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Thursday, November 21, 2019

Smartphone

From Wikipedia, the free encyclopedia
 
Two smartphones: a Samsung Galaxy J5 (left) and an iPhone 6S (right)
Customized phone
 
Smartphones are a class of mobile phones and of multi-purpose mobile computing devices. They are distinguished from feature phones by their stronger hardware capabilities and extensive mobile operating systems, which facilitate wider software, internet (including web browsing over mobile broadband), and multimedia functionality (including music, video, cameras, and gaming), alongside core phone functions such as voice calls and text messaging. Smartphones typically include various sensors that can be leveraged by their software, such as a magnetometer, proximity sensors, barometer, gyroscope and accelerometer, and support wireless communications protocols such as Bluetooth, Wi-Fi, and satellite navigation.

Early smartphones were marketed primarily towards the enterprise market, attempting to bridge the functionality of standalone personal digital assistant (PDA) devices with support for cellular telephony, but were limited by their bulky form, short battery life, slow analog cellular networks, and the immaturity of wireless data services. These issues were eventually resolved with the exponential scaling and miniaturization of MOS transistors down to sub-micron levels (Moore's law), the improved lithium-ion battery, faster digital mobile data networks (Edholm's law), and more mature software platforms that allowed mobile device ecosystems to develop independently of data providers.

In the 2000s, NTT DoCoMo's i-mode platform, BlackBerry, Nokia's Symbian platform, and Windows Mobile began to gain market traction, with models often featuring QWERTY keyboards or resistive touchscreen input, and emphasizing access to push email and wireless internet. Since the unveiling of the iPhone in 2007, the majority of smartphones have featured thin, slate-like form factors, with large, capacitive screens with support for multi-touch gestures rather than physical keyboards, and offer the ability for users to download or purchase additional applications from a centralized store, and use cloud storage and synchronization, virtual assistants, as well as mobile payment services.

Improved hardware and faster wireless communication (due to standards such as LTE) have bolstered the growth of the smartphone industry. In the third quarter of 2012, one billion smartphones were in use worldwide. Global smartphone sales surpassed the sales figures for feature phones in early 2013.

History

The development of the smartphone was enabled by several key technological advances. The exponential scaling and miniaturization of MOSFETs (MOS transistors) down to sub-micron levels during the 1990s–2000s (as predicted by Moore's law) made it possible to build portable smart devices such as smartphones, as well as enabling the transistion from analog to faster digital wireless mobile networks (leading to Edholm's law). Other important enabling factors include the lithium-ion battery, an indispensable energy source for smartphones, being commercialized in 1991, and the development of more mature software platforms that allowed mobile device ecosystems to develop independently of data providers.

Forerunner

IBM Simon and charging base (1994)

In the early 1990s, IBM engineer Frank Canova realised that chip-and-wireless technology was becoming small enough to use in handheld devices. The first commercially available device that could be properly referred to as a "smartphone" began as a prototype called "Angler" developed by Canova in 1992 while at IBM and demonstrated in November of that year at the COMDEX computer industry trade show. A refined version was marketed to consumers in 1994 by BellSouth under the name Simon Personal Communicator. In addition to placing and receiving cellular calls, the touchscreen-equipped Simon could send and receive faxes and emails. It included an address book, calendar, appointment scheduler, calculator, world time clock, and notepad, as well as other visionary mobile applications such as maps, stock reports and news.

The IBM Simon was manufactured by Mitsubishi Electric, which integrated features from its own wireless personal digital assistant (PDA) and cellular radio technologies. It featured a liquid-crystal display (LCD) and PC Card support. The Simon was commercially unsuccessful, particularly due to its bulky form factor and limited battery life, using NiCad batteries rather than the nickel–metal hydride batteries commonly used in mobile phones in the 1990s, or lithium-ion batteries used in modern smartphones.

The term "smart phone" or "smartphone" was not coined until a year after the introduction of the Simon, appearing in print as early as 1995, describing AT&T's PhoneWriter Communicator.

PDA/phone hybrids

Beginning in the mid-late 1990s, many people who had mobile phones carried a separate dedicated PDA device, running early versions of operating systems such as Palm OS, Newton OS, Symbian or Windows CE/Pocket PC. These operating systems would later evolve into early mobile operating systems. Most of the "smartphones" in this era were hybrid devices that combined these existing familiar PDA OSes with basic phone hardware. The results were devices that were bulkier than either dedicated mobile phones or PDAs, but allowed a limited amount of cellular Internet access. PDA and mobile phone manufacturers competed in reducing the size of devices. The bulk of these smartphones combined with their high cost and expensive data plans, plus other drawbacks such as expansion limitations and decreased battery life compared to separate standalone devices, generally limited their popularity to "early adopters" and business users who needed portable connectivity.

In March 1996, Hewlett-Packard released the OmniGo 700LX, a modified HP 200LX palmtop PC with a Nokia 2110 mobile phone piggybacked onto it and ROM-based software to support it. It had a 640×200 resolution CGA compatible four-shade gray-scale LCD screen and could be used to place and receive calls, and to create and receive text messages, emails and faxes. It was also 100% DOS 5.0 compatible, allowing it to run thousands of existing software titles, including early versions of Windows

The Nokia 9000 Communicator (right) and the updated 9110 model (left)
 
In August 1996, Nokia released the Nokia 9000 Communicator, a digital cellular PDA based on the Nokia 2110 with an integrated system based on the PEN/GEOS 3.0 operating system from Geoworks. The two components were attached by a hinge in what became known as a clamshell design, with the display above and a physical QWERTY keyboard below. The PDA provided e-mail; calendar, address book, calculator and notebook applications; text-based Web browsing; and could send and receive faxes. When closed, the device could be used as a digital cellular telephone.

In June 1999 Qualcomm released the "pdQ Smartphone", a CDMA digital PCS smartphone with an integrated Palm PDA and Internet connectivity.

Subsequent landmark devices included:
  • The Ericsson R380 (December 2000) by Ericsson Mobile Communications, the first phone running the operating system later named Symbian (it ran EPOC Release 5, which was renamed Symbian OS at Release 6). It had PDA functionality and limited Web browsing on a resistive touchscreen utilizing a stylus. While it was marketed as a "smartphone", users could not install their own software on the device.
  • The Kyocera 6035 (February 2001), a dual-nature device with a separate Palm OS PDA operating system and CDMA mobile phone firmware. It supported limited Web browsing with the PDA software treating the phone hardware as an attached modem.
  • The Nokia 9210 Communicator (June 2001), the first phone running Symbian (Release 6) with Nokia's Series 80 platform (v1.0). This was the first Symbian phone platform allowing the installation of additional applications. Like the Nokia 9000 Communicator it's a large clamshell device with a full physical QWERTY keyboard inside.
  • Handspring's Treo 180 (2002), the first smartphone that fully integrated the Palm OS on a GSM mobile phone having telephony, SMS messaging and Internet access built into the OS. The 180 model had a thumb-type keyboard and the 180g version had a Graffiti handwriting recognition area, instead.

Japanese cell phones

In 1999, Japanese wireless provider NTT DoCoMo launched i-mode, a new mobile internet platform which provided data transmission speeds up to 9.6 kilobits per second, and access web services available through the platform such as online shopping. NTT DoCoMo's i-mode used cHTML, a language which restricted some aspects of traditional HTML in favor of increasing data speed for the devices. Limited functionality, small screens and limited bandwidth allowed for phones to use the slower data speeds available. The rise of i-mode helped NTT DoCoMo accumulate an estimated 40 million subscribers by the end of 2001, and ranked first in market capitalization in Japan and second globally. Japanese cell phones increasingly diverged from global standards and trends to offer other forms of advanced services and smartphone-like functionality that were specifically tailored to the Japanese market, such as mobile payments and shopping, near-field communication (NFC) allowing mobile wallet functionality to replace smart cards for transit fares, loyalty cards, identity cards, event tickets, coupons, money transfer, etc., downloadable content like musical ringtones, games, and comics, and 1seg mobile television. Phones built by Japanese manufacturers used custom firmware, however, and didn't yet feature standardized mobile operating systems designed to cater to third-party application development, so their software and ecosystems were akin to very advanced feature phones. As with other feature phones, additional software and services required partnerships and deals with providers. 

The degree of integration between phones and carriers, unique phone features, non-standardized platforms, and tailoring to Japanese culture made it difficult for Japanese manufacturers to export their phones, especially when demand was so high in Japan that the companies didn't feel the need to look elsewhere for additional profits.

The rise of 3G technology in other markets and non-Japanese phones with powerful standardized smartphone operating systems, app stores, and advanced wireless network capabilities allowed non-Japanese phone manufacturers to finally break in to the Japanese market, gradually adopting Japanese phone features like emojis, mobile payments, NFC, etc. and spreading them to the rest of the world.

Early smartphones

Several BlackBerry smartphones, which were highly popular in the mid-late 2000s
 
Phones that made effective use of any significant data connectivity were still rare outside Japan until the introduction of the Danger Hiptop in 2002, which saw moderate success among U.S. consumers as the T-Mobile Sidekick. Later, in the mid-2000s, business users in the U.S. started to adopt devices based on Microsoft's Windows Mobile, and then BlackBerry smartphones from Research In Motion. American users popularized the term "CrackBerry" in 2006 due to the BlackBerry's addictive nature. In the U.S., the high cost of data plans and relative rarity of devices with Wi-Fi capabilities that could avoid cellular data network usage kept adoption of smartphones mainly to business professionals and "early adopters."

