Category Archives: Teknologi

Huawei WIFI HG8245A

It is recommened to have minimum of 10 MBPS Speedy Line so that more clients can share the Internet Connection without loosing speed.

Overview

Quick Details

Place of Origin: Guangdong, China (Mainland)
Brand Name: Huawei
Model Number: Huawei ONU
Product name: Huawei ONU
Color: White
XPON: GPON
Condition: Brand New
Power supply: EU, US, UK, AU
Software: English
Pots: 2POTS+4FE+Wi-Fi+1USB
Product Keywords: epon wifi router,epon terminal ont,epon splitter

Product Detail

Product name Huawei ONU
Color White
XPON EPON
Condition Brand New
Power supply EU, US, UK, AU
software English
pots 4GE+2voice
Product Keywords Epon wifi router,gpon terminal ont,gpon splitter

Application and Advantage :

HUAWEI HG8245A WIFI GPON ONU with 4 FE + 2 POTS ports , is a high-end home gateway in Huawei FTTH solution.

By using the EPON technology, ultra-broadband access is provided for home and SOHO users.

The HG8245 provides two POTS ports, four FE ports and one WiFi antenna.

The HG8245 A features high-performance forwarding capabilities to ensure excellent experience with VoIP, Internet and HD video services.

Features:

  • Port: 2POTS+4GE+1USB+WiFi.
  • Plug-and-play (PnP): Internet, IPTV and VoIP services can be deployed by one click on the NMS and on-site configuration is not required.
  • Remote diagnosis: Remote fault locating is implemented by the loop-line test of POTS ports, call emulation and PPPoE dialup emulation initiated by the NMS.
  • High speed forwarding: GE line rate forwarding in the bridge scenario and 900 Mbit/s forwarding in the NAT scenario.
  • Green energy-saving: 25% power consumption is saved with highly integrated system on chipset (SOC) solution, in which, a single chip integrates with PON, voice, gateway and LSW modules.

A Brief History of the Internet of Things

ByChris Nolter | Oct 18, 2016

A look at some of the most significant events in the development of the Internet of Things.

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Networked devices predate the term “Internet of Things,” going all the way back to a toaster that was connected to the Internet back in 1990. Since then, industry, utilities and trucking and logistics companies have all begun connecting their machines and assets to various systems and to each other, with the actual phrase “The Internet of Things” being coined in 1999.

Since 2008, the use of networked devices by consumers and companies has accelerated dramatically, and Cisco (CSCO – Get Report) now predicts that there will be 10 billion connected mobile devices by 2018, or 1.4 for each person on the planet. Here’s a look at some key moments in the development of the transformative trend.

Opera Snapshot_2017-12-06_181539_www.thestreet.com

 

 

Pengertian SEO (Search Engine Optimization)

December 25, 2017 / Admin Saktipedia

Dikalangan blogger (Blogosphere) khususnya webmaster tentu sudah tidak asing lagi dengan yang namanya SEO (Search Engine Optimization). Ya SEO bisa dikatakan adalah sebuah metode atau cara agar Search Engine atau mesin pencari mengindex suatu website di internet agar setiap proses pencarian dengan menggunakan keyword / kata kunci tertentu melalui search engine dapat ditampilkan pada halaman utama.

SEO-Search-Engine-Optimization

Ada juga yang menyatakan bahwa SEO adalah proses yang sangat khusus dalam membangun sebuah website yang sukses, alasannya adalah karena sebuah website komersil tidak akan dikatakan sukses jika tidak dapat ditemukan oleh search engine. Ini merupakan tugas serta tantangan bagi para webmaster untuk mengoptimalkan sebuah website dengan cara memperbaiki struktur pada tag HTML tertentu di halaman web.

Tentu saja bagaimana mungkin mendatangkan pengunjung, meningkatkan pengunjung dan mendapatkan ranking pada website jika halaman-halaman website kita tidak dapat ditemukan oleh mesin pencari utama seperti Google, Bing, Yahoo, MSN, Live Search, dll.

Memang benar bahwa para pengunjung baru bisa menemukan sebuah website dari hasil pencarian di Search Engine dan Search Directory dengan kata kunci tertentu, selebihnya mungkin dengan melakukan blogwalking dll. Disinilah tantangan menarik belajar SEO karena para pengunjung datang dengan kata kunci tertentu sehingga dapat menemukan situs yang relevan dengan kata kunci yang diketikkan.

Jadi untuk promosi sebuah website, SEO adalah cara yang efektif untuk meningkatkan traffic yang nantinya akan memperbanyak pengunjung yang datang ke website kita.

Dari sedikit ulasan SEO di atas maka dapat disimpulkan tentang fungsi dan tujuan dari SEO, yaitu :

  • Menaikkan ranking sebuah website agar selalu terindex pada search engine, sehingga website kita dapat ditampilkan dihalaman utama
  • Mendatangkan banyak pengunjung atau pengunjung ke website kita melalui hasil pencarian di mesin pencari
  • Dan masih banyak lagi fungsi serta manfaat SEO yang tentunya baik untuk blog kita.

Itulah sedikit ulasan dari Saya tentang Pengertian SEO semoga bisa menambah wawasan serta pengetahuan kita tentang pentingnya teknik SEO untuk blog. Bagi yang ingin menambahkan info seputar SEO silakan isi di kolom komentar.

 

Closed-Circuit Television | CCTV

From Wikipedia, the free encyclopedia

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Surveillance cameras on the corner of a building.

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Dome CCTV cameras.

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Dome camera in a rail station

Closed-Circuit Television (CCTV), also known as video surveillance, is the use of video cameras to transmit a signal to a specific place, on a limited set of monitors. It differs from broadcast television in that the signal is not openly transmitted, though it may employ point to point (P2P), point to multipoint (P2MP), or mesh wired or wireless links. Though almost all video cameras fit this definition, the term is most often applied to those used for surveillance in areas that may need monitoring such as banks, stores, and other areas where security is needed. Though Videotelephony is seldom called “CCTV” one exception is the use of video in distance education, where it is an important tool.

Surveillance of the public using CCTV is common in many areas around the world. In recent years, the use of body worn video cameras has been introduced as a new form of surveillance, often used in law enforcement, with cameras located on a police officer’s chest or head. Video surveillance has generated significant debate about balancing its use with individuals’ right to privacy even when in public.

In industrial plants, CCTV equipment may be used to observe parts of a process from a central control room, for example when the environment is not suitable for humans. CCTV systems may operate continuously or only as required to monitor a particular event. A more advanced form of CCTV, utilizing digital video recorders (DVRs), provides recording for possibly many years, with a variety of quality and performance options and extra features (such as motion detection and email alerts). More recently, decentralized IP cameras, some equipped with megapixel sensors, support recording directly to network-attached storage devices, or internal flash for completely stand-alone operation.

There are about 350 million surveillance cameras worldwide as of 2016. About 65% of these cameras are installed in Asia. The growth of CCTV has been slowing in recent years.

Contents
1 History
1.1 Technology
1.2 Application
2 Uses
2.1 Crime prevention
2.2 Body worn
2.3 Industrial processes
2.4 Traffic monitoring
2.5 Transport safety
2.6 Sporting events
2.7 Monitor employees
2.8 Use in schools
2.9 Criminal use
2.10 Home security
3 Prevalence
3.1 United States
3.2 United Kingdom
3.3 Canada
3.4 South Africa
3.5 Around the world
4 Video surveillance and terrorism
5 Privacy
6 Technological developments
6.1 Computer-controlled analytics and identification
6.2 Retention, storage and preservation
6.3 Closed-circuit digital photography (CCDP)
6.4 IP cameras
6.5 Networking CCTV cameras
6.6 Integrated systems
6.7 Wireless security cameras
6.8 Talking CCTV
7 Countermeasures
8 CCTV camera vandalism
9 Cost
9.1 Factors affecting security camera installation cost

History


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Closed circuit TV monitoring at the Central Police Control Station, Munich Germany in 1973.

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A typical CCTV control-room set-up, Alkmaar, Netherlands in 2007.

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Desk in one of the regional control-rooms of the National Police in the Netherlands in 2017.

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CCTV control-room monitor wall for 176 open-street cameras in 2017.

The first CCTV system was installed by Siemens AG at Test Stand VII in Peenemünde, Nazi Germany in 1942, for observing the launch of V-2 rockets. The noted German engineer Walter Bruch was responsible for the technological design and installation of the system.

In the U.S. the first commercial closed-circuit television system became available in 1949, called Vericon. Very little is known about Vericon except it was advertised as not requiring a government permit.

