Department of Computer Science
COURSES:
NETB 224 Operating Systems Project (NETB 202) &
NETB 232 Operating Systems Labs Project (NETB 213)
A PAPER ON THE TOPIC OF
Operating systems for handheld and mobile devices
Semester 3
Student: Lecturer:
Volen Ilarionov / F39998 Assoc. Prof. N. Gadzhev
Contents
Introduction: …………………………………………………………………………….…3
- What is a Mobile device?
- Examples of mobile computing devices
PDAs
Smartphones
- What is a Mobile Operating Systems (Mobile OS)?
-Some of the more common and well-known Mobile OS
Symbian OS
Windows Mobile
Palm OS
Mobile Linux
Historical facts: …………………………………………………………………………...6
-
Psion – company, creator of the first handheld computer
-
EPOC16 – the first version of Psion’s OS system
-
EPOC32 - The 32-bit OS developed by Project “Protea” resulted in the eventual formation of Symbian Ltd. in June 1998 in conjunction with Nokia, Ericsson and Motorola. EPOC32 was renamed “Symbian OS”
Today’s mobile Operating Systems: …………………………...………………….7
- Symbian OS from Symbian
- iPhone OS from Apple Inc.
- RIM BlackBerry operating system
- Windows Mobile from Microsoft
- Linux operating system
- Palm OS developed by PalmSource
- Android from Google
Introduction to the Architecture of Symbian OS ………………….……………9
- Design Goals and Architecture
- Basic Design Patterns of Symbian OS
Symbian OS Layer by Layer ………………………………………………..………11
Conclusion ……………………………………………………………………………..…16
References/Bibliography
Introduction
What is a Mobile/handheld device?
A mobile device (also known as cellphone device, handheld device, handheld computer, "Palmtop" or simply handheld) is a pocket-sized computing device, typically having a display screen with touch input or a miniature keyboard.
Today's mobile devices are multi-functional devices capable of hosting a broad range of applications for both business and consumer use. PDAs and the ever-growing category of smartphones allow people to access the Internet for e-mail, instant messaging, text messaging and Web browsing, as well as work documents, contact lists and more. Mobile devices are often seen as an extension to your own PC. Work done on the road, or away from the office can be synchronized with your PC to reflect changes and new information.Smartphones and PDAs are popular amongst those who require the assistance and convenience of a conventional computer, in environments where carrying one would not be practical.
Types of Mobile Computing Devices
The term mobile device is used to mean a wide range of consumer electronics. Usually mobile device is used to describe the devices that can connect to the Internet. Some will classify digital cameras and standard MP3 players as mobile devices as well however the most reffered to as mobile devices are PDAs and smartphones. The category of mobile devices include the following devices, as well as others:
Personal Digital Assistant (PDA)
(sometimes called pocket computers)
PDAs are handheld devices that combine elements of computing, telephone/fax, Internet and networking in a single device. A typical PDA can function as a cellular phone, fax sender, Web browser and personal organizer. Unlike portable computers, most PDAs began as pen-based, using a stylus rather than a keyboard for input. This means that they also incorporated handwriting recognition features. Some PDAs can also react to voice input by using voice recognition technologies. PDAs of today are available in either a stylus or keyboard version (called a datapad).
Examples of PDA Devices: Palm Pilot, Revo, Sony Clie, Hewlett-Packard Jornado, Casio Cassiopedia, Compaq iPaq, Toshiba Pocket PC
Smartphones
Smartphones combine both mobile phone and handheld computers into a single device. Smartphones allow users to store information (e.g., e-mail), install programs, along with using a mobile phone in one device. A Smartphone could be a mobile phone with some PDA functions integrated into the device or vise versa.
Examples of Smartphones: Sony Ericsson, Palm Treo, Blackberry, Nokia T-Mobile Sidekick, Torq, Motorola Q, E-Ten, HP iPaq, I-mate,
What is a Mobile Operating Systems (Mobile OS)
Like a computer operating system, a mobile operating system is the software platform on top of which other programs run. When you purchase a mobile device, the manufacturer will have chosen the operating system for that specific device. The operating system is responsible for determining the functions and features available on your device, such as thumbwheel, keyboards, WAP, synchronization with applications, e-mail, text messaging and more. The mobile operating system will also determine which third-party applications can be used on your device. Some of the more common and well-known Mobile operating systems include the following:
Symbian OS
Symbian OS has become a standard operating system for smartphones, and is licensed by more than 85 percent of the world's handset manufacturers. The Symbian OS is designed for the specific requirements of 2.5G and 3G mobile phones.
