes turns talking to a listener. The speaker talks for a short time and then stops to let another pair talk. There is never more than one speaker talking in the room, no one has to worry about two conversations mixing. In CDMA, any speaker can talk at any time; however each uses a different language. Each listener can only understand the language of their partner. As more and more couples talk, the background noise (representing the noise floor) gets louder, but because of the difference in languages, conversations do not mix.

Feature of GSM

• Technology: TDMA
• Generation: 2G
• Digital: Yes
• Year of First Use: 1991
• Market share : 72%
• Roaming: Worldwide
• Handset interoperability: SIM Card
• Operator locking: Unlockable
• Signal quality/coverage area: Good coverage indoors on 850/900 MHz.
• Battery life: Very Good due to simple protocol, ggod coverage.
  

Features of CDMA 2000

• Technology: CDMA
• Generation: 3G
• Digital: Yes
• Year of First Use: 200/2002
• Market share : 12%
• Roaming: Limited
• Handset interoperability: RUIM (not commonly implemented)
• Operator locking: ESN
• Signal quality/coverage area: Unlimited cell size, low transmitter.
• Battery life: Lower due to high demands of CDMA power control snd young chipsets.

WiMAX - The Future of Everything

WiMAX, meaning Worldwide Interoperability for Microwave Access, is a telecommunications technology that provides wireless transmission of data using a variety of transmission modes. In WiMax technology, differnet modes like point-to-multipoint links to portable and fully mobile internet access are used. The technology provides up to 72 Mbit/s symmetric broadband speed without the need for cables. The technology is based on the IEEE 802.16 standard (also called Broadband Wireless Access or Fixes WiMax). The name "WiMAX" was created by the WiMAX Forum, which was formed in June 2001 to promote conformity and interoperability of the standard. The forum defined WiMAX as - a standards-based technology enabling the delivery of last mile wireless broadband access as an alternative to cable and DSL. The WiMAX Forum now claims there are over 400 WiMAX networks deployed in over 130 countries.

Companies are closely examining WiMAX for last mile connectivity. The resulting competition may bring lower pricing for both home and business customers or bring broadband access to places where it has been economically unavailable.

The bandwidth and range of WiMAX make it suitable for the following potential applications:

• Connecting Wi-Fi hotspots to the Internet.
• Providing a wireless alternative to cable and DSL for "last mile" broadband access.
• Providing data and telecommunications services.
• Providing a source of Internet connectivity as part of a business continuity plan. That is, if a business has a fixed and a wireless Internet connection, especially from unrelated providers, they are unlikely to be affected by the same service outage.
• Providing portable connectivity.

WiMAX access was used to assist with communications in Aceh, Indonesia, after the tsunami in December 2004. All communication infrastructure in the area, other than amateur radio, was destroyed, making the survivors unable to communicate with people outside the disaster area and vice versa. WiMAX provided broadband access that helped regenerate communication to and from Aceh. In addition, WiMAX was used by Intel Corporation to assist the FCC and FEMA in their communications efforts in the areas affected by Hurricane Katrina.

WiMAX subscriber units are available in both indoor and outdoor versions from several manufacturers. Self-install indoor units are convenient, but radio losses mean that the subscriber must be significantly closer to the WiMAX base station than with professionally-installed external units. As such, indoor-installed units require a much higher infrastructure investment as well as operational cost (site lease, backhaul, maintenance) due to the high number of base stations required to cover a given area. Indoor units are comparable in size to a cable modem or DSL modem. Outdoor units are roughly the size of a laptop PC, and their installation is comparable to a residential satellite dish.

With the potential of mobile WiMAX, there is an increasing focus on portable units. This includes handsets (similar to cellular smartphones) and PC peripherals (PC Cards or USB dongles). In addition, there is much emphasis from operators on consumer electronics devices (game terminals, MP3 players and the like); it is notable this is more similar to Wi-Fi than 3G cellular technologies.

Current certified devices can be found at the WiMAX Forum web site. This is not a complete list of devices available as certified modules are embedded into laptops, MIDs (Mobile Internet Devices), and private labeled devices.

WiMAX is a possible replacement candidate for cellular phone technologies such as GSM and CDMA, or can be used as a layover to increase capacity. It has also been considered as a wireless backhaul technology for 2G, 3G, and 4G networks in both developed and poor nations.

