Dial-up Internet access
Dial-up Internet access is a form of Internet access that uses the facilities of the public switched telephone network to establish a connection to an Internet service provider by dialing a telephone number on a conventional telephone line. The user's computer or router uses an attached modem to encode and decode information into and from audio frequency signals, respectively. In 1979, Tom Truscott and Steve Bellovin, graduates of Duke University, created an early predecessor to dial-up Internet access called the USENET; the USENET was a UNIX based system that used a dial-up connection to transfer data through telephone modems. Dial-up Internet has been around since the 1980s via public providers such as NSFNET-linked universities and was first offered commercially in July 1992 by Sprint. Despite losing ground to broadband since the mid-2000s, dial-up is still used where other forms are not available or where the cost is too high, such as in some rural or remote areas. Dial-up connections to the Internet require no infrastructure other than the telephone network and the modems and servers needed to make and answer the calls.
Where telephone access is available, dial-up is the only choice available for rural or remote areas, where broadband installations are not prevalent due to low population density and high infrastructure cost. Dial-up access may be an alternative for users on limited budgets, as it is offered free by some ISPs, though broadband is available at lower prices in many countries due to market competition. Dial-up requires time to establish a telephone connection and perform configuration for protocol synchronization before data transfers can take place. In locales with telephone connection charges, each connection incurs an incremental cost. If calls are time-metered, the duration of the connection incurs costs. Dial-up access is a transient connection, because either the user, ISP or phone company terminates the connection. Internet service providers will set a limit on connection durations to allow sharing of resources, will disconnect the user—requiring reconnection and the costs and delays associated with it.
Technically inclined users find a way to disable the auto-disconnect program such that they can remain connected for more days than one. A 2008 Pew Research Center study stated that only 10% of US adults still used dial-up Internet access; the study found. Users cited lack of infrastructure as a reason less than stating that they would never upgrade to broadband; that number had fallen to 6% by 2010, to 3% by 2013. The CRTC estimated that there were 336,000 Canadian dial-up users in 2010. Broadband Internet access via cable, digital subscriber line, satellite and FTTx has replaced dial-up access in many parts of the world. Broadband connections offer speeds of 700 kbit/s or higher for two-thirds more than the price of dial-up on average. In addition broadband connections are always on, thus avoiding the need to connect and disconnect at the start and end of each session. Broadband does not require exclusive use of a phone line and so one can access the Internet and at the same time make and receive voice phone calls without having a second phone line.
However, many rural areas still remain without high speed Internet despite the eagerness of potential customers. This can be attributed to population, location, or sometimes ISPs' lack of interest due to little chance of profitability and high costs to build the required infrastructure; some dial-up ISPs have responded to the increased competition by lowering their rates and making dial-up an attractive option for those who want email access or basic web browsing. Dial-up Internet access has undergone a precipitous fall in usage, approaches extinction as modern users turn towards broadband. In contrast to the year 2000 when about 34% of the U. S. population used dial-up, this dropped to 3% in 2013. One contributing factor to the extinction of dial-up is the bandwidth requirements of newer computer programs, like antivirus software, which automatically download sizable updates in the background when a connection to the internet is first made; these background downloads can take several minutes or longer and, until all updates are completed, they can impact the amount of bandwidth available to other applications like web browsers.
Since an "always on" broadband is the norm expected by most newer applications being developed, this automatic upload trend in the background is expected to continue to eat away at dial-up's available bandwidth to the detriment of dial-up users' applications. Many newer websites now assume broadband speeds as the norm and when confronted with slower dial-up speeds may drop these slower connections to free up communication resources. On websites that are designed to be more dial-up friendly, use of a reverse proxy prevents dial-ups from being dropped as but can introduce long wait periods for dial-up users caused by the buffering used by a reverse proxy to bridge the different data rates. Modern dial-up modems have a maximum theoretical transfer speed of 56 kbit/s, although in most cases, 40–50 kbit/s is the norm. Factors such as phone line noise as well as the quality of the modem itself play a large part in determining connection speeds; some connections may be as low as 20 kbit/s in noisy environments, such as in a hotel room where the phone line is shared with many extensions, or in a rural area, many miles from the phone exchange.
