Mobile Devices

Mobile computing devices are portable electronic tools such as cell phones, Pager and MP3 player etc.

People use these devices to communicate with others, remain productive and access a wide range of information from different sources.

1.Paging Device:

A paging device is also called pager. It is a small wireless device that is used to receive and sometimes send numeric and text messages on a small display screen.Pagers are cheep and have very low power consumption.

Different types of pagers are as follows:

• Numeric pager: It displays only numbers on the screen. It tells the user that he has received a page and provides him with the number to call.Numeric pagers do not allow the user to send a response.
• Alphanumeric pager:It can receive numeric and text messages.It does not allow the user to send messages.
• Two-way pagers:It can receive and send messages. It has a built-in keyboard to compose text messages. Advanced two-way pager also includes an address book. It can notify the user of e-mail. It also allows the user to check email and send replies.

2.Cell Phone:

Cell phones provide all of the features available on a traditional telephone.It includes auto-redial, call timers and voice-mail. Some cell phones also feature voice-activated dialing that is important for hands- free operation. It can offer Internet access, text messaging, personal information management (PIM) features, voice recording and digital image and video capture.

• Cell Phone Hardware:

Cell phone has a processor, memory and input and output devices. The processor coordinates sending data between the components inside the phone. It also runs cell phone's OS that provides a user interface to change phone settings, store information etc.Full- featured cell phones use Symbian OS or Windows Mobile operating system. The operating system is stored in ROM. Other phone data is stored in separate internal memory chips. Full- featured phones have 16 MB of memory to store contact data, ringtones, images,  and small software applications such as currency converters or world clock.The input devices of a cell phone are primarily the microphone and a keypad.Some phones use Palm Graffiti pad as well as touch- sensitive screens to input data. Many cell phones include digital cameras. Cell phone output devices include a speaker and an LCD display. Higher-end models include full-color,high-resolution plasma displays.

• Cell phone Features: 

Some cell hone features are as follows:

SMS: SMS stands for Short Message Service. It is a technology to send short text messages up to 160 characters over mobile networks.The numeric keypad is used to send SMS messages from cell phone.

MMS: MMS stands for Multimedia Message Service. It is used to send messages that include text, sound, images and video clips to other phones or e-mail addresses.
Cell phone Internet Connectivity:

• Cell phone connects at a speed of 200 to 300 Kbps.
• It is difficult to display Web Pages on cell phones without a great deal of horizontal scrolling to view content. 
• Micro browser software is optimized to display Web content on a smaller screen.
• A popular feature of cell phones with Internet access is checking e-mail.

3.Portable Media Player:

Portable media player (PMP) is a small portable device such as an i pad to play MP3 files anywhere. MP3 is a format for efficiently storing music as digital files. Digital files use special data formats such as AVI or MPEG-4 and can hold video, audio or images. Inexpensive PMPs use built- in flash memory to store files. Some of the PMPs use flash memory to add storage capacity by purchasing removable flash memory cards.Other PMPs use a hard disk drive and can store a much larger amount of music.Another factor that determines how much music a player can hold is the quality of the MP3 music files. The sampling rate is the number of times per second the music is measured and converted to a digital value. Sampling rates are measured in kilobits per second (Kbps). The higher sampling rate increases the quality but also increases the file size.

4.Pod casting:

Pod casting allows users to download and listen audio content on their MP3 players at any time.Pod casting is paving the way to enable anyone to create a radio show at home and to easily distribute it to an audience.Plugging your i pad into a data port on your computer causes synchronization. The i pad searches i Tunes for new content and automatically transfers it.