Mobile and compact devices become more and more popular in our society. Each of us faces with them every day. Certainly each of us has mobile phone, hand-held computers or other hi-tech devices. All of these devices have different mobile platforms. There are such known platforms as Windows Mobile, iPhone, BlackBerry, Symbian OS, Android etc. All of them have different history and advantages and failings.

Such platforms as Windows Mobile, BlackBerry, and iPhone are «closed» enough and limited by either their own devices (BlackBerry, iPhone) or development complexity. Among other problems of above mentioned platforms there is limited API. Even Java platform for mobile devices has some failings such as great number of limitations; very different APIs; device dependent code. Symbian and Windows Mobile platforms are better from this point as far as they support wider range of devices and their APIs give more options. Common problem here is also that there are a lot of platforms. Talking about Open Source and Cross-Platform solutions we should say that they are still developing at the moment and are not widespread yet.

Purpose of Mobile framework:

The purpose of a mobile framework is to utilize a standards-based architecture that leverages existing IT infrastructure and maximizes return on investment. Such a framework is relatively easily deployed and extends enterprise content to mobile users with both good quality and user experience. The purpose of a mobile framework is somewhat different from actual mobile development tools, which are specifically used to develop mobile applications. Mobile frameworks extend existing applications (such as Customer Resource Management (CRM) to mobile workforces and their devices. Just make sure the mobile framework is truly a mobile framework.

The SDK, also known as the ‘tool chain’ includes:

Xcode: It is the integrated development environment (IDE), wherein iPhone applications are developed. It is the integral part of the iPhone application development kit and consists of a graphical debugger and a powerful source editor too. Interface builder: It helps in the designing and testing of user interfaces. The graphical editing environment of the interface builder is utilized by the iPhone application developer to design user interfaces and seamlessly integrate the applications to the 3G environment of iPhone. Instruments: The instrument retrieves data, analyzes and compares performance and displays the results graphically in real-time. It plays a pivotal role in the real-time optimization of iPhone applications.

An iPhone application developer should have a sound knowledge about using the SDK. The SDK uses the objective C language and runs only on the MAC OS X 1.5 platform (the OS of iPhone). The applications developed needs to be approved by Apple and can be distributed solely through App Store.      

iPhone website development

There are various categories catering to which, iPhone applications are developed. Many companies specialize in a particular category. For example, a company may specialize in the domain of iPhone website development. An iPhone mobile development domain includes useful web 2.0 applications designed exclusively for iPhone, like:<ul>

Search tools. Web utilities. Social networking. Ecommerce websites. Travel, sports and entertainment and so on.

Outsourcing of iPhone application development

Outsource of iPhone application development has several advantages which mainly includes:

Firstly, it is cost effective. Outsourcing of IPhone applications gets the job done in lower costs. Customized applications can be developed without much investment which was otherwise necessary for the technical manpower and training. The rigmaroles of the iPhone applications- approval by Apple, guidelines etc are taken care by the companies.

Every feature in the iPhone is just a revolution. Say display, you have got a 3.5 inch wide complete touchscreen, for imaging there is a highly effective 2 MP camera, for connectivity there are Wi-Fi and Edge and much more. There is also an advanced GPS navigation feature that helps you choose the right track while walking or driving. Video playback with solid output makes the device one of the most sought after gadgets in the market presently.

Being a 3G phone, the Apple iPhone allows you to do more as compared to a normal phone. A number of third generation mobile application development firms are now developing a variety of applications for the iPhone. iPhone web application for entertainment, business, game, weather and much more can be availed from such a firm. Because of the growing demand for iPhone apps, iPhone programming and application development have turned into a very lucrative business now.

An iPhone developer generally uses the iMac and simulator to create powerful iPhone applications. Catchy and attractive themes for iPhones, iPhone calendar and organizers are now also being developed by many an iPhone application developers globally.

The iPhone not only sets you apart from the crowd, it gives a new definition to your entire communication habits thus making you stand tall from the rest. And by installing powerful iPhone web apps, you can make your gadget look even more stunning and perform even more superior. With the developers, there are iPhone apps available for all requirements.

