Que. $1$: Statement: A given geographical region has population of $75$ crores and area of $100,00,000$ square kilometers. The geographical region has various categories of region like metro city category, other city category, town category and village category. In the given geographical region these categories are in number as $3$ metro cities, $10$ other cities, $100$ towns and $500$ villages. The area covered by metro cities category, other cities category, town category and village category are given in percentage wise in table number $-1$ of the total geographical area. The Signal to Interference Ratio $($SIR$)$ should not fall below $18$ dB $($strictly$)$ for better voice clarity. The region has variable path loss exponents as given below in the table number $-1.$ In this geographical system the operator wants to start the cellular mobile telephony services. Table Number: $-2$

Design the system for all regions for following parameters:$-$

Cell Specifications: Cell radius, cell area, cluster area, cluster size $($depending upon the SIR value

of $18$ dB $)$ for all regions, Number of Clusters in each category of region.

$(10$Marks$)$

Area Specifications: Area of each region in square kilometers. Also calculate the area of every metro

city, every other city, every town and every village of the given geographical area.

$(05$Marks$)$

Band Specifications: Band al location, channel width, number of channels available in this band.

Specify the band structure used here with channel separation between two same numbers of channels

for forward and reverse link.

$(05$Marks$)$

System Capacity specifications: System capacity for every region, total system capacity for every

category of region, and total system capacity for the entire geographical region. Also calculate the

percentage of the population with respect to the total population which is willing to access the mobile

telephony services.

$(05$Marks$)$

Hint:

Here you assume one region means one metro city or one other city or one town or one village. In this

regard, please go through the first paragraph andlor all tables of the problem statement for getting number

of metro cities, other cities, etc. Follow standard formulas in your design steps. Total customers for villages,

towns and other cities are given in table number $-2.$ You need to do the calculations for per region basis

and then for entire geographical region.

Notations used:

$1MHz=1{}^{6}Hz$;FFMA$=$ Frequency Division Multiple Access; $1kHz={10}^{3}Hz$;

$1$ crores $=1,00,00,000$;$dB=$ Decibel ;$KM=$ Kilo Meters

Please Note: As per Erlang $-$ B chart for $125$ channels and $2\%$ blocking we have total capacity as: $-112\mathrm{.}3$

Erlang

$($CO$1,$ CO$2)$

Table Number: $-1$

$\backslash$table$[[$Category of Region,Path Loss Exponents,$\backslash$table$[[$Percentage Area Covered $($of$],[$Total Geographical Area$)]]],[$City $($Metro $-1),3\mathrm{.}25,4\%],[$City $($Metro $-2),3\mathrm{.}50,3\mathrm{.}5\%],[$City $($Metro $-3),3\mathrm{.}76,2\mathrm{.}5\%],[$Other Cities $(1$ to $10),2\mathrm{.}7,\backslash$table$[[20\%($Equal area for all other cities$],[$in this category$)]]],[$Town $(1$ to $100),3\mathrm{.}8,\backslash$table$[[30\%($Equal area for all towns in$],[$this category$)]]],[$Village $(1$ to $500),4\mathrm{.}0,\backslash$table$[[40\%($Equal area for all village in$],[$this category$)]]]]$

The band allotted to the operator is in the range of $890$ MHz to $960$ MHz including $20$ MHz guard band for separation of forward and reverse link for providing cellular mobile telephony in the specified geographical region. The channels having width of $200$ kHz simplex is used for one way traffic but in cellular telephony a duplex communication is expected. The area of each category of region is as given in the table number $-1.$ Assume in every region with FDD$,$ FDMA, and TDMA for multiplexing of various users is followed. The system works on an on demand type of channel assignment strategy with one channel means eight user for a typical call duration as specified in the table number $-2.$ The system is an on $-$ demand system and has probability of blocking as $2\%$ using Erlang $-$ B mechanism.