Tablets aren’t new. They’ve been around almost as long as portable computers. Like electric cars, they have come, gone, and reappeared with even more success than they have had in the past (see “All-Electric Vehicles Prepare To Shock The Automotive Market” at electronicdesign.com).
There’s no doubt that Apple’s iPad and iPad 2 have been rousing successes (Fig. 1). But now there’s lots of competition, even if some competitors have essentially withdrawn from the market such as HP’s TouchPad, which disappeared in a $99 fire sale (see “webOS, We Hardly Knew Ye”).
There have been significant improvements since the tablets of yore, involving more than solid-state disk (SSD) drives and multicore single-chip processors. Tablets can trace their roots to 1952’s Styalator, which wasn’t portable and was more of a pen interface.
Tablets in the 1980s and 1990s like the GRiDPad that ran MS-DOS and Apple’s Newton essentially were standalone devices, and they were more about the hardware than the environment. Handwriting recognition was the darling interface and a stylus was a necessary evil.
Contrast these older platforms with the latest crop of tablets and the significant differences are easy to see. Larger screens and higher resolution have been critical when they have been coupled with multitouch interfaces. A stylus is still an option on some systems, but fingers are the input device of choice and on-screen keypads are the norm.
Likewise, tablets are sometimes viewed as large smart phones, or conversely a smart phone is just a small tablet. This is an oversimplification, but typically smart phones and tablets from the same company will share at least the base operating system and user interface as well as many apps that run on their platforms.
The biggest difference is connectivity, colloquially known as the “cloud,” and the “walled gardens” associated with both the cloud services and the app store system that has greatly simplified product distribution.
For our grand tour through tabletville, we examine the hardware characteristics of some of the latest tablets on the market and move on to the cloud/app store environments and finally the development environments.
The iPad 2
The iPad 2 set the mark for tablets. Its 9.7-in., 1024- by 768-pixel LCD uses the more conventional 4:3 screen size versus the 16:4 ratio for HD-oriented tablets. The 4:3 ratio provides a nice rectangular shape, while the 16:4 ratio tends to be longer. Many 7-in. tablets use the longer 16:4 screens to provide more reading room as well as the ability to display HD video without resorting to letterbox or clipping. It has one of the most responsive capacitive multitouch displays.
Also, the iPad 2 uses a 1-GHz dual-core A5 with Arm Cortex-A9-style cores, 512 Mbytes of RAM, and up to 64 Gbytes of flash. Wi-Fi and Bluetooth are standard, and 3G is optional. Touch input is standard, as is a three-axis gryo and accelerometer that are used to turn the iPad into its own game controller.
On the multimedia side, the iPad 2 sports a VGA resolution front camera for teleconferencing and a rear camera that can record 720p video but lacks a flash unit. Stereo audio output and a built-in microphone round out the recording capability. It has HDMI and VGA output via adapters as well. And, all of Apple’s iPads and iPhones run the company’s iOS operating system.
Apple’s Competition
Other tablets follow the iPad’s description with a few differences such as more or less memory, expansion slots, hotspot capability, and GPS support. With the demise of the HP TouchPad, the Research In Motion (RIM) BlackBerry PlayBook is the one platform that stands alone like Apple’s iPads (Fig. 2).
The PlayBook runs QNX, a well respected embedded operating system that RIM purchased. QNX is still used in a variety of products, and it is supported by toolsets that run on Windows, Linux, and QNX (see “Visualization Tools Target Multicore Systems Development” at electronicdesign.com).
The PlayBook’s 7-in LCD multitouch screen boasts 1024-by-600 resolution and a 16:4 aspect ratio. The 1-GHz dual-core Cortex-A9 has 1 Gbyte of RAM to use with up to 64 Gbytes of flash. Like the iPad 2, it lacks an SD card slot but includes Bluetooth, Wi-Fi, and GPS support. It also has an accelerometer but no gyro. At 0.9 lb, the PlayBook is lighter than the iPad 2 and many larger Android tablets.
Google Android is the operating system choice if you aren’t Apple, Microsoft, or RIM. Users can take advantage of the Android App Market for applications that are usually written in Java, which runs on the Dalvik virtual machine.