Comparisons and confusion between WiMAX and Wi-Fi are frequent, possibly because both begin with the same two letters, are based upon IEEE standards beginning with "802.", and are related to wireless connectivity and Internet access. However, the two standards are aimed at different applications.

• WiMAX uses licensed spectrum to deliver a point-to-point connection to the Internet from an ISP to an end user. Different 802.16 standards provide different types of access, from portable (similar to a cordless phone) to fixed (an alternative to wired access, where the end user's wireless termination point is fixed in location.) WiMax is developed primarily for wireless metropolitan area networks (WMANs), with a transmission range of a few kilometers.
• Wi-Fi uses unlicensed spectrum to provide access to a network. Wi-Fi has primarily been developed for wireless local area networks (WLANs), with a transmission range of up to 100m. Wi-Fi therefore is often used for last-mile delivery, such as hotspots.
• WiMAX and Wi-Fi have quite different Quality of Service (QoS) mechanisms. WiMAX uses a mechanism based on connections between the Base Station and the user device. Each connection is based on specific scheduling algorithms. Wi-Fi has introduced a QoS mechanism similar to fixed Ethernet, where packets can receive different priorities based on their tags. For example VoIP traffic may be given priority over web browsing.
• Wi-Fi runs on the MAC's CSMA/CA protocol, which is connectionless and contention based, whereas WiMAX runs a connection-oriented MAC.

A commonly-held misconception is that WiMAX will deliver 70 Mbit/s over 31 miles/50 kilometers. In reality, WiMAX can only do one or the other — operating over maximum range (31 miles/50 km) increases bit error rate and thus must use a lower bitrate. Lowering the range allows a device to operate at higher bitrates.

Typically, fixed WiMAX networks have a higher-gain directional antenna installed near the client (customer) which results in greatly increased range and throughput. Mobile WiMAX networks are usually made of indoor "customer premises equipment" (CPE) such as desktop modems, laptops with integrated Mobile WiMAX or other Mobile WiMAX devices. Mobile WiMAX devices typically have an omni-directional antenna which is of lower-gain compared to directional antennas but are more portable. In practice, this means that in a line-of-sight environment with a portable Mobile WiMAX CPE, speeds of 10 Mbit/s at 6 miles/10 km could be delivered. However, in urban environments they may not have line-of-sight and therefore users may only receive 10 Mbit/s over 2 km. In current deployments, throughputs are often closer to 2 Mbit/s symmetric at 10 km with fixed WiMAX and a high gain antenna. It is also important to consider that a throughput of 2 Mbit/s can mean 2 Mbit/s, symmetric simultaneously, 1 Mbit/s symmetric or some asymmetric mix (e.g. 0.5 Mbit/s downlink and 1.5 Mbit/s uplink or 1.5 Mbit/s downlink and 0.5 Mbit/s uplink), each of which required slightly different network equipment and configurations. Higher-gain directional antennas can be used with a Mobile WiMAX network with range and throughput benefits but the obvious loss of practical mobility.

Like most wireless systems, available bandwidth is shared between users in a given radio sector, so performance could deteriorate in the case of many active users in a single sector. In practice, many users will have a range of 2-, 4-, 6-, 8-, 10- or 12 Mbit/s services and additional radio cards will be added to the base station to increase the capacity as required.

Because of this, various granular and distributed network architectures are being incorporated into WiMAX through independent development and within the IEEE 802.16j mobile multi-hop relay (MMR) task group. This includes wireless mesh, grids, network remote station repeaters which can extend networks and connect to backhaul.