Windows Mobile
The Windows Mobile platform is available on a variety of devices from a variety of wireless operators. You will find Windows Mobile software on Dell, HP, Motorola, Palm and i-mate products. Windows Mobile powered devices are available on GSM or CDMA networks.
Palm OS
Since the introduction of the first Palm Pilot in 1996, the Palm OS platform has provided mobile devices with essential business tools, as well as capability to access the Internet or a central corporate database via a wireless connection.
Mobile Linux
The first company to launch phones with Linux as its OS was Motorola in 2003. Linux is seen as a suitable option for higher-end phones with powerful processors and larger amounts of memory.
Historical Facts:
(The first handheld computer and the first mobile OS)
It all started with a company named Psion…
Psion was established by David Potter in 1980 as a software house. Its name means "Potter Scientific Investments" named after the company's founder. The acronym PSI was already in use elsewhere in the world so ON was added to make the name PSION unique.
1984 marked Psion's first foray into hardware; the Psion Organiser, the world's first handheld computer, in appearance resembling early games machines.
In 1986 the vastly improved Psion Organiser II was released, whose success led the company into a decade long period of "Psion" Computer and operating system development. It included a simple-to-use database programming language, OPL, which sparked a large independent software market.
EPOC16, originally simply named EPOC, is the operating system developed by Psion in the late 1980s and early 1990s for Psion's "SIBO" (SIxteen Bit Organisers) devices. EPOC came from epoch, the beginning of an era, but was backfitted by the engineers to "Electronic Piece Of Cheese". All EPOC16 devices feature an 8086-family processor and a 16-bit architecture. EPOC16 is a single-user pre-emptive multitasking operating system, written in Intel 8086 assembler language and C and designed to be delivered in ROM. This development effort produced the Psion Series 3 (1993-1998) and the Psion MC-series laptops.
Work started on the 32bit EPOC version in late 1994. The Psion Series 5 device, released in June 1997, used the first iterations of the EPOC32 OS, codenamed "Protea", and the "Eikon" graphical user interface.
The 32-bit EPOC developed by Project “Protea” resulted in the eventual formation of Symbian Ltd. in June 1998 in conjunction with Nokia, Ericsson and Motorola. The OS was renamed the Symbian Operating System and was envisioned as the base for a new range of smartphones. Psion gave 130 key staff to the new company and retained a 31% shareholding in the spun-out business. The Symbian operating system as of 2007[update] powers around 125 million mobile phones.
Today’s mobile Operating Systems
Operating systems that can be found on mobile devices include Symbian OS, iPhone OS, RIM's BlackBerry, Windows Mobile, Linux, Palm WebOS and Android.
The most common operating systems (OS) used in smartphones are in Q3 2008:
Symbian OS from Symbian Ltd. (46.6% Market Share Sales Q3 2008 )
Symbian has the largest share in most markets worldwide, but lags behind other companies in the relatively small but highly visible North American market. This matches the success of its largest shareholder and customer, Nokia, in all markets except Japan. Nokia itself enjoys 52.9% of the smartphone market. In Japan Symbian is strong due to a relationship with NTT DoCoMo, with only one of the 44 Symbian handsets released in Japan coming from Nokia. It is used by many major handset manufacturers, including BenQ, LG, Motorola, Samsung, and Sony Ericsson. Various implementations of user interfaces on top of Symbian ,most notable being UIQ (formerly known as User Interface Quartz) and Nokia's own S60, are incompatible, which along with the requirement that applications running on mobile phones be signed is hindering the potential for a truly widely accepted mobile application platform. It has received some adverse press attention due to virus threats (namely trojan horses).
iPhone OS from Apple Inc. (17.3% Market Share Sales Q3 2008)
The iPhone and iPod Touch use an operating system called iPhone OS, which is derived from Mac OS X. Third party applications were not officially supported until the release of iPhone OS 2.0 on July 11th 2008. Before this,"jailbreaking" allowed third party applications to be installed, and this method is still available.
