1.2 Smartphones

Nowadays, billions of people around the world use smartphones and phablets, and many of them are children. The great advantage of smartphones is that the phone provides many tools in a single, readily available, and relatively inexpensive package. When we are away from home or office, we can do the same things as using desktop computers or notebook computers. For example, we can conveniently access the Internet wirelessly at any time. When we are online, we can send and receive e-mail, pay bills, listen to music and watch TV, play interactive games and even make purchases.

In 2014, sales of smartphones worldwide topped 1.2 billion, which was up 28% from 2013. In Q1 2015 in the US, Android market share was 53.2%; Apple's iPhone had a 41.3% share and Samsung's Android smartphones had 29.3%.

1.2.1 Functions

High-end smartphones are sophisticated devices that combine the revolutionary Multi-touch technology with powerful functions, such as GPS, Wi-Fi, Bluetooth, processors, accelerometers, gyroscopes and so on.

●Multi-touch interface (see Fig 1-3): It is a technology that enables a surface (touchscreen) to recognize the presence of more than one points of contact with the surface. The surface usually fills almost the entire phone surface. The screen size usually defines the size of a smartphone whose aspect ratio is normally 4:3 or 16:9. It is measured in diagonal inches, starting from 2.45 inches.

●GPS: The Global Positioning System is a space-based navigation system that provides location and time information in all weather conditions, anywhere on or near the earth where there is an unobstructed line of sight to four or more GPS satellites. The system provides critical capabilities to military, civil, and commercial users around the world. The United States government created the system, maintains it, and makes it freely accessible to anyone with a GPS receiver.

●Wi-Fi：It is a local area wireless computer networking technology that allows electronic devices to connect to the network, mainly using the 2.4 GHz UHF and 5 GHz SHF ISM radio bands. Smartphones can connect to a network resource such as the Internet via a wireless network access point. Such an access point (or hotspot) has a range of about 20 meters indoors and a greater range outdoors. Hotspot coverage can be as small as a single room with walls that block radio waves, or as large as many square kilometers achieved by using multiple overlapping access points.

●Bluetooth: It is a wireless technology standard for exchanging data over short distances using short-wavelength UHF radio waves in the ISM band from 2.4 to 2.485 GHz from fixed and mobile devices, and building personal area networks (PANs). It can connect several devices, overcoming problems of synchronization.

●System on Chip (SoC): A system on a chip is an integrated circuit (IC) that integrates all components of a computer or other electronic system into a single chip. SoCs are very common in the mobile electronics market because of their low power consumption. In the area of smartphones, the SoC chip usually integrates a multi-core processor, GPU and so on. A multi-core processor is a single computing component with two or more independent actual processing units called “cores”, which are the units that read and execute program instructions. A graphics processing unit (GPU), also occasionally called a visual processing unit (VPU), is a specialized processor. It is designed to rapidly manipulate and alter memory to accelerate the creation of images in a frame buffer intended for output to a display.

●A motion co-processor: A co-processor is a computer processor used to supplement the functions of the primary processor. A motion co-processor for smartphones can collect, process, and store sensor data from integrated accelerometers, gyroscopes, compasses, and enables applications to be aware of what type of movement the user is experiencing, such as driving, walking, running, or sleeping. An accelerometer detects the physical movement and orientation of the smartphone.

1.2.2 iPhone

iPhone is a line of smartphones designed and marketed by Apple Inc. and runs Apple's iOS mobile operating system. In 2007, Apple Inc. introduced the iPhone, one of the first smartphones to use a multi-touch interface. The iPhone was notable for its use of a large touchscreen for direct finger input as its main means of interaction, instead of a stylus, keyboard, or keypad typical for smartphones at the time. The first generation iPhone features a 3.5-inch touchscreen display, Bluetooth, and Wi-Fi, and it includes web-based Dashboard apps such as Google Maps and Weather. There are nine generations of iPhone models, each accompanied by one of the nine major releases of iOS.