Outside the U.S. and Japan, Nokia was seeing success with its smartphones based on Symbian, originally developed by Psion for their personal organisers, and it was the most popular smartphone OS in Europe during the middle to late 2000s. Initially, Nokia's Symbian smartphones were focused on business with the Eseries, similar to Windows Mobile and BlackBerry devices at the time. From 2006 onwards, Nokia started producing consumer-focused smartphones, popularized by the entertainment-focused Nseries. Until 2010, Symbian was the world's most widely used smartphone operating system.

Form factor and operating system shifts

The original Apple iPhone; following its introduction the common smartphone form factor shifted to large touchscreen software interfaces without physical keypads
 
The touchscreen PDA-derived nature of adapted operating systems like Palm OS, the "Pocket PC" versions of what was later Windows Mobile, and the UIQ interface that was originally designed for pen-based PDAs on Symbian OS devices resulted in some early smartphones having stylus-based interfaces. These allowed for virtual keyboards and/or handwriting input, thus also allowing easy entry of Asian characters.

By the mid-2000s, the majority of smartphones had a physical QWERTY keyboard. Most used a "keyboard bar" form factor, like the BlackBerry line, Windows Mobile smartphones, Palm Treos, and some of the Nokia Eseries. A few hid their full physical QWERTY keyboard in a sliding form factor, like the Danger Hiptop line. Some even had only a numeric keypad using T9 text input, like the Nokia Nseries and other models in the Nokia Eseries. Resistive touchscreens with stylus-based interfaces could still be found on a few smartphones, like the Palm Treos, which had dropped their handwriting input after a few early models that were available in versions with Graffiti instead of a keyboard. 

The late 2000s and early 2010s saw a shift in smartphone interfaces away from devices with physical keyboards and keypads to ones with large finger-operated capacitive touchscreens.

The first phone of any kind with a large capacitive touchscreen was the LG Prada, announced by LG in December 2006. This was a fashionable feature phone created in collaboration with Italian luxury designer Prada with a 3" 240x400 pixel screen.

In January 2007, Apple Computer introduced the iPhone. It had a 3.5" capacitive touchscreen with twice the common resolution of most smartphone screens at the time, and introduced multi-touch to phones, which allowed gestures such as "pinching" to zoom in or out on photos, maps, and web pages. The iPhone was notable as being the first device of its kind targeted at the mass market to abandon the use of a stylus, keyboard, or keypad typical of contemporary smartphones, instead using a large touchscreen for direct finger input as its main means of interaction.

The iPhone's operating system was also a shift away from previous ones that were adapted from PDAs and feature phones, to one powerful enough to avoid using a limited, stripped down web browser requiring pages specially formatted using technologies such as WML, cHTML, or XHTML that previous phones supported and instead run a version of Apple's Safari browser that could easily render full websites not specifically designed for phones.

Later Apple shipped a software update that gave the iPhone a built-in on-device App Store allowing direct wireless downloads of third-party software. This kind of centralized App Store and free developer tools quickly became the new main paradigm for all smartphone platforms for software development, distribution, discovery, installation, and payment, in place of expensive developer tools that required official approval to use and a dependence on third-party sources providing applications for multiple platforms.

The advantages of a design with software powerful enough to support advanced applications and a large capacitive touchscreen affected the development of another smartphone OS platform, Android, with a more BlackBerry-like prototype device scrapped in favor of a touchscreen device with a slide-out physical keyboard, as Google's engineers thought at the time that a touchscreen could not completely replace a physical keyboard and buttons. Android is based around a modified Linux kernel, again providing more power than mobile operating systems adapted from PDAs and feature phones. The first Android device, the HTC Dream, was released in September 2008, with both a 3.2" capacitive touchscreen and a hardware keyboard that was revealed when the user slid the screen open. By 2010 the majority of Android phones were touchscreen-only.

The iPhone and later touchscreen-only Android devices together popularized the smartphone form factor based on a large capacitive touchscreen as the sole means of interaction, and led to the decline of earlier, keyboard- and keypad-focused platforms. Other smartphone manufacturers soon started projects to replace their existing operating systems with new ones that could support touch interfaces on larger screens and web browsers that could render full web pages. Microsoft, for instance, discontinued Windows Mobile and started a new touchscreen-oriented OS from scratch, called Windows Phone. Nokia abandoned Symbian and partnered with Microsoft to use Windows Phone on its smartphones. Palm replaced their Palm OS with webOS. BlackBerry Limited, formerly known as Research In Motion and known for phones with a full qwerty keyboard below the screen, made a new platform for touchscreen phones based on QNX, BlackBerry 10.

By the mid-2010s, almost all smartphones were touchscreen-only and had discarded legacy mobile operating systems for more recently developed ones that were more capable.

Camera advancements

The Huawei P30 features three rear-facing camera lenses 
 
The first commercial camera phone was the Kyocera Visual Phone VP-210, released in Japan in May 1999. It was called a "mobile videophone" at the time, and had a 110,000-pixel front-facing camera. It could send up to two images per second over Japan's Personal Handy-phone System (PHS) cellular network, and store up to 20 JPEG digital images, which could be sent over e-mail. The first mass-market camera phone was the J-SH04, a Sharp J-Phone model sold in Japan in November 2000. It could instantly transmit pictures via cell phone telecommunication.

By the mid-2000s, higher-end cell phones commonly had integrated digital cameras. In 2003 camera phones outsold stand-alone digital cameras, and in 2006 they outsold film and digital stand-alone cameras. Five billion camera phones were sold in five years, and by 2007 more than half of the installed base of all mobile phones were camera phones. Sales of separate cameras peaked in 2008.

Many early smartphones didn't have cameras at all, and earlier models that had them had low performance and insufficient image and video quality that could not compete with budget pocket cameras and fullfill user's needs. By the beginning of the 2010s almost all smartphones had an integrated digital camera. The decline in sales of stand-alone cameras accelerated due to the increasing use of smartphones with rapidly improving camera technology for casual photography, easier image manipulation, and abilities to directly share photos through the use of apps and web-based services. By 2011, cell phones with integrated cameras were selling hundreds of millions per year. In 2015, digital camera sales were 35.395 million units or only less than a third of digital camera sales numbers at their peak and also slightly less than film camera sold number at their peak.

Contributing to the rise in popularity of smartphones being used over dedicated cameras for photography, smaller pocket cameras have difficulty producing bokeh in images, but nowadays, some smartphones have dual-lens cameras that reproduce the bokeh effect easily, and can even rearrange the level of bokeh after shooting. This works by capturing multiple images with different focus settings, then combining the background of the main image with a macro focus shot.

In 2007 the Nokia N95 was notable as a smartphone that had a 5.0 Megapixel (MP) camera, when most others had cameras with around 3 MP or less than 2 MP. Some specialized feature phones like the LG Viewty, Samsung SGH-G800, and Sony Ericsson K850i, all released later that year, also had 5.0 MP cameras. By 2010 5.0 MP cameras were common; a few smartphones had 8.0 MP cameras and the Nokia N8, Sony Ericsson Satio, and Samsung M8910 Pixon12 feature phone had 12 MP. In 2009 the Samsung Omnia HD was the first phone with 720p video recording. A 14-megapixel smartphone with 3x optical zoom was announced in late 2010. In 2012 Nokia announced the Nokia 808 PureView, featuring a 41-megapixel 1/1.2-inch sensor and a high-resolution f/2.4 Zeiss all-aspherical one-group lens. 1080p video recording on a smartphone was achieved in 2011, and 2160p (4K) video recording in 2013. In 2016 Apple introduced the iPhone 7 Plus, one of the phones to popularize a dual camera setup. The iPhone 7 Plus included a main 12 MP camera along with a 12 MP telephoto camera which allowed for 2x optical zoom and Portrait Mode (simulated Bokeh). In early 2018 Huawei released a new flagship phone, the Huawei P20 Pro, with one of the first triple camera lens setups. In late 2018, Samsung released a new mid-range smartphone, the Galaxy A9 (2018) with the world's first quad camera setup. The Nokia 9 PureView was released in 2019 featuring a penta-lens camera system.

Display advancements

 
In the early 2010s, larger smartphones with screen sizes of at least 5.5 inches diagonal, dubbed "phablets", began to achieve popularity, with the 2011 Samsung Galaxy Note series gaining notably wide adoption. In 2013, Huawei launched the Huawei Mate series, sporting a 6.1-inch HD (1280x720) IPS+ LCD display, which was considered to be quite large at the time.

Some companies began to release smartphones in 2013 incorporating flexible displays to create curved form factors, such as the Samsung Galaxy Round and LG G Flex.

By 2014, 1440p displays began to appear on high-end smartphones. In 2015, Sony released the Xperia Z5 Premium, featuring a 4K resolution display, although only images and videos could actually be rendered at that resolution (all other software is upscaled from 1080p).