Technology

The earliest video surveillance systems involved constant monitoring because there was no way to record and store information. The development of reel-to-reel media enabled the recording of surveillance footage. These systems required magnetic tapes to be changed manually, which was a time consuming, expensive and unreliable process, with the operator having to manually thread the tape from the tape reel through the recorder onto an empty take-up reel. Due to these shortcomings, video surveillance was not widespread. VCR technology became available in the 1970s, making it easier to record and erase information, and use of video surveillance became more common.

During the 1990s, digital multiplexing was developed, allowing several cameras to record at once, as well as time lapse and motion-only recording. This increased savings of time and money which then led to an increase in the use of CCTV.

Recently CCTV technology has been enhanced with a shift toward Internet-based products and systems, and other technological developments.

Application

In September 1968, Olean, New York was the first city in the United States to install video cameras along its main business street in an effort to fight crime. Another early appearance was in 1973 in Times Square in New York City. The NYPD installed it in order to deter crime that was occurring in the area; however, crime rates did not appear to drop much due to the cameras. Nevertheless, during the 1980s video surveillance began to spread across the country specifically targeting public areas. It was seen as a cheaper way to deter crime compared to increasing the size of the police departments. Some businesses as well, especially those that were prone to theft, began to use video surveillance. From the mid-1990s on, police departments across the country installed an increasing number of cameras in various public spaces including housing projects, schools and public parks departments. CCTV later became common in banks and stores to discourage theft, by recording evidence of criminal activity. In 1998, 3,000 CCTV systems were in use in New York City. A study by Nieto in 2008 found many businesses in the United States had invested heavily in video surveillance technology to protect products and promote safe workplace and consumer environments. A nationwide survey of a wide variety of companies found that 75 percent utilize CCTV surveillance. In private sector CCTV surveillance technology is operated in a wide variety of establishments such as in industry/manufacturing, retailing, financial/insurance/banking, transportation and distribution, utilities/communications, health care, and hotels/motels.

Experiments in the UK during the 1970s and 1980s, including outdoor CCTV in Bournemouth in 1985, led to several larger trial programs later that decade. The first use by local government was in King’s Lynn, Norfolk, in 1987. These were deemed successful in the government report “CCTV: Looking Out For You”, issued by the Home Office in 1994, and paved the way for an increase in the number of CCTV systems installed. Today, systems cover most town and city centres, and many stations, car-parks and estates.

Uses


Crime prevention

Bulger_cctv

The two-year-old James Bulger being led away by his killers, recorded on shopping centre CCTV in 1993. This narrow-bandwidth television system had a low frame rate.
iFacility Warning Sign

800px-IFacility-cctv-warning-signSign warning  that premises are watched by CCTV cameras.

A 2009 systematic review by researchers from Northeastern University and University of Cambridge used meta-analytic techniques to pool the average effect of CCTV on crime across 41 different studies. The results indicated that

  1. CCTV caused a significant reduction of crime by on average 16%.
    The largest effects of CCTV were found in car parks, where cameras reduced crime by on average 51%.
  2. CCTV schemes in other public settings had small and non-statistically significant effects on crime: 7% reduction in city and town centers and 23% reduction in public transport settings.
  3. When sorted by country, systems in the United Kingdom accounted for the majority of the decrease; the drop in other areas was insignificant.

The studies included in the meta-analysis used quasi-experimental evaluation designs that involve before-and-after measures of crime in experimental and control areas. However, several researchers have pointed to methodological problems associated with this research literature. First, researchers have argued that the British car park studies included in the meta-analysis cannot accurately control for the fact that CCTV was introduced simultaneously with a range of other security-related measures. Second, some have noted that, in many of the studies, there may be issues with selection bias since the introduction of CCTV was potentially endogenous to previous crime trends. In particular, the estimated effects may be biased if CCTV is introduced in response to crime trends.

It has been argued that problems of selection bias and endogeneity can be addressed by stronger research designs such as randomized controlled trials and natural experiments. A 2017 review published in Journal of Scandinavian Studies in Criminology and Crime Prevention compiles seven studies that use such research designs. The studies included in the review found that CCTV reduced crime by 24-28% in public streets and urban subway stations. It also found that CCTV could decrease unruly behaviour in football stadiums and theft in supermarkets/mass merchant stores. However, there was no evidence of CCTV having desirable effects in parking facilities or suburban subway stations. Furthermore, the review indicates that CCTV is more effective in preventing property crimes than in violent crimes.

Another question in the effectiveness of CCTV for policing is around uptime of the system; in 2013 City of Philadelphia Auditor found that the $15M system was operational only 32% of the time. There is still much research to be done to determine the effectiveness of CCTV cameras on crime prevention before any conclusions can be drawn.

Alexis_Navy_Yard_012_1dsLQLVk7nY

Closed-circuit video cameras in the Navy Yard complex caught gunman Aaron Alexis during his shooting rampage.

There is strong anecdotal evidence that CCTV aids in detection and conviction of offenders; indeed UK police forces routinely seek CCTV recordings after crimes. Moreover, CCTV has played a crucial role in tracing the movements of suspects or victims and is widely regarded by antiterrorist officers as a fundamental tool in tracking terrorist suspects. Large-scale CCTV installations have played a key part of the defences against terrorism since the 1970s. Cameras have also been installed on public transport in the hope of deterring crime, and in mobile police surveillance vehicles, often with automatic number plate recognition, and a network of APNI-linked cameras is used to manage London’s congestion charging zone. Even so, there is political hostility to surveillance and several commentators downplay the evidence of CCTV’s effectiveness, especially in the US. However, most of these assertions are based on poor methodology or imperfect comparisons.

A more open question is whether most CCTV is cost-effective. While low-quality domestic kits are cheap the professional installation and maintenance of high definition CCTV is expensive. Gill and Spriggs did a Cost-effectiveness analysis (CEA) of CCTV in crime prevention that showed little monetary saving with the installation of CCTV as most of the crimes prevented resulted in little monetary loss. Critics however noted that benefits of non-monetary value cannot be captured in a traditional Cost Effectiveness Analysis and were omitted from their study. A 2008 Report by UK Police Chiefs concluded that only 3% of crimes were solved by CCTV. In London, a Metropolitan Police report showed that in 2008 only one crime was solved per 1000 cameras. In some cases CCTV cameras have become a target of attacks themselves.

Cities such as Manchester in the UK are using DVR-based technology to improve accessibility for crime prevention.

In October 2009, an “Internet Eyes” website was announced which would pay members of the public to view CCTV camera images from their homes and report any crimes they witnessed. The site aimed to add “more eyes” to cameras which might be insufficiently monitored. Civil liberties campaigners criticized the idea as “a distasteful and a worrying development”.

In 2013 Oaxaca hired deaf police officers to lip read conversations to uncover criminal conspiracies.

In Singapore, since 2012, thousands of CCTV cameras have helped deter loan sharks, nab litterbugs and stop illegal parking, according to government figures.

Body Worn

In recent years, the use of body worn video cameras has been introduced for a number of uses. For example, as a new form of surveillance in law enforcement, with cameras located on a police officer’s chest or head.

Industrial Processes

Industrial processes that take place under conditions dangerous for humans are today often supervised by CCTV. These are mainly processes in the chemical industry, the interior of reactors or facilities for manufacture of nuclear fuel. Special cameras for some of these purposes include line-scan cameras and thermographic cameras which allow operators to measure the temperature of the processes. The usage of CCTV in such processes is sometimes required by law.

Traffic onitoring

Many cities and motorway networks have extensive traffic-monitoring systems, using closed-circuit television to detect congestion and notice accidents. Many of these cameras however, are owned by private companies and transmit data to drivers’ GPS systems.

The UK Highways Agency has a publicly owned CCTV network of over 3000 Pan-Tilt-Zoom cameras covering the British motorway and trunk road network. These cameras are primarily used to monitor traffic conditions and are not used as speed cameras. With the addition of fixed cameras for the active traffic management system, the number of cameras on the Highways Agency’s CCTV network is likely to increase significantly over the next few years.

The London congestion charge is enforced by cameras positioned at the boundaries of and inside the congestion charge zone, which automatically read the licence plates of cars. If the driver does not pay the charge then a fine will be imposed. Similar systems are being developed as a means of locating cars reported stolen.

Other surveillance cameras serve as traffic enforcement cameras.

Transport Safety

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Digital Video Recorder for Public Transport

A CCTV system may be installed where any example, on a subway train, CCTV cameras may allow the operator to confirm that people are clear of doors before closing them and starting the train.

Sporting Events

Many sporting events in the United States use CCTV inside the venue for fans to see the action while they are away from their seats. The cameras send the feed to a central control center where a producer selects feeds to send to the television monitors that fans can view. CCTV monitors for viewing the event by attendees are often placed in lounges, hallways, and restrooms. This use of CCTV is not used for surveillance purposes.

Monitor Employees

Organizations use CCTV to monitor the actions of workers. Every action is recorded as an information block with subtitles that explain the performed operation. This helps to track the actions of workers, especially when they are making critical financial transactions, such as correcting or cancelling of a sale, withdrawing money or altering personal information.

