Technical university of mombasa

 Kernel Services & Hardware Interface Layer The Base Services Layer is the lowest level reachable by user-side operations it includes the File Server and User Library, a Plug-In Framework which manages all plugins, Store, Central Repository, DBMS and cryptographic services. It also includes the Text Window Server and the Text Shell the two basic services from which a completely functional port can be created without the need for any higher layer services.
Symbian has a microkernel architecture, which means that the minimum necessary is within the kernel to maximise robustness, availability and responsiveness. It contains a scheduler, memory management and device drivers, but other services like networking, telephony and filesystem support are placed in the OS Services Layer or the Base Services Layer. The inclusion of device drivers means the kernel is not a true microkernel. The EKA2 real-time kernel, which has been termed a nanokernel, contains only the most basic primitives and requires an extended kernel to implement any other abstractions.
Symbian is designed to emphasise compatibility with other devices, especially removable media file systems. Early development of EPOC led to adopting FAT as the internal file system, and this remains, but an object-oriented persistence model was placed over the underlying FAT to provide a POSIX-style interface and a streaming model. The internal data formats rely on using the same APIs that create the data to run all file manipulations. This has resulted in data- dependence and associated difficulties with changes and data migration. There is a large networking and communication subsystem, which has three main servers called
ETEL (EPOC telephony, ESOCK (EPOC sockets) and C (responsible for serial communication. Each of these has a plugin scheme. For example, ESOCK allows different ".PRT" protocol modules to implement various networking protocol schemes. The subsystem also contains code that supports short-range communication links, such as Bluetooth, IrDA and USB. There is also a large volume of user interface (UI) Code. Only the base classes and substructure were contained in Symbian OS, while most of the actual user interfaces were maintained by third parties. This is no longer the case. The three major UIs
– S, UIQ and MOAP – were contributed to Symbian in 2009. Symbian also contains graphics, text layout and font rendering libraries. Document shared on www.docsity.com
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All native Symbian C+ applications are built up from three framework classes defined by the application architecture an application class, a document class and an application user interface class. These classes create the fundamental application behaviour. The remaining needed functions, the application view, data model and data interface, are created independently and interact solely through their APIs with the other classes. Many other things do not yet fit into this model
– for example, SyncML, Java ME providing another set of APIs on top of most of the OS and multimedia. Many of these are frameworks, and vendors are expected to supply plugins to these frameworks from third parties (for example, Helix Player for multimedia codecs). This has the advantage that the APIs to such areas of functionality are the same on many phone models, and that vendors get a lot of flexibility. But it means that phone vendors needed to do a great deal of integration work to make a Symbian OS phone.
Symbian includes a reference user-interface called "TechView." It provides a basis for starting customisation and is the environment in which much Symbian test and example code runs. It is very similar to the user interface from the Psion Series 5 personal organiser and is not used for any production phone user interface.
Symbian UI variants/platforms
Symbian, as it advanced to OS version 7.0, spun off into several different graphical user interfaces, each backed by a certain company or group of companies. Unlike Android OS's cosmetic GUIs, Symbian GUIs are referred to as "platforms" due to more significant modifications and integrations. Things became more complicated when applications developed for different Symbian GUI platforms were not compatible with each other, and this led to OS fragmentation.
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User Interfaces platforms that run on or are based on Symbian OS include
 S, Symbian, also called Series 60. Document shared on www.docsity.com
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Sony Ericsson G on Symbian UIQ 3.0, which comes with a resistive touchscreen It was backed mainly by Nokia. There are several editions of this platform, appearing first as S (st Edition) on Nokia 7650. It was followed by S 2nd Edition (e.g. Nokia NS rd Edition (e.g. Nokia N) and S 5th Edition (which introduced touch UI e.g. Nokia N. The name, S, was changed to just Symbian after the formation of Symbian Foundation, and subsequently called Symbian^1, 2 and 3.
 Series 80 used by Nokia Communicators such as Nokia i.
 Series 90 Touch and button based. The only phone using this platform is Nokia 7710.
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UIQ backed mainly by Sony Ericsson and then Motorola. It is compatible with both buttons and touch/stylus based inputs. The last major release version is UIQ3.1 in 2008, on Sony
Ericsson G. It was discontinued after the formation of Symbian Foundation, and the decision to consolidate different Symbian UI variants into one led to the adoption of S as the version going forward.
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MOAP (Mobile Oriented Applications Platform) Japan Only used by Fujitsu, Mitsubishi, Sony Ericsson and Sharp-developed phones for NTT DoCoMo. It uses an interface developed specifically for DoCoMo's FOMA "Freedom of Mobile Access" network brand and is based on the UI from earlier Fujitsu FOMA models. The user cannot install new C+ applications. (Japan Only)
 OPP Japan Only, successor of MOAP, used on NTT DoCoMo's FOMA phone. Market share and competition In Q 2004 2.4 million Symbian phones were shipped, double the number as in Q 2003.
Symbian Ltd. was particularly impressed by progress made in Japan million devices were shipped in Q 2004, a growth of 201% compared to Q 2003 and market share growing from 30.5% to 50.2%. However in the United States it was much less popular, with a 6% market share in Q 2004, well behind Palm OS (43%) and Windows Mobile (25%). This has been attributed to North American customers preferring wireless PDAs over smartphones, as well as Nokia's low popularity there.
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On 16 November 2006, the 100 millionth smartphone running the OS was shipped As of 21 July 2009, more than 250 million devices running Symbian OS had been produced.
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In 2006, Symbian had 73% of the smartphone market compared with 22.1% of the market in the second quarter of By the end of May 2006, 10 million Symbian-powered phones were sold in Japan, representing
11% of Symbian's total worldwide shipments of 89 million By November 2007 the figure was 30 million, achieving a market share of 65% by June 2007 in the Japanese market.
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Symbian has lost market share over the years as the market has dramatically grown, with new competing platforms entering the market, though its sales have increased during the same timeframe. E.g., although Symbian's share of the global smartphone market dropped from 52.4% into in 2009, shipments of Symbian devices grew 4.8%, from 74.9 million units to
78.5 million units From Q 2009 to Q 2010, shipments of Symbian devices grew 41.5%, by
8.0 million units, from 19,178,910 units to 27,129,340; compared to an increase of 9.6 million units for Android, 3.3 million units for RIM, and 3.2 million units for Apple.
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Prior reports on device shipments as published in February 2010 showed that the Symbian devices formed a 47.2% share of the smart mobile devices shipped in 2009, with RIMhaving
20.8%, Apple having 15.1% (via iOS), Microsoft having 8.8% (via Windows CE and Windows Mobile) and Android having In the number of "smart mobile device" sales, Symbian devices were the market leaders for
2010. Statistics showed that Symbian devices formed a 37.6% share of smart mobile devices sold, with Android having 22.7%, RIM having 16%, and Apple having 15.7% via iOS).
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Some estimates indicate that the number of mobile devices shipped with the
Symbian OS up to the end of Q 2010 is 385 million.
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Over the course of 2009
–10, Motorola, Samsung, LG, and Sony Ericsson announced their withdrawal from Symbian in favour of alternative platforms including Google's Android,
Microsoft's Windows Phone.
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In Q 2012, according to IDC worldwide market share has dropped to an all-time low of
4.4%.
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