Wednesday, July 22, 2009

history of trade

Trade originated with the start of communication in prehistoric times. Trading was the main facility of prehistoric people, who bartered goods and services from each other before the innovation of the modern day currency. Peter Watson dates the history of long-distance commerce from circa 150,000 years ago.
Trade is believed to have taken place throughout much of recorded human history. There is evidence of the exchange of obsidian and flint during the stone age. Materials used for creating jewelry were traded with Egypt since 3000 BC. Long-range trade routes first appeared in the 3rd millennium BC, when Sumerians in Mesopotamia traded with the Harappan civilization of the Indus Valley. The Phoenicians were noted sea traders, traveling across the Mediterranean Sea, and as far north as Britain for sources of tin to manufacture bronze. For this purpose they established trade colonies the Greeks called emporia. From the beginning of Greek civilization until the fall of the Roman empire in the 5th century, a financially lucrative trade brought valuable spice to Europe from the far east, including China. Roman commerce allowed its empire to flourish and endure. The Roman empire produced a stable and secure transportation network that enabled the shipment of trade goods without fear of significant piracy.
The fall of the Roman empire, and the succeeding Dark Ages brought instability to Western Europe and a near collapse of the trade network. Nevertheless some trade did occur. For instance, Radhanites were a medieval guild or group (the precise meaning of the word is lost to history) of Jewish merchants who traded between the Christians in Europe and the Muslims of the Near East.
The Sogdians dominated the East-West trade route known as the Silk Road after the 4th century AD up to the 8th century AD, with Suyab and Talas ranking among their main centeres in the north. They were the main caravan merchants of Central Asia.
From the 8th to the 11th century, the Vikings and Varangians traded as they sailed from and to Scandinavia. Vikings sailed to Western Europe, while Varangians to Russia. The Hanseatic League was an alliance of trading cities that maintained a trade monopoly over most of Northern Europe and the Baltic, between the 13th and 17th centuries.
Vasco da Gama restarted the European Spice trade in 1498. Prior to his sailing around Africa, the flow of spice into Europe was controlled by Islamic powers, especially Egypt. The spice trade was of major economic importance and helped spur the Age of Exploration. Spices brought to Europe from distant lands were some of the most valuable commodities for their weight, sometimes rivaling gold.
In the 16th century, Holland was the centre of free trade, imposing no exchange controls, and advocating the free movement of goods. Trade in the East Indies was dominated by Portugal in the 16th century, the Netherlands in the 17th century, and the British in the 18th century. The Spanish Empire developed regular trade links across both the Atlantic and the Pacific Oceans.
In 1776, Adam Smith published the paper An Inquiry into the Nature and Causes of the Wealth of Nations. It criticised Mercantilism, and argued that economic specialisation could benefit nations just as much as firms. Since the division of labour was restricted by the size of the market, he said that countries having access to larger markets would be able to divide labour more efficiently and thereby become more productive. Smith said that he considered all rationalisations of import and export controls "dupery", which hurt the trading nation at the expense of specific industries.
In 1799, the Dutch East India Company, formerly the world's largest company, became bankrupt, partly due to the rise of competitive free trade.
In 1817, David Ricardo, James Mill and Robert Torrens showed that free trade would benefit the industrially weak as well as the strong, in the famous theory of comparative advantage. In Principles of Political Economy and Taxation Ricardo advanced the doctrine still considered the most counterintuitive in economics:
When an inefficient producer sends the merchandise it produces best to a country able to produce it more efficiently, both countries benefit.
The ascendancy of free trade was primarily based on national advantage in the mid 19th century. That is, the calculation made was whether it was in any particular country's self-interest to open its borders to imports.
John Stuart Mill proved that a country with monopoly pricing power on the international market could manipulate the terms of trade through maintaining tariffs, and that the response to this might be reciprocity in trade policy. Ricardo and others had suggested this earlier. This was taken as evidence against the universal doctrine of free trade, as it was believed that more of the economic surplus of trade would accrue to a country following reciprocal, rather than completely free, trade policies. This was followed within a few years by the infant industry scenario developed by Mill promoting the theory that government had the "duty" to protect young industries, although only for a time necessary for them to develop full capacity. This became the policy in many countries attempting to industrialise and out-compete English exporters. Milton Friedman later continued this vein of thought, showing that in a few circumstances tariffs might be beneficial to the host country; but never for the world at large.
The Great Depression was a major economic recession that ran from 1929 to the late 1930s. During this period, there was a great drop in trade and other economic indicators.
The lack of free trade was considered by many as a principal cause of the depression. Only during the World War II the recession ended in the United States. Also during the war, in 1944, 44 countries signed the Bretton Woods Agreement, intended to prevent national trade barriers, to avoid depressions. It set up rules and institutions to regulate the international political economy: the International Monetary Fund and the International Bank for Reconstruction and Development (later divided into the World Bank and Bank for International Settlements). These organisations became operational in 1946 after enough countries ratified the agreement. In 1947, 23 countries agreed to the General Agreement on Tariffs and Trade to promote free trade.
Free trade advanced further in the late 20th century and early 2000s:
* 1992 European Union lifted barriers to internal trade in goods and labour.
* January 1, 1994 the North American Free Trade Agreement (NAFTA) took effect
* 1994 The GATT Marrakech Agreement specified formation of the WTO.
* January 1, 1995 World Trade Organization was created to facilitate free trade, by mandating mutual most favoured nation trading status between all signatories.
* EC was transformed into the European Union, which accomplished the Economic and Monnetary Union (EMU) in 2002, through introducing the Euro , and creating this way a real single market between 13 member states as of January 1, 2007.
* 2005, the Central American Free Trade Agreement was signed; It includes the United States and the Dominican Republic.