In essence Apple’s new Edge mobile (or the iPhone) integrates three very different applications – a widescreen iPod, a great mobile phone and a revolutionary web surfing device. A virtual keyboard and a multi touch screen complete the jaw dropping package. When the iPhone was released in July 2008, it didn’t take long for consumers to realize the potential of this device, and to make this powerful new possession of theirs even more versatile, they started approaching offshore iPhone application development companies to design customized applications for iPhone and instigated extensive iphone website development.

For companies that are into developing applications for mobile phones, the popularity of the iPhone has given their business a huge boost. One of best biggest draws of developing customized applications for iPhone is its density and popularity with the users. Moreover, iPhone’s OS platform is far more cost effective than all other platforms in the same class. Not to mention, iphone website development is not far behind, which avail these applications for wider public usage.

If you are planning to outsource iPhone application development to a company, it’s well worth the effort to look into their credentials. However, most companies that develop customized applications for iPhone are well equipped to design unique applications for your phone. The reason is simple. To develop iPhone applications, the designer should have access to a specific technology. Thankfully, all the necessary tools and software are available to the public with the iPhone’s SDK.

The SDK being an open source tool requires no licensing and can be run on any system including Windows. Most companies that develop customized applications for iPhone have a dedicated team of developers who keep coming up with sleek applications for the phone. So if you want to get more bangs for your bucks outsource iphone application development to a reputed company!

If you are not in this mobile application era, these commercials might seem a little weird. If you do a little research on the web, you will find the answers. The expected size of the mobile applications market is huge. If you think about the size of the new consumers that will come with new gadgets that will be capable of using applications, you will understand the push for mobile application market. As in many businesses, the first company to establish their name in this new growing field will most likely be the winner of this huge market.

Take a look at the case of RIM, the maker of BlackBerry smart phones, which is trying to increase its footprint in this market. Starting late gave RIM a big disadvantage. Addition to this disadvantage, some developers were not happy with some of the rules. Two of these rules warrant the most attention. (Other side of this debate supports these rules to eliminate the useless applications and keeping the app store clean.)

The first one is that you have to pay for each submission. The cost for each submission is not that much, but overall might have some effect, especially on the free app space and new app versions.

The second rule has to do with pricing. The minimum price for any app is $2.99. This rule might have an effect on the customers. Most people are happy to pay $0.99 for an app, but when the minimum price is $2.99, this limits the number of customers dramatically.

We cannot know the whole impact of these two rules but they were not the rules that people were used to up until then. Most app stores did not charge for each submission and the minimum price for the apps was a lot lower than $2.99.

With Jengun, we are one of these small application development companies. We design BlackBerry calculator applications to help people to solve their daily problems. We design calculator apps and from the feedback we get from our customers, we are pleased to know that we are helping them.

In long run will these rules have any effect, positive or negative? We will all see how the whole thing plays out. Now new companies coming into the app market, including cell phone providers, will make the app store market a lot more competitive. Usually competition is good for customers, but in this case there is a third party in the game, who is app developers. Most app developers are doing the apps as hobbies or as a second job. If the competition starts to hurt the app developers, some believe that smaller developers will start to leave the market. At the end, most of the smaller developers are not making any significant amount of the money from the app business at all.

While everybody is benefiting from a growing market and new technology, people should think about what is fueling the growth of the market- app developers. If we hurt these small developers, in the end this might hurt the number of new apps, prices and quality of future apps as well.

iPhone OS is the platform used to develop applications for iPhone and iPod touch devices. We can develop two kinds of applications for iPhone, native and web applications. Development of native iPhone applications is quite similar to building Mac OS X applications. The programmers for both purposes use the similar tools and many general frameworks. The tools and technologies required to develop native applications for iPhone OS are included with the iPhone SDK. iPhone SDK(Software Development Kit) allows developers to build genuine and native applications for iPhone and iPod, which can be tested in “iPhone simulator” and then debugged.

As iPhone provides an instant connection to the Internet, it makes the iPhone web application development for this portable device almost the same process as creating a website or a web application.  The functionalities and features make it a wonderful browsing experience for the users and therefore, applications on iPhone are also getting popular every day. iPhone interface software is also available to help with data transfer. Nevertheless, if you want to customize your web applications exclusively for iPhone users then the iPhone application development can be done easily with the help of standard web tools which produce the HTML that the iPhone needs. Modern high-end technologies such AJAX or the PHP platform are involved typically in the web applications designed for the iPhone. As these applications are not cross-browser compatible, they can freely influence the Safari-supported CSS styles. The Canvas object can relatively be a good option to popular Flash to implement the sophisticated animation techniques when involved in iPhone application development.