Actions which an employer may wish to monitor could include:

  • Scanning of goods, selection of goods, introduction of price and quantity;
  • Input and output of operators in the system when entering passwords;
  • Deleting operations and modifying existing documents;
  • Implementation of certain operations, such as financial statements or operations with cash;
  • Moving goods, revaluation scrapping and counting;
  • Control in the kitchen of fast food restaurants;
  • Change of settings, reports and other official functions.

Each of these operations is transmitted with a description, allowing detailed monitoring of all actions of the operator. Some systems allow the user to search for a specific event by time of occurrence and text description, and perform statistical evaluation of operator behaviour. This allows the software to predict deviations from the standard workflow and record only anomalous behaviour.

Use in Schools

In the United States, Britain, Australia and New Zealand, CCTV is widely used in schools due to its success in preventing bullying, vandalism, monitoring visitors and maintaining a record of evidence in the event of a crime. There are some restrictions on installation, with cameras not being installed in an area where there is a “reasonable expectation of privacy”, such as bathrooms, gym locker areas and private offices (unless consent by the office occupant is given). Сameras are generally acceptable in hallways, parking lots, front offices where students, employees, and parents come and go, gymnasiums, cafeterias, supply rooms and classrooms. The installation of cameras in classrooms may be objected to by some teachers.

Criminal Use

Criminals may use surveillance cameras to monitor the public. For example, a hidden camera at an ATM can capture people’s PINs as they are entered, without their knowledge. The devices are small enough not to be noticed, and are placed where they can monitor the keypad of the machine as people enter their PINs. Images may be transmitted wirelessly to the criminal.

Home Security

In the early to mid 2000s, companies including ADT, LiveWatch, and SimpliSafe started offering CCTVs to the consumer market for home safety and security. Cameras typically come as part of alarm monitoring packages that may also include fire and flood detection.

Prevalence


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A crowdsourced map of CCTV cameras near Grande Arche using OpenStreetMap data.

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Surveillance camera mounted on the walls of Rosenbad, one of the Swedish’s government buildings in central Stockholm, which houses the Prime Minister’s office. One of the parliament’s (Riksdagen) building can be seen in the background.

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A surveillance camera, aimed at a public street (Kungsgatan) in Stockholm, Sweden, mounted on top of the pole.

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The headquarters of the United Nations in New York, with cameras visible on the side of the UN General Assembly building.

There are an estimated 350 million surveillance cameras worldwide as of 2016 compared with about 160 million in 2012. About 65% of these cameras are installed in Asia. The growth of CCTV has been slowing in recent years.

United States

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Surveillance camera mounted on a tripod in Sunriver, Oregon.

There were an estimated 30 million surveillance cameras in the United States in 2011. Video surveillance has been common in the United States since the 1990s; for example, one manufacturer reported net earnings of $120 million in 1995. With lower cost and easier installation, sales of home security cameras increased in the early 21st century. Following the September 11 attacks, the use of video surveillance in public places became more common to deter future terrorist attacks. Under the Homeland Security Grant Program, government grants are available for cities to install surveillance camera networks. In 2009, there were an estimated 15,000 CCTV systems in Chicago, many linked to an integrated camera network. New York City’s Domain Awareness System has 6,000 video surveillance cameras linked together, there are over 4,000 cameras on the subway system (although nearly half of them do not work), and two-thirds of large apartment and commercial buildings use video surveillance cameras. In the Washington D.C.-area, there are more than 30,000 surveillance cameras in schools, and the Metro has nearly 6,000 cameras in use across the system. 

United Kingdom

In the United Kingdom, the vast majority of CCTV cameras are not operated by government bodies, but by private individuals or companies, especially to monitor the interiors of shops and businesses. According to 2011 Freedom of Information Act requests, the total number of local government operated CCTV cameras was around 52,000 over the entirety of the UK.

Although specific legalities of running a home CCTV system in the UK are rather vague there are published rules and regulations that although are mostly common sense, do include some laws that most people may not be aware of, including registering with ICO as a data controller if any CCTV camera catch images of any of the public on, or outside of your property.

An article published in CCTV Image magazine estimated the number of private and local government operated cameras in the United Kingdom was 1.85 million in 2011. The estimate was based on extrapolating from a comprehensive survey of public and private cameras within the Cheshire Constabulary jurisdiction. This works out as an average of one camera for every 32 people in the UK, although the density of cameras varies greatly from place to place. The Cheshire report also claims that the average person on a typical day would be seen by 70 CCTV cameras.

The Cheshire figure is regarded as more dependable than a previous study by Michael McCahill and Clive Norris of UrbanEye published in 2002. Based on a small sample in Putney High Street, McCahill and Norris extrapolated the number of surveillance cameras in Greater London to be around 500,000 and the total number of cameras in the UK to be around 4,200,000. According to their estimate the UK has one camera for every 14 people. Although it has been acknowledged for several years that the methodology behind this figure is flawed, it has been widely quoted. Furthermore, the figure of 500,000 for Greater London is often confused with the figure for the police and local government operated cameras in the City of London, which was about 650 in 2011.

The CCTV User Group estimated that there were around 1.5 million private and local government CCTV cameras in city centres, stations, airports, and major retail areas in the UK. This figure does not include the smaller surveillance systems such as those that may be found in local corner shops and is therefore broadly in line with the Cheshire report.

Research conducted by the Scottish Centre for Crime and Justice Research and based on a survey of all Scottish local authorities, identified that there are over 2,200 public space CCTV cameras in Scotland.

Defra made it legal in 2017 to have all Abbatoirs in the UK now covered by CCTV to prevent cruelty to animals during the slaughter process.

Canada

Project SCRAM is a policing effort by the Halton Regional Police Service to register and help consumers understand the complex issues of privacy and safety that confront households when dealing with installations of home security systems. “The SCRAM program enables community members to voluntarily identify and register their residential video surveillance equipment through a simple, secure, confidential, online form.”. It has not been extended to commercial businesses. A wide-ranging effort to provide registration and monitoring of home security and systems. “Security camera registration and monitoring is a community-based crime prevention opportunity and investigative tool that enlists the help of residents and can help prevent crime on three levels. Residential video surveillance cameras can deter criminals from entering the area, can prevent crimes from occurring and help solve crimes by providing valuable evidence to the police.”

South Africa

In South Africa due to the high crime rate CCTV surveillance is widely prevalent but the country has been slow to implement the latest technology e.g. the first IP camera was released in 1996 by Axis Communications but IP cameras didn’t arrive in South Africa till 2008. In order to regulate the number of suppliers in 2001 the Private Security Industry Regulation Act was passed requiring all security companies to be registered with the Private Security Industry Regulatory Authority (PSIRA).

Around the World

In Latin America, the CCTV market is growing rapidly with the increase of property crime. In Asia, different human activities attracted the use of surveillance camera systems and services, including but not limited to business and related industries, transportation, sports, and care for the environment.

Video Surveillance and Terrorism


Material collected by surveillance cameras has been used as a tool in post-event forensics to identify tactics, techniques and perpetrators of terrorist attacks. Furthermore, there are various projects − such as INDECT − that aim to detect suspicious behaviours of individuals and crowds. It has been argued that terrorists won’t be deterred by cameras, that terror attacks aren’t really the subject of the current use of video surveillance and that terrorists might even see it as an extra channel for propaganda and publication of their acts. In Germany calls for extended video surveillance by the country’s main political parties, SPD, CDU and CSU have been dismissed as “little more than a placebo for a subjective feeling of security”.

Privacy


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A mobile closed-circuit TV van monitoring a street market

Many civil liberties campaign groups, academics and consultants have published research papers into CCTV systems. Opponents of CCTV point out the loss of privacy of people under surveillance, and the negative impact of surveillance on civil liberties. Furthermore, they argue that CCTV displaces crime, rather than reducing it. Critics often dub CCTV as “Big Brother surveillance”, a reference to George Orwell’s novel Nineteen Eighty-Four, which featured a two-way telescreen in every home through which The Party would monitor the populace.

Proponents of CCTV cameras argue that cameras are effective at deterring and solving crime, and that appropriate regulation and legal restrictions on surveillance of public spaces can provide sufficient protections so that an individual’s right to privacy can reasonably be weighed against the benefits of surveillance. However, anti-surveillance activists have held that there is a right to privacy in public areas. Furthermore, while it is true that there may be scenarios wherein a person’s right to public privacy can be both reasonably and justifiably compromised, some scholars have argued that such situations are so rare as to not sufficiently warrant the frequent compromising of public privacy rights that occurs in regions with widespread CCTV surveillance. For example, in her book Setting the Watch: Privacy and the Ethics of CCTV Surveillance, Beatrice von Silva-Tarouca Larsen argues that CCTV surveillance is ethically permissible only in “certain restrictively defined situations”, such as when a specific location has a “comprehensively documented and significant criminal threat”. Her central reasoning is that widespread CCTV surveillance violates citizens’ rights to privacy and anonymity within the public sphere by jeopardizing both their liberty and dignity. She concludes that CCTV surveillance should therefore be reserved for specific circumstances in which there are clear and reasonably demonstrated benefits to its implementation and few ethical compromises.