The Motorola Xoom, Samsung Galaxy Tab, Toshiba Thrive, Acer Iconia, Asus Eee Pad Transformer, and Lenovo IdeaPad K1 look rather similar (Fig. 3). These Android 3.0 (Honeycomb) tablets have a 10.1-in., 1280-by-800 resolution LCD screen with a 16:4 aspect ratio. They also have 1-GHz dual-core Cortex-A9 nVidia Tegra 2 processors with 1 Gbyte of RAM, varying amounts of flash, and usually an SD card slot.
Android 3.0 was designed for tablets, whereas Android 2.2 (Froyo) and 2.3 (Gingerbread) were really smart-phone platforms. Much of the change was to accommodate the larger screen. This includes improved versions of apps like mail programs.
Front and rear cameras are the norm, as are audio input and output, three-axis accelerometers, and gyros. Wi-Fi and Bluetooth are standard with some 3G and 4G in the mix as well as GPS and electronic compass support.
This common hardware architecture is similar to the PC market except the biggest player, Apple, has an incompatible platform. These larger Android tablets are just the tip of the iceberg. Many smaller tablets also run Android. Some have as much horsepower and as many features as the larger platforms, and some reduce the number of features to keep costs down.
The top-end systems are the dual-core platforms already mentioned. Next year, quad-core systems based on hardware like nVidia’s Tegra 3, Freescale’s i.MX 6, or Texas Instruments’ OMAP 5 will be common. Performance requirements could peak as they integrate with automobiles. But as long as vendors can deliver more MIPS in the same package for the same price, the hardware will continue to follow the performance curve.
The gorilla in the corner is Microsoft, which has dabbled in tablets for years with its partners. Some application-specific solutions have been lucrative, but general adoption of Windows-based tablets has been elusive. Windows has provided a range of tablet-oriented features from onscreen keyboards to stylus input, but typically the applications were still PC-oriented.
Windows 8 promises to bring the environment to tablets and smart phones, again. Microsoft already has interested hardware parties, but hardware cannot ship until the software is available.
Super E-Readers Or Tiny Tablets?
Tablets can handle e-books. They compete with e-readers that typically employ E Ink’s E-paper, which provides great gray-scale images that are viewable in bright sunlight where most LCDs are washed out (see “E-paper Makes E-books Exciting” at electronicdesign.com).
E Ink even has a color e-paper (see “Color Comes To E-Books” at electronicdesign.com). However, this technology suffers from a slow refresh rate, making it unsuitable for video and multimedia presentations common on tablets.
The Barnes & Noble Nook Color and the Amazon Kindle Fire, which use the “walled garden” approach, initially are targeting e-books and similar content via Web browsing (Fig. 4). Both are based on Android with 7-in. LCD screens. The providers want users to get all their apps, content, and communication through them, though.
The Nook Color came out first. It runs Android 2.x and has a single-core, 800-MHz Cortex-A8 processor with 512 Mbytes of RAM. Also, it has 8 Gbytes of flash plus a MicroSD slot. The Nook Color can boot from the MicroSD slot, allowing it to easily run different versions of Android, although the system is underpowered for Android 3.x.
The Kindle Fire has a bit more horsepower. It is based on a 1-GHz, dual-core, Cortex-A9 TI OMAP processor with 512 Mbytes of RAM. It also has 8 Gbytes of flash but no MicroSD slot. The Fire runs a very customized version of Android 2.x.
The Nook Color and Kindle Fire have Wi-Fi support but no Bluetooth interface. They also lack features like GPS and cameras, but they do have a USB interface that allows files to be transferred via a PC. This puts them in a class between the typical e-reader and a full-blown Android Tablet.
Cloudy With A Chance Of Apps
The cloud and app stores are an integral part of the tablet experience. Each major platform has its own app store. There’s Apple’s App Store and the Android App Market, and Microsoft has indicated that Windows 8 will be supported by an app store.