As the iPhone application development is growing day by day, the popular and customized application of the handset gives users the satisfaction of using a high-end and top-notch device. The software development kit takes about 3-4 months to master if you are already a Cocoa / Mac developer . Currently there are very few companies that have expertise in iPhone Development services of high quality to create your own customized iPhone applications which meet all your requirements. One among them is Sourcebits, based out of Bangalore, India and among the top runners in iPhone development field.

Think about publishing your book or eBook as an iPhone app and get paid for your work! It’s a great new way of publishing whether you’re an author and your book is already published or if you are an aspiring author looking for a publisher.

For publishers – consider making iPhone apps for your existing titles. iPhone apps allow your eBooks to be read both on the iPhone and the iPod Touch. A paid iPhone app adds another revenue stream to your publishing line, helping both your list of authors and your own bottom line. Not big enough to partner with Stanza? We can create your own eBook reader for you and incorporate it into your line of eBook iPhone applications.

For authors – iPhone apps for your eBooks can get your work published and on the paid marketplace without waiting for an established publisher to select your book. You as the author control the publication, the price, and the royalties. You get 70% of your book app’s sales price from the iTunes App Store, after Apple’s 30% cut. This means after Apple’s commission, you get ALL of the royalties.  And with the new iPhone 3.0 upgrade coming out later this year, you will even be able to offer your eBook apps on a subscription basis so you can charge more for adding content periodically!

iPhone apps for eBooks FAQ:

Q: Why should I invest in an iPhone app for my book instead of publishing an eBook for Kindle?

A:  You should do both! An author should monetize his or her book in as many ways as possible (unless you’re independently wealthy).

Q: What advantages does an iPhone app have over Kindle? Kindle publishing is free, and iPhone apps cost money!

A:  Your eBook as an iPhone app nets you 70% of the sale price vs. 35% from Kindle. Also, your eBook iPhone app can be upgraded or have added content at any time. You can even sell your publication by subscription with your iPhone app. Also, Apple has sold almost 40 million iPhone and iPod Touch units vs about 500,000 Amazon Kindles. Publishing your eBook with an iPhone app is a market you can’t ignore.

Q: Does an eBook published with an iPhone app also need a reader?

A:  Yes, your iPhone eBook application will need an eBook reader incorporated into the app. Your iPhone app developer can help you create your own eBook reader of may license their reader for your eBook application.

Q: Can’t I use the Kindle reader or Stanza reader for my own eBook iPhone application?

A:  No – Kindle and Stanza are not licensing their readers for use in individual iPhone apps. You or your publisher would need to have the publishing volume to make a special partnership to list your books with Amazon/Kindle/Stanza like the bigger publishing houses are doing.

Q: How much does it cost to turn my eBook into an iPhone app?

A:  The cost for your eBook iPhone app will depend on the number of pages in your eBook, any illustrations or pictures included in your eBook, and any added features you may need included. A basic cost for starters would be $2500.00 – but keep in mind that this is just a rough estimate and a starting point until your chosen developer can review your actual material and necessary requirements. And an app developer can offer volume disounts – the more eBook iPhone apps a developer creates for you, the lower the cost for each can be.

eBooks are the fastest growing segment in the iTunes App Store, ranking even higher than games! If you are an author looking to monetize your work then you should seriously consider creating iPhone apps for each book you already have on the market and each book you may have in the works.

With the iPhone Software Development Kit (SDK), programmers can make your ideas reality – even if you yourself don’t know the difference between a C-pointer  and a SQLite database.

More than 200 iPhone application projects have already  been posted on Elance.com. Check out these tips in this article to get  your project kick-started.

We focus on the development of applications for the Apple iPhone, and we asked Nick Dalton, iPhone SDK specialist, to give Elance buyers a few tips on how to scope and post an iPhone Application project. Here’s what he had to say:

The iPhone is an amazing device that invites creativity. If you’re an iPhone owner I’m sure you’ve said to yourself: ‘I wish I could do that on my iPhone, or I have a great idea for an iPhone application’.

