Learn about Mobile Computing

<span style="font-weight:bold;"> Mobile Computing. </span>
 
<span style="font-weight:bold;">Q 1. Define cellular infrastructure?</span>

    * The cellular system have a large zone with a number of smaller flexagonal cell with a single Base station covering a fraction of the area, the wireless device called be a wireless telephone , PDA (personal digital assistance), laptop etc, these are called Mobile station(MS). In a cellular structure, a MS need to communication with the Base station (BS) of the cell where the MS is currently located. BS act as a gateway to the rest of the world several BS are connected by BSC (Base station controller), which is connected to a MSC (Mobile station controller) & several MSC is connected to a PSTN (Public switched telephone network). A BS consists of BTS (Base Transiver signal) & BSC, both tower & antenna are a part of BTS while all electronics are contained in BSC.

<span style="font-weight:bold;">Q2. Define Cell in Mobile Computing?
</span>
    * The term cell basically represent the area that can be covered by a transmitting station usually called BS, PICO, MAC, MACRO, GLOBAL indicates the size of the area that can be covered. The cell is approx by the Hexagonal. The entire users in the cell are served by BS. If the coverage area is to increase then additional BS are placed to take care of the added area.

<span style="font-weight:bold;">Q3. Explain the generation in mobile computing?</span>

         1. First Generation: - In the first generation we transfer the data in analog Form i.e. Voice.

            Example: - AMPS (Advance mobile page service).

         2. Second Generation: - In this generation we are able to transfer voice + Data i.e. GSM. Firstly called Group Special mobile and Later- Global System for Mobile communication.
         3. Third Generation: - Third generation introduce us CDMA phone.

<span style="font-weight:bold;">Q4. Define Database in Mobile computing?</span>

    * Basically there are two types of registers who stored the data of user of mobile in Database which is stored in MSC (Mobile switching center).
    * The registers are (Home location register) & VLR (Visitor location register).

 

<span style="font-weight:bold;">Q5. Define Home location register (HLR) and Visitor location register (VLR)?</span>

    * The Home location register and Visitor location register are two set of database that support mobility and enable the use of same telephone number worldwide. Home location register is located at mobile switching center, where the MS is registered & where the initial Home location for billing access information is maintained. Visitor location register basically contain information about all visiting MS in that particular mobile switching center area.

<span style="font-weight:bold;">Q6. Define channel in cellular scheme?</span>

    * In any cellular scheme/screen Four simplex channel are needed to exchange synchronization and data between BS and MS, the control link are use to exchange control message.
    * These channel are:-
               1. Forward control channel.
               2. Reverse control channel.
               3. Forward traffic channel.
               4. Reverse traffic channel.

<span style="font-weight:bold;">Q7. Define Control Link?</span>

    * The control link are use to exchange control message (such as authentication, subscriber information) between BS and MS, while information channel or traffic channel are use to transfer actual data between these two. The channel from BS to MS forward channel (downlink) & the term reverse channel (uplink) is use for communication from MS to BS.

Prepared by faculty of DIMS
Keyword: - Cellular infrastructure, Control Link, cellular infrastructure, Home location register, Visitor location register.