Corruption Perceptions Index - The Report

Since 1995, Transparency International has published an annual Corruption Perceptions Index (CPI). The index is the ordering of countries of the world according to the existance of corruption among the public officials and oliticians. TI defines corruption as "the abuse of entrusted power for private gain".
In 2003 TI covered 133 countries which became 180 in 2007. A higher score means less (perceived) corruption. The results show seven out of every ten countries (and nine out of every ten developing countries) with an index of less than 5 points out of 10.
Transparency International commissioned Johann Graf Lambsdorff of the University of Passau to produce the Corruption Perceptions Index (CPI). The CPI 2005 draws on "16 different polls and surveys from 10 independent institutions.
The institutions who provided data for the CPI 2005 are: Columbia University, Economist Intelligence Unit, Freedom House, Information International, International Institute for Management Development, Merchant International Group, Political and Economic Risk Consultancy, United Nations Economic Commission for Africa, World Economic Forum and World Markets Research Centre.
Early CPIs used public opinion surveys, but now only "experts" are used. TI requires at least three sources to be available in order to rank a country in the CPI.
As this index is based on polls, the results are subjective, and less reliable for countries with fewer sources. Also, what is legally defined (or perceived) to be corruption, differs between jurisdictions: a political donation legal in some jurisdiction may be illegal in another; a matter viewed as acceptable tipping in one country may be viewed as bribery in another.
The Corruption Perceptions Index has drawn increasing criticism in the decade since its launch. This criticism has been directed at the quality of the Index itself, and the lack of actionable insights created from a simple country ranking. Because corruption is willfully hidden, it is impossible to measure directly; instead proxies for corruption are used. The CPI uses an eclectic mix of third-party surveys to sample public perceptions of corruption through a variety of questions, ranging from "Do you trust the government?" to "Is corruption a big problem in your country?"
The use of third-party survey data is a source of critcism. The data can vary widely in methodology and completeness from country to country. The methodology of the Index itself changes from year to year, thus making even basic better-or-worse comparisons difficult. Media outlets, meanwhile, frequently use the raw numbers as a yardstick for government performance, without clarifying what the numbers mean.
The lack of standardization and precision in these surveys is cause for concern. The authors of the CPI argue that averaging enough survey data will solve this; others argue that aggregating imprecise data only masks these flaws without addressing them. In one case, a local Transparency International chapter disowned the index results after a change in methodology caused a country's scores to increase -- media reported it as an "improvement". Other critics point out that definitional problems with the term "corruption" makes the tool problematic for social science.
Aside from precision issues, a more fundamental critique is aimed at the uses of the Index. Critics are quick to conceed that the CPI has been instrumental in creating awareness and stimulating debate about corruption. However, as a source of quantitative data in a field hungry for international datasets, the CPI can take on a life of it's own, appearing in cross-country and year-to-year comparisons that the CPI authors themselves admit are not justified by their methodology. The authors state in 2008: "Year-to-year changes in a country's score can either result from a changed perception of a country's performance or from a change in the CPI’s sample and methodology. The only reliable way to compare a country’s score over time is to go back to individual survey sources, each of which can reflect a change in assessment."
The CPI produces a single score per country, which as noted above, cannot be compared year-to-year. As such, the Index is nearly useless as a tool for evaluating the impact of new policies. In the late 2000s, the field has moved towards unpackable, action-oriented indices (such as those by the International Budget Partnership or Global Integrity), which typically measure public policies that relate to corruption, rather than try to assess "corruption" as a whole via proxy measures like perceptions. These alternative measures use original (often locally collected) data and are limited in scope to specific policy practices (such as public access to parliamentary budget documents).

Transparency International - The International Movement Against Corruption

Transparency International (TI) is an international non-governmental organization addressing corruption. This includes, but is not limited to, political corruption. It is widely known for producing its annual Corruptions Perceptions Index, a comparative listing of corruption worldwide. The international headquarters is located in Berlin, Germany

TI is organised as a group of some 100 national chapters. Originally founded in Germany in 1993 as a not-for-profit organisation, TI is now an international non-governmental organisation, and claims to be moving towards a completely democratic organisational structure. TI says of itself:
"Transparency International is the global civil society organisation leading the fight against corruption. It brings people together in a powerful worldwide coalition to end the devastating impact of corruption on men, women and children around the world. TI's mission is to create change towards a world free of corruption."

It rejects any idea of "northern superiority" regarding corruption and is committed to exposing corruption worldwide.

Since 1995, TI has issued different report related with Corruption. The reports are:

• Corruption Perceptions Index (CPI);
• Global Corruption Report, a Global Corruption Barometer
• Bribe Payers Index.