The iPhone 6 and iPhone 6 Plus shown in Figure 1-4 are relatively new models of the iPhone series, and jointly serve as the successors to the iPhone 5S and iPhone 5C. These new models include a number of changes over its predecessor, including a faster processor, upgraded cameras, improved LTE (see7.1.2) and Wi-Fi connectivity. The newest iPhone models are the iPhone 6S and iPhone 6S Plus, shown in Figure 1-5, which were unveiled on September 9, 2015 in Beijing China. The 3D touch is the main change for iPhone 6S and iPhone 6S Plus.

1. iPhone 6

The design of iPhone 6 is influenced by that of the iPad Air, with a glass front that is curved around the edges of the display, and an aluminum rear that contains two plastic strips for the antenna. The model comes in gold, silver, and “space gray” finishes. The iPhone 6 has a thickness of 6.9 mm and is thinner than iPhone 5S and iPhone 5C, being Apple's thinnest phone to date. The most significant changes to the iPhone 6 is its displays branded as “Retina HD Display” and “ion-strengthened”. The iPhone 6's battery is 1810 mAh.

●The display: It uses a multiple-domain LCD panel, dubbed “dual-domain pixels”; the RGB pixels themselves are skewed in pattern, so that every pixel is seen from a different angle. This technique helps improve the viewing angles of the display. The display is 4.7 inches in size with a 16:9 aspect ratio and resolution of 1334x750.

●The rear-facing camera: Unlike the previous model, the rear-facing camera is not flush with the rear of the device, and has a slight “bulge” around the lens. The iPhone 6's rear-facing camera includes a new sensor which is like the camera in the iPhone 5S, and it has 1.5 micron pixels, an f/2.2 aperture lens, and the ability to shoot 1080p video at either 30 or 60 frames per second. The camera also includes phase detection autofocus. It can also record slow-motion video at either 120 or 240 frames per second.

●Processor: iPhone 6 has a Dual-core 1.4 GHz Cyclone processor (ARM v8-based). The model includes an Apple A8 system-on-chip, and an M8 motion co-processor—an update of the M7 chip from the iPhone 5S. The main difference between the M8 and the original M7 coprocessor is that the M8 also includes a barometer to measure altitude changes. The A8 chip would provide, in comparison to the 5S, a 25% increase in CPU performance, a 50% increase in graphics performance, and less heat output.

2. iOS 9

When first released, the iPhone 6 was pre-loaded with iOS 8, while currently it is iOS 9. iOS 9 is the ninth release of the iOS mobile operating system designed by Apple Inc which is the successor to iOS 8. It was announced at the company's Worldwide Developers Conference 2015 on June 8, 2015, and was released on September 16, 2015. iOS 9 focuses less on new features and more on under-the-hood optimizations, as well as battery improvements. iOS 9 can be used in iPhone4s or later iPhone modes. Here, we will describe some common features of iOS 9, including Photos and Camera, Notification Center, Messages, Keyboards, Family Share and so on.

●Photos and Camera: With iPhone, you can take still photos, live photos, and HD videos. There are two cameras—in addition to the iSight camera on the back of iPhone, there's a camera in the front that you can use for FaceTime calls and selfies. The photos app contains more tools for editing photos. The cropping feature now enables rotating images both clockwise and counter-clockwise. Furthermore, users can set the desired brightness and colors for photos. The Camera app now features a shot timer for the front camera, which can be set to 3 or 10 seconds.

●Notification Center：It collects your notifications in one place, so you can review them whenever you are ready. View details about your day—such as the weather forecast, appointments, birthdays, stock quotes, and even a quick summary of what is coming up tomorrow. Tap the Notifications tab to review all your alerts. Dragging down from the top edge of the screen, you can open Notification Center.

●Messages: It enables you to exchange text messages with other SMS and MMS devices using your cellular connection, and with other iOS devices and Mac computers using iMessage. iMessage is an Apple feature that lets you send messages over Wi-Fi (or cellular connections) to others using iOS 5 or later, or OS X Mountain Lion or later. Messages you send using iMessage don't count against your text messaging plan with your carrier. Messages can include photos, videos, and other informafion. You can see when other people are typing, and let them know when you have read their messages.

●Keyboards: It includes a new predictive typing feature called QuickType, which displays word selections above the keyboard as one types. The feature can be turned off in Settings, or hidden using a swipe gesture. Additionally, it allows users to install third-party keyboards. Many developers have ported their keyboards to iOS, including Minuum, Swype, SwiftKey, Fleksy and Adaptxt.