In the United States, the Constitution does not explicitly include the right to privacy although the Supreme Court has said several of the amendments to the Constitution implicitly grant this right. Access to video surveillance recordings may require a judge’s writ, which is readily available. However, there is little legislation and regulation specific to video surveillance.

All countries in the European Union are signatories to the European Convention on Human Rights which protects individual rights including the right to privacy. The EU’s Data Protection Directive regulates access to personal data including CCTV recordings. This directive is translated into the national law of each country within the European Union.

In the United Kingdom the Data Protection Act 1998 imposes legal restrictions on the uses of CCTV recordings and mandates the registration of CCTV systems with the Data Protection Agency. In 2004, the successor to the Data Protection Agency, the Information Commissioner’s Office clarified that this required registration of all CCTV systems with the Commissioner, and prompt deletion of archived recordings. However, subsequent case law (Durant vs. FSA) limited the scope of the protection provided by this law, and not all CCTV systems are currently regulated. Nonetheless, private sector personnel in the UK who operate or monitor CCTV devices or systems are considered security guards and have been made subject to state licensing.

A 2007 report by the UK Information Commissioner’s Office, highlighted the need for the public to be made more aware of the growing use of surveillance and the potential impact on civil liberties. In the same year, a campaign group claimed the majority of CCTV cameras in the UK are operated illegally or are in breach of privacy guidelines. In response, the Information Commissioner’s Office rebutted the claim and added that any reported abuses of the Data Protection Act are swiftly investigated. Even if there are some concerns arising from the use of CCTV such as involving privacy, more commercial establishments are still installing CCTV systems in the UK.

In 2012, the UK government enacted the Protection of Freedoms Act which includes several provisions related to controlling and restricting the collection, storage, retention, and use of information about individuals. Under this Act, the Home Office published a code of practice in 2013 for the use of surveillance cameras by government and local authorities. The aim of the code is to help ensure their use is “characterised as surveillance by consent, and such consent on the part of the community must be informed consent and not assumed by a system operator. Surveillance by consent should be regarded as analogous to policing by consent.”

In Canada, the use of video surveillance has grown very rapidly. In Ontario, both the municipal and provincial versions of the Freedom of Information and Protection of Privacy Act outline very specific guidelines that control how images and information can be gathered by this method and or released. In some areas in Ontario the use of surveillance cameras are strictly prohibited and controlled based on individual by-laws.

Technological Developments


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Surveillance camera at London Heathrow Airport with a wiper for clear images during rain

Computer-controlled Analytics and Identification

Computer-controlled cameras can identify, track, and categorize objects in their field of view.

Video content analysis (VCA) is the capability of automatically analyzing video to detect and determine temporal events not based on a single image. As such, it can be seen as the automated equivalent of the biological visual cortex.

A system using VCA can recognize changes in the environment and even identify and compare objects in the database using size, speed, and sometimes colour. The camera’s actions can be programmed based on what it is “seeing”. For example; an alarm can be issued if an object has moved in a certain area, or if a painting is missing from a wall, or if a smoke or fire is detected, or if running people are detected, or if fallen people are detected and if someone has spray painted the lens, as well as video loss, lens cover, defocus and other so called camera tampering events.

VCA analytics can also be used to detect unusual patterns in an environment. The system can be set to detect anomalies in a crowd, for instance a person moving in the opposite direction in airports where passengers are supposed to walk only in one direction out of a plane or in a subway where people are not supposed to exit through the entrances.

VCA can track people on a map by calculating their position from the images. It is then possible to link many cameras and track a person through an entire building or area. This can allow a person to be followed without having to analyze many hours of film. Currently the cameras have difficulty identifying individuals from video alone, but if connected to a key-card system, identities can be established and displayed as a tag over their heads on the video.

There is also a significant difference in where the VCA technology is placed, either the data is being processed within the cameras (on the edge) or by a centralized server. Both technologies have their pros and cons.

A facial recognition system is a computer application for automatically identifying or verifying a person from a digital image or a video frame from a video source. One of the ways to do this is by comparing selected facial features from the image and a facial database.
The combination of CCTV and facial recognition has been tried as a form of mass surveillance, but has been ineffective because of the low discriminating power of facial recognition technology and the very high number of false positives generated. This type of system has been proposed to compare faces at airports and seaports with those of suspected terrorists or other undesirable entrants.

400px-CCTV_camera_and_iFacility_IP_Audio_speaker_on_a_pole

CCTV surveillance camera with IP audio PA horn watching from a high steel pole

Computerized monitoring of CCTV images is under development, so that a human CCTV operator does not have to endlessly look at all the screens, allowing an operator to observe many more CCTV cameras. These systems do not observe people directly. Insta Types of body-movement behavior, or particular types of clothing or baggage.

To many, the development of CCTV in public areas, linked to computer databases of people’s pictures and identity, presents a serious breach of civil liberties. Conservative critics fear the possibility that one would no longer have anonymity in public places. Demonstrations or assemblies in public places could be affected as the state would be able to collate lists of those leading them, taking part, or even just talking with protesters in the street.

Comparatively harmless are people counter systems. They use CCTV equipment as front end eyes of devices which perform shape recognition technology in order to identify objects as human beings and count people passing pre-defined areas.

Retention, Storage and Preservation

Most CCTV systems may record and store digital video and images to a digital video recorder (DVR) or, in the case of IP cameras, directly to a server, either on-site or offsite.

There is a cost in the retention of the images produced by CCTV systems. The amount and quality of data stored on storage media is subject to compression ratios, images stored per second, image size and is effected by the retention period of the videos or images. DVRs store images in a variety of proprietary file formats. Recordings may be retained for a preset amount of time and then automatically archived, overwritten or deleted, the period being determined by the organisation that generated them.

Closed-circuit digital photography (CCDP)

Closed-circuit digital photography (CCDP) is more suited for capturing and saving recorded high-resolution photographs, whereas closed-circuit television (CCTV) is more suitable for live-monitoring purposes.

However, an important feature of some CCTV systems is the ability to take high resolution images of the camera scene, e.g. on a time lapse or motion-detection basis. Images taken with a digital still camera often have higher resolution than those taken with some video cameras. Increasingly, low-cost high-resolution digital still cameras can also be used for CCTV purposes.

Images may be monitored remotely when the computer is connected to a network.

IP Cameras

Intellinet_Network_Solutions_NSC11-WN_Home_Network_IP_Camera

Easy Connect Wireless IP camera

A growing branch in CCTV is internet protocol cameras (IP cameras). It is estimated that 2014 was the first year that IP cameras outsold analog cameras. IP cameras use the Internet Protocol (IP) used by most Local Area Networks (LANs) to transmit video across data networks in digital form. IP can optionally be transmitted across the public internet, allowing users to view their cameras through any internet connection available through a computer or a phone, this is considered remote access. For professional or public infrastructure security applications, IP video is restricted to within a private network or VPN, or can be recorded onto a remote server.

Networking CCTV cameras

The city of Chicago operates a networked video surveillance system which combines CCTV video feeds of government agencies with those of the private sector, installed in city buses, businesses, public schools, subway stations, housing projects etc. Even homeowners are able to contribute footage. It is estimated to incorporate the video feeds of a total of 15,000 cameras.

The system is used by Chicago’s Office of Emergency Management in case of an emergency call: it detects the caller’s location and instantly displays the real-time video feed of the nearest security camera to the operator, not requiring any user intervention. While the system is far too vast to allow complete real-time monitoring, it stores the video data for later usage in order to provide possible evidence in criminal cases.

New York City has a similar network called the Domain Awareness System.

London also has a network of CCTV systems that allows multiple authorities to view and control CCTV cameras in real time. The system allows authorities including the Metropolitan Police Service, Transport for London and a number of London boroughs to share CCTV images between them. It uses a network protocol called Television Network Protocol to allow access to many more cameras than each individual system owner could afford to run and maintain.

The Glynn County Police Department uses a wireless mesh-networked system of portable battery-powered tripods for live megapixel video surveillance and central monitoring of tactical police situations. The systems can be used either on a stand-alone basis with secure communications to nearby police laptops, or within a larger mesh system with multiple tripods feeding video back to the command vehicle via wireless, and to police headquarters via 3G.

Integrated Systems

Integrated_LCD_DVR

An integrated systems unit.