Other factors such as long loops, loading coils, pair gain, electric fences, digital loop carriers can slow con
Japan is an island country in East Asia. Located in the Pacific Ocean, it lies off the eastern coast of the Asian continent and stretches from the Sea of Okhotsk in the north to the East China Sea and the Philippine Sea in the south; the kanji that make up Japan's name mean "sun origin", it is called the "Land of the Rising Sun". Japan is a stratovolcanic archipelago consisting of about 6,852 islands; the four largest are Honshu, Hokkaido and Shikoku, which make up about ninety-seven percent of Japan's land area and are referred to as home islands. The country is divided into 47 prefectures in eight regions, with Hokkaido being the northernmost prefecture and Okinawa being the southernmost one; the population of 127 million is the world's tenth largest. 90.7 % of people live in cities. About 13.8 million people live in the capital of Japan. The Greater Tokyo Area is the most populous metropolitan area in the world with over 38 million people. Archaeological research indicates; the first written mention of Japan is in Chinese history texts from the 1st century AD.
Influence from other regions China, followed by periods of isolation from Western Europe, has characterized Japan's history. From the 12th century until 1868, Japan was ruled by successive feudal military shōguns who ruled in the name of the Emperor. Japan entered into a long period of isolation in the early 17th century, ended in 1853 when a United States fleet pressured Japan to open to the West. After nearly two decades of internal conflict and insurrection, the Imperial Court regained its political power in 1868 through the help of several clans from Chōshū and Satsuma – and the Empire of Japan was established. In the late 19th and early 20th centuries, victories in the First Sino-Japanese War, the Russo-Japanese War and World War I allowed Japan to expand its empire during a period of increasing militarism; the Second Sino-Japanese War of 1937 expanded into part of World War II in 1941, which came to an end in 1945 following the Japanese surrender. Since adopting its revised constitution on May 3, 1947, during the occupation led by SCAP, the sovereign state of Japan has maintained a unitary parliamentary constitutional monarchy with an Emperor and an elected legislature called the National Diet.
Japan is a member of the ASEAN Plus mechanism, UN, the OECD, the G7, the G8, the G20, is considered a great power. Its economy is the world's third-largest by nominal GDP and the fourth-largest by purchasing power parity, it is the world's fourth-largest exporter and fourth-largest importer. Japan benefits from a skilled and educated workforce. Although it has renounced its right to declare war, Japan maintains a modern military with the world's eighth-largest military budget, used for self-defense and peacekeeping roles. Japan is a developed country with a high standard of living and Human Development Index, its population enjoys the highest life expectancy and third lowest infant mortality rate in the world, but is experiencing issues due to an aging population and low birthrate. Japan is renowned for its historical and extensive cinema, influential music industry, video gaming, rich cuisine and its major contributions to science and modern technology; the Japanese word for Japan is 日本, pronounced Nihon or Nippon and means "the origin of the sun".
The character nichi means "sun" or "day". The compound therefore means "origin of the sun" and is the source of the popular Western epithet "Land of the Rising Sun"; the earliest record of the name Nihon appears in the Chinese historical records of the Tang dynasty, the Old Book of Tang. At the end of the seventh century, a delegation from Japan requested that Nihon be used as the name of their country; this name may have its origin in a letter sent in 607 and recorded in the official history of the Sui dynasty. Prince Shōtoku, the Regent of Japan, sent a mission to China with a letter in which he called himself "the Emperor of the Land where the Sun rises"; the message said: "Here, I, the emperor of the country where the sun rises, send a letter to the emperor of the country where the sun sets. How are you". Prior to the adoption of Nihon, other terms such as Yamato and Wakoku were used; the term Wa is a homophone of Wo 倭, used by the Chinese as a designation for the Japanese as early as the third century Three Kingdoms period.