Like tablets, app stores aren’t new. But the scope of today’s app stores is considerably greater than in the past. Likewise, the purchasing and distribution infrastructure is larger and ubiquitous. For many applications, the app phenomenon has put some brick and mortar stores out of business while enhancing others.
Like brick and mortar stores, app stores get a cut of what they sell. A 30% cut for most applications is typical with a similar amount for online subscriptions. App store companies like Apple and Amazon love the golden goose because the infrastructure tends to run itself with few people required to manage it, compared to conventional stores.
In one sense, the app stores are just an extension of online sales but there are two primary differences. First, the target market for apps and subscriptions is a specific class of devices that are often directly related to the app store vendor. Apple is the prime example with Amazon and RIM in the mix as well. Google is now in this group since it picked up Motorola Mobility, which makes Android-based hardware.
The app store approach is beneficial to consumers as well as binding. The interface for purchasing and using a purchased app or content is part of the device as delivered to the consumer. This brings up the second issue of a focused market. The devices that an app store serves tend to be more limited, although cross-vendor solutions like Android have a wider audience.
The range of targets is an issue I will discuss later when it comes to application development, because newer devices typically increase performance, capacity, and screen resolution and often add new peripherals such as GPS or an extra camera.
App stores tend to be the distribution point for apps and content, but connectivity allows a host of services to be based in the cloud. These stores encourage easy access to applications and services and discourage side loading, usually via USB or Wi-Fi. It’s not as if these changes are hard to make, but they relinquish some control to the hardware and app store vendors. Some devices even prevent side loading.
Most vendors and service providers actively try to prevent “jailbreaking,” or unlocking devices sold to consumers. But hackers typically take these measures as a challenge, and most popular devices can be modified. Still, jailbreakers tend to be only a small fraction of users.
As an aside, remember when this ecosystem just used to be called the Internet? The term “cloud” tends to further blur the issue because there is so much more involved when discussing it, from Software as a Service (SaaS) to Platforms as a Service (PaaS) and more (see “The Embedded Cloud Floats Everywhere” at electronicdesign.com).
Apple typically develops more buzz when it announces products and services, but its iCloud isn’t the first cloud service to become popular. Web-based e-mail and even documents like Google Docs have been around for quite a while.
Cloud Engines’ PogoPlug was one of the first services to provide cloud-based storage and storage passthrough services (see “Pogoplug And DockStar Are Internet NAS Boxes” at electronicdesign.com). Of course, there are apps that provide access to the cloud to store files.
Many Internet-based services for smart phones were initially developed using more conventional Internet hosting services. But these days, most services will be taking advantage of cloud-based computing platforms like Amazon’s Elastic Compute Cloud (EC2), which has a lot of competition from the likes of GoGrid and Rackspace.
Cloud computing provides a scalable, pay-as-you-go approach that doesn’t require the investment in hardware. Services can be up and running in minutes and managed from anywhere on the planet. There is flexibility in storage, networking, and load balancing with configurable options rather than hardware that needs to be wired together.
Also, cloud computing is a good complement to apps that work with the cloud. App developers always want a blockbuster, but this calibre of app is rarely found. It can also be a surprise to the developers, so having a scalable server side allows vendors to take advantage of the growing popularity of their product.
What’s interesting is the comparison between app stores for smart phones and tablets and similar app stores for cloud computing service providers. The number of applications is significantly smaller but the scope of the applications is much larger because of the available underlying hardware. We can expect quad-core tablets and cell phones, but they don’t hold a candle to the performance of a public cloud that has hundreds of Intel Xeon or AMD Opteron cores in a cluster.
Changing Environments
Tablets and smart phones bring an interesting collection of peripherals and connectivity that can be utilized in different ways. Take Amazon’s Silk Web browser, which is found on the Fire tablet. Silk has an option that uses the cloud for caching and partial rendering. The caching may improve performance but the “feature” may have more to do with tracking since it can obtain more information than search engines like Google.
Caching systems like Silk are not new. Opera’s Mini Mobile Web browser has been doing it for years. In theory, this cache could be another place for apps to reside, although I don’t know of any that do right now.