With the iPhone Software Development Kit (SDK), programmers can make your ideas reality – even if you yourself don’t know the difference between a C-pointer and a SQLite database. But before you go ahead and post your application idea to the buzzing iPhone project area on www.Elance,com. here are some pointers to get your project kick-started:

Study the Masters
Apple has already spent a lot of time thinking about how to present information and build interactive applications on the iPhone. The applications that come with the iPhone are the results of this research. Study them in great detail and try to apply as many of the user interface metaphors as possible to your application.

Not only will Apple be flattered if you imitate the user interface in their applications, but they actually mandate it to a great level of detail as described in their Human Interface Guidelines.

Dream in Color Screens
Most applications for the iPhone will be very visual. Therefore it makes sense to provide your requirements as screen images or sketches. You don’t have to be a graphics artist to do this effectively. An iPhone programmer is looking for the following information:

- The type of layout each screen should have

- The buttons on the screens

- The actions associated with each button

The exact shape and format of your screen sketches is secondary. As long as they are readable, it’s a great way to communicate your application design to a programmer.

Be Realistic About Your Budget
Look at other iPhone projects posted on Elance to get a sense for the bid amounts on these projects. Read the descriptions of these projects to see if they seem to be larger or smaller projects than what you have in mind. If you set your budget to under $500 for something that is realistically going to take a programmer two months to implement, you are not likely to attract many bidders.

From a programming perspective, some things are easy to do on the iPhone, while other seemingly simple things are very time consuming. For example the beautiful cover-flow animation used in the music application on the iPhone should be simple to use in other applications. Unfortunately you can’t. If you want this animation within your application it will have to be written from scratch, probably costing a one month of work.

If you talk to an approved iPhone developer early in your application design process you can learn how to get most out of your budget by avoiding the things that are really difficult to do on the iPhone.

Don’t Be Too Original
iPhone users already know how to do certain tasks on their phones by convention. For example, if you tap an item in a list that has a > icon next to it, you expect to be taken to another screen with more information about that item. If your application needs similar functionality, don’t be creative and come up with a new way to solve the same problem. Use the conventions already established by Apple.

New conventions are difficult to establish especially with the touch interface because there is no way to discover how your application works on the iPhone. Unlike a website where you can hover with the mouse pointer over areas that look like you can interact with them and a tool tip or the status bar will reveal some clues to you.

Know Your Limitations
The current version of the iPhone SDK, which is used to write applications for the iPhone, has many restrictions and limitations. Some of them are common sense, e.g. you can’t send text messages from an application. Imagine an application that sends out thousands of text messages without your knowledge, who is going to pay the phone bill for that?

Other restrictions are maddening: applications cannot access the log of phone calls, or interact in any way with the calendar or the music stored on the iPhone.

To Apple’s credit, the iPhone SDK is an amazing piece of software especially given that it was publicly released as a Beta just three months ago. Some of the shortcomings listed above will likely be addressed in future releases of the SDK.

As a buyer with an idea for an iPhone application, you should educate yourself about these limitations before you spend too much time designing an application that is impossible to implement. Talk to a developer or company that specializes in iPhone development (and there are many available on Elance) and they can help you get on the right track from the start.

About
Nick Dalton (username: 360mind) is an experienced iPhone SDK specialist and Elance.com service provider. He has 15+ years of background in programming, and currently focuses his business, 360mind, 100% on the development of iPhone applications. For more information on Nick, check out his book, 101 iPhone Tips and Tricks.

All of these devices have different mobile platforms. There are such known platforms as Windows MobileM, iPhone, BlackBerry, Symbian OS, Android, Maemo, OpenMoko etc. All of them have different history and advantages and failings.

Introduction

Such platforms as Windows Mobile, BlackBerry, iPhone are «closed» enough and limited by either their own devices (BlackBerry, iPhone) or development complexity. Among other problems of above mentioned platforms there is limited API. Even Java platform for mobile devices has some failings such as great number of limitations; very different APIs; device dependent code. Symbian and Windows Mobile platforms are better from this point as far as they support wider range of devices and their APIs give more options.

Common problem here is also that there are a lot of platforms. Talking about OpenSource and Cross-Platform solutions we should say that they are still developing at the moment and are not widespread yet.

In this article we’ll pay our attention to the Windows Mobile platform.

