The term mobility can be classified into two parts:
1. User mobility and
2. Device mobility
User mobility refers to as users who have access to similar communication services at different places.
Example: User can have a mobile and he can login to his mail account from any desktop to check or compose emails.
Device portability refers to the movement of a communication device with or without a user.
Example: A mobile phone system which is a mechanism presents either within the device system or within the network handover the control from one transmitter to another if the signal is weak.
In order to achieve device portability we may have to use another mechanism called wireless.
The term wireless refers to accessing a network as a communication media without the use of a wire. In such a case, communication takes place in the form of electromagnetic waves.
Depending upon whether a communication device is kept at a fixed place or is mobile and is wired or wireless, there are four categories of communication devices viz.
1. Fixed and wired
2. Fixed and wireless: The device is fixed and the communication is achieved with or without a wire.
3. Mobile and wired.
4. Mobile and wireless: The device keeps moving and the communication is achieved either with or without a wire.
Example 1: A desktop present in an office cannot be moved and hence uses fixed network such as LAN, WAN, MAN etc.
Example 2: If the desktop is placed is a building that has historical significance wiring should damage the watts, floors etc. of the building, hence we make use of wireless communication.
Example 3: A laptop can be carried anywhere and can be plugged into any existing wire network (LAN or WAN).
Example 4: A GSM can be carried anywhere and can access a number of wireless networks.
Related Topics: Broadcast Systems
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