Integrated systems allow different security systems, like CCTV, access control, intruder alarms and intercoms to operate together. For example, when an intruder alarm is activated, CCTV cameras covering the intrusion area are recorded at a higher frame rate and transmitted to an Alarm Receiving Centre.

Wireless Security Cameras

800px-Lorex_digital_wireless_camera

Wireless security camera

Many consumers are turning to wireless security cameras for home surveillance. Wireless cameras do not require a video cable for video/audio transmission, simply a cable for power. Wireless cameras are also easy and inexpensive to install, but lack the reliability of hard-wired cameras. Previous generations of wireless security cameras relied on analog technology; modern wireless cameras use digital technology which delivers crisper audio, sharper video, and a secure and interference-free signal.

Talking CCTV

In Wiltshire, UK, 2003, a pilot scheme for what is now known as “Talking CCTV” was put into action; allowing operators of CCTV cameras to order offenders to stop what they were doing, ranging from ordering subjects to pick up their rubbish and put it in a bin to ordering groups of vandals to disperse. In 2005 Ray Mallon, the mayor and former senior police officer of Middlesbrough implemented “Talking CCTV” in his area.

Other towns have had such cameras installed. In 2007 several of the devices were installed in Bridlington town centre, East Riding of Yorkshire.

Countermeasures


Due to the widespread implementation of surveillance cameras, glasses are being built which can defeat CCTV cameras. In December 2016 a form of anti-CCTV and facial recognition sunglasses called ‘reflectacles’ were invented by a custom-spectacle-craftsmen based in Chicago named Scott Urban. They reflect infrared and, optionally, visible light which makes the users face a white blur to cameras. The project easily surpassed its funding goal of $28,000 and reflectacles will be commercially available by June 2017.

CCTV Camera Vandalism


Unless physically protected, CCTV cameras have been found to be vulnerable against a variety of (mostly illegal) tactics:

  • Some people will deliberately destroy cameras. Some cameras can come with dust-tight, pressurized, explosion proof, and bullet-resistant housings.
  • Spraying substances over the lens can make the image too blurry to view.
  • Lasers can blind or damage them. However, since most lasers are monochromatic, color filters can reduce the effect of laser pointers. But filters also impair image quality and overall light sensitivity of cameras (see laser safety article for details on issues with filters). Also, complete protection from lasers of any wavelength would require use of completely black filters, rendering the camera useless.

Cost


The security camera installation cost in Los Angeles, United States ranges from US$300 to US$3,500. On average, however, the cost can be anywhere from US$893 – US$2,267. The price will go up depending on specific requirements or the extent of the security that will be required.

Factors affecting security camera installation cost

Among other factors, the specific type of camera being used has the most significant impact on its cost. The average cost of two digital cameras packaged with an LCD monitor is around US$450. Different brands can also have different prices. The type of technology used also has an impact of security camera installation cost. Wireless camera systems are generally more expensive than their wired counterparts.

The specific type of software that is being used also has a role to play on its price. On average, professional level software is offered at US$75, with some of them requiring annual fees for membership. Network attached storage or DVR, used for storing recorded video, will also be part of the cost. On average, that can cost about US$499. This will depend on the storage capacity and other features of the device chosen by the user.

CCTV | Televisi Sirkuit Tertutup

Dari Wikipedia bahasa Indonesia, ensiklopedia bebas

Televisi Sirkuit Tertutup (bahasa Inggris: Closed Circuit Television (CCTV) yang berarti menggunakan sinyal yang bersifat tertutup, tidak seperti televisi biasa yang merupakan sinyal siaran.

Daftar isi
1 Penggunaan
2 Perlengkapan
2.1 Kamera
2.2 DVR

Penggunaan


Pada umumnya CCTV digunakan sebagai pelengkap keamanan dan banyak dipakai di dalam industri-industri seperti militer, bandara, toko, kantor, pabrik dan bahkan sekarang perumahan pun telah banyak yang menggunakan teknologi ini.

Perlengkapan


CCTV sebagai satu kesatuan system mepunyai beberapa perlengkapan yaitu:

  • Kamera
  • DVR (Digital Video Recorder)

Kamera

Kamera CCTV ini berfungsi sebagai alat pengambil gambar, ada beberapa tipe kamera yang membedakan dari segi kualitas, penggunaan dan fungsinya 2 hal yang paling utama adalah, camera CCTV analog dan Camera CCTV Network dimana kamera analog menggunakan satu solid kable untuk setiap kamera yang berarti, setiap kamera akan harus terhubung ke DVR atau system secara langsung sedangkan Camera Network atau yang biasa di sebut IP Kamera, bisa menggunakan jejaring yang berarti akan menghemat dari segi installasi karena network bersifat pararel dan bercabang tidak memerlukan satu kabel khusus untuk tiap kamera dalam pengaksesannya.

DVR

DVR (Digital Video Recorder). ini adalah system yang digunakan oleh kamera CCTV untuk merekam semua gambar yang di kirim oleh kamera dalam sistem ini banyak fitur yang bisa kita manfaatkan untuk pelengkap keamanan, salah satunya adalah merekam semua kejadian dan hasil rekaman ini yang biasa digunakan di dalam peradilan untuk membuktikan suatu kejadian dalam sebuah sistem kamera, jumlah dan kualitas rekaman akan ditentukan oleh DVR ini.

History of the Internet

Posted on 06/10/2014 by Dr. Shahid Mughal

In the late 1950’s the Advanced Research Projects Agency (ARPA) was founded in the United States with the primary focus of developing information technologies that could survive a nuclear attack. (Networking the Nerds) In 1967 ARPA university and private sector contractors met with representatives of the Department of Defense to discuss possible protocols for sharing information via computers.

In 1969, two years before the calculator was introduced to consumers (History of the Internet and WWW) and the year after National Public Radio was established, the precursor of the Internet, ARPANET, was born. It connected four sites at the University of California at Los Angeles, the University of California at Santa Barbara, Stanford Research Institute, and the University of Utah.

Throughout the 1970’s researchers concentrated on developing protocols for controlling networks, moving messages across a system of networks, and allowing for remote access to the networks.

There were computers connected at about two dozen sites when the first email was sent in 1972, but the number of sites and messages soon mushroomed. By 1975 there were 63 sites. In 1980, 200 host computers were connecting 20,000 people at university, military, and government locations. Twelve years later the number of hosts had grown to more than a million internationally (PBS Timeline), and in January of 1999 there were more than 43 million. (Hobbes’ Internet Timeline v4.1)

Internet

If the 1970’s were a time of research, the 1980’s were a time of development. The TCP/IP protocol was introduced in 1983, and at the University of Wisconsin the name server was developed.

The next year domain name server (DNS) was established. In 1986, the National Science Foundation developed a system to connect the growing number of hosts.

Regional networks were connected to a backbone network, which became known as the NSFNET. As the “Internet” continued to grow and prosper, ARPANET came to an end in 1989 (PBS Timeline) just before HTML protocol was introduced in 1990. HTML allowed graphics to be sent along with text to create hypertext pages customized to the sender’s preference. ( Networking the Nerds ) Everything was now in place for explosive growth.

Commercial Development

In 1963 during the early days of computers and six years before ARPANET, students at MIT developed the first computer game called Space War. It would be twenty years before the TCP/IP protocol stimulated the growth of various networks and nearly thirty years (1991) before the United States government opened the Internet to private enterprise (PBS Timeline), but this game foreshadowed the commercialization of the Internet. In the 1970’s and 80’s people who were online put out information about furniture and cars they wanted to sell. Debates raged about whether this was an appropriate use of the new research tool, the Internet, but when the Commercial Internet Exchange (CIX) was formed in 1991 the genie would not go back in the bottle.

Commercial contractors have been involved in the development of ARPANET from its inception. As Tang and Teflon began as curiosities of the space program and later became common consumer products, so too have email, web research, and home shopping on the Web.

It has only been ten years since the first relay between a commercial entity (MCI Mail) and the Internet was made. Since that time technologies have emerged that have fueled the growth of private enterprise on the Web.

In 1992 Paul Linder and Mark McCahill at the University of Minnesota released Gopher, a tool that allowed researchers to retrieve specific data from myriad locations. The next year Mosaic, a web browser, was developed at the University of Illinois by Netscape founder Marc Andreesen, the World Wide Web became a public domain, and the Pentium processor was introduced by Intel to speed up the whole process. (From ARAPNET to World Wide Web)

As the technology advanced, the Internet became easier to use and the World Wide Web sites became more intricate and inviting. In 1994 shopping malls arrived on the Net. You could order pizza from Pizza Hut online or bank at First Virtual Bank, the first cyberbank. Of course, the advancements came with a downside.

