SectionSmartphones Title Here Editor: Editor Name HereEditor: n Roy Editor Want affiliation n here n n [email protected] editor email here

Smartphones: Past, Present, and Future

Nayeem Islam, Qualcomm Roy Want, Google

or most of us, it’s hard to imagine a few useful applications. The user inter- US market. However, success was F a time when we couldn’t read our face was typically a small, restricted key- mainly limited to enterprise custom- email using a or post pic- board, and novel (but painfully slow) ers who wanted secure email access. tures of events and then instantly use of the number keypad allowed for The Blackberry was small, but with a them. Today, we use like text input. Nonetheless, these devices well-designed full-feature miniature personal assistants to search for and hinted at the tremendous possibilities keyboard, suited to rapid two-thumb locate stores, hotels, and restaurants. We for an integrated device. typing, but it never became a fully gen- even use our smartphones to monitor Later came IBM’s Simon, Nokia’s eral-purpose mobile computing device. our health through activity logging, find Communicator, and Qualcomm’s PdQ, In the 2000s, 3G networks were our location on maps, watch videos, and which were launched through the latter deployed, further increasing speeds and buy products on the Internet. We have 1990s, combining an expanded com- the reach of high-speed data. Other devel- lived through an unprecedented revolu- puting and phone functionality. These opments, such as Qualcomm’s Binary tion in which cellphones have evolved devices were more generally character- Runtime Environment for Wireless from devices primarily used to make ized as feature phones, rather than smart- (BREW), also allowed cellular carriers phone calls, to computing devices that phones, but that changed in 1999, when to deploy mobile ecosystems worldwide. let us stay connected with other people Japan’s NTT DoCoMo introduced the In 2007, Apple launched its iPhone, and information at all times. i-mode system. setting a new standard for mobile Here, we review this evolution—dis- The one major thing missing from computer-integrated , with an cussing how technology finally caught the user experience of these devices was open developer community contribut- up with the vision of an integrated rich content, and the i-mode system ing a wide spectrum of novel capabili- device—and consider what’s next on let mobile users access sophisticated ties through Apple’s app store opened in the horizon. In particular, we focus on Internet services, such as websites and 2008. Subsequently, Google released the six trends that we predict will strongly Internet email. The initial i-mode sys- Android operating system as the AOSP influence the function and design of tem took advantage of websites written (Android Open Source Project), which future smartphones. in a restricted subset of HTML, called was adopted by many C-HTML, enabling data to be viewed handset manufacturers and launched History of the Mobile on a mobile phone browser with a lim- worldwide. Accelerated by both open Phone ited display. The i-mode system had software and the wide variety of phone As long ago as the 1970s, researchers widespread adoption and attracted tens hardware it could run on, the developer such as Theodore G. Paraskevakos con- of millions of subscribers within a few community expanded even more rap- ceptualized devices that combined tele- short years of its release. Clearly, i-mode idly, creating its own extensive app store. phony and computing. Two decades devices brought increased functionality, later, in the early 1990s, several pro- facilitated by higher network speeds that Today’s Smartphones totype multifunction devices finally let users have a more compelling user According to IDC, Android and iOS appeared (see Table 1). Many of these experience than previous technologies. currently lead the world smartphone prototypes were bulky, ran on low data- At about the same time, the Black- market, with Android holding a share rate networks at speeds less than 100 berry smartphone became estab- of approximately 81.1 percent, and iOS kbps (typically­ 14.4 kbps), and had only lished and started flourishing in the holding 15.2 percent. The remaining

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Table 1 market share is Windows Mobile at 2.7 A history of the mobile phone leading up to the modern smartphone. (Only models with significant evolution in phone capability are listed.) percent, Blackberry at 0.5 percent, and others at 0.6 percent (see Figure 1).1 Year phone model Company This revolution has made Internet 1973 “First Cellphone” demo applications, once only available to desk- 1984 DynaTAC 8000X Motorola top users, easily accessible to anybody 1989 MicroTAC 9800X Motorola with a , resulting in almost anytime, anywhere access. Along the way, 1992 1011 Nokia several innovations have been critical for 1994 Simon IBM the adoption of smartphones—namely, 1996 9000 Communicator Nokia high-speed data networks such as 3G 1999 pdQ Qualcomm and 4G (LTE), which have been widely 1999 9110 Nokia deployed; modern operating systems with 1999 8210 Nokia easy-to-program interfaces and rich pro- 1999 850 Blackberry gramming tools; and business models for deploying applications such as app stores. 2000 R320 Ericsson Components such as the capacitive mul- 2002 SCP-5300 Sanyo titouch screen that let our fingers easily 2002 N21i (i-mode) NEC zoom and select graphical components 2003 7230 BlackBerry of a complex user interface are equally 2004 Razr V3 (Symbian) Motorola important ingredients for improved 2005 II Sidekick usability, reducing the difficulty of inter- acting with a pocket-sized device for 2007 iPhone (iOS) Apple real-world tasks. These innovations have 2007 m550i (i-mode) Ericsson transformed the mobile phone ecosystem. 2009 Droid (Android) Motorola 2011 HD7 (Windows Phone 7) HTC What’s Next? 2012 Galaxy S3 (Android) Samsung As we look forward to the next decade, the 2012 iPhone 5 (iOS) Apple smartphone experience is about to change 2012 Lumia 920 (Windows Phone 8) Nokia once again. Here, we look into our crystal ball and predict tremendous growth in the 2014 Galaxy S5 (Android) Samsung following six areas (see Table 2). 2014 iPhone 6 (iOS) Apple Personal Computers Smartphones are already being designed around multicore proces- sors and will follow a path to similar 80 desktop and laptop performance, only 70 lagging behind due to limited battery 60 capacity and operating temperatures. 50 However, desktops already have more 40 processing performance than is neces- sary for many common applications, Percentage 30 and a lower-power smartphone can 20 still meet many of our requirements. As 10 CMOS transistor technology continues 0 to improve, the future smartphone will Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 be capable of all but the most compute- 2011 2012 2013 2014 intensive tasks required for our daily work. Some of the improvements in Android iOS Windows phone Blackberry OS Others performance will result from system- on-chip (SoC) designs, which might Figure 1. The market share of the various mobile OSs by year.1 include highly specialized low-power