Another form of Wa, Wei in Chinese) was used for an early state in Japan called Nakoku during the Han dynasty. However, the Japanese disliked some connotation of Wa 倭, it was therefore replaced with the substitute character Wa, meaning "togetherness, harmony"; the English word Japan derives from the historical Chinese pronunciation of 日本. The Old Mandarin or early Wu Chinese pronunciation of Japan was recorded by Marco Polo as Cipangu. In modern Shanghainese, a Wu dialect, the pronunciation of characters 日本; the old Malay word for Japan, Japun or Japang, was borrowed from a southern coastal Chinese dialect Fukienese or Ningpo – and this Malay word was encountered by Portuguese traders in Southeast Asia in the 16th century. These Early Portuguese traders brought the word
In telecommunications and signal processing, frequency modulation is the encoding of information in a carrier wave by varying the instantaneous frequency of the wave. In analog frequency modulation, such as FM radio broadcasting of an audio signal representing voice or music, the instantaneous frequency deviation, the difference between the frequency of the carrier and its center frequency, is proportional to the modulating signal. Digital data can be encoded and transmitted via FM by shifting the carrier's frequency among a predefined set of frequencies representing digits – for example one frequency can represent a binary 1 and a second can represent binary 0; this modulation technique is known as frequency-shift keying. FSK is used in modems such as fax modems, can be used to send Morse code. Radioteletype uses FSK. Frequency modulation is used for FM radio broadcasting, it is used in telemetry, seismic prospecting, monitoring newborns for seizures via EEG, two-way radio systems, music synthesis, magnetic tape-recording systems and some video-transmission systems.
In radio transmission, an advantage of frequency modulation is that it has a larger signal-to-noise ratio and therefore rejects radio frequency interference better than an equal power amplitude modulation signal. For this reason, most music is broadcast over FM radio. Frequency modulation and phase modulation are the two complementary principal methods of angle modulation; these methods contrast with amplitude modulation, in which the amplitude of the carrier wave varies, while the frequency and phase remain constant. If the information to be transmitted is x m and the sinusoidal carrier is x c = A c cos , where fc is the carrier's base frequency, Ac is the carrier's amplitude, the modulator combines the carrier with the baseband data signal to get the transmitted signal: y = A c cos = A c cos = A c cos where f Δ = K f A m, K f being the sensitivity of the frequency modulator and A m being the amplitude of the modulating signal or baseband signal. In this equation, f is the instantaneous frequency of the oscillator and f Δ is the frequency deviation, which represents the maximum shift away from fc in one direction, assuming xm is limited to the range ±1.
While most of the energy of the signal is contained within fc ± fΔ, it can be shown by Fourier analysis that a wider range of frequencies is required to represent an FM signal. The frequency spectrum of an actual FM signal has components extending infinitely, although their amplitude decreases and higher-order components are neglected in practical design problems. Mathematically, a baseband modulating signal may be approximated by a sinusoidal continuous wave signal with a frequency fm; this method is named as single-tone modulation. The integral of such a signal is: ∫ 0 t x m d τ = A m sin
Japanese postal mark
〒 is the service mark of Japan Post and its successor, Japan Post Holdings, the postal operator in Japan. It is used as a Japanese postal code mark since the introduction of the latter in 1968; the mark is a stylized katakana syllable te, from the word teishin. The mark was introduced on February 8th, 1887. To indicate a postal code, the mark is written first, the postal code is written after. For example, one area of Meguro, would have 〒153-0061 written on any mail, in order to direct mail to that location; this usage has resulted in the inclusion of the mark into the Japanese character sets for computers, thus their inclusion into Unicode, where it can be found on the Japanese Post Office emoji. In most keyboard-based Japanese input systems, it can be created by typing "yuubin" and doing a kanji conversion. Of the versions shown to the right, the one on the far right is the standard mark used in addressing; the circled yūbin mark in the middle is used on maps to denote post offices. Japan Post § Postal symbol History of Japanese postal services Japanese addressing system Japanese typographic symbols Japanese map symbols Kazakhstani tenge Official Postal Site
A VoIP phone or IP phone uses voice over IP technologies for placing and transmitting telephone calls over an IP network, such as the Internet, instead of the traditional public switched telephone network. Digital IP-based telephone service uses control protocols such as the Session Initiation Protocol, Skinny Client Control Protocol or various other proprietary protocols. VoIP phones can be simple software-based softphones or purpose-built hardware devices that appear much like an ordinary telephone or a cordless phone. Traditional PSTN phones are used as VoIP phones with analog telephone adapters. A VoIP phone or application may have many features an analog phone doesn't support, such as e-mail-like IDs for contacts that may be easier to remember than names or phone numbers, or easy sharing of contact lists among multiple accounts; the features of VoIP phones follow those of Skype and other PC-based phone services, which have richer feature sets but latency-related audio problems. A competing view is that as mainstream operating systems become better at voice applications with appropriate Quality of Service guarantees and 5G handoff becomes available from outdoor wireless carriers and smartphones will become the dominant interfaces.
