Wiley.Developing.Software.for.Symbian.OS.2nd.Edition.Dec.2007 (779887), страница 5
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For example, Blister Entertainment has a fishing game called Swordfish where you find schools offish based on your phone’s real location (launched in North Americaon Sprint Nextel, Bell Mobility, and Boost Mobile). Once you findthem, you can catch them, arcade style. There are a few other LBSgames around, and could be many more to come.THE MOBILE OS11LBS is at a very early stage for smartphones at the time of this writing,but its future looks promising. Reference http://www.lbszone.com formore details on LBS.1.3.6 Mobile TVAs smartphones get more powerful, have better displays and faster connections, mobile TV video is becoming a reality for these devices. MobileTV content can consist of live television shows, news and sports, as wellas movies on demand and music videos.Currently, most mobile TV services use the existing cellular networkfor transferring video data using both 2G and 3G transport protocols.
3Gis, of course, the better transport since a good TV picture requires a lot ofbandwidth.However, to realize its full benefits, mobile TV needs a dedicatedvideo communication protocol, and the most promising protocol for thisis DVB-H. DVB-H is an adaptation of the standard digital TV DVB-Tprotocol to make it viable for handheld devices. Mobile TV services on asmartphone would use a combination of DVB-H and the 2G/3G network.Although not common yet, some carriers have launched DVB-H mobileTV services (Vodafone in Italy is an example).
The Nokia N92 and NokiaN77 are examples of smartphones that support DVB-H.1.4 The Mobile OSIn the past, portable devices such as cell phones did not require sophisticated operating systems. These earlier devices used simple, and usuallyproprietary, system software. In many cases they used no operating system at all, and all software remained fixed in the device’s Read OnlyMemory (ROM). Now that mobile devices such as PDAs and smartphoneshave greater hardware power and implement sophisticated, media-rich(downloadable) applications, it’s apparent that a sophisticated operatingsystem is needed.1.4.1 What Makes a Good Smartphone OS?Smartphone devices have certain characteristics that are different from traditional desktop computers, and that must be addressed by a smartphoneoperating system.Run on resource-limited hardwareSmartphones should be small, have long battery life, and cost as little aspossible.
To meet these requirements, smartphones, like other mobiledevices, have limited memory and processing power compared with12SMARTPHONES AND SYMBIAN OSdesktop PCs and laptops. The operating system must be frugal in usinghardware resources – especially memory. Not only must the OS itself notuse much memory, but the architecture should be such that it provideslimits and support to help OS applications also limit their use of memory,as well as allowing them to handle low-memory situations gracefully.RobustnessA user expects a mobile phone to be stable and will not tolerate thedevice locking up.
This is a challenge for any full-featured operatingsystem due to the complexity of the system software itself; however, it isespecially challenging for resource-limited devices like smartphones,which also allow third-party applications – that may be of questionablequality – to be downloaded.Not only must the OS itself be designed to avoid crashing onits own, the OS must also provide support functions and policies forapplications to follow, allowing the device to handle application errorsand (as alluded to before) out-of-memory situations without lockingup the phone.User interface for limited user hardwareThe OS should implement a user interface environment that is efficientand intuitive to use, despite the smaller screen and limited user inputcapabilities of a smartphone. Also, screen sizes and input capabilitiesvary between different models of smartphones, so the UI architectureshould also be flexible, so that it can be customized for the varyingform factors.Library support for smartphone featuresSmartphone operating systems should contain middleware librariesand frameworks with APIs that implement and abstract the functionality of the features of the smartphone.
The purpose is to providefunctional consistency and to ease software development. Examples ofsmartphone middleware include libraries and frameworks for email,SMS, MMS, Bluetooth technology, cryptography, multimedia, UI,GSM/GPRS – the more smartphone feature support the better.Support for application developmentSmartphone buyers want to know that there are many good applications available for their device, and that they can expect more andbetter software for it in the future.
In order for this to be a reality,the OS must have good software development tools, support, training,and documentation. The more productive the developers, the morepowerful, easy to use, and bug-free applications will appear for thesmartphone.1.5 Symbian OS – A Little HistoryThe creation of Symbian OS can be traced back to a talented team ofsoftware developers at a company called Psion, an early pioneer in theSYMBIAN OS – A LITTLE HISTORY13handheld computer market.
After successive generations of software forPsion’s handheld devices, the team created an object-oriented operatingsystem called EPOC, which was designed specifically for the uniquerequirements of mobile computing devices.Psion realized that there was a need for a mobile OS that could belicensed to other manufacturers for use in their mobile products, andthat their EPOC operating system was well suited for this.
At the time,the mobile phone industry was looking for a general operating systemsuitable for mobile phones and was interested in using EPOC. In June of1998, Symbian was formed as a joint venture owned by the major cellphone manufacturers of the day (Nokia, Ericsson, and Motorola) as wellas Psion, with the primary goal of licensing the EPOC operating systemand improving it.Fast forward to today, and we find that Symbian’s operating system – now known as Symbian OS – is a major player in the smartphonemarketplace, residing in the majority of today’s smartphone devices.Symbian is jointly owned by Ericsson (15.6%), Nokia (47.9%), Panasonic(10.5%), Samsung (4.5%), Siemens (8.4%), and Sony Ericsson (13.1%),which, together, represent a major portion of the cell phone industry.1.5.1 Symbian OS OverviewSymbian OS was designed from the ground up for mobile communicationsdevices.
While some competing operating systems (such as Microsoft’sWindows Mobile for Smartphones OS) evolved from operating systemswritten for larger, more resource-laden systems, Symbian OS approachedit from the other direction. Symbian’s earlier versions (when known asEPOC) would run on devices with as little as 2 MB of memory.Symbian OS is a multitasking operating system with features thatinclude a file system, a graphical user interface framework, multimediasupport, a TCP/IP stack, and libraries for all the communication featuresfound on smartphones.Symbian OS has software development kits available for third-partyapplication development.
Furthermore, the hardware layers of the operating system are abstracted, so that phone manufacturers can port the OSto the specific requirements of their phone.1.5.2 One OS, Various FlavorsIt is challenging to create an operating system that provides common corecapabilities and a consistent programming environment across all smartphones – yet at the same time allows for manufacturers to differentiatetheir products. Smartphones come in many different shapes and sizes,with varying screen sizes and user input capabilities; the user interfacesoftware needs to vary to fit these differences.14SMARTPHONES AND SYMBIAN OSSymbian OS has a flexible architecture that allows for different userinterfaces to exist on top of the core operating system functionality.Of course, it is not wise to be too flexible for two reasons: (1) havingtoo many different user interfaces inhibits code reuse among differentdevices and (2) too much work is required by the original equipmentmanufacturer (OEM) to create a GUI user interface from scratch for theirsmartphone.So, to give the phone makers a starting point, Symbian created a fewreference platforms, each packaging the Symbian OS core functionalityalong with a user interface that matched one of the basic smartphoneform factors (screen size and input capability).
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