New trends for smartphone displays began to emerge in 2017, with both LG and Samsung releasing flagship smartphones (LG G6 and Galaxy S8), utilizing displays with taller aspect ratios than the common 16:9 ratio, and a high screen-to-body ratio, also known as "bezel-less design". These designs allow the display to have a larger diagonal measurement, but with a slimmer width than 16:9 displays with an equivalent screen size.

Another trend popularized in 2017 was having a display that contained a tab-like cut-out at the top-centre—colloquially known as a "notch"—to contain the front-facing camera, and sometimes other sensors typically located along the top bezel of a device. These designs allow for "edge-to-edge" displays that take up nearly the entire height of the device, with little to no bezel along the top, and sometimes a minimal bottom bezel as well. This design characteristic appeared almost simultaneously on the Sharp Aquos S2 and the Essential Phone, which featured circular tabs for their cameras, followed just a month later by the iPhone X, which used a wider tab to contain a camera and facial scanning system.

An example of a flexible display
 
Smartphones with foldable displays were theorized as possible once manufacturing costs and production processes were feasible. In November 2018, the startup company Royole unveiled the first commercially available foldable smartphone, the Royole FlexPai. Also that month, Samsung presented a prototype phone featuring an "Infinity Flex Display" at its developers conference, with a smaller, outer display on its "cover", and a larger, tablet-sized display when opened. Samsung stated that it also had to develop a new polymer material to coat the display as opposed to glass. Early examples of foldable phones from other manufacturers became the subject of rumors in early 2019; Samsung officially announced the Galaxy Fold, based on the previously-demonstrated prototype, in February 2019 for an originally-scheduled release in late-April.

In 2019, 4.7-inches to 5.5 inches have become the industry standard size, with most companies abandoning smaller, under 4.7-inch displays.

Other developments in the 2010s

2011

The first smartphone with a fingerprint reader was the Motorola Atrix 4G in 2011. In September 2013, the iPhone 5S was unveiled as the first smartphone on a major U.S. carrier since the Atrix to feature this technology.

2012

In 2012, Samsung introduced the Galaxy S3 (GT-i9300) with retrofittable wireless charging, pop-up video playback, 4G-LTE variant (GT-i9305) quad-core processor.

2013

In 2013, Fairphone launched its first "socially ethical" smartphone at the London Design Festival to address concerns regarding the sourcing of materials in the manufacturing followed by Shiftphone in 2015. In late 2013, QSAlpha commenced production of a smartphone designed entirely around security, encryption and identity protection.

In October 2013, Motorola Mobility announced Project Ara, a concept for a modular smartphone platform that would allow users to customize and upgrade their phones with add-on modules that attached magnetically to a frame. Ara was retained by Google following its sale of Motorola Mobility to Lenovo, but was shelved in 2016. That year, LG and Motorola both unveiled smartphones featuring a limited form of modularity for accessories; the LG G5 allowed accessories to be installed via the removal of its battery compartment, while the Moto Z utilizes accessories attached magnetically to the rear of the device.

2014

Microsoft, expanding upon the concept of Motorola's short-lived "Webtop", unveiled functionality for its Windows 10 operating system for phones that allows supported devices to be docked for use with a PC-styled desktop environment.

2015

Samsung and LG used to be the “last standing” manufacturers to offer flagship devices with user-replaceable batteries. But in 2015, Samsung succumbed to the minimalism trend set by Apple, introducing the Galaxy S6 with a non-user-replaceable battery. In addition, Samsung was criticised for pruning long-standing features such as MHL, MicroUSB 3.0, water resistance and MicroSD card support, of which the latter two came back in 2016 with the Galaxy S7 and S7 Edge.

As of 2015, the global median for smartphone ownership was 43%. Statista forecast that 2.87 billion people would own smartphones in 2020.

2016

Major technologies that began to trend in 2016 included a focus on virtual reality and augmented reality experiences catered towards smartphones, the newly introduced USB-C connector, and improving LTE technologies.

2018

In 2018, the first smartphones featuring fingerprint readers embedded within OLED displays were announced, followed in 2019 by an implementation using an ultrasonic sensor on the Samsung Galaxy S10.

Hardware

Central processing unit

Smartphones have central processing units (CPUs), similar to those in computers, but optimised to operate in low power environments. 

The performance of mobile CPU depends not only on the clock rate (generally given in multiples of hertz) but also on the memory hierarchy. Because of these challenges, the performance of mobile phone CPUs is often more appropriately given by scores derived from various standardized tests to measure the real effective performance in commonly used applications.

Display

A smartphone touchscreen
 
One of the main characteristics of smartphones is the screen. Depending on the device's design, the screen fills most or nearly all of the space on a device's front surface. Many smartphone displays have an aspect ratio of 16:9, but taller aspect ratios became more common in 2017.

Screen sizes are measured in diagonal inches. Phones with screens larger than 5.2 inches are often called "phablets". Smartphones with screens over 4.5 inches in size are commonly difficult to use with only a single hand, since most thumbs cannot reach the entire screen surface; they may need to be shifted around in the hand, held in one hand and manipulated by the other, or used in place with both hands. Due to design advances, some modern smartphones with large screen sizes and "edge-to-edge" designs have compact builds that improve their ergonomics, while the shift to taller aspect ratios have resulted in phones that have larger screen sizes whilst maintaining the ergonomics associated with smaller 16:9 displays.

Liquid-crystal displays and OLED displays are the most common. Some displays are integrated with pressure-sensitive digitizers, such as those developed by Wacom and Samsung, and Apple's Force Touch system.

Sound

Some audio quality enhancing features, such as Voice over LTE and HD Voice have appeared and are often available on newer smartphones. Sound quality can remain a problem due to the design of the phone, the quality of the cellular network and compression algorithms used in long distance calls. Audio quality can be improved using a VoIP application over WiFi. Cellphones have small speakers so that the user can use a speakerphone feature and talk to a person on the phone without holding it to their ear. The small speakers can also be used to listen to digital audio files of music or speech or watch videos with an audio component, without holding the phone close to the ear.

Battery

A high-capacity portable battery charger
 
By the end of 2017, smartphone battery life has become generally adequate; however, earlier smartphone battery life was poor due to the weak batteries that could not handle the significant power requirements of the smartphones' computer systems and color screens.

Smartphone users purchase additional chargers for use outside the home, at work, and in cars and by buying portable external "battery packs". External battery packs include generic models which are connected to the smartphone with a cable, and custom-made models that "piggyback" onto a smartphone's case. In 2016, Samsung had to recall millions of the Galaxy Note 7 smartphones due to an explosive battery issue. For consumer convenience, wireless charging stations have been introduced in some hotels, bars, and other public spaces.

Cameras

Cameras have become standard features of smartphones. As of 2019 phone cameras are now a highly competitive area of differentiation between models, with advertising campaigns commonly based on a focus on the quality or capabilities of a device's main cameras. 

Typically smartphones have at least one main rear-facing camera and a lower-resolution front-facing camera for "selfies" and video chat. Owing to the limited depth available in smartphones for image sensors and optics, rear-facing cameras are often housed in a "bump" that's thicker than the rest of the phone. Since increasingly thin mobile phones have more abundant horizontal space than the depth that is necessary and used in dedicated cameras for better lenses, there's additionally a trend for phone manufacturers to include multiple cameras, with each optimized for a different purpose (telephoto, wide angle, etc.). 

Images are usually saved in the JPEG file format; some high-end phones also have RAW image capability. 

Modern advanced smartphones have cameras with optical image stabilisation (OIS), larger sensors, bright lenses, and even optical zoom plus RAW images. HDR, "Bokeh mode" with multi lenses and multi-shot night modes are now also familiar. Many new smartphone camera features are being enabled via computational photography image processing and multiple specialized lenses rather than larger sensors and lenses, due to the constrained space available inside phones that are being made as slim as possible.

Accessories

A wide range of accessories are sold for smartphones, including cases, screen protectors, power charging cables, wireless power stations, USB On-The-Go adapters (for connecting USB drives and or, in some cases, a HDMI cable to an external monitor), add-on batteries, headphones, combined headphone-microphones (which, for example, allow a person to privately conduct calls on the device without holding it to the ear), and Bluetooth-enabled powered speakers that enable users to listen to media from their smartphones wirelessly. 

Cases range from relatively inexpensive rubber or soft plastic cases which provide moderate protection from bumps and good protection from scratches to more expensive, heavy-duty cases that combine a rubber padding with a hard outer shell. Some cases have a "book"-like form, with a cover that the user opens to use the device; when the cover is closed, it protects the screen. Some "book"-like cases have additional pockets for credit cards, thus enabling people to use them as wallets

Accessories include products sold by the manufacturer of the smartphone and compatible products made by other manufacturers.

Software

Mobile operating systems

A mobile operating system (or mobile OS) is an operating system for phones, tablets, smartwatches, or other mobile devices.

Mobile operating systems combine features of a personal computer operating system with other features useful for mobile or handheld use; usually including, and most of the following considered essential in modern mobile systems; a touchscreen, cellular, Bluetooth, Wi-Fi Protected Access, Wi-Fi, Global Positioning System (GPS) mobile navigation, video- and single-frame picture cameras, speech recognition, voice recorder, music player, near field communication, and infrared blaster. By Q1 2018, over 383 million smartphones were sold with 85.9 percent running Android, 14.1 percent running iOS and a negligible number of smartphones running other OSes. Android alone is more popular than the popular desktop operating system Windows, and in general smartphone use (even without tablets) exceeds desktop use. 