RIM BlackBerry operating system
(15.2% Market Share Sales Q3 2008)
This OS is focused on easy operation and was originally designed for business. Recently it has seen a surge in third-party applications and has been improved to offer full multimedia support.
Windows Mobile from Microsoft
(13.6% Market Share Sales Q3 2008)
The Windows CE operating system and Windows Mobile middleware are widely spread in Asia. The two improved variants of this operating system, Windows Mobile 6 Professional (for touch screen devices) and Windows Mobile 6 Standard, were unveiled in February 2007. Windows Mobile is enjoying great popularity because of the low barrier to entry for third-party developers to write new applications for the platform.
Linux operating system (5.1% Market Share Sales Q3 2008)
Linux is strongest in China where it is used by Motorola, and in Japan, used by DoCoMo. Rather than being a platform in its own right, Linux is used as a basis for a number of different platforms developed by several vendors, including Motorola and TrollTech, which are mostly incompatible.
Palm OS developed by PalmSource
(now a subsidiary of ACCESS)
PalmSource traditionally used its own platform developed by Palm Inc. Access Linux Platform (ALP) is an improvement that was planned to be launched in the first half of 2007. It will use technical specifications from the Linux Phone Standards Forum. The Access Linux Platform will include an emulation layer to support applications developed for Palm-based devices.
Binary Runtime Environment for Wireless (BREW)
BREW was developed in the USA by Qualcomm, Inc and is popular in North America. BREW is a mobile application development platform and end-to-end content delivery ecosystem. BREW has recently gained a foothold in Europe via the 3 Skypephones offered by network 3.
Android from Google (Released 22 Oct 2008)
Android, which was developed by Google, has yet to own even a small part of the smartphone market because of its recent release date. Android is an Open Source platform backed by Google, along with major hardware and software developers (such as Intel, HTC, ARM, and eBay, to name a few), that form the Open Handset Alliance. This OS, though very new, already has a cult following among programmers eager to develop apps for its flexible, Open Source, back end. Android promises to give developers access to every aspect of the phone's operation. This lends many to foresee the promise of further growth for the Android platform.
Introduction to the Architecture of Symbian OS
Design Goals and Architecture
Architecture is goal driven. The architecture of a system is the vehicle through which its design goals are realized. Even systems with relatively little formal architecture, such as Unix, evolve according to more or less well-understood principles, to meet more or less well-understood goals. And while not all systems are ‘architected’, all systems have an architecture.
Symbian OS follows a small number of strong design principles. Many of these principles evolved as responses to the product ethos that was dominant when the system was first being designed. That ethos can be summarized in a few simple rules:
• User data is sacred
• User time is precious
• All resources are scarce
Symbian OS certainly aims at unequaled robustness, making strong guarantees about the integrity and safety (security) of user data and the ability of the system to run without failure (to be crash-proof, in other words). From the beginning, it has also aimed to be easy and intuitive to use and fully driven by a graphical user interface (GUI). (The original conception included a full set of integrated applications and an attractive, intuitive and usable GUI; ‘charming the user’ is an early Symbian OS slogan)
Perhaps as important as anything else, the operating system set out from the beginning to be extensible, providing open application programming interfaces (APIs), including native APIs as well as support for the Visual Basic-like OPL language and Java, and easy access to Software Development Kits (SDKs) and development tools.
However, systems do not stand still; architectures are dynamic and
evolve. Symbian OS has been in a state of continuous evolution since it
first reached market in late 2000; and for the three years before that it had been evolving from a PDA operating system to one specifically targeting the emerging market for mobile phones equipped with PDA functions.
Basic Design Patterns of Symbian OS
The design principles of a system derive from its design goals and are realized in the concrete design patterns of the system. The key design patterns of Symbian OS include the following:
• the microkernel pattern: kernel responsibilities are reduced to an
essential minimum
• the client–server pattern: resources are shared between multiple users, whether system services or applications
• frameworks: design patterns are used at all levels, from applications
(plug-ins to the application framework) to device drivers (plug-ins to
the kernel-side device-driver framework) and at all levels in between,
but especially for hardware adaptation-level interfaces
• the graphical application model: all applications are GUI and only
servers have no user interface
• an event-based application model: all user interaction is captured
as events that are made available to applications through the event
queue
Symbian OS Layer by Layer
The simplest architectural view of Symbian OS is the layered view given by the Symbian OS System Model :
UI Framework Layer
The topmost layer of Symbian OS, the UI Framework layer provides the frameworks and libraries for constructing a user interface, including the basic class hierarchies for user interface controls and other frameworks and utilities used by user interface components.