IPhone and the QNX OS used in 2012-and-later BlackBerry phones are capable of VoIP performance on small battery-charged devices. They typically support the USB but not Ethernet or Power over Ethernet interfaces, at least as of late 2011. According to this view, the smartphone becomes the dominant VoIP phone because it works both indoors and outdoors and shifts base stations/protocols to trade off access costs and call clarity and other factors personal to the user, the PoE/USB VoIP phone is thus the transitional device. A VoIP telephone consist of the software components; the software requires standard networking components such as a TCP/IP network stack, client implementation for DHCP, the Domain Name System. In addition, a VoIP signalling protocol stack, such as for the Session Initiation Protocol, H.323, Skinny Call Control Protocol, Skype, is needed. For media streams, the Real-time Transport Protocol is used in most VoIP systems. For voice and media encoding, a variety of coders are available, such as for audio: G.711, GSM, iLBC, Speex, G.729, G.722, G.722.2, other audio codecs, for video H.263, H.263+, H.264.
User interface software controls the operation of the hardware components, may respond to user actions with messages to a display screen. To enable the VoIP communications, the SIP/RTP packets should be utilised and STUN client would be the key component for VoIP communications with management of the SIP/RTP packets. A Session Traversal Utilities for NAT client is used on some SIP-based VoIP phones as firewalls on network interface sometimes block SIP/RTP packets; some special mechanism is required in this case to enable routing of SIP packets from one network to other. STUN is used in some of the sip phones to enable the SIP/RTP packets to cross boundaries of two different IP networks. A packet becomes unroutable between two sip elements if one of the networks uses private IP address range and other is in public IP address range. Stun is a mechanism to enable this border traversal. There are alternate mechanisms for traversal of NAT, STUN is just one of them. STUN or any other NAT traversal mechanism is not required when the two SIP phones connecting are routable from each other and no firewall exists in between.
DHCP client software simplifies connection of a device to an IP network. The software automatically configures the network and VoIP service parameters; the overall hardware may look like mobile phone. A VoIP phone has the following hardware components Speakerphone and a microphone Keypad or touchpad to enter phone number and text Display hardware to feedback user input and show caller-id/messages General-purpose macro processor to process application messages A voice engine or a digital signal processor to process RTP messages; some IC manufacturers provides GPP and DSP in single chip AD and DA converters: To convert voice to digital data and vice versa Ethernet or wireless network hardware to send and receive messages on data network Power source - a battery or DC/AC source. Analog telephone adapters provide an interface for traditional analog telephones to a voice-over-IP network, they connect to the Internet or local area network using an Ethernet port and have jacks that provide a standard RJ11interface for an analog local loop.
Another type of gateway device acts as a simple GSM base station and regular mobile phones can connect to this and make VoIP calls. While a license is required to run one of these in most countries these can be useful on ships or remote areas where a low-powered gateway transmitting on unused frequencies is to go unnoticed; some VoIP phones support PSTN phone lines directly. Caller ID display Call transfer and call hold Dialing using name/ID Locally stored and network-based directories Conference calling and multiparty calls Call park Call blocking feature. Support for multiple VoIP accounts – the phone may register with more than one VoIP server/provider. Accounts are set and memorized on the pho
China the People's Republic of China, is a country in East Asia and the world's most populous country, with a population of around 1.404 billion. Covering 9,600,000 square kilometers, it is the third- or fourth-largest country by total area. Governed by the Communist Party of China, the state exercises jurisdiction over 22 provinces, five autonomous regions, four direct-controlled municipalities, the special administrative regions of Hong Kong and Macau. China emerged as one of the world's earliest civilizations, in the fertile basin of the Yellow River in the North China Plain. For millennia, China's political system was based on hereditary monarchies, or dynasties, beginning with the semi-legendary Xia dynasty in 21st century BCE. Since China has expanded, re-unified numerous times. In the 3rd century BCE, the Qin established the first Chinese empire; the succeeding Han dynasty, which ruled from 206 BC until 220 AD, saw some of the most advanced technology at that time, including papermaking and the compass, along with agricultural and medical improvements.