Vladimir Levin of Russia became the first publicly known Internet bank robber when he used the Internet to illegally transfer funds to his account. ( Hobbes’ Internet Timeline v4.1 )

network cables connected to switch

1995 saw the introduction of several emerging technologies such as JAVA and JAVAscript, Virtual Environments, and RealAudio which further enhanced the kind of product information which could be made available to consumers.

Commercial users now outnumbered research and academic users by a two to one margin, and Bill Gates decided to redefine Microsoft as an Internet company. (History of the Internet)

Today one can shop online for books, food and wine, travel, and real estate. Other business activities include buying stocks and bonds, banking, and retirement planning. Online shopping accounted for over $9 billion in 1997 and is expected to be $30 billion by the year 2000.

In light of this growth, the U.S. Commerce Department will begin studying the impact of online shopping on total retail activity. (Commerce Department to Measure Online Sales)

Consumer spending via the Internet draws much interest, but business to business activity is also booming. The consulting group Piper Jaffray estimates that by the year 2001 Internet based business to business transactions will total US $201.6 billion.

Forrester Research estimates that by 2002 online business to business transactions will total US $327 billion, (Internet Statistics), while other projections indicate that by 2003, consumers will spend $108 billion, while businesses will spend $1.3 trillion. (Spotlight: Corporate E-commerce Kicks Into Gear)

World Wide Web

From Wikipedia, the free encyclopedia

1280px-Web_Index.svg

A global map of the web index for countries in 2014

The World Wide Web (abbreviated WWW or the Web) is an information space where documents and other web resources are identified by Uniform Resource Locators (URLs), interlinked by hypertext links, and can be accessed via the Internet. English scientist Tim Berners-Lee invented the World Wide Web in 1989. He wrote the first web browser computer program in 1990 while employed at CERN in Switzerland. The Web browser was released outside CERN in 1991, first to other research institutions starting in January 1991 and to the general public on the Internet in August 1991.

The World Wide Web has been central to the development of the Information Age and is the primary tool billions of people use to interact on the Internet. Web pages are primarily text documents formatted and annotated with Hypertext Markup Language (HTML). In addition to formatted text, web pages may contain images, video, audio, and software components that are rendered in the user’s web browser as coherent pages of multimedia content.

Embedded hyperlinks permit users to navigate between web pages. Multiple web pages with a common theme, a common domain name, or both, make up a website. Website content can largely be provided by the publisher, or interactively where users contribute content or the content depends upon the users or their actions. Websites may be mostly informative, primarily for entertainment, or largely for commercial, governmental, or non-governmental organisational purposes.

Contents
1 History
2 Function
2.1 Linking
2.2 Dynamic updates of web pages
2.3 WWW prefix
2.4 Scheme specifiers
3 Web security
4 Privacy
5 Standards
6 Accessibility
7 Internationalisation
8 Statistics
9 Web caching

History


NeXTcube_first_webserver

The NeXT Computer used by Tim Berners-Lee at CERN.

449px-CERN_web_corridor

The corridor where WWW was born. CERN, ground floor of building No.1

Tim Berners-Lee’s vision of a global hyperlinked information system became a possibility by the second half of the 1980s. By 1985, the global Internet began to proliferate in Europe and the Domain Name System (upon which the Uniform Resource Locator is built) came into being. In 1988 the first direct IP connection between Europe and North America was made and Berners-Lee began to openly discuss the possibility of a web-like system at CERN. In March 1989 Berners-Lee issued a proposal to the management at CERN for a system called “Mesh” that referenced ENQUIRE, a database and software project he had built in 1980, which used the term “web” and described a more elaborate information management system based on links embedded in readable text: “Imagine, then, the references in this document all being associated with the network address of the thing to which they referred, so that while reading this document you could skip to them with a click of the mouse.” Such a system, he explained, could be referred to using one of the existing meanings of the word hypertext, a term that he says was coined in the 1950s. There is no reason, the proposal continues, why such hypertext links could not encompass multimedia documents including graphics, speech and video, so that Berners-Lee goes on to use the term hypermedia.

With help from his colleague and fellow hypertext enthusiast Robert Cailliau he published a more formal proposal on 12 November 1990 to build a “Hypertext project” called “WorldWideWeb” (one word) as a “web” of “hypertext documents” to be viewed by “browsers” using a client–server architecture. At this point HTML and HTTP had already been in development for about two months and the first Web server was about a month from completing its first successful test. This proposal estimated that a read-only web would be developed within three months and that it would take six months to achieve “the creation of new links and new material by readers, [so that] authorship becomes universal” as well as “the automatic notification of a reader when new material of interest to him/her has become available.” While the read-only goal was met, accessible authorship of web content took longer to mature, with the wiki concept, WebDAV, blogs, Web 2.0 and RSS/Atom.

1024px-Cern_datacenter

The CERN data centre in 2010 housing some WWW servers

The proposal was modelled after the SGML reader Dynatext by Electronic Book Technology, a spin-off from the Institute for Research in Information and Scholarship at Brown University. The Dynatext system, licensed by CERN, was a key player in the extension of SGML ISO 8879:1986 to Hypermedia within HyTime, but it was considered too expensive and had an inappropriate licensing policy for use in the general high energy physics community, namely a fee for each document and each document alteration. A NeXT Computer was used by Berners-Lee as the world’s first web server and also to write the first web browser, WorldWideWeb, in 1990. By Christmas 1990, Berners-Lee had built all the tools necessary for a working Web: the first web browser (which was a web editor as well) and the first web server. The first web site, which described the project itself, was published on 20 December 1990.

The first web page may be lost, but Paul Jones of UNC-Chapel Hill in North Carolina announced in May 2013 that Berners-Lee gave him what he says is the oldest known web page during a 1991 visit to UNC. Jones stored it on a magneto-optical drive and on his NeXT computer. On 6 August 1991, Berners-Lee published a short summary of the World Wide Web project on the newsgroup alt.hypertext. This date is sometimes confused with the public availability of the first web servers, which had occurred months earlier. As another example of such confusion, several news media reported that the first photo on the Web was published by Berners-Lee in 1992, an image of the CERN house band Les Horribles Cernettes taken by Silvano de Gennaro; Gennaro has disclaimed this story, writing that media were “totally distorting our words for the sake of cheap sensationalism.”

The first server outside Europe was installed at the Stanford Linear Accelerator Center (SLAC) in Palo Alto, California, to host the SPIRES-HEP database. Accounts differ substantially as to the date of this event. The World Wide Web Consortium’s timeline says December 1992, whereas SLAC itself claims December 1991, as does a W3C document titled A Little History of the World Wide Web. The underlying concept of hypertext originated in previous projects from the 1960s, such as the Hypertext Editing System (HES) at Brown University, Ted Nelson’s Project Xanadu, and Douglas Engelbart’s oN-Line System (NLS). Both Nelson and Engelbart were in turn inspired by Vannevar Bush’s microfilm-based memex, which was described in the 1945 essay “As We May Think”.

Berners-Lee’s breakthrough was to marry hypertext to the Internet. In his book Weaving The Web, he explains that he had repeatedly suggested that a marriage between the two technologies was possible to members of both technical communities, but when no one took up his invitation, he finally assumed the project himself. In the process, he developed three essential technologies:

  • a system of globally unique identifiers for resources on the Web and elsewhere, the universal document identifier (UDI), later known as uniform resource locator (URL) and uniform resource identifier (URI);
  • the publishing language HyperText Markup Language (HTML);
  • the Hypertext Transfer Protocol (HTTP).

The World Wide Web had a number of differences from other hypertext systems available at the time. The Web required only unidirectional links rather than bidirectional ones, making it possible for someone to link to another resource without action by the owner of that resource. It also significantly reduced the difficulty of implementing web servers and browsers (in comparison to earlier systems), but in turn presented the chronic problem of link rot. Unlike predecessors such as HyperCard, the World Wide Web was non-proprietary, making it possible to develop servers and clients independently and to add extensions without licensing restrictions. On 30 April 1993, CERN announced that the World Wide Web would be free to anyone, with no fees due. Coming two months after the announcement that the server implementation of the Gopher protocol was no longer free to use, this produced a rapid shift away from Gopher and towards the Web. An early popular web browser was ViolaWWW for Unix and the X Windowing System.

Cailliau_Abramatic_Berners-Lee_10_years_WWW_consortium

Robert Cailliau, Jean-François Abramatic, and Tim Berners-Lee at the 10th anniversary of the World Wide Web Consortium.

