We assume that ABC Corporation has two business offices. These offices are in the cities of Orlando and Miami. These cities are located 220 miles apart. We assume that there are 3 employees in Orlando and 6 employees in Miami. Further, we assume that each employee calls the other site 4 times a day and talks for an average of 5 minutes. Further, each employee calls others in the same office 10 times a day for an average of 3 minutes. We will assume that 20% of the calls happen in the peak hours of the day. A blocking rate of 5% is acceptable for calls between the 2 sites.
a. What is the cost of PSTN (straightforward) solution?
b. Perform the Erlang calculation
c. Calculate the Blocking
d. Number of links required between these sites with respect to 5% blocking rate.
e. Number of Leased lines and PSTN lines
f. Total cost of your design
The cost of communications services and components
Item Cost
Line to PSTN $25/Month
Local Call $0.05/Minute
Long Distance Call $0.40/Minute
PBX $2000 Purchase Price
Leased Line $275/Month

Respuesta :

Answer:

The following are the answer to the given points:

Explanation:

In point (a):

Calculating the long-distance call cost:

[tex]= 4 \times 5 \times 0.40 \\= 20 \times 0.40\\= 8[/tex]

Calculating the local call cost:

[tex]= 10 \times 3 \times 0.05\\ = 30 \times 0.05\\= 1.5[/tex]

Calculating the overall cost of PSTN:

[tex]= 25 + (4 \times 5 \times 0.40) + (10 \times 3 \times 0.05) + 2000 + 275 \\= 25 + 8 + 1.5 + 2000 + 275 \\= 2309.5[/tex]

In point (b):

Calculating the call rate per second and the average arrival rate:

[tex]\to (\lambda) = 0.2[/tex]

The call average length:

[tex]\to (T_s) = - 8 \\\\ = (8 \times 60) \ seconds \\\\ = 480 \ seconds[/tex]  

The complete agent number:

[tex]\to (m) = 9[/tex]

The strength of traffic:

[tex]\to u = \lambda \times T_s \\\\ = (0.2 \times 480) \\\\ = 96[/tex]    

The occupancy of the agent:

[tex]\to p = \frac{u}{m} \\\\[/tex]

      [tex]= \frac{96}{9} \\ \\= 10.66[/tex]  

Calculation of obtained:

[tex]= \frac{(\frac{um}{m!})}{(\frac{um}{m!})} + (1-p) \sum {m-1} _{k=0} \ \frac{uk}{k!}[/tex]

We get = 0.329 to substitute values.  

In point (c):

The rate of blocking = [tex]5 \%[/tex]

average call time [tex](T_s) = 480 \ seconds[/tex]

                                    [tex]= 0.05 \times 480 \ seconds \\ = 24 \ second[/tex]

In point (d):

Calculating the number of link, which is required:  

[tex]= \frac{275}{5} \\\\ =55[/tex]

In point (e):

Calculating the Line Number:

[tex]= \frac{275}{5} \\\\ =55[/tex]

PSTN line number:

[tex]= (\frac{2000}{55}) \\\\ = 36.3636\\\\= 37[/tex]

In point (f):

The gross design expense = $ 2309. 5

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