The invention of gunpowder and movable type in the Tang dynasty and Northern Song completed the Four Great Inventions. Tang culture spread in Asia, as the new Silk Route brought traders to as far as Mesopotamia and Horn of Africa. Dynastic rule ended in 1912 with the Xinhai Revolution; the Chinese Civil War resulted in a division of territory in 1949, when the Communist Party of China established the People's Republic of China, a unitary one-party sovereign state on Mainland China, while the Kuomintang-led government retreated to the island of Taiwan. The political status of Taiwan remains disputed. Since the introduction of economic reforms in 1978, China's economy has been one of the world's fastest-growing with annual growth rates above 6 percent. According to the World Bank, China's GDP grew from $150 billion in 1978 to $12.24 trillion by 2017. Since 2010, China has been the world's second-largest economy by nominal GDP and since 2014, the largest economy in the world by purchasing power parity.
China is the world's largest exporter and second-largest importer of goods. China is a recognized nuclear weapons state and has the world's largest standing army and second-largest defense budget; the PRC is a permanent member of the United Nations Security Council as it replaced the ROC in 1971, as well as an active global partner of ASEAN Plus mechanism. China is a leading member of numerous formal and informal multilateral organizations, including the Shanghai Cooperation Organization, WTO, APEC, BRICS, the BCIM, the G20. In recent times, scholars have argued that it will soon be a world superpower, rivaling the United States; the word "China" has been used in English since the 16th century. It is not a word used by the Chinese themselves, it has been traced through Portuguese and Persian back to the Sanskrit word Cīna, used in ancient India."China" appears in Richard Eden's 1555 translation of the 1516 journal of the Portuguese explorer Duarte Barbosa. Barbosa's usage was derived from Persian Chīn, in turn derived from Sanskrit Cīna.
Cīna was first used including the Mahābhārata and the Laws of Manu. In 1655, Martino Martini suggested that the word China is derived from the name of the Qin dynasty. Although this derivation is still given in various sources, it is complicated by the fact that the Sanskrit word appears in pre-Qin literature; the word may have referred to a state such as Yelang. The meaning transferred to China as a whole; the origin of the Sanskrit word is still a matter of debate, according to the Oxford English Dictionary. The official name of the modern state is the "People's Republic of China"; the shorter form is "China" Zhōngguó, from zhōng and guó, a term which developed under the Western Zhou dynasty in reference to its royal demesne. It was applied to the area around Luoyi during the Eastern Zhou and to China's Central Plain before being used as an occasional synonym for the state under the Qing, it was used as a cultural concept to distinguish the Huaxia people from perceived "barbarians". The name Zhongguo is translated as "Middle Kingdom" in English.
Archaeological evidence suggests that early hominids inhabited China between 2.24 million and 250,000 years ago. The hominid fossils of Peking Man, a Homo erectus who used fire, were discovered in a cave at Zhoukoudian near Beijing; the fossilized teeth of Homo sapiens have been discovered in Fuyan Cave in Hunan. Chinese proto-writing existed in Jiahu around 7000 BCE, Damaidi around 6000 BCE, Dadiwan from 5800–5400 BCE, Banpo dating from the 5th millennium BCE; some scholars have suggested. According to Chinese tradition, the first dynasty was the Xia, which emerged around 2100 BCE; the dynasty was considered mythical by historians until scientific excavations found early Bronze Age sites at Erlitou, Henan in 1959. It remains unclear whether these sites are the remains of the Xia dynasty or of another culture from the same period; the succeeding Shang dynasty is the earliest to be confirmed by contemporary records. The Shang ruled the plain of the Yellow River in eastern China from the 17th to the 11th century BCE.
Their oracle bone script
Mobile phone industry in Japan
The Japanese mobile phone industry is one of the most advanced in the world. As of July 31, 2013 there were 139,180,300 mobile phones in use in Japan; this is 110 percent of Japan's total population according to the Ministry of Internal Affairs and Communications. In Japanese, mobile phone handsets are referred to as keitai denwa or keitai for short. In the year 1979, Nippon Telegraph and Telephone launched the world's first first generation mobile phone service in Tokyo as a car phone. In 1985, NTT offered Japan's first mobile phone service, called the "Shoulder Phone." In 1988, Mobile Communication Group, absorbed into KDDI, started mobile phone service In 1993, NTT DoCoMo started its first digital mobile phone service, using a Time division multiple access variant called Personal Digital Cellular. In 1994, Digital Phone Group and Tu-Ka Group, both of which became SoftBank Mobile, started mobile phone service. In the same year, DDI Pocket, a subsidiary of KDDI, started PHS mobile phone service.