Scholars generally agree that a turning point for the World Wide Web began with the introduction of the Mosaic web browser in 1993, a graphical browser developed by a team at the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign (NCSA-UIUC), led by Marc Andreessen. Funding for Mosaic came from the U.S. High-Performance Computing and Communications Initiative and the High-Performance Computing and Communication Act of 1991, one of several computing developments initiated by U.S. Senator Al Gore. Prior to the release of Mosaic, graphics were not commonly mixed with text in web pages and the web’s popularity was less than older protocols in use over the Internet, such as Gopher and Wide Area Information Servers (WAIS). Mosaic’s graphical user interface allowed the Web to become, by far, the most popular Internet protocol. The World Wide Web Consortium (W3C) was founded by Tim Berners-Lee after he left the European Organization for Nuclear Research (CERN) in October 1994. It was founded at the Massachusetts Institute of Technology Laboratory for Computer Science (MIT/LCS) with support from the Defense Advanced Research Projects Agency (DARPA), which had pioneered the Internet; a year later, a second site was founded at INRIA (a French national computer research lab) with support from the European Commission DG InfSo; and in 1996, a third continental site was created in Japan at Keio University. By the end of 1994, the total number of websites was still relatively small, but many notable websites were already active that foreshadowed or inspired today’s most popular services.

Connected by the Internet, other websites were created around the world. This motivated international standards development for protocols and formatting. Berners-Lee continued to stay involved in guiding the development of web standards, such as the markup languages to compose web pages and he advocated his vision of a Semantic Web. The World Wide Web enabled the spread of information over the Internet through an easy-to-use and flexible format. It thus played an important role in popularising use of the Internet. Although the two terms are sometimes conflated in popular use, World Wide Web is not synonymous with Internet. The Web is an information space containing hyperlinked documents and other resources, identified by their URIs. It is implemented as both client and server software using Internet protocols such as TCP/IP and HTTP. Berners-Lee was knighted in 2004 by Queen Elizabeth II for “services to the global development of the Internet”.

Function


Internet_Key_Layers

The World Wide Web functions as an application layer protocol that is run “on top of” (figuratively) the Internet, helping to make it more functional. The advent of the Mosaic web browser helped to make the web much more usable, to include the display of images and moving images (gifs).

The terms Internet and World Wide Web are often used without much distinction. However, the two are not the same. The Internet is a global system of interconnected computer networks. In contrast, the World Wide Web is a global collection of documents and other resources, linked by hyperlinks and URIs. Web resources are usually accessed using HTTP, which is one of many Internet communication protocols.

Viewing a web page on the World Wide Web normally begins either by typing the URL of the page into a web browser, or by following a hyperlink to that page or resource. The web browser then initiates a series of background communication messages to fetch and display the requested page. In the 1990s, using a browser to view web pages—and to move from one web page to another through hyperlinks—came to be known as ‘browsing,’ ‘web surfing’ (after channel surfing), or ‘navigating the Web’. Early studies of this new behaviour investigated user patterns in using web browsers. One study, for example, found five user patterns: exploratory surfing, window surfing, evolved surfing, bounded navigation and targeted navigation.

The following example demonstrates the functioning of a web browser when accessing a page at the URL http://www.example.org/home.html. The browser resolves the server name of the URL (www.example.org) into an Internet Protocol address using the globally distributed Domain Name System (DNS). This lookup returns an IP address such as 203.0.113.4 or 2001:db8:2e::7334. The browser then requests the resource by sending an HTTP request across the Internet to the computer at that address. It requests service from a specific TCP port number that is well known for the HTTP service, so that the receiving host can distinguish an HTTP request from other network protocols it may be servicing. The HTTP protocol normally uses port number 80. The content of the HTTP request can be as simple as two lines of text:

GET /home.html HTTP/1.1
Host: http://www.example.org

The computer receiving the HTTP request delivers it to web server software listening for requests on port 80. If the web server can fulfil the request it sends an HTTP response back to the browser indicating success:

HTTP/1.0 200 OK
Content-Type: text/html; charset=UTF-8

followed by the content of the requested page. HyperText Markup Language (HTML) for a basic web page might look like this:

<html>
<head>
<title>Example.org – The World Wide Web</title>
</head>
<body>
<p>The World Wide Web, abbreviated as WWW and commonly known …</p>
</body>
</html>

The web browser parses the HTML and interprets the markup (<title>, <p> for paragraph, and such) that surrounds the words to format the text on the screen. Many web pages use HTML to reference the URLs of other resources such as images, other embedded media, scripts that affect page behavior, and Cascading Style Sheets that affect page layout. The browser makes additional HTTP requests to the web server for these other Internet media types. As it receives their content from the web server, the browser progressively renders the page onto the screen as specified by its HTML and these additional resources.

Linking

Most web pages contain hyperlinks to other related pages and perhaps to downloadable files, source documents, definitions and other web resources. In the underlying HTML, a hyperlink looks like this: <a href=”http://www.example.org/home.html”>Example.org Homepage</a>

WorldWideWebAroundWikipedia

Graphic representation of a minute fraction of the WWW, demonstrating hyperlinks

Such a collection of useful, related resources, interconnected via hypertext links is dubbed a web of information. Publication on the Internet created what Tim Berners-Lee first called the WorldWideWeb (in its original CamelCase, which was subsequently discarded) in November 1990.

The hyperlink structure of the WWW is described by the webgraph: the nodes of the web graph correspond to the web pages (or URLs) the directed edges between them to the hyperlinks. Over time, many web resources pointed to by hyperlinks disappear, relocate, or are replaced with different content. This makes hyperlinks obsolete, a phenomenon referred to in some circles as link rot, and the hyperlinks affected by it are often called dead links. The ephemeral nature of the Web has prompted many efforts to archive web sites. The Internet Archive, active since 1996, is the best known of such efforts.

Dynamic updates of web pages

JavaScript is a scripting language that was initially developed in 1995 by Brendan Eich, then of Netscape, for use within web pages. The standardised version is ECMAScript. To make web pages more interactive, some web applications also use JavaScript techniques such as Ajax (asynchronous JavaScript and XML). Client-side script is delivered with the page that can make additional HTTP requests to the server, either in response to user actions such as mouse movements or clicks, or based on elapsed time. The server’s responses are used to modify the current page rather than creating a new page with each response, so the server needs only to provide limited, incremental information. Multiple Ajax requests can be handled at the same time, and users can interact with the page while data is retrieved. Web pages may also regularly poll the server to check whether new information is available.

WWW prefix

Many hostnames used for the World Wide Web begin with www because of the long-standing practice of naming Internet hosts according to the services they provide. The hostname of a web server is often www, in the same way that it may be ftp for an FTP server, and news or nntp for a USENET news server. These host names appear as Domain Name System (DNS) or subdomain names, as in http://www.example.com. The use of www is not required by any technical or policy standard and many web sites do not use it; indeed, the first ever web server was called nxoc01.cern.ch. According to Paolo Palazzi, who worked at CERN along with Tim Berners-Lee, the popular use of www as subdomain was accidental; the World Wide Web project page was intended to be published at http://www.cern.ch while info.cern.ch was intended to be the CERN home page, however the DNS records were never switched, and the practice of prepending www to an institution’s website domain name was subsequently copied. Many established websites still use the prefix, or they employ other subdomain names such as www2, secure or en for special purposes. Many such web servers are set up so that both the main domain name (e.g., example.com) and the www subdomain (e.g., http://www.example.com) refer to the same site; others require one form or the other, or they may map to different web sites. The use of a subdomain name is useful for load balancing incoming web traffic by creating a CNAME record that points to a cluster of web servers. Since, currently, only a subdomain can be used in a CNAME, the same result cannot be achieved by using the bare domain root.

When a user submits an incomplete domain name to a web browser in its address bar input field, some web browsers automatically try adding the prefix “www” to the beginning of it and possibly “.com”, “.org” and “.net” at the end, depending on what might be missing. For example, entering ‘microsoft’ may be transformed to http://www.microsoft.com/ and ‘openoffice’ to http://www.openoffice.org. This feature started appearing in early versions of Firefox, when it still had the working title ‘Firebird’ in early 2003, from an earlier practice in browsers such as Lynx. It is reported that Microsoft was granted a US patent for the same idea in 2008, but only for mobile devices.

In English, www is usually read as double-u double-u double-u. Some users pronounce it dub-dub-dub, particularly in New Zealand. Stephen Fry, in his “Podgrams” series of podcasts, pronounces it wuh wuh wuh. The English writer Douglas Adams once quipped in The Independent on Sunday (1999): “The World Wide Web is the only thing I know of whose shortened form takes three times longer to say than what it’s short for”. In Mandarin Chinese, World Wide Web is commonly translated via a phono-semantic matching to wàn wéi wǎng (万维网), which satisfies www and literally means “myriad dimensional net”, a translation that reflects the design concept and proliferation of the World Wide Web. Tim Berners-Lee’s web-space states that World Wide Web is officially spelled as three separate words, each capitalised, with no intervening hyphens. Use of the www prefix has been declining, especially when Web 2.0 web applications sought to brand their domain names and make them easily pronounceable. As the mobile Web grew in popularity, services like Gmail.com, Outlook.com, Myspace.com, Facebook.com and Twitter.com are most often mentioned without adding “www.” (or, indeed, “.com”) to the domain.