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Table 2 Six major trends affecting future smartphone design and use.

Trends Impact Personal computing Smartphones will become our primary computing platform and will dock with nearby displays and key- boards. They will become our computation, storage, and network hub. (IoT) The smartphone will be the on-ramp for the IoT, letting you locate and interact with the world around you as easily as you currently search for information on the Internet. Multimedia delivery The smartphone will rival more traditional platforms, such as the TV or desktop computer, for watching videos, and even storing libraries of multimedia content. Low power operation The battery in smartphones will last longer, aided by new software structuring techniques and low- power hardware accelerators. Wearable computing The smartphone will be foldable and will take on unconventional shapes. It will merge into a diverse set of wearable technologies, from wrist-mounted devices to glasses and extensions of our clothing. Smartphones will be more context-aware and able to adapt to nearby people, places, and things. accelerator hardware for common to the need for high-bandwidth links larger screens, or devices known today as applications, such as video compression used in the general Internet. Exam- phablets—something that is in-between a or cryptographic encryption. ples of technologies that facilitate IoT phone and tablet. There will soon be a lot New memory technologies that have are near-field communication and the more devices with five-inch screens. higher capacities, consume less power, nascent Bluetooth Low Energy stan- The challenge won’t be the screen and are cheaper will enable smartphones dard, which can be used in conjunction resolution but the enormous comput- to store terabytes of data. This will lead with existing cellular and Wi-Fi radio ing power in the CPU and GPU, and the to a new breed of applications that store technologies. As these newer standards hardware interconnects required to move personal content and context, enhancing are used more widely, the mobile phone such large amounts of data inside the the speed of access and privacy of user will become a control and sensing hub. SoC. The cellular service provider proto- data. As a result, sophisticated apps will The applications of IoT are immense cols supported by the handsets must also be developed that mine person data to and can take over areas that have tra- evolve to support the download of high- present relevant information or that take ditionally been the domain of bespoke resolution streaming video. These issues necessary automatic actions given a per- solutions, such as home security and will be addressed through new wireless sonal context. home automation. For example, you’ll standards and new protocols.2 The combination of enhanced pro- be able to receive security alerts on your cessing and super dense storage capacity phone from home sensors while travel- Low Power Operation will enable a new generation of compu- ing or shut down appliances you acci- Battery technology for smartphones has tational photography and augmented dently left on. A smartphone connected not kept up with demand in terms of the reality applications. With memories to devices in the home can also moni- energy requirements of sophisticated that are effectively more extensive and tor energy usage, leading to energy and hardware, such as multicore CPUs, accurate than our own, there will also monetary savings and increased conve- GPUs, and large screens, and of appli- be applications that augment our own nience. However, the real benefit is the cations such as video on demand, mul- minds, helping us remember people and ability to enter an area that you have tiplayer games, and always-connected events, supported by sound and imagery not encountered before and easily con- social networking. Promising battery captured years before. trol nearby devices, or make use of sen- solutions are on the horizon, such as sors that are discovered in the proximity technology being developed at the Stan- Internet of Things (IoT) (with appropriate security safeguards). ford Linear Accelerator Center (SLAC) The IoT, or Internet of everything, with a goal of 5x the capacity of conven- has been talked about in academia Multimedia Delivery tional Li-ion,3 but it’s not likely that it for a long time but hasn’t become an The majority of data traffic on the Inter- will be enough to satisfy all the energy ­everyday reality. The idea of IoT refers net has been driven by streaming vid- needs of smartphone applications. to connecting together all the electronic eos. Initially, users just watched videos However, improvements in CMOS devices around us—such as TV, cars, on personal computers, but that usage semiconductor technology can reduce and thermostats—and enabling them to model is expanding to tablets and smart- power consumption on mobile devices by be discoverable and Internet connected. phones. Furthermore, viewing 8,000– using smaller lithography and improved This communication is characterized 16,000 pixel images will become com- transistor design, such as high-k gate by low-power, low-bandwidth, and mon for future smartphones. This will dielectrics that reduce leakage current low-latency connectivity, in contrast be accompanied by smartphones with and hence static power consumption.