Microsoft Company released its first platform for inbuilt devices at the end of the 90th. In 2002 Windows CE.NET platform appeared. And at that time Pocket PC based on Windows CE 3.0 platform and higher were released. Further development of wireless communication technologies managed to combine telephone and personal computer. Thus Pocket PC 2002 Phone Edition appeared which supported the standards of GSM, GPRS, Bluetooth and wireless HS network access. In the same time another device concept was developing that was much similar to the above mentioned but was closer to the telephone then to personal computer. This device was named SmartPhone 2002. Fundamental difference between Smartphone and Pocket PC is that Pocket PC has touch screen while Smartphone has only control buttons. They also had different application scopes and supported different standards and technologies.

Windows Mobile platform more belongs to smartphones, communicators and small personal devices. Windows CE and Windows Embedded platforms are commonly used in different industrial equipment.

Now we have Windows Mobile 5 and Windows Mobile 6 generations and Windows Mobile 7 will be released soon. Modern devices based on Windows Mobile Pocket PC; have 500-600 MHz processors and 64-128 MB RAM that is not little for such devices.

1. Development Tools

There are a few models of development of applications for Windows Mobile:

Win32 API MFC .NET Compact Framework.

Microsoft Co gives developers all necessary tools for development of applications for PDA, Pocket PC; and Smartphone.

Here are some advices about different code type choosing.

Use Native Code for achieving the burst performance, direct work with hardware, and also for minimization of system resource requirements. Use Managed Code for development of GUI-oriented applications which main requirements are development and market deployment terms. Managed Code is also good for the easy work with web-services. Use Server-Side Code for work with different devices through a single code base, and also if wide stable communication channel with a device is present.

Below are the reviews of present development tools for PDAs, Pocket PCs and Smartphones.

eMbedded Visual C++ 4.0

Microsoft eMbedded Visual C++ 4.0 development environment is meant to create applications for devices with Windows CE .NET 4.2 operating system and also (with package of updates SP3) for PDA and Smartphones on the Windows Mobile 2003 Second Edition platform. The development environment eMbedded Visual C++ 4.0 is good for creation of native code for mobile and inbuilt devices with Windows CE .NET 4.2 OS. It allows developer to perform Just-In-Time Debugging for diagnostics of unhandled exceptions, Attach-to the process for the extended debugging of processes, and also interaction with an emulator.

Visual Studio .NET and SDP functions

SDP (Smart Device Programming) functions of the integrated environment of development Visual Studio .NET 2003 (2005, 2008) allow to create applications, that uses possibilities of Microsoft .NET Compact Framework platform. Thus a developer can create the distributed mobile data-processing systems, workings both in scenarios with connection and without permanent connection. Vast class library of .NET Compact Framework platform makes application development much quicker than with traditional development tools.

Visual Studio .NET lets create applications for the Pocket PC 2002 devices and (with proper SDKs) Pocket PC 2003, 2005 and Smartphone 2003, 2005, applying the same tools as those used for the development of applications for desktop PCs. Library .NET Compact Framework is installed together with Visual Studio .NET. This library is specially developed for devices with the limited resources. Developers can also use new languages C# and Visual Basic .NET for applications for mobile and inbuilt devices. They are good in workings with web-services and ADO.NET technologies.

Control elements of ASP .NET Mobile Controls extend SDP functions and .NET Compact Framework platform. They give opportunities to use possibilities of .NET Compact Framework and Visual Studio .NET for development of mobile web-applications due to the data delivery to various mobile devices by means of ASP.NET technology. This approach allows to create single mobile web-application in the Visual Studio .NET environment, that will automatically perform data rendering for displaying on various devices: mobile phones, smartphones, PDA, Pocket PC. The integrated development environment makes it possible to create mobile web-applications simply by dragging control elements on forms.

ASP.NET System sets no components on a client device. For adaptation of formatting under concrete browsers server logic is used. It generates information in the formats of Wireless Markup Language (WML), HTML, and Compact HTML (cHTML).

Microsoft SQL Server

Microsoft SQL Server Compact Edition (SQL Server CE) is a compact DBMS for rapid development of applications that extend possibilities of work with enterprise data due to the mobile devices using. SQL Server CE is a tool facilitating development of mobile applications due to support of SQL syntax and usage of application and API interface model that is compatible with SQL Server.