Mobile devices with mobile communications abilities (e.g., smartphones) contain two mobile operating systems – the main user-facing software platform is supplemented by a second low-level proprietary real-time operating system which operates the radio and other hardware. Research has shown that these low-level systems may contain a range of security vulnerabilities permitting malicious base stations to gain high levels of control over the mobile device.

Mobile app

A mobile app is a computer program designed to run on a mobile device, such as a smartphone. The term "app" is a short-form of the term "software application".

Application stores

The introduction of Apple's App Store for the iPhone and iPod Touch in July 2008 popularized manufacturer-hosted online distribution for third-party applications (software and computer programs) focused on a single platform. There are a huge variety of apps, including video games, music products and business tools. Up until that point, smartphone application distribution depended on third-party sources providing applications for multiple platforms, such as GetJar, Handango, Handmark, and PocketGear. Following the success of the App Store, other smartphone manufacturers launched application stores, such as Google's Android Market (later renamed to the Google Play Store) and RIM's BlackBerry App World and Android-related app stores like F-Droid. In February 2014, 93% of mobile developers were targeting smartphones first for mobile app development.

Sales

Since 1996, smartphone shipments have had positive growth. In November 2011, 27% of all photographs created were taken with camera-equipped smartphones. In September 2012, a study concluded that 4 out of 5 smartphone owners use the device to shop online. Global smartphone sales surpassed the sales figures for feature phones in early 2013. Worldwide shipments of smartphones topped 1 billion units in 2013, up 38% from 2012's 725 million, while comprising a 55% share of the mobile phone market in 2013, up from 42% in 2012. In Q1 2016 for the first time the shipments dropped by 3 percent year on year. The situation was caused by the maturing China market.

By manufacturer

Worldwide smartphones producers market share
Source Date Samsung Huawei Apple Inc. Xiaomi Oppo Others
Gartner Q2 2018 19.3% 13.3% 11.9% 8.8% 7.6% 39.0%
IDC Q2 2018 21.0% 15.9% 12.1% 9.5% 8.6% 32.9%

In 2011, Samsung had the highest shipment market share worldwide, followed by Apple. In 2013, Samsung had 31.3% market share, a slight increase from 30.3% in 2012, while Apple was at 15.3%, a decrease from 18.7% in 2012. Huawei, LG and Lenovo were at about 5% each, significantly better than 2012 figures, while others had about 40%, the same as the previous years figure. Only Apple lost market share, although their shipment volume still increased by 12.9%; the rest had significant increases in shipment volumes of 36–92%. In Q1 2014, Samsung had a 31% share and Apple had 16%. In Q4 2014, Apple had a 20.4% share and Samsung had 19.9%. In Q2 2016, Samsung had a 22.3% share and Apple had 12.9%. In Q1 2017, IDC reported that Samsung was first placed, with 80 million units, followed by Apple with 50.8 million, Huawei with 34.6 million, Oppo with 25.5 million and Vivo with 22.7 million.

Samsung's mobile business is half the size of Apple's, by revenue. Apple business increased very rapidly in the years 2013 to 2017.

Use

Mobile banking and payment


Mobile payment system.
 
In many countries, mobile phones are used to provide mobile banking services, which may include the ability to transfer cash payments by secure SMS text message. Kenya's M-PESA mobile banking service, for example, allows customers of the mobile phone operator Safaricom to hold cash balances which are recorded on their SIM cards. Cash can be deposited or withdrawn from M-PESA accounts at Safaricom retail outlets located throughout the country and can be transferred electronically from person to person and used to pay bills to companies.

Branchless banking has been successful in South Africa and the Philippines. A pilot project in Bali was launched in 2011 by the International Finance Corporation and an Indonesian bank, Bank Mandiri.

Another application of mobile banking technology is Zidisha, a US-based nonprofit micro-lending platform that allows residents of developing countries to raise small business loans from Web users worldwide. Zidisha uses mobile banking for loan disbursements and repayments, transferring funds from lenders in the United States to borrowers in rural Africa who have mobile phones and can use the Internet.

Mobile payments were first trialled in Finland in 1998 when two Coca-Cola vending machines in Espoo were enabled to work with SMS payments. Eventually, the idea spread and in 1999, the Philippines launched the country's first commercial mobile payments systems with mobile operators Globe and Smart

Some mobile phones can make mobile payments via direct mobile billing schemes, or through contactless payments if the phone and the point of sale support near field communication (NFC). Enabling contactless payments through NFC-equipped mobile phones requires the co-operation of manufacturers, network operators, and retail merchants.

Facsimile

Some apps allows for sending and receiving facsimile (Fax), over a smartphone, including facsimile data (composed of raster bi-level graphics) generated directly and digitally from document and image file formats.

Convergence with other devices

The rise in popularity of touchscreen smartphones and mobile apps distributed via app stores along with rapidly advancing network, mobile processor, and storage technologies led to a convergence where separate mobile phones, organizers, and portable media players were replaced by a smartphone as the single device most people carried. Advances in digital camera sensors and on-device image processing software more gradually led to smartphones replacing simpler cameras for photographs and video recording. The built-in GPS capabilities and mapping apps on smartphones largely replaced stand-alone satellite navigation devices, and paper maps became less common. Mobile gaming on smartphones greatly grew in popularity, allowing many people to use them in place of handheld game consoles, and some companies tried creating game console/phone hybrids based on phone hardware and software. People frequently have chosen not to get fixed-line telephone service in favor of smartphones. Music streaming apps and services have grown rapidly in popularity, serving the same use as listening to music stations on a terrestrial or satellite radio. Streaming video services are easily accessed via smartphone apps and can be used in place of watching television. People have often stopped wearing wristwatches in favor of checking the time on their smartphones, and many use the clock features on their phones in place of alarm clocks.

Additionally, in many lesser technologically developed regions smartphones are people's first and only means of Internet access due to their portability, with personal computers being relatively uncommon outside of business use. The cameras on smartphones can be used to photograph documents and send them via email or messaging in place of using fax (facsimile) machines. Payment apps and services on smartphones allow people to make less use of wallets, purses, credit and debit cards, and cash. Mobile banking apps can allow people to deposit checks simply by photographing them, eliminating the need to take the physical check to an ATM or teller. Guide book apps can take the place of paper travel and restaurant/business guides, museum brochures, and dedicated audio guide equipment.

Criticism and issues

Social impacts

A 2012 University of Southern California study found that unprotected adolescent sexual activity was more common among owners of smartphones. A study conducted by the Rensselaer Polytechnic Institute's (RPI) Lighting Research Center (LRC) concluded that smartphones, or any backlit devices, can seriously affect sleep cycles. Some persons might become psychologically attached to smartphones resulting in anxiety when separated from the devices. A "smombie" (a combination of "smartphone" and "zombie") is a walking person using a smartphone and not paying attention as they walk, possibly risking an accident in the process, an increasing social phenomenon. The issue of slow-moving smartphone users led to the temporary creation of a "mobile lane" for walking in Chongqing, China. The issue of distracted smartphone users led the city of Augsburg, Germany to embed pedestrian traffic lights in the pavement.

While driving

A New York City driver holding two phones
 
A user consulting a mapping app on a phone
 
Mobile phone use while driving—including calling, text messaging, playing media, web browsing, gaming, using mapping apps or operating other phone features—is common but controversial, since it is widely considered dangerous due to what is known as distracted driving. Being distracted while operating a motor vehicle has been shown to increase the risk of accidents. In September 2010, the US National Highway Traffic Safety Administration (NHTSA) reported that 995 people were killed by drivers distracted by phones. In March 2011 a US insurance company, State Farm Insurance, announced the results of a study which showed 19% of drivers surveyed accessed the Internet on a smartphone while driving. Many jurisdictions prohibit the use of mobile phones while driving. In Egypt, Israel, Japan, Portugal and Singapore, both handheld and hands-free calling on a mobile phone (which uses a speakerphone) is banned. In other countries including the UK and France and in many US states, only the use of calling on handheld phones is banned, while hands-free use is permitted.

A 2011 study reported that over 90% of college students surveyed text (initiate, reply or read) while driving. The scientific literature on the danger of driving while sending a text message from a mobile phone, or texting while driving, is limited. A simulation study at the University of Utah found a sixfold increase in distraction-related accidents when texting. Due to the complexity of smartphones that began to grow more after, this has introduced additional difficulties for law enforcement officials when attempting to distinguish one usage from another in drivers using their devices. This is more apparent in countries which ban both handheld and hands-free usage, rather than those which ban handheld use only, as officials cannot easily tell which function of the phone is being used simply by looking at the driver. This can lead to drivers being stopped for using their device illegally for a call when, in fact, they were using the device legally, for example, when using the phone's incorporated controls for car stereo, GPS or satnav.