Scheme specifiers

The scheme specifiers http:// and https:// at the start of a web URI refer to Hypertext Transfer Protocol or HTTP Secure, respectively. They specify the communication protocol to use for the request and response. The HTTP protocol is fundamental to the operation of the World Wide Web, and the added encryption layer in HTTPS is essential when browsers send or retrieve confidential data, such as passwords or banking information. Web browsers usually automatically prepend http:// to user-entered URIs, if omitted.

Web Security


For criminals, the Web has become a venue to spread malware and engage in a range of cybercrimes, including identity theft, fraud, espionage and intelligence gathering. Web-based vulnerabilities now outnumber traditional computer security concerns, and as measured by Google, about one in ten web pages may contain malicious code. Most web-based attacks take place on legitimate websites, and most, as measured by Sophos, are hosted in the United States, China and Russia. The most common of all malware threats is SQL injection attacks against websites. Through HTML and URIs, the Web was vulnerable to attacks like cross-site scripting (XSS) that came with the introduction of JavaScript and were exacerbated to some degree by Web 2.0 and Ajax web design that favours the use of scripts. Today by one estimate, 70% of all websites are open to XSS attacks on their users. Phishing is another common threat to the Web. “SA, the Security Division of EMC, today announced the findings of its January 2013 Fraud Report, estimating the global losses from phishing at $1.5 Billion in 2012”. Two of the well-known phishing methods are Covert Redirect and Open Redirect.

Proposed solutions vary. Large security companies like McAfee already design governance and compliance suites to meet post-9/11 regulations, and some, like Finjan have recommended active real-time inspection of programming code and all content regardless of its source. Some have argued that for enterprises to see Web security as a business opportunity rather than a cost centre, while others call for “ubiquitous, always-on digital rights management” enforced in the infrastructure to replace the hundreds of companies that secure data and networks. Jonathan Zittrain has said users sharing responsibility for computing safety is far preferable to locking down the Internet.

Privacy


Every time a client requests a web page, the server can identify the request’s IP address and usually logs it. Also, unless set not to do so, most web browsers record requested web pages in a viewable history feature, and usually cache much of the content locally. Unless the server-browser communication uses HTTPS encryption, web requests and responses travel in plain text across the Internet and can be viewed, recorded, and cached by intermediate systems. When a web page asks for, and the user supplies, personally identifiable information—such as their real name, address, e-mail address, etc.—web-based entities can associate current web traffic with that individual. If the website uses HTTP cookies, username and password authentication, or other tracking techniques, it can relate other web visits, before and after, to the identifiable information provided. In this way it is possible for a web-based organization to develop and build a profile of the individual people who use its site or sites. It may be able to build a record for an individual that includes information about their leisure activities, their shopping interests, their profession, and other aspects of their demographic profile. These profiles are obviously of potential interest to marketeers, advertisers and others. Depending on the website’s terms and conditions and the local laws that apply information from these profiles may be sold, shared, or passed to other organizations without the user being informed. For many ordinary people, this means little more than some unexpected e-mails in their in-box or some uncannily relevant advertising on a future web page. For others, it can mean that time spent indulging an unusual interest can result in a deluge of further targeted marketing that may be unwelcome. Law enforcement, counter terrorism, and espionage agencies can also identify, target and track individuals based on their interests or proclivities on the Web.

Social networking sites try to get users to use their real names, interests, and locations, rather than pseudonyms. These website’s leaders believe this makes the social networking experience more engaging for users. On the other hand, uploaded photographs or unguarded statements can be identified to an individual, who may regret this exposure. Employers, schools, parents, and other relatives may be influenced by aspects of social networking profiles, such as text posts or digital photos, that the posting individual did not intend for these audiences. On-line bullies may make use of personal information to harass or stalk users. Modern social networking websites allow fine grained control of the privacy settings for each individual posting, but these can be complex and not easy to find or use, especially for beginners. Photographs and videos posted onto websites have caused particular problems, as they can add a person’s face to an on-line profile. With modern and potential facial recognition technology, it may then be possible to relate that face with other, previously anonymous, images, events and scenarios that have been imaged elsewhere. Because of image caching, mirroring and copying, it is difficult to remove an image from the World Wide Web.

Standards


Many formal standards and other technical specifications and software define the operation of different aspects of the World Wide Web, the Internet, and computer information exchange. Many of the documents are the work of the World Wide Web Consortium (W3C), headed by Berners-Lee, but some are produced by the Internet Engineering Task Force (IETF) and other organisations.

Usually, when web standards are discussed, the following publications are seen as foundational:

  • Recommendations for markup languages, especially HTML and XHTML, from the W3C. These define the structure and interpretation of hypertext documents.
  • Recommendations for stylesheets, especially CSS, from the W3C.
  • Standards for ECMAScript (usually in the form of JavaScript), from Ecma International.
  • Recommendations for the Document Object Model, from W3C.

Additional publications provide definitions of other essential technologies for the World Wide Web, including, but not limited to, the following:

  • Uniform Resource Identifier (URI), which is a universal system for referencing resources on the Internet, such as hypertext documents and images. URIs, often called URLs, are defined by the IETF’s RFC 3986 / STD 66: Uniform Resource Identifier (URI): Generic Syntax, as well as its predecessors and numerous URI scheme-defining RFCs;
  • HyperText Transfer Protocol (HTTP), especially as defined by RFC 2616: HTTP/1.1 and RFC 2617: HTTP Authentication, which specify how the browser and server authenticate each other.

Accessibility


There are methods for accessing the Web in alternative mediums and formats to facilitate use by individuals with disabilities. These disabilities may be visual, auditory, physical, speech-related, cognitive, neurological, or some combination. Accessibility features also help people with temporary disabilities, like a broken arm, or ageing users as their abilities change. The Web receives information as well as providing information and interacting with society. The World Wide Web Consortium claims that it is essential that the Web be accessible, so it can provide equal access and equal opportunity to people with disabilities. Tim Berners-Lee once noted, “The power of the Web is in its universality. Access by everyone regardless of disability is an essential aspect.” Many countries regulate web accessibility as a requirement for websites. International cooperation in the W3C Web Accessibility Initiative led to simple guidelines that web content authors as well as software developers can use to make the Web accessible to persons who may or may not be using assistive technology.

Internationalisation


The W3C Internationalisation Activity assures that web technology works in all languages, scripts, and cultures. Beginning in 2004 or 2005, Unicode gained ground and eventually in December 2007 surpassed both ASCII and Western European as the Web’s most frequently used character encoding. Originally RFC 3986 allowed resources to be identified by URI in a subset of US-ASCII. RFC 3987 allows more characters—any character in the Universal Character Set—and now a resource can be identified by IRI in any language.

Statistics


Between 2005 and 2010, the number of web users doubled, and was expected to surpass two billion in 2010. Early studies in 1998 and 1999 estimating the size of the Web using capture/recapture methods showed that much of the web was not indexed by search engines and the Web was much larger than expected. According to a 2001 study, there was a massive number, over 550 billion, of documents on the Web, mostly in the invisible Web, or Deep Web. A 2002 survey of 2,024 million web pages determined that by far the most web content was in the English language: 56.4%; next were pages in German (7.7%), French (5.6%), and Japanese (4.9%). A more recent study, which used web searches in 75 different languages to sample the Web, determined that there were over 11.5 billion web pages in the publicly indexable web as of the end of January 2005. As of March 2009, the indexable web contains at least 25.21 billion pages. On 25 July 2008, Google software engineers Jesse Alpert and Nissan Hajaj announced that Google Search had discovered one trillion unique URLs. As of May 2009, over 109.5 million domains operated. Of these, 74% were commercial or other domains operating in the generic top-level domain com. Statistics measuring a website’s popularity, such as the Alexa Internet rankings, are usually based either on the number of page views or on associated server “hits” (file requests) that it receives.

Web Caching


A web cache is a server computer located either on the public Internet, or within an enterprise that stores recently accessed web pages to improve response time for users when the same content is requested within a certain time after the original request. Most web browsers also implement a browser cache for recently obtained data, usually on the local disk drive. HTTP requests by a browser may ask only for data that has changed since the last access. Web pages and resources may contain expiration information to control caching to secure sensitive data, such as in online banking, or to facilitate frequently updated sites, such as news media. Even sites with highly dynamic content may permit basic resources to be refreshed only occasionally. Web site designers find it worthwhile to collate resources such as CSS data and JavaScript into a few site-wide files so that they can be cached efficiently. Enterprise firewalls often cache Web resources requested by one user for the benefit of many users. Some search engines store cached content of frequently accessed websites.