Another mobile technology that has been getting a bit of buzz is Siri for the Apple 4S smart phone (Fig. 5). This natural language voice interface is a more refined system than those found on most high-end car navigation systems.
Voice dialing on cell phones has been common as well. Vlingo’s Virtual Assistant for Android is similar to Siri for Android platforms. These kinds of apps are possible because of improved peripherals, faster processors, and faster connectivity.
Development Environments
Applications for tablets and smart phones can be native, platform-based, browser-based, and Web-based. The diversity tends to be hidden from users but is a challenge for developers. There are advantages and disadvantages to each.
Native applications usually have hooks into all the hardware and can potentially be the most efficient. On the other hand, they are often bound to a more limited set of hardware-compatible platforms. They will also be specific to the operating systems and possibly operating environments.
Apple’s iOS, Google’s Android, and RIM’s QNX are the operating environments found on most tablets and smart phones these days. Microsoft’s Windows can be included in the bunch, although its forthcoming Windows 8 is likely to be more of a factor than the existing Windows 7. Microsoft’s Windows 8 Metro environment is yet another Windows presentation mechanism developers need to use to their advantage (Fig. 6).
Apple’s approach is one of the simplest with developers employing Objective-C as their programming language. Android tries a more portable approach with Java and its Dalvik virtual machine. Just in time (JIT) compilation provides performance.
Microsoft tries to be even more diverse. Its .NET platform underlies much of its system. Its virtual machine supports C# as well as a wide range of programming languages. It also addresses the desktop and server markets. This can actually be an advantage when dealing with apps that communicate with the cloud since the server-based cloud portion of the application can be developed using the same tools and application programming interfaces (APIs).
Browser-based applications can be local or delivered via the Internet on demand. The browser experience has often been augmented by software such as Adobe’s Flash, but HTML 5 is finally coming online. HTML 5’s better support for video and 3D graphics is likely to make this approach significantly more desirable. It is the most portable of the bunch but does have limitations.
Likewise, HTML 5 depends upon the browser implementation, so the look and possibly the feel of an app can differ from device to device. There is also the issue of compatibility between browser implementations. HTML 5 is significantly better than its predecessor but there will simply be applications that it cannot handle on its own. On the other hand, it can be the front end to local or cloud-based apps.
Many developers also will use Rapid Application Development (RAD) tools for tablets. These tools often provide cross-platform solutions that hide the underlying operating system and user interface, presenting the developer with a common API.
Many RAD tools are designed for non-programmers, such as cross-platform gaming tools like those from MoMinis (see “Smart-Phone Gaming Platform Includes Distribution” at electronicdesign.com). The development environment includes the RAD tool as well as application distribution support. The costs associated with these applications when distributed via the app stores get interesting. Now the app store vendor gets a cut as well as the RAD vendor. Often, even the RAD tools run on the cloud.
Gaming isn’t the only area where RAD tools are used. Cross-platform development tools are available from a number of vendors such as rhomobile, appcelerator, WidgetPad, PhoneGap, and MoSync. Motorola now owns rhomobile, and PhoneGap is part of Adobe. Some platforms are open source. Some address two platforms like iOS and Android while others target many platforms. And, some provide distribution and marketing services.
The challenge with cross-platform systems is the complexity of testing as well as determining the user experience for such a wide variety of devices. In some cases, developers will target specific, usually popular, devices to optimize the user experience or to take advantage of some hardware built into the device.
The challenge for developers using Google’s Android and probably Microsoft’s Windows 8 will be addressing the range of hardware devices. This can start with low-end, slower, single-core devices possibly using resistive touchscreens. At the other end of the spectrum will be high-end systems based on quad-core processors and fast, accurate, multitouch interfaces like Cypress Semiconductor’s TrueTouch Gen 4 (see “Direct Lamination Multitouch Technology Delivers Top-Notch SNR,” p. xx).
Some people think that tablets are a passing fad that will disappear into obscurity like they have in the past. I don’t think that’s the case. Developers are just beginning to take advantage of them. Likewise, developers and consumers are beginning to realize the advantages and limitations of the distribution system, connectivity, and payment systems being dropped on them.