From Wikipedia, the free encyclopedia

Tuesday, July 21, 2009

Wi-fi

Wi-Fi uses both single carrier direct-sequence spread spectrum radio technology (part of the larger family of spread spectrum systems) and multi-carrier OFDM (Orthogonal Frequency Division Multiplexing) radio technology. The regulations for unlicensed spread spectrum enabled the development of Wi-Fi, its onetime competitor HomeRF, Bluetooth, and many other products such as some types of cordless telephones.
Unlicensed spread spectrum was first made available in the US by the Federal Communications Commission in 1985 and these FCC regulations were later copied with some changes in many other countries enabling use of this technology in all major countries.[3] The FCC action was proposed by Michael Marcus of the FCC staff in 1980 and the subsequent regulatory action took 5 more years. It was part of a broader proposal to allow civil use of spread spectrum technology and was opposed at the time by mainstream equipment manufacturers and many radio system operators
The precursor to Wi-Fi was invented in 1991 by NCR Corporation/AT&T (later Lucent & Agere Systems) in Nieuwegein, the Netherlands. It was initially intended for cashier systems; the first wireless products were brought on the market under the name WaveLAN with speeds of 1 Mbit/s to 2 Mbit/s. Vic Hayes, who held the chair of IEEE 802.11 for 10 years and has been named the 'father of Wi-Fi,' was involved in designing standards such as IEEE 802.11b, and 802.11a.
The original patents behind 802.11 Wi-Fi technology, filed in 1996, are held by the CSIRO, an Australian research body. The patents have been the subject of protracted and ongoing legal battles between the CSIRO and major IT corporations over the non-payment of royalties. In 2009 the CSIRO reached a settlement with 14 companies, including Hewlett-Packard, Intel, Dell, Toshiba, ASUS, Microsoft and Nintendo, on the condition that the CSIRO did not broadcast the resolution.
A Wi-Fi enabled device such as a PC, game console, mobile phone, MP3 player or PDA can connect to the Internet when within range of a wireless network connected to the Internet. The coverage of one or more interconnected access points — called a hotspot — can comprise an area as small as a single room with wireless-opaque walls or as large as many square miles covered by overlapping access points. Wi-Fi technology has served to set up mesh networks, for example, in London Both architectures can operate in community networks.
In addition to restricted use in homes and offices, Wi-Fi can make access publicly available at Wi-Fi hotspots provided either free of charge or to subscribers to various providers. Organizations and businesses such as airports, hotels and restaurants often provide free hotspots to attract or assist clients. Enthusiasts or authorities who wish to provide services or even to promote business in a given area sometimes provide free Wi-Fi access. There are already[update] more than 300 metropolitan-wide Wi-Fi (Muni-Fi) projects in progress. There were 879 Wi-Fi based Wireless Internet service providers in the Czech Republic as of May 2008.
Wi-Fi also allows connectivity in peer-to-peer (wireless ad-hoc network) mode, which enables devices to connect directly with each other. This connectivity mode can prove useful in consumer electronics and gaming applications.
When wireless networking technology first entered the market many problems ensued for consumers who could not rely on products from different vendors working together. The Wi-Fi Alliance began as a community to solve this issue — aiming to address the needs of the end-user and to allow the technology to mature. The Alliance created the branding Wi-Fi CERTIFIED to reassure consumers that products will interoperate with other products displaying the same branding.
Many consumer devices use Wi-Fi. Amongst others, personal computers can network to each other and connect to the Internet, mobile computers can connect to the Internet from any Wi-Fi hotspot, and digital cameras can transfer images wirelessly.
Routers which incorporate a DSL-modem or a cable-modem and a Wi-Fi access point, often set up in homes and other premises, provide Internet-access and internetworking to all devices connected (wirelessly or by cable) to them. One can also connect Wi-Fi devices in ad-hoc mode for client-to-client connections without a router. Wi-Fi also enables places which would traditionally not have network to be connected, for example bathrooms, kitchens and garden sheds.
As of 2007 Wi-Fi technology had spread widely within business and industrial sites. In business environments, just like other environments, increasing the number of Wi-Fi access-points provides redundancy, support for fast roaming and increased overall network-capacity by using more channels or by defining smaller cells. Wi-Fi enables wireless voice-applications (VoWLAN or WVOIP). Over the years, Wi-Fi implementations have moved toward "thin" access-points, with more of the network intelligence housed in a centralized network appliance, relegating individual access-points to the role of mere "dumb" radios. Outdoor applications may utilize true mesh topologies. As of 2007 Wi-Fi installations can provide a secure computer networking gateway, firewall, DHCP server, intrusion detection system, and other functions.

From Wikipedia, the free encyclopedia