SQL Server CE provides the basic set of relational database functions, in particular optimized query handler; support of transactions and heterogeneous types of data – with unpretentious requirements to the system resources. Remote access to the data and replication by confluence provide reliable delivery of information from the SQL Server bases, possibility of autonomous work with by information and subsequent synchronization with the server. SQL Server CE is good for the systems with mobile devices and wireless networks.

SQL Server CE DBMS is developed for integration with .NET Compact Framework by means of Visual Studio .NET. It simplifies development of applications for work with databases on mobile and built devices. New data supplier of SQL Server CE for code management in the Common Language Runtime environment helps to develop distensible applications with possibilities of autonomous work with information in scenarios without permanent connection.

Microsoft .NET SqlClient gives API for work of both .NET Framework and .NET Compact Framework applications. For the common Windows systems SqlClient Microsoft with SQL Server are used, and SqlServerCe for Microsoft SQL Server Compact Edition databases for Compact Framework.

Name space of SqlClient is in both versions. So we can interact:

Using .NET Compact Framework SqlClient to have an access to SQL Server from device on Desktop. Using .NET Compact Framework SqlServerCe to have an access to SQL Server Compact Edition directly on a device.

Work with databases on a device is similar to the work on Desktop. To access to SQLServer on Desktop system SQL uses TCP/IP connection thus in this case it is possible not to have SQL Server Compact Edition installed on a device.

All of the mentioned models are implemented on the desktop systems. So the experience of their application can be carried for development of the programs for Windows Mobile. Using Win32 API we rapidly get compact code, and also can use it for development of drivers and system component.  Using MFC we have extensions of API functions, and also designer for development of interface. And using Compact Framework we have at our disposal well developed interface, automatic garbage collection, support of XML and other options. Also there is even more truncated version — Micro Framework, where there are less SDK functions.

After SDK for MS Visual Studio installation new configurations of assembling appear as well as new functions for assembling under these platforms. Suit also contains Emularor for software development and testing without physical connection between device and computer.

As far as many devices that are based on Windows Mobile have ARM processor it is also possible to compile units using other compilers: AVR32, ARM (RealView), GNUARM, IAR Systems.

2. Building Windows Mobile Applications for Windows Mobile devices using MS Visual Studio .NET

Visual Studio development environment together with Compact Framework enable to develop applications using a vast graphic interface, databases, archiving and encrypting tools,  USB, Serial, Bluetooth, and also wireless network connections and telephony. All of these is provided by SDK as well as libraries and heading files from Platform Builder.

2.1 User Interface

Due to the presence of good designer in VS and SDK we can easily develop GUI for mobile applications just the same as for Desktop applications. The only difference is in sets of  graphic components for Desktop systems and for Windows Mobile. There is also difference between components of Smartphone and Pocket PC versions caused by that Pocket PC has a touch screen and SmartPhone has not. Therefore development of interface for SmartPhone is more complex. One should take it into account when developing software for both platforms.

Here we should also mention that software built for Pocket PC won’t start on the SmartPhone platform while the opposite situation is possible – till the moment when some special Smartphone function is called.

It is naturally that many graphic components as well as majority of functions from full-size Framework were taken away from Windows Mobile SDK to reduce the size of the SDK on the device side. Only the most needful elements were left. But the productivity and volumes of memory are increasing so the number of function included in SDK becomes greater. So the difference between Compact Framework 1.0 and 2.0 is enormous. Version 1.0 was very limited.

In general the development of GUI with ?ompact Framework on ?# is similar to the development of the common Win32 application on C#.

It is also possible to develop a graphic interface using assembling of the 3D rendering-engines. They are such as GAPI (Game API), OPENGL ES (Embedded System), OPENVG (Vector Graphics), and other projects. Certainly it is rather labor intensive process as far as it is very important to write an optimal code because of the relatively low  productivity of mobile devices.

2.2 Communications

To date mobile devices have a wide range of communicational options. They have an access to the wireless high-speed network using 802.11 WiFi Connection standard. They also use IrDa, Bluetooth, and USB host/client functionality. While the usage of Irda is gradually getting less protocols and standards of Bluetooth, WiFi, Edge, GSM, and also USB are used quit often.

