Soln) Mobile communication system defines the communication fir radio frequency.its range varies fir 30 hz (extreme low) to 100Ghz ( extreme high) level frequency because it is used to penetrate inside the submarine. There are many challenges comes in radio transmission for example-
1) Architecture and framework for future mobile radio system, the security privacy of the system.
2) Physical layer algorithm for future mobile radio system.
3) Medium access control
4) Resourc management utilization
5) Energy efficiency enhancement
6) Allocation of different cells
7) Interference with near frequency channel
Cell is wireless communications technology, the geographical region covers by transmission facility. Cell is the radio Network distributed over land are cellular cell to other area.. Each ce have it’s own base station located at it centre. And if person want to communicate it give signal to its own base station and by that two different base station connect. The cell size is determined by
1) no. Of users
2) Multiplexing and Transmission Techinique
And by the formula
N = i^2+ij+ j^2
i= move along the adjacent cell in straight line
j= turn 60 anticlockwise nd move along
Each communication divided into three types
Simplex – only one way transmission
Half duplex – you can transmit bt not able to get the information at same time
Full duplex – you will able to transmot and get the information at the same time
Each cell phone uses two frequency at a time there are 395 voice channel per carrier . Channel width is 50 Khz/ duplex. So that 600 channel total available for 4 cell reuse factor the total (600/4) the total 150 channel per cell is available
Each cell having its own base station nd own frequency so that no interference between them taking place while communication.
There are different type of cell propagation system
Pico cell for building
Micro cell for urban area
Macro cell for suburban area
Micro , macrco, pico cell depend upon diffraction, deflection scattering phenomenon from the nearby object nd it also depend on the size of antenna.
The communication delay is 1sec .
The cellular range is from 10-50km
The one cell is used for more distance because there is less interference of different frequency range signal. Low trafficking of signal. Less interference. Low losses.
Delay spread 3 sec
The cellular range is from 1 to 10km
The one cell is not enough in uran there is a combination of different cells because of large distance more loss, more trafficking of signal. More interference between the signal