However the TI USA Chapter has never commented within its publications on any corruption case within the USA, and has taken money from the Boeing Corporation, whose executive Darleen A. Druyun was imprisoned for corrupt activities, leading to the resignation of Boeing CEO Phil Condit.

TI does not undertake investigations on single cases of corruption or expose individual cases. It develops tools for fighting corruption and works with other civil society organisations, companies and governments to implement them. The goal of TI is to be non-partisan and to build coalitions against corruption.

TI's biggest success has been to put the topic of corruption on the world's agenda. International Institutions such as the World Bank and the International Monetary Fund now view corruption as one of the main obstacles for development, whereas prior to the 1990s this topic was not broadly discussed. TI furthermore played a vital role in the introduction of the United Nations Convention against Corruption and the OECD Anti-Bribery Convention.

Corruption- It's Definationa and classification

The basic defination of Corruption can be stated as an "impairment of integrity, virtue or moral principle; depravity, decay, and/or an inducement to wrong by improper or unlawful means, a departure from the original or from what is pure or correct, and/or an agency or influence that corrupts."

In technical term corruption indicate as a general concept describing any organized, interdependent system in which part of the system is either not performing duties it was originally intended to, or performing them in an improper way, to the detriment of the system's original purpose.

Its terminological usage possesses connotations of evil, malignance, sickness, and loss of innocence or purity.

Mike W. Peng describes corruption as the abuse of public power for private benefits, usually in the form of bribery. Also, corruption distorts the basics of competitions by misallocating resources and slowing economic development. Furthermore, according to Transparency International, which is headquarted in Berlin, Germany, and is probably the most influential anticorruption nongovernment organization (NGO), there is a high correlation between corruption and low economic development.

Specific types of corruption include:

• Political corruption, as the dysfunction of a political system or institution in which government officials, political officials or employees seek illegitimate personal gain through actions such as bribery, extortion, cronyism, nepotism, patronage, graft, and embezzlement. Political corruption is a specific form of rent seeking, where access to politics is organized with limited transparency, limited competition and directed towards promoting narrow interests (rent seeking is not to be confused with property rental).
• Corporate corruption, as the abuse of power by corporate managers against the shareholders or consumers.
• Data corruption, as an unintended change to data in storage or in transit.
• Linguistic corruption, as the change in meaning to a language or a text introduced by cumulative errors in transcription as changes in the language speakers' comprehension.
• Visual Corruption, as change of colors , shape , volume couse of resize Computer image.
• Putrefaction or decomposition of recently living matter. This physical process is the primary model of the metaphorical meaning of corruption, so advanced states of corruption in, e.g. a political structure are said to result in their putrefaction.
• Tahrif is the corruption of the Bible according to Islamic doctrine.
  

Facebook's attempt to take user's content right

Facebook, the famous social network in Internet, faces difficulties and it is reverting to its old policy on user information for the present time. The site posted a message on the users home page that it returning to its previous policy and will be return to the latest one after resolving the issues raised by its users and other. The problem started when Facebook changed some words in their policy of Terms of Use. As per the previous Terms of Use, Facebook don’t have any right over the things that posted on this network. But in the latest Terms of Use they replace the said one with “You may remove your User content from the site anytime….(H)owever, you acknowledge that the company may retain archived copies of your user content.” The change was first identified by a consumer advocate Website, The consumerist”, and they flagged the change. After that the users submit their petition to change the Terms of Use and after a long battle Facebook authority said on last Wednesday that they will return to its previous Terms of Use.

Microsoft's fight against Hackers

Software giant Microsoft is offering a $250,000 reward for information leading to the arrest and conviction of hackers behind a powerful computer virus that could lead to millions of PCs being hijacked.

Experts have so far been baffled by the true purpose of the Conficker or Downadup virus, but have described its spread as one of the most serious infections ever seen.
The worm exploits a bug in Microsoft Windows to infect mainly corporate networks, then -- although it has yet to cause any harm -- it opens a link back to its point of origin, meaning it can receive further orders to wreak havoc.

Microsoft has issued a patch to fix the bug, however if a single machine is infected in a large network, it will spread unchecked -- often reinfecting machines that have been disinfected.
The threat from the virus prompted Microsoft in collaboration with other technology industry names to this week announce a $250,000 reward for information to track down those behind Conficker.