What Symbian ?

Symbian OS is a free operating system is not developed by Symbian Ltd.. designed for use of mobile equipment (mobile). Before Nokia announced the purchase of all remaining shares of Symbian Ltd.. he did not have on June 24, 2008, Symbian is owned by Nokia (47.9%), Ericsson (15.6%), Panasonic (10.5%), Samsung (4.5%), Siemens / BenQ (8.4% ), Sony Ericsson (13.1%). The latest version of Symbian is a Symbian ^ 3 with PR 02 called symbian belle. While most phones currently available using the Symbian OS v6.1s, v7.0s, RV 47 75, v8.OS, v9.1s and s60 v5. Nokia Nseries on average using the Symbian OS v9.1s, except the Nokia N95 is using Symbian OS v9.2s. Symbian s60 v5 phones and Symbian ^ 3 on average using the touch screen except nokia e6-00 and e7.ponsel nokia symbian ^ 3 of the first slide aadalah nokia n8 with a 12 megapiksel.symbian ^ 3 gets the updates first called anna symbian. used in mobile phones nokia x7-00 and G6-00. while the latest update is called symbian belle. all phones symbian ^ 3 can be upgraded to a symbian belle. Now the whole shares in Symbian Limited have been owned by nokia symbian operating system and the position as ruler of the operating system market moves have been taken by the operating system that is made by google android operating system that came at the end of 2009 with its first mobile phone htc mobile phones like samsung dreaam g1.vendor, lg, sony ericsson now laagi oprasi symbian system and states to stop supporting this operating system.OverviewSymbian OS is currently a lot has been widely used by many vendors of mobile communications equipment products on various types of products they are varied. Variations from the hardware side is where the Symbian OS is implemented can be possible because the operating system application programming interface has (Application Programming Interface; API). API support for communication and behavior are common in hardware that can be used by other application objects. This is possible because the API is an interface object is defined at the application level, which contains procedures and functions (and also variables and data structures) that manage / call the kernel where as a liaison between software and hardware. With the standard API helps developers to make adjustments on an application made in order to be installed on the mobile phone product assortment. Much like the desktop operating system, Symbian OS capable of operating in multithreading, multitasking and memory protection against. Symbian and all programming is done on the event-based, meaning that the CPU hardware becomes inactive when no input in the form of a particular activity. However, it should be understood the operating system is intended to be installed on mobile devices with limited resources. Multithreaded and multitasking Symbian OS provides the ability to run more than one application at once. But this particular, a preemptive multitasking kernel would give each division a processing time of a program carried out alternately so quickly that it seems to the user as if the process is executed simultaneously. For it has given priority based scheduling is defined to determine which processes are running first and subsequent process of what and how much time will be given.Symbian OS itself is not the nature of open source software in full as though there is availability of the API and documentation, which much to help the application developers to create software that runs on these operating systems, published to the public but not for its own source code.
HistoryIn 1980, stood firm Psion software developer founded by David Potter. The product of the company was named EPOC. The operating system is more focused on its use in mobile phones. In 1998, there was a collaboration between the companies Ericsson, Nokia, Motorola and Psion to explore further kekonvergensian between the PDA and mobile phone named Symbian. In 2004, Psion sold its stake and the results of this cooperation produces EPOC Release 5, which became known as Symbian OS v5. The operating system of Symbian OS v5 it has begun to integrate the needs of the implementation of applications on a device like a PDA than a mobile phone.Then came the so-called smartphones, and came also the latest versions of Symbian OS to something called the Symbian v6.0 or better known as the ER6 which is the first version of the Symbian OS. Are open because the system can be installed by a variety of software application developers. In early 2005, appeared Symbian OS v9.1 with the new platform security system which is known as a capability-based security. This security system set permissions for the application to be installed on the equipment in terms of accessing the API. There is also known as Symbian OS v9.2 which do perbaharuan on Bluetooth connectivity technology with the use of Bluetooth v.2.0. While the latest, to Symbian Symbian OS v9.3 (released on July 12, 2006) has brought the wifi 802.11 and HSDPA technology as part of standard components.Operating System ArchitectureThe general architecture of Symbian OS itself can be described into four layers based on the use of APIs that are available, namely:Application support layer (Application Layer Utility)This layer consists of a variety of application-oriented support. This allows other applications (outside of the operating system) to integrate with applications that are available on the basis of the operating system. Other services include the form of data exchange and data management.

Framework services layer and the graphical interface (GUI Framework)This layer is an API framework that is available to provide support for handling user input in graphics and sound that can be used by other applications.
Communication layerThis layer serves as the focus of the operating system is implemented on mobile communications devices, Symbian OS has a set of APIs that focus on the communication layer. At the top of this layer there is support for search and text messaging. Next is the interface that provides support for communication such as Bluetooth and infrared (IrDA) and USB. The latter in this layer is the communication protocol of TCP / IP, HTTP, WAP and telephone service.Basic API layer systemThis layer is a collection of API that supports pengasksesan memory data, the date and time, as well as other basic systemClassification of Operating SystemsThis classification is based on functionality and access rights of a particular API. The purpose of defining the system in addition to distinguish any API that can be accessed by an application made by the application developer, also maintain the integration of services provided for the application developers with a common API used. This is also done to maximize interoperability between different products that use the Symbian OS. There are four categories in the classification of APIs that are available, namely:(API) General SymbianThis component is a component (API) core of Symbian OS. Any application developer can assume that these components are present in every version of the Symbian OS so it can be used on any mobile device that uses Symbian OS as the operating system. In other words, any program code that only uses the API in this category may dikompail and run without errors on any phone that uses Symbian OS. With the cooperation of the license, application developers can add the condition does not replace or modify the standard API functions are categorized in this section.(API) General Symbian replacedComponents that require customization of the General Symbian component is needed to work with the ROM of the system where it is installed. This component is a component that works on low-level of a particular hardware. To get this component party application developers require a license with the Symbian version of this component as provided by the Symbian. But basically this is a standard component parts (general) available on all versions of Symbian OS.(API) Symbian OptionalThese components are optional (not always) on all versions of Symbian OS. However, if available, then the application developer received assurances that the application can use the API in this category on the same version of Symbian OS.(API) Symbian Optional replaceableThis category is similar to the shape Symbian Optional category is a collection of APIs that are not bound by existing public APIs on Symbian OS version and can be added by the developer with a license from the Symbian.