The UI Framework layer also includes a number of specialist, graphicsbased frameworks which are used by the user interface but which are also available to applications, including the Animation framework, the Front End Processor (FEP) base framework and Grid.
The user interface architecture in Symbian OS is based on a core
framework called Uikon and a class hierarchy for user interface controls
called the control environment. Together, they provide the framework
which defines basic GUI behavior, which is specialized by a concrete
GUI implementation (for example, S60, UIQ or MOAP), and the internal
plumbing which integrates the GUI with the underlying graphics
architecture.
Uikon was originally created as a refactoring of the Eikon user interface library, which was part of the earliest versions of the operating
system.Uikon was created to support easier user interface customization, including ‘pluggable’ look-and-feel modules.
The Application Services Layer
The Application Services layer provides support independent of the user interface for applications on Symbian OS. These services divide into three broad groupings:
• system-level services used by all applications, for example the Application Architecture or Text Handling
• services that support generic types of application and application- like services, for example personal productivity applications (vCard and vCal, Alarm Server) and data synchronization services (OMA Data Sync, for example); also included are a number of key application engines which are used and extended by licensees (Calendar and Agenda Model), as well as legacy engines which licensees may Choose to retain (Data Engine)
•services based on more generic but application-centric technologies, for example mail, messaging and browsing (Messaging Store, MIME Recognition Framework, HTTP Transport Framework).
Applications in Symbian OS broadly follow the classic object-oriented Model–Viewer–Controller (MVC) pattern. The framework level support encapsulates the essential relationships between the main application classes (representing the application data model, the views onto it, and the document and document user interface that allow it to be manipulated and persisted) and abstracts all of the necessary underlying system-level behavior. In principle, a complete application can be written without any further direct dependencies (with the exception of the User Library). The Application Services layer reflects the way that the system as a whole has evolved. On the one hand, it contains essential application engines that almost no device can do without (the Contacts Model for example), as well as a small number of application engines that are mostly now considered legacy (e.g. the WYSIWYG printing services and the office application engines, including Sheet Engine, a full spreadsheet engine more appropriate for PDA-style devices). On the other hand, it contains (from Symbian OS v9.3) the SIP Framework, which provides the foundation for the next generation of mobile applications and services.
Java ME
In some senses, Java does not fit neatly into the layered operating system model. Symbian’s Java implementation is based around:
• a virtual machine (VM) and layered support for the Java system which complements it, based on the MIDP 2.0 Profile
• a set of standard MIDP 2.0 Packages
• an implementation of the CLDC 1.1 language, I/O, and utilities
services
• a number of low-level plug-ins which implement the interface
between CLDC, the supported packages, and the native system.
Java support has been included in Symbian OS from the beginning,
but the early Java system was based on pJava and JavaPhone. A standard system based on Java ME first appeared in Symbian OS v7.0s. Since Symbian OS v8, the Java VM has been a port of Sun’s CLDC HI.
The OS Services Layer
The OS Services layer is, in effect, the ‘middleware’ layer of Symbian OS, providing the servers, frameworks, and libraries that extend the bare system below it into a complete operating system. The services are divided into four major blocks, by broad functional area:
• generic operating system services
• communications services
• multimedia and graphics services
• connectivity services.
Together, these provide technology - specific but applicationindependent services in the operating system. In particular, the following servers are found here:
• communications framework: the Comms Root Server and ESock (Sockets) Server provide the foundation for all communications services
• telephony: ETel (Telephony) Server, Fax Server and the principal
servers for all telephony-based services
• networking: the TCP/IPv4/v6 networking stack implementation
• serial communications: the C32 (Serial) Server, providing standard serial communications support
• graphics and event handling: the Window Server and Font and Bitmap Server provide all screen-drawing and font support, as well as systemand application-event handling
• connectivity: the Software Install Server, Remote File Server and
Secure Backup Socket Server provide the foundation for connectivity services
• generic: the Task Scheduler provides scheduled task launching.