●Family Sharing: In Family Sharing, a user can add five others as family members. Family members can share purchased apps, music, movies, TV shows, and books using the same credit card. They can also sync photo streams, calendars and their location history with each other. One can send iTunes download requests to another accounts for approval if the user is signed up as a child.

●Others： Included in iOS 9 are many other capabilities, like iCloud Drive, HealthKit and HomeKit, etc. iCloud Drive is Apple's file hosting service for devices running iOS. Users can save photos, videos, documents, music and application data to iCloud. HealthKit is a service that allows developers to make software that integrates with the new health application. This application allows users to track their steps, oxygen, sleep levels, and other health related data. HomeKit is a database similar to HealthKit and it allows developers to make software that discovers, configures, communicates with and controls devices for home automation. With HomeKit, you can use iPhone to control any “Works With Apple HomeKit” accessory that you have in your home, such as lights, locks, thermostats, smart plugs, and so on.

1.2.3 Android Phones

Android phones refer to the smartphones using Android OS. They share the largest worldwide market, including Samsung Galaxy, Huawei, Xiaomi and so on. According to IDC (International Data Corporation), Samsung remains at the first place despite declining shipment volume, followed by Apple Inc. at the second place. Xiaomi is now the third largest smartphone maker in the world.

1. Samsung Galaxy

Samsung Galaxy is a series of Android-powered mobile computing devices designed, manufactured and marketed by Samsung Electronics. The product line includes the Galaxy S series of high-end smartphones, the Galaxy Tab series of tablets, the Galaxy Note series of tablets and phablets with the added functionality of a stylus, and the first version of the Galaxy Gear smartwatch, with later versions dropping the Galaxy branding.

●Galaxy S series: It refers to the flagship Android smartphones in the Samsung Galaxy series and includes Super Smart devices of the Galaxy series. According to Samsung, the company sold more than 200 million of units. The Samsung Galaxy S6 serves as successors to the Galaxy S5. The smartphones were officially unveiled in a press conference at Mobile World Congress on 1st March 2015. Alongside the S6, Samsung also unveiled the S6 Edge, a variant whose screen is wrapped along the sides of the device; the curvature is usable for several additional features. The Galaxy S6 was released on 10 April 2015 in 20 countries.

●Samsung Galaxy Note: It is a series of Android-based high-end tablets and phablets. The line is primarily oriented towards pen computing devices; all Galaxy Note models ship with a stylus pen and incorporate a pressure-sensitive Wacom digitizer and also include software features that are oriented towards the stylus and the devices' large screens, such as note-taking and digital scrapbooking apps, and split-screen multitasking. The Samsung's first-generation smartphones, Galaxy Note, have been considered the first commercially successful examples of “phablets”. Samsung sold over 50 million Galaxy Note devices between September 2011 and October 2013. The Galaxy Note 4, the relatively new model released in October 2014, introduced a new design with a plastic leather backing and metal frame, a 5.7-inch QHD display, a 16MP camera with OIS, an improved S-Pen, an upgraded digitizer with 2,048 levels of pressure sensitivity and expanded functionality, a fingerprint scanner, and other features taken from the Galaxy S5.

2. Huawei Smartphones

Huawei Technologies Co. Ltd. is a Chinese multinational networking and telecommunications equipment and services company headquartered in Shenzhen, Guangdong. It is the largest telecommunications equipment maker in the world, having overtaken Ericsson in 2012. Huawei's Devices division provides white-label products to content-service providers, including USB modems, wireless modems and wireless routers. Huawei also produces and sells a variety of devices under its own name, such as the IDEOS smartphones, tablet PCs and HuaWei Smartwatch.

On April 15, 2015, Huawei launched the Huawei P8 and Huawei P8 Max, two high-end Android smartphones. Huawei P8 is the proud successor to the Huawei Ascend P7. The metal case and the slim profile carry a distinctly premium feel. The P8 is quite an impressive package but so is its price, especially on international markets. Its key features include:

●Optional Dual Sim, 2680mAh battery and Android OS v5.0 Lollipop with Emotion UI 3.1.