A sign along Bellaire Boulevard in Southside Place, Texas (Greater Houston) states that using mobile phones while driving is prohibited from 7:30 am to 9:00 am and from 2:00 pm to 4:15 pm
 
A 2010 study reviewed the incidence of phone use while cycling and its effects on behavior and safety. In 2013 a national survey in the US reported the number of drivers who reported using their phones to access the Internet while driving had risen to nearly one of four. A study conducted by the University of Vienna examined approaches for reducing inappropriate and problematic use of mobile phones, such as using phones while driving.

Accidents involving a driver being distracted by being in a call on a phone have begun to be prosecuted as negligence similar to speeding. In the United Kingdom, from 27 February 2007, motorists who are caught using a handheld phone while driving will have three penalty points added to their license in addition to the fine of £60. This increase was introduced to try to stem the increase in drivers ignoring the law. Japan prohibits all use of phones while driving, including use of hands-free devices. New Zealand has banned handheld phone use since 1 November 2009. Many states in the United States have banned text messaging on phones while driving. Illinois became the 17th American state to enforce this law. As of July 2010, 30 states had banned texting while driving, with Kentucky becoming the most recent addition on July 15.

Public Health Law Research maintains a list of distracted driving laws in the United States. This database of laws provides a comprehensive view of the provisions of laws that restrict the use of mobile devices while driving for all 50 states and the District of Columbia between 1992, when first law was passed through December 1, 2010. The dataset contains information on 22 dichotomous, continuous or categorical variables including, for example, activities regulated (e.g., texting versus talking, hands-free versus handheld calls, web browsing, gaming), targeted populations, and exemptions.

Legal

A "patent war" between Samsung and Apple started when the latter claimed that the original Galaxy S Android phone copied the interface‍—‌and possibly the hardware‍—‌of Apple's iOS for the iPhone 3GS. There was also smartphone patents licensing and litigation involving Sony Mobile, Google, Apple Inc., Samsung, Microsoft, Nokia, Motorola, HTC, Huawei and ZTE, among others. The conflict is part of the wider "patent wars" between multinational technology and software corporations. To secure and increase market share, companies granted a patent can sue to prevent competitors from using the methods the patent covers. Since the 2010s the number of lawsuits, counter-suits, and trade complaints based on patents and designs in the market for smartphones, and devices based on smartphone OSes such as Android and iOS, has increased significantly. Initial suits, countersuits, rulings, license agreements, and other major events began in 2009 as the smartphone market stated to grow more rapidly by 2012.

Medical

With the rise in number of mobile medical apps in the market place, government regulatory agencies raised concerns on the safety of the use of such applications. These concerns were transformed into regulation initiatives worldwide with the aim of safeguarding users from untrusted medical advice.

Security

Smartphone malware is easily distributed through an insecure app store. Often, malware is hidden in pirated versions of legitimate apps, which are then distributed through third-party app stores. Malware risk also comes from what is known as an "update attack", where a legitimate application is later changed to include a malware component, which users then install when they are notified that the app has been updated. As well, one out of three robberies in 2012 in the United States involved the theft of a mobile phone. An online petition has urged smartphone makers to install kill switches in their devices. In 2014, Apple's "Find my iPhone" and Google's "Android Device Manager" can locate, disable, and wipe the data from phones that have been lost or stolen. With BlackBerry Protect in OS version 10.3.2, devices can be rendered unrecoverable to even BlackBerry's own Operating System recovery tools if incorrectly authenticated or dissociated from their account.

Leaked documents published by WikiLeaks, codenamed Vault 7 and dated from 2013–2016, detail the capabilities of the United States Central Intelligence Agency (CIA) to perform electronic surveillance and cyber warfare, including the ability to compromise the operating systems of most smartphones (including iOS and Android).

Guidelines for mobile device security were issued by NIST and many other organizations. For conducting a private, in-person meeting, at least one site recommends that the user switch the smartphone off and disconnect the battery.

Sleep

Using smartphones late at night can disturb sleep, due to the blue light and brightly lit screen, which affects melatonin levels and sleep cycles. In an effort to alleviate these issues, "Night Mode" functionality to change the color temperature of a screen to a warmer hue based on the time of day to reduce the amount of blue light generated became available through several apps for Android and the f.lux software for jailbroken iPhones. iOS 9.3 integrated a similar, system-level feature known as "Night Shift." Several Android device manufacturers bypassed Google’s initial reluctance to make Night Mode a standard feature in Android and included software for it on their hardware under varying names, before Android Oreo added it to the OS for compatible devices.

It has also been theorized that for some users, addiction to use of their phones, especially before they go to bed, can result in "ego depletion." Many people also use their phones as alarm clocks, which can also lead to loss of sleep.

Social media use in politics

From Wikipedia, the free encyclopedia
 
Social media use in politics refers to the use of online social media platforms in political processes and activities. Social media platforms encompass websites such as Facebook, YouTube, WeChat, Instagram, QQ, QZone, Weibo, Twitter, Tumblr, Reddit, Baidu Tieba, LinkedIn, LINE, Snapchat, Pinterest, Viber, and VK.

Political processes and activities include all activities that pertain to the governance of a country or area. This includes political organization, global politics, political corruption, political parties, and political values.

The internet has created channels of communication that play a key role in circulating news, and social media has the power to change not just the message, but the dynamics of political corruption, values, and the dynamics of conflict in politics. Through the use of social media in election processes, global conflict, and extreme politics, diplomacy both in the United States and around the world has become less private and susceptive to the public perception.

Background

Participatory role

Social media have been championed as allowing anyone with an Internet connection to become a content creator and empowering their users. The idea of “new media populism” encompasses how citizens can include disenfranchised citizens, and allow the public to have an engaged and active role in political discourse. New media, including social media platforms such as Facebook and Twitter, can enhance people’s access to political information.

Social media platforms and the internet have facilitated the dissemination of political information that counters mainstream media tactics that are often centralized and top-down, and include high barriers to entry. Writer Howard Rheingold characterized the community created on social networking sites:
"The political significance of computer mediated communication lies in its capacity to challenge the existing political hierarchy’s monopoly on powerful communications media, and perhaps thus revitalize citizen-based democracy." 
Scholar Derrick de Kerckhove described the new technology in media:
"In a networked society, the real powershift is from the producer to the consumer, and there is a redistribution of controls and power. On the Web, Karl Marx’s dream has been realized: the tools and the means of production are in the hands of the workers."
The role of social media in democratizing media participation, which proponents herald as ushering in a new era of participatory democracy, with all users able to contribute news and comments, may fall short of the ideals. International survey data suggest online media audience members are largely passive consumers, while content creation is dominated by a small number of users who post comments and write new content. Others argue that the effect of social media will vary from one country to another, with domestic political structures playing a greater role than social media in determining how citizens express opinions about stories of current affairs involving the state.

As a news source

Adults in the United States who have access to the internet are increasingly getting political news and information from social media platforms. A 2016 Pew Research study found that 62% of adults get news on social media

% of Adults Who Get News from Social Media.png

In addition, Reddit, Twitter, Facebook, lead the social media platforms in which the majority of the users use the platforms to acquire news information. Of all United States adults, 67% use the platform with 44% who use the platform to get news. 

Social networking site user graph.png

According to the Reuters Institute Digital News Report in 2013, the percentage of online news users who blog about news issues ranges from 1–5%. Greater percentages use social media to comment on news, with participation ranging from 8% in Germany to 38% in Brazil. But online news users are most likely to just talk about online news with friends offline or use social media to share stories without creating content.

The rapid propagation of information on social media, spread by word of mouth, can impact the perception of political figures quickly with information that may or may not be true. When political information is propagated in this manner on purpose, the spread of information on social media for political means can benefit campaigns. On the other hand, the word-of-mouth propagation of negative information concerning a political figure can be damaging. For example, the use of the social media platform Twitter by United States congressman Anthony Weiner to send inappropriate messages played a role in his resignation.

Attention economy

Social media, especially news that is spread through social media sites, plays into the idea of the attention economy. In which content that attracts more attention will be seen, shared, and disseminated far more than news content that does gather as much traction from the public. Tim Wu from Columbia Law School coins the attention economy as “the resale of human attention.” 

A communication platform such as social media is persuasive, and often works to change or influence opinions when it comes to political views because of the abundance of ideas, thoughts, and opinions circulating through the social media platform. It is found that news use leads to political persuasion, therefore the more that people use social media platforms for news sources, the more their political opinions will be affected. Despite that, people are expressing less trust in their government and others due to media use- therefore social media directly affects trust in media use. It is proven that while reading newspapers there is an increase in social trust where on the contrary watching the news on television weakened trust in others and news sources. Social media, or more specifically news media- plays an important role in democratic societies because they allow for participation among citizens.Therefore, when it comes to healthy democratic networks, it is crucial that that news remains true so it doesn’t affect citizens’ levels of trust. A certain amount of trust is necessary for a healthy and well functioning democratic system.

Younger generations are becoming more involved in politics due to the increase of political news posted on various types of social media. Due to the heavier use of social media among younger generations, they are exposed to politics more frequently, and in a way that is integrated into their online social lives. While informing younger generations of political news is important, there are many biases within the realms of social media. In May 2016, former Facebook Trending News curator Benjamin Fearnow revealed his job was to "massage the algorithm," but dismissed any "intentional, outright bias" by either human or automated efforts within the company. Fearnow was fired by Facebook after being caught leaking several internal company debates about Black Lives Matter and presidential candidate Donald Trump.