Microsoft Company provides such APIs:

ActiveSync API provides functionality for work with services of synchronization, file filters, etc. Bluetooth API provides functionality for wireless access to mobile and peripheral devices. Connection Manager API serves for the automation of connection process, network connection management. Devices are using Connection Manager to establish connection and also to inform about the supposed connection (for example Internet). Object Exchange (OBEX) API provides functionality for work with effective, compact binary protocol just suitable for devices with the limited possibilities. Remote API (RAPI) provides functions for management and remote call of methods on the device side. Such functions are available: access to the register, files, databases and different configurations of device from the Desktop-system. The most important option is Remote Procedure Call when we simply call the method «CeRapiInvoke()» on the Desktop side, transmit the name of DLL on the device side and the name of function in this DLL and then just call this method. Pocket Outlook Object Model API provides functions for work with the objects of Pocket Outlook. It provides interfaces for synchronization and access to the objects: Task, Calendar, Contacts. Telephony API (TAPI) includes: Assisted API Extended API Phone API SIM Manager API Short Messages Service (SMS) API Telephony Service Provider (TSP) API Wireless Application Protocol (WAP)  API.

Also mobile devices have possibility to work with Serial (USB) ports. There are a few COM-ports in many devices. Usually the first 3-5 of them are reserved for IrDa, Bluetooth, SerialPort and others. Other ports are available to for user. Some devices have USB-Host functionality in other words they are USB On-The-Go (OTG) devices which can serve both as USB Client and USB Host. For this purpose device should have necessary Hardware and Software (Device Driver).

Device Driver is a driver which is an intermediate layer between the driver of HOST and  level of applications. Such driver provides «Stream Interface Driver» and must contain such functions as:

XXX_Init XXX_Open XXX_Close XXX_Write XXX_Read XXX_IOControl

Here “XXX” is replaced with «prefix» (for example «COM», «DSK»).

This prefix registers in the registry when a driver registers in the system. More detailed information about Device Driver Interface can be obtained from MSDN.

Also a developer can use such APIs not concerning communicational ones:

Device Configuration API File and Application Management API Game API Home Screen API HTML Control API MIDI API Shell API Speech Recognizer API Vibrate API Voice Recorder Control API. 2.3 P/Invoke and Native Interop

As far as Compact Framework contains basic functions and methods from complete

Framework we have such functionality as:

XML Serialization Cryptography Security Reflection Interop Services et al.

Certainly Platform Invoke calls are accessible. For this purpose – as well as in complete Framework – we use functions and attributes from namespace System.Runtime.InteropServices and DllImport attribute for description of functions which will be called from non-managed code.

However the functionality of these methods is limited. So Marshal class has PtrToStructure, GetComInterfaceForObject, Copy() and Read() functions but, for example, there is no such function as GetDelegateForFunctionPointer() in it. So it is impossible to make Marshaling just with Delegate. The GetFunctionPointerForDelegate function is available only. If we want to transmit a pointer to the function from Managed code we should get its FunctionPointer and only after that transmit it to the unmanaged code for subsequent call of it from there. Also we can not transmit some objects because Compact Framework can not count SizeOf() for some objects. Therefore frequently we have to transmit  data of Blitable types only and arrays of these types (Int, byte, char, but not bool),  and transmit and receive  classes and structures by means of IntPtr. Certainly it is explained by aspiration to increase the performance. It is therefore recommended to use primary types for Marshaling and «GCHandle» class for storing an object in the process memory and to make this memory «visible» for unmanaged code

Certainly the performance of P/Invoke calls from C# application in C++ DLL is almost twice less than the performance of method calls between C++ DLLs. However the performance of devices grows and it becomes possible to use such calls.

2.4 Debugging

MS Visual Studio enables to make debugging of applications under

Windows Mobile just the same as for Desktop applications. We have Emulator, Device Emulator Manager and other to functionality such as Breakpoints, Threads, Watches panel etc.