●5.2-inch 1080p IPS-NEO LCD (424 ppi) capacitive touchscreen with Gorilla Glass 3.

●Huawei HiSilicon Kirin 930 chipset-quad-core 2GHz Cortex-A53&quad-core 1.5GHz Cortex-A53, Mali-T628 MP4 GPU; 3GB of RAM.

●13MP autofocus camera with dual-tone LED flash, RBGW sensor and F/2.0 aperture, 1080p video recording, some unique camera modes such as Light Trails and Light Painting.

●8MP front-facing camera, 1080p video recording, selfie panorama mode.

●16GB/64GB of built-in storage; microSD card slot, doubling as a secondary SIM slot on the Dual SIM model.

●Dual-band Wi-Fi; Bluetooth 4.1; GPS/GLONASS/BeiDou (BDS); FM radio; NFC; microUSB port with USB On-The-Go.

The Huawei P8's refined exterior is actually quite sturdy, a testament to Huawei's expertise in making premium-quality handsets. Huawei offers amazing build quality in the high-end segment.

3. Xiaomi Smartphones

Xiaomi Inc. the world's 3rd largest smartphone distributor is a privately owned Chinese electronics company headquartered in Beijing, China. Xiaomi designs, develops, and sells smartphones, mobile apps, and consumer electronics. Since the release of its first smartphone in August 2011, Xiaomi has gained market share in mainland China. The company's founder and CEO is Lei Jun, China's 23rd richest person according to Forbes. The company sold over 60 million smartphones in 2014. The company has over 8,000 employees, mainly in mainland China, Malaysia, and Singapore, and is expanding to other countries such as India, Indonesia, the Philippines and Brazil. Xiaomi also became the largest smartphone vendor in China in 2014, having overtaken Samsung, according to an IDC report. At the end of December 2014, Xiaomi became the world's most valuable technology start-up after it received US$1.1 billion funding from investors, making Xiaomi's valuation more than US$46 billion.

●Mi series: Until January 2015, Xiaomi's flagship mobile handset line was the Xiaomi Mi series. The widely used model in this line is the Xiaomi Mi4, succeeding the Xiaomi Mi3. It was initially launched in mainland China, followed by Singapore, Malaysia, Thailand and India on March, May and July 2014 respectively. The Xiaomi Mi3 uses a modified Qualcomm Snapdragon 800 and had been tested as the world's fastest Android smartphone according to benchmark testing apps Antutu, Quadrant and Geekbench. Announced at Xiaomi's annual product launch in Beijing on July 22, 2014, Xiaomi Mi 4 features a Qualcomm Snapdragon 801, 3GB RAM, 8Megapixel front camera, and a further optimized phone exterior. It was reported that Xiaomi had ordered 50,000 sapphire covers from South Korean manufacturers, for a new premium smartphone.

●Redmi series: Another mobile phone series of Xiaomi's is the Redmi, and the models include the Redmi 1, Redmi 1S and Redmi Note. Redmi Note is a phablet and the second smartphone in the Redmi Series. In India, the Redmi Note comes in three variants, one with 4G, another with 3G, and the other with LTE. In India, Redmi Note was available exclusively on Flipkart until Xiaomi announced its partnership with both Amazon.com and Snapdeal on April 7, 2015. Earlier Xiaomi used to sell exclusively through highly successful flash sales on Flipkart. The first flash sale of the Redmi Note was held on December 2, 2014, and all 50,000 units in stock were sold in a mere 6 seconds.

●Mi Note, Mi Note Pro: In an exclusive event in Beijing, China in January 2015, Xiaomi unveiled its new flagship phones Mi Note and Mi Note Pro to rival iPhone 6 at almost half the price. Both devices feature 5.7-inch display and use a dual-glass design with a 2.5D front and 3D rear glass. Since its release, a number of US-based publications have dubbed the Mi Note “the best smartphone you can't buy in America.” While Mi Note is powered by hardware that is more than one year old, Mi Note Pro features bleeding edge hardware such as octa-core Qualcomm Snapdragon 810 processor, Adreno 360 GPU, 4GB LPDDR4 RAM and LTE Cat 9. Mi Note Pro delivers superior performance yet still maintains similar battery consumption to Mi Note.