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An intelligent system’s software can making use of body motion, or the heat six trends listed here follow from what also reduce power by managing the hard- differential between the human body and we see occurring in our industry, but ware resources of the phone and using the outside temperature.4 there are sure to be surprises. the most energy-efficient components, The ultimate smartphone might well and by ensuring various parts of the SoC Context Awareness be a bio-electronic device, perhaps a are turned off to conserve power when Context-aware operation for a smart- neural implant, and might even derive its not in use. For the most popular appli- phone enables a better user experi- power from our own body chemistry.­ At cations, using energy-efficient hardware ence by adapting smartphone behavior that point, we could potentially be con- accelerators will also extend battery life. based on location, nearby objects, and nected to the Internet, and hence each New advances in mobile heteroge- characteristics of the user. In fact, any other, at all times. This is reminiscent of neous processors and run-time sched- parameter or state that can be sensed the fictionalStar Trek’s Borg collective, uling will allow computation to be by a phone can improve context-aware an adversary of the human race—and offloaded to the most power-efficient operation. For example, the phone can maybe something that we should avoid! core. These new runtimes will be one of show a map based on your current In the meantime, smartphones will the main drivers reducing mobile phone location or dim the display when you continue to provide us with a perva- power consumption in the future. put the phone near your ear. Context sive computing platform that’s evolv- is determined through sensors, which ing almost as fast as we can invent new Wearable Computing can be classified as soft sensors, based applications and continuing to support In the near term, flexible electronics on data triggers, or hard sensors, built our needs for work, entertainment, and will enable smartphones to be fold- from physical components. education. able and conform to our bodies—in Soft sensors provide an output when tight clothing, for example. However, a virtual state matches the trigger condi- References in the future, the entire form factor of tion—for example, receiving an email or a smartphone will likely diverge into a an entry in your calendar. In the future, 1. “Smartphone OS Market Share, Q2 set of technologies that are more read- as apps become more interdependent, 2014,” IDC, 2014; www.idc.com/­ prodserv/smartphone-os-market-share.jsp. ily associated with wearable comput- the use of software sensors will increas- ing. The smartphone is equally likely ingly exploit all available information. 2. “The 1000x Data Challenge,” Qual- to evolve from a pocket device to one Hard sensors are based on compo- comm, 2014; www.qualcomm. com/#/1000x. that’s on your wrist or is part of your nents that are sensitive to a physical eyeglasses (such as Google Glass). The parameter. They’re usually attached to 3. “A Look Inside SLAC’s Battery Lab,” smartphone might also be integrated the phone itself, or nearby, and con- SLAC, 17 July 2014; https://www6.slac. stanford.edu/news/2014-07-17-slac- into our clothing or fashion accessories. nected through a wireless link. Examples battery-lab.aspx. A distributed phone platform makes a include a 3D accelerometer and a solid- lot of sense from a functional perspec- state compass, also integrated with most 4. IEEE Pervasive Computing, special issue on energy harvesting and conserva- tive. By placing the I/O components modern smartphones, or a Bluetooth tion, Jan.–Mar. 2005; www.computer. close enough to your eyes and ears, pedometer (such as the FitBit Flex) that org/csdl/mags/pc/2005/01/index.html. it can directly augment your senses; wirelessly reports the user’s daily step allowing processing technology, storage count. In the future, there will be more devices, and batteries to be placed in hardware sensors attached to the phone Nayeem Islam is a vice more convenient locations on the body. platform, and probably many other sen- president and head of Qual- A key ingredient for wearable comput- sors on our body to which the phone can comm Research Silicon ing is access to power. In existing phones, connect. It is likely that standards will Valley. He leads a group all components use the same battery. also be created for modular physical sen- that conducts research and Users only need to charge one device sor technologies, letting users enhance development in various (battery) to have a working system. By phones by snapping on a variety of sen- aspects of mobile computing. Contact him at distributing the components of a smart- sors, chosen for specific applications. [email protected]. phone, the battery must be replicated, and then all these batteries must be charged. Roy Want is a research sci- This is a challenge, but it could be solved martphones have been one of the entist at Google and an IEEE by reducing the power consumption of a S greatest drivers of pervasive com- and ACM Fellow. Contact component so it can operate for its life- puting. We’re living in exciting times, as him at roywant@google. time on one battery, or by scavenging the the pace of innovation and development com. energy from the environment, ­perhaps in this area continues to accelerate. The

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