As a public utility

A key debate centers on whether or not social media is a public good based on the premises of non-rival and non-excludable consumption. Social media can be considered an impure public good as it can be excludable given the rights of platforms such as Facebook and Twitter to censor content, disable accounts, and filter information based on algorithms and community standards.

Arguments for platforms such as Google in being treated as a public utility and public service provider include statements from Benjamin Barber in The Nation
"For new media to be potential equalizers, they must be treated as public utilities, recognizing that spectrum abundance (the excuse for privatization) does not prevent monopoly ownership of hardware and software platforms and hence cannot guarantee equal civic, educational, and cultural access to citizens."
Similarly, Zeynep Tufeckig argues online services are natural monopolies that underwrite the "corporatization of social commons" and the "privatization of our publics." 

One argument that displays the nature of social media as an impure public good is the fact that the control over content remains in the hands of a few large media networks, Google and Facebook, for example. Google and Facebook have the power to shape the environment under personal and commercial goals that promotes profitability, as opposed to promoting citizen voice and public deliberation.
Government regulation
Proponents and aims for regulation of social media are growing due to economic concerns of monopolies of the platforms, to issues of privacy, censorship, network neutrality and information storage. The discussion of regulation is complicated due to the issue how Facebook, and Google are increasingly becoming a service, information pipeline, and content provider, and thus centers on how the government would regulate both the platform as a service and information provider. Thus, other proponents advocate for “algorithmic neutrality”, or the aim for search engines on social media platforms to rank data without human intervention.

Opponents of regulation of social media platforms argue that platforms such as Facebook and Twitter do not resemble traditional public utilities, and regulation would harm consumer welfare as public utility regulation can hinder innovation and competition. Second, as the First Amendment values are criticized on social media platforms, the media providers should retain the power to how the platform is configured.

Role in social conflict

Social media is revolutionizing the way people communicate, as people around the world can communicate with each other by accessing a computer interface and share information across multiple platforms. There are four ways social media plays a significant role in conflict:.
  1. Social media platforms allow information to be framed in mainstream platforms which limits communication.
  2. Social media enables news stories to quickly go viral and later can lead to misinterpretations that can cause conflict.
  3. Strategies and the adaption of social media has caused a change in focus amongst leaders from administrative dynamics to new media technology.
  4. Technological advancements in communication can increase the power of persuasion leading to corruption, scandals, and violence on social media platforms.
Map of 2011 Arab Spring Protests
 
The role of technological communication and social media in the world can lead to political, economic, and social conflict due to its unmonitored system, cheap interface, and accessibility.

Civilian use during the Arab Spring

During the peak of the Egyptian Revolution of 2011, the Internet and social media played a huge role in facilitating information. At that time, Hosni Mubarak was the president of Egypt and head the regime for almost 30 years. Mubarak was so threatened by the immense power that the Internet and social media gave the people that the government successfully shut down the Internet, using the Ramses Exchange, for a period of time in February 2011.

Egyptians used Facebook, Twitter, and YouTube as a means to communicate and organize demonstrations and rallies to overthrow President Hosni Mubarak. Statistics show that during this time the rate of Tweets from Egypt increased from 2,300 to 230,000 per day and the top 23 protest videos had approximately 5.5 million views.

Non-state actors and militant groups

As the world is becoming increasingly connected via the power of the Internet, political movements, including militant groups, have begun to see social media as a major organizing and recruiting tool. The Islamic State of Iraq and the Levant, also known as ISIL, ISIS, and Daesh, has used social media to promote its cause. ISIS produces an online magazine named the Islamic State Report to recruit more fighters. ISIS produces online materials in a number of languages and uses recruiters to contact potential recruitees over the Internet. 

ISIS in Iraq and Syria
 
In Canada, two girls from Montreal left their country to join ISIS in Syria after exploring ISIS on social media and eventually being recruited. On Twitter, there is an app called the Dawn of Glad Tidings that users can download and keep up to date on news about ISIS. Hundreds of users around the world have signed up for the app, which once downloaded will post tweets and hash-tags from accounts that are in support of ISIS. As ISIS marched on the northern region of Iraq, tweets in support of their efforts reached a high of 40,000 a day. Support of ISIS online is a factor in the radicalization of youth. Mass media has yet to adopt the view that social media plays a vital link in the radicalization of people. When tweets supportive of ISIS make their way onto Twitter, they result in 72 re-tweets to the original, which further spreads the message of ISIS. These tweets have made their way to the account known as active hashtags, which further helps broadcast ISIS's message as the account sends out to its followers the most popular hashtags of the day. Other militant groups such as al-Qaeda and the Taliban are increasingly using social media to raise funds, recruit and radicalize persons, and it has become increasingly effective.

Weaponization by state actors

Social media platforms have been weaponized by state-sponsored cyber groups to attack governments in the United States, the European Union, and the Middle East. Although phishing attacks via email are the most commonly used tactic to breach government networks, phishing attacks on social media rose 500% in 2016. As with email-based phishing attacks, the majority of phishing attacks on social media are financially motivated cyber crimes that install malware. However, cyber groups associated with Russia, Iran, and China have used social media to conduct cyberattacks and undermine democratic processes in the West. During the 2017 French presidential election, for example, Facebook detected and removed fake accounts linked to the Russian cyber group Fancy Bear, who were posing as "friends of friends" of Emmanuel Macron associates to steal information from them. Cyber groups associated with Iran, China, and Russia have used LinkedIn to steal trade secrets, gain access to critical infrastructure, or recruit spies. These social engineering attacks can be multi-platform, with threat actors initiating contact on one platform but continuing communication on more private channel. The Iranian-backed cyber group COBALT GYPSY created a fake persona across multiple social media platforms and initiated contact on LinkedIn before moving to Facebook and email.

The 2016 United States Presidential Election was an example in which social media was used by the state actor Russia to influence public opinion. Tactics such as propaganda, trolling, and bots were used to leak fake news stories that included an "FBI agent had been killed after leaking Clinton’s emails" and "Pope Francis had endorsed Donald Trump.” Studies have found that pro-Trump news was as many as four-time more than pro-Clinton fake news, and a third of the pro-Trump tweets were generated by bots.
Social externalities of fake news
During the 2016 Presidential Election, Russia utilized disinformation and fake news to distort the truth and paint the United States Western powers in a negative light. Though fake news can generate some utility for consumers, in terms of confirming far-right beliefs and spreading propaganda in favor of a presidential candidate, it also imposes private and social costs. For example, one social cost to consumer is the spread of disinformation which can make it harder for consumers to seek out the truth and, in the case of the 2016 Election, for consumers to choose an electoral candidate. Summarized by a Congressional Research Service Study in 2017,
“Cyber tools were also used [by Russia] to create psychological effects in the American population. The likely collateral effects of these activities include compromising the fidelity of information, sowing discord and doubt in the American public about the validity of intelligence community reports, and prompting questions about the democratic process itself.” 
The marginal social cost of fake news is exponential, as the first article is shared it can affect a small number of people, but as the article is circulated more throughout Facebook, the negative externality multiplies. As a result, the quantity demanded of news can shift up around election season as consumers seek to find correct news, however the quantity demanded can also shift down as people have a lower trust in mainstream media. In the American public, a Gallup poll in 2016 found “Americans’ trust in the mass media ‘to report the news fully, accurately and fairly’ was, at 32%, the lowest in the organization’s polling history.” In addition, trust in mainstream media is lower in Republican and far-right political viewers at 14%.

Active-pixel sensor

From Wikipedia, the free encyclopedia
 
An active-pixel sensor (APS) is an image sensor where each pixel sensor unit cell has a photodetector (typically a pinned photodiode) and one or more active transistors. There are different types of active-pixel sensors, including the complementary metal–oxide–semiconductor (CMOS) APS used most commonly in digital camera technologies such as cell phone cameras, web cameras, most modern digital pocket cameras, most digital single-lens reflex cameras (DSLRs), and mirrorless interchangeable-lens cameras (MILCs). CMOS sensors emerged as an alternative to charge-coupled device (CCD) image sensors and eventually outsold them by the mid-2000s.

CMOS image sensor.
 
The term 'active pixel sensor' is also used to refer to the individual pixel sensor itself, as opposed to the image sensor. In this case, the image sensor is sometimes called an active pixel sensor imager, or active-pixel image sensor.

History

Background

The basis for modern image sensors is metal–oxide–semiconductor (MOS) technology, which originates from the MOSFET (MOS field-effect transistor) invented by Mohamed M. Atalla and Dawon Kahng at Bell Labs in 1959. They demonstrated two MOSFET fabrication processes in 1960, PMOS (p-type MOS) and NMOS (n-type MOS). Both processes were later combined and adapted into the CMOS (complementary MOS) process by Chih-Tang Sah and Frank Wanlass at Fairchild Semiconductor in 1963.

While researching MOS technology, Willard Boyle and George E. Smith realized that an electric charge could be stored on a tiny MOS capacitor, which became the basic building block of the charge-couple device (CCD), which they invented in 1969. An issue with CCD technology was that it required the need for nearly perfect charge transfer, which, according to Eric Fossum, "makes their radiation 'soft,' difficult to use under low light conditions, difficult to manufacture in large array sizes, difficult to integrate with on-chip electronics, difficult to use at low temperatures, difficult to use at high frame rates, and difficult to manufacture in non-silicon materials that extend wavelength response."

