Smartphone Messaging
Text messaging, such as email and instant messaging, is widely used on PCs connected to the Internet. It makes sense to use similar modes of communication in mobile devices. Below are the messaging features supported by smartphones.
SMS
SMS stands for Short Messaging Service. SMS allows mobile phone users to send and receive short text messages up to 160 characters. These messages are sent between phones with only a small delay and can occur even while a voice call is in progress. SMS is well suited to many types of communication exchange and is less intrusive than making a voice call. SMS is part of the GSM communication platform and is used by mobile phones all over the world. SMS is not yet widely used in the United States, but is slowly growing in popularity. SMS is a standard feature on today’s smartphones.
MMS
MMS, short for Multimedia Messaging Service, is an extension of SMS that provides the ability to send media data such as pictures, audio and video along with your text message. MMS is a natural complement to smartphones due to their audio and video capabilities. For example, a smartphone user could snap a picture of a landmark, record a quick voice comment on it and send it instantly to another mobile phone user.
MMS messages can even be sent to people who have only SMS capability by sending a text link to a browser URL containing the MMS message. You can also send and receive MMS messages between a smartphone and an email account used from a PC.
Email
Having the ability to keep up with your email while on the road is a standard feature found in smartphones. With high resolution scrollable displays and alphanumeric entry methods, it does not feel much different from email on a PC. Smartphones allow the user to set up multiple POP3 and IMAP email accounts.
Fax
Many smartphones include the ability to send and receive faxes, or can be customized to do so with fax software.
Web Browsing
Internet browsing is a standard feature for smartphones. There are many different browsers available, and they fall into two main types: WAP and HTML.
WAP
WAP, which stands for Wireless Application Protocol, was specifically designed for Internet browsing on resource-constrained devices. It includes lightweight markup languages designed to minimize the processing power and memory needed by the mobile device to render the web page. WAP also ensures that the page is usable on a small screen. Markup languages include WML and xHTML (mobile profile).
In many cases, proxy servers are used, which will automatically translate traditional HTML web sites to the WAP markup language before transferring to the mobile device. This is known as transcoding.
HTML
Although WAP was very important for earlier mobile devices, smartphones today have better memory, processing power and displays. Because of this, it is feasible to include traditional HTML browsers that directly load web sites in their native format similar to a browser on a PC. Many smartphones have HTML browsers and these usually include WAP capability – sometimes combined in one browser.
Local Device Communication FeaturesSmartphones have a variety of communication features in addition to basic access to the cellular network. These features allow a smartphone to directly link with other devices, including PCs, PDAs, wireless headsets and other smartphones, to undertake a wide variety of data transfer functions. Below are the popular device-to-device communicationmeans, along with some of their uses.
USB/Serial Cable Connection
Smartphones can be connected to a PC via either a USB or a serial cable (varies from phone to phone). This high speed link is normally used for downloading new applications to the smartphone as well as synchronizing user data, such as calendar and contact entries. A user can also access the PC’s high speed network connection directly from the smartphone for much faster network access than can be achieved through the cellular network. Many products provide a cradle into which the smartphone can be plugged, both for PC connectivity and for charging the phone’s battery.
Infrared (IR)
The smartphone provides the capability to communicate through an infrared port to a PC or other device such as a PDA. You can do all the things that can be done with the USB/Serial cable, but without plugging in any wires. IR requires a line-of-sight connection between the devices in the same way that a TV remote control does.
Bluetooth
Bluetooth is a short-range radio technology that enables devices to find and connect to each other. While technologies like GSM replace long lengths of wire, Bluetooth replaces the rat’s nest of short wires connecting various pieces of equipment. Unlike infrared, Bluetooth does not require line of sight and will even communicate through walls.
With Bluetooth technology you can connect more conveniently to PCs and PDAs to download applications and synchronize user data than you can with cable or IR. In addition to providing basic PC to smartphone linkage, Bluetooth technology makes more device-to-device communication scenarios possible. For instance, you can snap a picture on your smartphone and send it to a nearby printer for printing. Another use in a smartphone is in a wireless headset for hands-free operation.
Some smartphones allow themselves to be used as a modem with access to the cellular network. In this case, a device such as a PC connects to the smartphone via Bluetooth technology to provide the PC with Internet connectivity.
As more devices become available, expect many new possibilities for Bluetooth-enabled smartphones.
The Mobile OS
In the past, portable devices such as mobile phones did not require sophisticated operating systems. These earlier devices used simple, and usually proprietary, system software. In many cases they used no operating system at all and all software remained fixed in the device’s Read Only Memory (ROM). Now that mobile devices such as PDAs and smartphones have greater hardware power and implement sophisticated, media-rich (downloadable) applications, it’s apparent that a sophisticated operating system is needed.
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 smartphone operating system:
Resource-limited hardware Smartphones should be small, have a long battery life and cost as little as possible. To meet these requirements, smartphones, like other mobile devices, have limited memory and processing power as compared to desktop PCs and laptops. The operating system must be frugal in using hardware resources – especially memory. Not only must the OS itself use memory carefully, but the architecture should also provide support to help OS applications limit their use of memory, as well as allowing them to handle low-memory situations gracefully.
Robustness A user expects a mobile phone to be stable and will not tolerate the device locking up. This is a challenge for any full-featured operating system due to the complexity of the system software itself; however, it is especially challenging for resource-limited devices such as smartphones that also allow third-party applications – which may be of questionable quality – to be downloaded.
Not only must the OS itself be designed to avoid crashing, it must also provide support functions and policies for applications to follow, allowing the device to handle application errors and (as alluded to before) out-of-memory situations, without locking up the phone.
User interface for limited user hardware The OS should implement a user interface environment that is efficient and intuitive to use, despite the smaller screen and limited user input capabilities of a smartphone. Also, screen sizes and input capabilities vary between different models of smartphones, so the UI architecture should be flexible, so that it can be customized for the varying form factors.
Library support Smartphone operating systems should contain middleware libraries and frameworks with APIs that implement and abstract the functionality of the features of the smartphone. The purpose is to provide functional consistency and to ease software development. Examples of smartphone middleware include libraries and frameworks for email, SMS, MMS, Bluetooth, cryptography, multimedia, UI features, and GSM/GPRS – the more support for smartphone features the better.
Application development support Smartphone buyers want to know that there are many good applications available for their device, and that they can expect more and better 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 more powerful, easy to use and bug-free applications will appear for the smartphone.
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