In 1999, NTT DoCoMo started i-mode Internet service. In 2001, NTT DoCoMo premiered the world's first Third Generation mobile phone service, using W-CDMA technology called FOMA. In 2002, KDDI started 3G service in Okinawa. In the same year, J-Phone started 3G service using W-CDMA technology. In 2003, J-Phone changed its name to Vodafone. In 2006, Vodafone Japan was renamed to SoftBank Mobile. In the same year, MNP was introduced. In 2007, Japanese regulator introduced new guideline for unbundling new handset price and service plan. In 2010, SoftBank Mobile stopped all non-3G services. There are four cellular service operators in Japan. Willcom is the last PHS Personal Handy-phone System service operator. DoCoMo was spun off in 1991 from Nippon Telegraph and Telephone, NTT DoCoMo first offered its second-generation service known as Personal Digital Cellular, it now offers a 3G service using W-CDMA technology known as FOMA. The company is operating a world band W-CDMA network at 2100 MHz; as of March 2016, the number of subscribers is 71 million.
KDDI was formed by the merger of KDD, DDI, IDO in 2000. They offer the au mobile phone service: its second generation service, using CDMA technology, 3G service, using CDMA2000, their operating bands are 2100 MHz. As of March 2016, there are 46 million subscribers. Softbank Mobile is a subsidiary of Softbank. Softbank purchased Vodafone Japan at $15b in 2006. Softbank Mobile now offers 3G service using W-CDMA technology at 2100 MHz. Softbank Mobile was the exclusive service provider of Apple's iPhone in Japan until November 2011; as of March 2016, there were 40 million subscribers. Y!mobile EMOBILE, is the most recent entrant into the 3G market. Beginning in 2005, it has provided 3G data and voice service coverage to 90% of the Japanese population through its own network and a roaming agreement with NTT DoCoMo, their band is 1700 MHz, not compatible with other area's W-CDMA phone. As of December 2013, the projected subscriber base was over 10 million subscribers; the Japanese mobile phone market is known for its competitive and saturated market, combined with a complex regulatory environment, has led to growing consolidation among manufacturers and providers alike.
Mobile telecommunications operating licenses are administered by the Ministry of Internal Affairs and Communications. In Japan, there have never been band license auctions. MIC issues operating licenses by just paper checking. Collaboration by the various companies can be seen at the Yokosuka Research Park, near NTT's Yokosuka R&D Center, where many manufacturers have research and development laboratories offices. An outdoor testing site is located there. Since the introduction of new regulations about unbundling service plan and handset prices in 2008, the Japanese handset market has shrunk. At its peak in 2007, the total handset shipping amount was 52M units. However, the number for 2009 was 32M units; this caused a serious recession for the handset industry and a consolidation of companies due to the reliance which handset vendors had on the Japanese market. Japan's PHS technology has been exported to China and other countries. NTT DoCoMo's i-mode web technology had been used by Australia's Telstra, Russia's Mobile TeleSystems, UK's O2 and a few other mobile service providers overseas.
NTT has been one of the main contributors to the 3G W-CDMA standard. NTT DoCoMo collaborated with AT&T Mobility to set up a 3G-compatible mobile phone network in Hawaii; the following manufacturers market and sell handsets within Japan: Sanyo Electric, although an independent manufacturer of handsets, sold its handset business to Kyocera in 2008. Mitsubishi Electric exited the mobile phone market in April 2008. Nokia discontinued development of mobile phones for the Japanese market in 2009. The DoCoMo M702iS, released in December 2006, was the last Motorola phone launched in Japan until their return to the market in 2011. Japanese manufacturers have had difficulty marketing their phones overseas. In 2009, out of all Japanese handset manufacturers, Sony Ericsson sold the most handsets worldwide. Japan's mobile phones traditionally used the ITRON operating system, but as the functions become more complex, they moved over to more us