At RCA Laboratories, a research team including Paul K. Weimer, W.S. Pike and G. Sadasiv in 1969 proposed a solid-state image sensor with scanning circuits using thin-film transistors (TFTs), with photoconductive film used for the photodetector. A low-resolution "mostly digital" N-channel MOSFET (NMOS) imager with intra-pixel amplification, for an optical mouse application, was demonstrated by Richard F. Lyon in 1981. Another type of image sensor technology that is related to the APS is the hybrid infrared focal plane array (IRFPA), designed to operate at cryogenic temperatures in the infrared spectrum. The devices are two chips that are put together like a sandwich: one chip contains detector elements made in InGaAs or HgCdTe, and the other chip is typically made of silicon and is used to read out the photodetectors. The exact date of origin of these devices is classified, but they were in use by the mid-1980s.

A key element of the modern CMOS sensor is the pinned photodiode (PPD). It was invented by Nobukazu Teranishi, Hiromitsu Shiraki and Yasuo Ishihara at NEC in 1980, and then publicly reported by Teranishi and Ishihara with A. Kohono, E. Oda and K. Arai in 1982, with the addition of an anti-blooming structure. The pinned photodiode is a photodetector structure with low lag, low noise, high quantum efficiency and low dark current. The new photodetector structure invented at NEC was given the name "pinned photodiode" (PPD) by B.C. Burkey at Kodak in 1984. In 1987, the PPD began to be incorporated into most CCD sensors, becoming a fixture in consumer electronic video cameras and then digital still cameras. Since then, the PPD has been used in nearly all CCD sensors and then CMOS sensors.

Passive-pixel sensor

The precursor to the APS was the passive-pixel sensor (PPS), a type of photodiode array (PDA). A passive-pixel sensor consists of passive pixels which are read out without amplification, with each pixel consisting of a photodiode and a MOSFET switch. In a photodiode array, pixels contain a p-n junction, integrated capacitor, and MOSFETs as selection transistors. A photodiode array was proposed by G. Weckler in 1968, predating the CCD. This was the basis for the PPS, which had image sensor elements with in-pixel selection transistors, proposed by Peter J.W. Noble in 1968, and by Savvas G. Chamberlain in 1969.

Passive-pixel sensors were being investigated as a solid-state alternative to vacuum-tube imaging devices. The MOS passive-pixel sensor used just a simple switch in the pixel to read out the photodiode integrated charge. Pixels were arrayed in a two-dimensional structure, with an access enable wire shared by pixels in the same row, and output wire shared by column. At the end of each column was a transistor. Passive-pixel sensors suffered from many limitations, such as high noise, slow readout, and lack of scalability. Early photodiode arrays were complex and impractical, requiring selection transistors to be fabricated within each pixel, along with on-chip multiplexer circuits. The noise of photodiode arrays was also a limitation to performance, as the photodiode readout bus capacitance resulted in increased noise level. Correlated double sampling (CDS) could also not be used with a photodiode array without external memory. It was not possible to fabricate active pixel sensors with a practical pixel size in the 1970s, due to limited microlithography technology at the time. Because the MOS process was so variable and MOS transistors had characteristics that changed over time (Vth instability), the CCD's charge-domain operation was more manufacturable than MOS passive pixel sensors.

Active-pixel sensor

The active-pixel sensor consists of active pixels, each containing one or more MOSFET amplifiers which convert the photo-generated charge to a voltage, amplify the signal voltage, and reduce noise. The first MOS active-pixel sensor was the Charge Modulation Device (CMD) invented by Olympus in Japan during the mid-1980s. This was enabled by advances in MOSFET semiconductor device fabrication, with MOSFET scaling reaching smaller micron and then sub-micron levels during the 1980s to early 1990s. The first MOS APS was fabricated by Tsutomu Nakamura's team at Olympus in 1985. The term active pixel sensor (APS) was coined by Nakamura while working on the CMD active-pixel sensor at Olympus. The CMD imager had a vertical APS structure, which increases fill-factor (or reduces pixel size) by storing the signal charge under an output NMOS transistor. Other Japanese semiconductor companies soon followed with their own active pixel sensors during the late 1980s to early 1990s. Between 1988 and 1991, Toshiba developed the "double-gate floating surface transistor" sensor, which had a lateral APS structure, with each pixel containing a buried-channel MOS photogate and a PMOS output amplifier. Between 1989 and 1992, Canon developed the base-stored image sensor (BASIS), which used a vertical APS structure similar to the Olympus sensor, but with bipolar transistors rather than MOSFETs.

In the early 1990s, American companies began developing practical MOS active pixel sensors. In 1991, Texas Instruments developed the bulk CMD (BCMD) sensor, which was fabricated at the company's Japanese branch and had a vertical APS structure similar to the Olympus CMD sensor, but was more complex and used PMOS rather than NMOS transistors.

CMOS sensor

By the late 1980s to early 1990s, the CMOS process was well-established as a well-controlled stable semiconductor manufacturing process and was the baseline process for almost all logic and microprocessors. There was a resurgence in the use of passive-pixel sensors for low-end imaging applications, while active-pixel sensors began being used for low-resolution high-function applications such as retina simulation and high-energy particle detectors. However, CCDs continued to have much lower temporal noise and fixed-pattern noise and were the dominant technology for consumer applications such as camcorders as well as for broadcast cameras, where they were displacing video camera tubes

In 1993, the first practical APS to be successfully fabricated outside of Japan was developed at NASA's Jet Propulsion Laboratory (JPL), which fabricated a CMOS compatible APS, with its development led by Eric Fossum. It had a lateral APS structure similar to the Toshiba sensor, but was fabricated with CMOS rather than PMOS transistors. It was the first CMOS sensor with intra-pixel charge transfer.

Fossum, who worked at JPL, led the development of an image sensor that used intra-pixel charge transfer along with an in-pixel amplifier to achieve true correlated double sampling (CDS) and low temporal noise operation, and on-chip circuits for fixed-pattern noise reduction. He also published an extensive 1993 article predicting the emergence of APS imagers as the commercial successor of CCDs. The active pixel sensor (APS) was broadly defined by Fossum in this paper. He classified two types of APS structures, the lateral APS and the vertical APS. He also gave an overview of the history of APS technology, from the first APS sensors in Japan to the development of the CMOS sensor at JPL.

In 1994, Fossum proposed an improvement to the CMOS sensor: the integration of the pinned photodiode (PPD). A CMOS sensor with PPD technology was first fabricated in 1995 by a joint JPL and Kodak team that included Fossum along with P. P. K. Lee, R. C. Gee, R. M. Guidash and T. H. Lee. Between 1993 and 1995, the Jet Propulsion Laboratory developed a number of prototype devices, which validated the key features of the technology. Though primitive, these devices demonstrated good image performance with high readout speed and low power consumption. 

In 1995, being frustrated by the slow pace of the technology's adoption, Fossum and his then-wife Dr. Sabrina Kemeny co-founded Photobit Corporation to commercialize the technology. It continued to develop and commercialize APS technology for a number of applications, such as web cams, high speed and motion capture cameras, digital radiography, endoscopy (pill) cameras, digital single-lens reflex cameras (DSLRs) and camera-phones. Many other small image sensor companies also sprang to life shortly thereafter due to the accessibility of the CMOS process and all quickly adopted the active pixel sensor approach. 

Photobit's CMOS sensors found their way into webcams manufactured by Logitech and Intel, before Photobit was purchased by Micron Technology in 2001. The early CMOS sensor market was initially led by American manufacturers such as Micron, GoPro, and Omnivision, allowing the United States to briefly recapture a portion of the overall image sensor market from Japan, before the CMOS sensor market eventually came to be dominated by Japan, South Korea and China. The CMOS sensor with PPD technology was further advanced and refined by R. M. Guidash in 1997, K. Yonemoto and H. Sumi in 2000, and I. Inoue in 2003. This led to CMOS sensors achieve imaging performance on par with CCD sensors, and later exceeding CCD sensors.

By 2000, CMOS sensors were used in a variety of applications, including low-cost cameras, PC cameras, fax, multimedia, security, surveillance, and videophones.

The video industry switched to CMOS cameras with the advent of high-definition video (HD video), as the large number of pixels would require significantly higher power consumption with CCD sensors, which would overheat and drain batteries. Sony in 2007 commercialized CMOS sensors with an original column A/D conversion circuit, for fast, low-noise performance, followed in 2009 by the CMOS back-illuminated sensor (BI sensor), with twice the sensitivity of conventional image sensors and going beyond the human eye.

CMOS sensors went on to have a significant cultural impact, leading to the mass proliferation of digital cameras and camera phones, which bolstered the rise of social media and selfie culture, and impacted social and political movements around the world. By 2007, sales of CMOS active-pixel sensors had surpassed CCD sensors, with CMOS sensors accounting for 54% of the global image sensor market at the time. By 2012, CMOS sensors increased their share to 74% of the market. As of 2017, CMOS sensors account for 89% of global image sensor sales. In recent years, the CMOS sensor technology has spread to medium-format photography with Phase One being the first to launch a medium format digital back with a Sony-built CMOS sensor. 