Among the other important frameworks and libraries found in this layer is the Multimedia Framework (providing framework support for cameras, still- and moving-image recording, replay and manipulation, and audio players) and the C Standard Library, an important support library for software porting.
The Base Services Layer
The foundational layer of Symbian OS, the Base Services layer provides the lowest level of user-side services. In particular, the Base Services layer includes the File Server and the User Library. The microkernel architecture of Symbian OS places them outside the kernel in user space. (This is in contrast to monolithic system architectures, such as both Linux and Microsoft Windows, in which file system services and User Library equivalents are provided as kernel services.)
Other important system frameworks provided by this layer include
the ECom Plug-in Framework, which implements the standard management interface used by all Symbian OS framework plug-ins; Store, which provides the persistence model; the Central Repository, the DBMS framework; and the Cryptography Library.
The Base Services layer also includes the additional components which are needed to create a fully functioning base port without requiring any further high-level services: the Text Window Server and the Text Shell.
The Kernel Services and Hardware Interface Layer
The lowest layer of Symbian OS, the Kernel Services and Hardware Interface layer contains the operating system kernel itself, and the supporting components which abstract the interfaces to the underlying hardware, including logical and physical device drivers and ‘variant support’, which implements pre-packaged support for the standard, supported platforms (including the Emulator and reference hardware boards). In releases up to Symbian OS v8, the kernel was the EKA1 (Kernel Architecture 1) kernel, the original Symbian OS kernel. In Symbian OS v8, the EKA2 (Kernel Architecture 2) real-time kernel shipped for the first time as an option.
Conclusion
Users expect and demand rock-solid stability and performance from their phones; desktop computer performance standards are not acceptable. Yet a mobile OS is nowhere near the capabilities of desktop Operating Systems. I don’t think that Hand-helds are likely to replace other technologies. Instead, they can address specific problems and needs. The key to the hand-held is its portability. Great for field trips, home use, and anything requiring quick information access and recording, these devices can be used without the hassle of heavier technology. Of course, more powerful and architecturally different hardware of miniature dimensions is yet to be created. As a conclusion I would like to say that phones really are different from other systems and they are complex.
References/Bibliography
1. The Symbian OS Architecture Sourcebook: Design and Evolution of a Mobile Phone OS
by Ben Morris
Paperback: 630 pages; Publisher: Wiley (June 22, 2007); ISBN-10: 047001846; ISBN-13: 978-0470018460
2. Professional Symbian Programming: Mobile Solutions on the EPOC Platform
by Martin Tasker, Jonathan Dixon, Mark Shackman, Tim Richardson, John Forrest
Paperback: 1000 pages; Publisher: WROX Press Ltd. (1 Feb 2000); ISBN-10: 186100303X;
ISBN-13: 978-1861003034
3. Symbian OS C++ for Mobile Phones: Vol. 1 (Symbian Press)
by Richard Harrison
Paperback: 826 pages; Publisher: John Wiley and Sons Ltd. (15 April 2003); ISBN-10: 0470856114
ISBN-13: 978-0470856116
4. Webopedia.com
Introduction to Mobile Devices
by Vangie Bea, Sepember 22, 2006
http://www.webopedia.com/quick_ref/mobile_OS.asp
5. Symbian OS official website
http://www.symbian.com/
6. iPhone OS official website
http://developer.apple.com/iphone/
7. Windows Mobile OS official website
http://www.microsoft.com/windowsmobile/
8. Android OS official website
http://www.android.com/
9. Wikipedia.org
Smartphone http://en.wikipedia.org/wiki/Smartphone
EPOC http://en.wikipedia.org/wiki/EPOC_(computing)
Mobile device http://en.wikipedia.org/wiki/Mobile_device
Psion http://en.wikipedia.org/wiki/Psion
Symbian OS http://en.wikipedia.org/wiki/Symbian_OS
iPhone OS http://en.wikipedia.org/wiki/IPhone_OS
BlackBerry http://en.wikipedia.org/wiki/BlackBerry
Windows Mobile http://en.wikipedia.org/wiki/Windows_Mobile
Palm OS http://en.wikipedia.org/wiki/Palm_WebOS
Android OS by Google http://en.wikipedia.org/wiki/Android_(mobile_device_platform)
Binary Runtime Environment for Wireless(BREW) http://en.wikipedia.org/wiki/Binary_Runtime_Environment_for_Wireless
And others
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