However to make Debug using Native and Managed code simultaneously is impossible. Therefore it is possible to start either C++ projects or Managed ones. It’s also so for «Attach to process». There is a possibility of attaching to the processes on the device side (or emulator side). ActiveSync is required to provide communication between a device and the system, it is installed with SDK. An emulator also can be connected to the computer by means of ActiveSync. We obtain almost complete emulation of Windows Mobile devices. Here are both SmartPhone and Pocket PC (or Pocket PC Phone Edition) emulators. However only one Windows Mobile device can be connected to the computer at one time moment. Therefore Debug on two devices simultaneously which for example interact in some way is rather difficult. Certainly we talk only about Debug of applications developed by us but not about applications and services of the system. For such debugging we need the complete built of the system created by means of Platform Builder (in the last versions of Platform Builder it’s included in Visual Studio). We can also create our own SDK for Visual Studio and Windows CE platform.

An emulator also enables to emulate connection with the GSM network and GPS support. It makes possible to test and develop large spectrum of applications without having a physical device in hands.

Talking about Debug with IDA we should mention that version 5.1 already has the possibility to perform Debug by means of this interactive disassembler with the use of their plugin which is installed on a device.

With SDK appearance such option as «Deploy» appears in Visual Studio environment. Now there is «Deploy» item in project context menu additionally to “Build”, “Clean”, “Debug”. After you choose this item DLL or EXE file built by current configuration is transmitted to the device. Also new column appears in Configuration Manager where not only «Build» in some configuration option is available but also «Deploy». Deployment of .NET projects transmits not only the unit but also those builds that are depended on it (Dependencies).

3. Deployment and installation

Development of applications for Windows Mobile supposes also their assembling and creation of installation package. For this purpose there is such concept as ?abinet (.cab) file in Windows Mobile. It is a common archive but it is a installation package also (a sort of MSI package). It is assembled by means of Cab Wizard (cabwiz.exe) from MS VisualStudio (or from a command line). This utility creates processor dependent «.cab» file. WinCEApplicationManager transmits and starts CAB on a device, so user can install the application using instructions appearing on device screen. It is also possible to create the project of MSI Installation which includes CAB file by means of Visual Studio. This built package will be started on user computer and then transmit ?AB installation on a device to continue installation process.

There is special Uninstall Manager on the device side. One should attach configuration INI-file to CAB file. This INI file includes settings to manage installation process such as path, shortcut name to create, minimal OS version to install the application and others written in special syntax. It is also possible to include your own DLL into CAB-file to widen installation options. This DLL contains such functions as «Installer_AfterInstall», «Installer_BeforeInstall», «Installer_AfterUnInstall», «Installer_BeforeUnInstall», code in these functions will be executed on the device side in the certain moments of installation or uninstallation process.

When developing CAB installation it is possible to attach files, different resources, built units, add information to the registry. They are designated as «Project Output. That’s why there is no need to reset anything after CAB-file creation: it will collect all included projects and files and assemble in an archive.

4. Security Model for Windows Mobile 5 and Windows Mobile 6

Devices based on Windows Mobile receive, send and analyze potentially important information which should be protected from unsafe applications. To protect device the starting of unknown applications is disabled, the access to some API is restricted and some registry parts changing is forbidden. Units can be marked as Trusted and Untrusted and system uses this information to prevent starting of unauthorized applications and limit their access to the system. Also the access to the system by means of RAPI (Remote API) through ActiveSync can be restricted. Security Certificates Security Rights are used for the executable units (EXE, DLL) and for CAB-files.

Protection Against Threats and Risks

The followings options help to protect devices:

Strict password protection. PIN code protection. Devices corrupt deleted information to prevent access to it (WM 6). Devices corrupt deleted information on memory cards to prevent access to it (WM 6). Storages encryption and Advanced Encryption Standard for SSL (WM 6). Own certificates usage. Detecting a device via Bluetooth can be protected (WM 6 Smartphone). 2 layer system of application starting (One-tier and Two-tier access). No support of macros, therefore viruses can make much harm.

The start of applications is based on Permissions. Windows Mobile devices use such models:

Privileged Normal Blocked

Privileged applications have the widest access. They can access any API, write in the protected areas of registry and have the complete access to the system.

Most applications have Normal model. They do not have access to the trusted API and do not have the complete control of the system.

Application can not be started at all if it has “Blocked” status. It means that it’s not signed with the proper certificate or user forbade the start by the proper warning of the system.

Analogical situation is with Cab-files. The executable units with Normal status can start Privileged DLL but then they will work as Normal. However Privileged executable units can not start the units having Normal status.

Written by Eugene Kordin, Apriorit specialist.

Learn more about development process of Apriorit here.