In 2012, Sony introduced the stacked CMOS BI sensor. Fossum now performs research on the Quanta Image Sensor (QIS) technology. The QIS is a revolutionary change in the way we collect images in a camera that is being invented at Dartmouth. In the QIS, the goal is to count every photon that strikes the image sensor, and to provide resolution of 1 billion or more specialized photoelements (called jots) per sensor, and to read out jot bit planes hundreds or thousands of times per second resulting in terabits/sec of data.

Comparison to CCDs

APS pixels solve the speed and scalability issues of the passive-pixel sensor. They generally consume less power than CCDs, have less image lag, and require less specialized manufacturing facilities. Unlike CCDs, APS sensors can combine the image sensor function and image processing functions within the same integrated circuit. APS sensors have found markets in many consumer applications, especially camera phones. They have also been used in other fields including digital radiography, military ultra high speed image acquisition, security cameras, and optical mice. Manufacturers include Aptina Imaging (independent spinout from Micron Technology, who purchased Photobit in 2001), Canon, Samsung, STMicroelectronics, Toshiba, OmniVision Technologies, Sony, and Foveon, among others. CMOS-type APS sensors are typically suited to applications in which packaging, power management, and on-chip processing are important. CMOS type sensors are widely used, from high-end digital photography down to mobile-phone cameras.

Advantages of CMOS compared with CCD

Blooming in a CCD image
 
A big advantage of a CMOS sensor is that it is typically less expensive than a CCD sensor.

A CMOS sensor also typically has better control of blooming (that is, of bleeding of photo-charge from an over-exposed pixel into other nearby pixels).

In three-sensor camera systems that use separate sensors to resolve the red, green, and blue components of the image in conjunction with beam splitter prisms, the three CMOS sensors can be identical, whereas most splitter prisms require that one of the CCD sensors has to be a mirror image of the other two to read out the image in a compatible order. Unlike CCD sensors, CMOS sensors have the ability to reverse the addressing of the sensor elements. CMOS Sensors with a film speed of ISO 4 million exist. 

Disadvantages of CMOS compared with CCD

Distortion caused by a rolling shutter
 
Since a CMOS sensor typically captures a row at a time within approximately 1/60th or 1/50th of a second (depending on refresh rate) it may result in a "rolling shutter" effect, where the image is skewed (tilted to the left or right, depending on the direction of camera or subject movement). For example, when tracking a car moving at high speed, the car will not be distorted but the background will appear to be tilted. A frame-transfer CCD sensor or "global shutter" CMOS sensor does not have this problem, instead captures the entire image at once into a frame store.

The active circuitry in CMOS pixels takes some area on the surface which is not light-sensitive, reducing the photon-detection efficiency of the device (back-illuminated sensors can mitigate this problem). But the frame-transfer CCD also has about half non-sensitive area for the frame store nodes, so the relative advantages depend on which types of sensors are being compared.

Architecture

Pixel

A three-transistor active pixel sensor.
 
The standard CMOS APS pixel today consists of a photodetector (pinned photodiode), a floating diffusion, and the so-called 4T cell consisting of four CMOS (complementary metal–oxide–semiconductor) transistors, including a transfer gate, reset gate, selection gate and source-follower readout transistor. The pinned photodiode was originally used in interline transfer CCDs due to its low dark current and good blue response, and when coupled with the transfer gate, allows complete charge transfer from the pinned photodiode to the floating diffusion (which is further connected to the gate of the read-out transistor) eliminating lag. The use of intrapixel charge transfer can offer lower noise by enabling the use of correlated double sampling (CDS). The Noble 3T pixel is still sometimes used since the fabrication requirements are less complex. The 3T pixel comprises the same elements as the 4T pixel except the transfer gate and the photodiode. The reset transistor, Mrst, acts as a switch to reset the floating diffusion to VRST, which in this case is represented as the gate of the Msf transistor. When the reset transistor is turned on, the photodiode is effectively connected to the power supply, VRST, clearing all integrated charge. Since the reset transistor is n-type, the pixel operates in soft reset. The read-out transistor, Msf, acts as a buffer (specifically, a source follower), an amplifier which allows the pixel voltage to be observed without removing the accumulated charge. Its power supply, VDD, is typically tied to the power supply of the reset transistor VRST. The select transistor, Msel, allows a single row of the pixel array to be read by the read-out electronics. Other innovations of the pixels such as 5T and 6T pixels also exist. By adding extra transistors, functions such as global shutter, as opposed to the more common rolling shutter, are possible. In order to increase the pixel densities, shared-row, four-ways and eight-ways shared read out, and other architectures can be employed. A variant of the 3T active pixel is the Foveon X3 sensor invented by Dick Merrill. In this device, three photodiodes are stacked on top of each other using planar fabrication techniques, each photodiode having its own 3T circuit. Each successive layer acts as a filter for the layer below it shifting the spectrum of absorbed light in successive layers. By deconvolving the response of each layered detector, red, green, and blue signals can be reconstructed.

Array

A typical two-dimensional array of pixels is organized into rows and columns. Pixels in a given row share reset lines, so that a whole row is reset at a time. The row select lines of each pixel in a row are tied together as well. The outputs of each pixel in any given column are tied together. Since only one row is selected at a given time, no competition for the output line occurs. Further amplifier circuitry is typically on a column basis.

Size

The size of the pixel sensor is often given in height and width, but also in the optical format.

Lateral and vertical structures

There are two types of active-pixel sensor (APS) structures, the lateral APS and vertical APS. Eric Fossum defines the lateral APS as follows:
A lateral APS structure is defined as one that has part of the pixel area used for photodetection and signal storage, and the other part is used for the active transistor(s). The advantage of this approach, compared to a vertically integrated APS, is that the fabrication process is simpler, and is highly compatible with state-of-the-art CMOS and CCD device processes.
Fossum defines the vertical APS as follows:
A vertical APS structure increases fill-factor (or reduces pixel size) by storing the signal charge under the output transistor.

Thin-film transistors

A two-transistor active/passive pixel sensor
 
For applications such as large-area digital X-ray imaging, thin-film transistors (TFTs) can also be used in APS architecture. However, because of the larger size and lower transconductance gain of TFTs compared with CMOS transistors, it is necessary to have fewer on-pixel TFTs to maintain image resolution and quality at an acceptable level. A two-transistor APS/PPS architecture has been shown to be promising for APS using amorphous silicon TFTs. In the two-transistor APS architecture on the right, TAMP is used as a switched-amplifier integrating functions of both Msf and Msel in the three-transistor APS. This results in reduced transistor counts per pixel, as well as increased pixel transconductance gain. Here, Cpix is the pixel storage capacitance, and it is also used to capacitively couple the addressing pulse of the "Read" to the gate of TAMP for ON-OFF switching. Such pixel readout circuits work best with low capacitance photoconductor detectors such as amorphous selenium.

Design variants

Many different pixel designs have been proposed and fabricated. The standard pixel is the most common because it uses the fewest wires and the fewest, most tightly packed transistors possible for an active pixel. It is important that the active circuitry in a pixel take up as little space as possible to allow more room for the photodetector. High transistor count hurts fill factor, that is, the percentage of the pixel area that is sensitive to light. Pixel size can be traded for desirable qualities such as noise reduction or reduced image lag. Noise is a measure of the accuracy with which the incident light can be measured. Lag occurs when traces of a previous frame remain in future frames, i.e. the pixel is not fully reset. The voltage noise variance in a soft-reset (gate-voltage regulated) pixel is , but image lag and fixed pattern noise may be problematic. In rms electrons, the noise is .

Hard reset

Operating the pixel via hard reset results in a Johnson–Nyquist noise on the photodiode of or , but prevents image lag, sometimes a desirable tradeoff. One way to use hard reset is replace Mrst with a p-type transistor and invert the polarity of the RST signal. The presence of the p-type device reduces fill factor, as extra space is required between p- and n-devices; it also removes the possibility of using the reset transistor as an overflow anti-blooming drain, which is a commonly exploited benefit of the n-type reset FET. Another way to achieve hard reset, with the n-type FET, is to lower the voltage of VRST relative to the on-voltage of RST. This reduction may reduce headroom, or full-well charge capacity, but does not affect fill factor, unless VDD is then routed on a separate wire with its original voltage.

Combinations of hard and soft reset

Techniques such as flushed reset, pseudo-flash reset, and hard-to-soft reset combine soft and hard reset. The details of these methods differ, but the basic idea is the same. First, a hard reset is done, eliminating image lag. Next, a soft reset is done, causing a low noise reset without adding any lag. Pseudo-flash reset requires separating VRST from VDD, while the other two techniques add more complicated column circuitry. Specifically, pseudo-flash reset and hard-to-soft reset both add transistors between the pixel power supplies and the actual VDD. The result is lower headroom, without affecting fill factor.

Active reset

A more radical pixel design is the active-reset pixel. Active reset can result in much lower noise levels. The tradeoff is a complicated reset scheme, as well as either a much larger pixel or extra column-level circuitry.

Common Gateway Interface

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