EXPERIMENT NO 6

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BE(EXTC) SEM VIII (RCOE) Page 1

Name:

______________________________________

Branch:

Electronics & Telecommunication (SEM VIII)

Subject: Wireless Network

Experiment No: 06

Title:

To Plan & Design an Wireless Network.

Date:

Subject In-Charge Sign

:

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EXPERIMENT NO: 06

AIM

: To Plan & Design an Wireless Network.

APPARATUS

: MATLAB 7

THEORY:

Planning & design of a Wireless Network

The planning of wireless network is a multidiscipline task in which comparing requirements must be balanced. Network plans change throughout the life of a wireless network. During the initial phase, coverage is the primary issue & traffic demand is secondary. Too small a network initial will require expansion later; in the first few years, human resources need to be devoted to the roll-out of the network, not to re-engineering the existing network.

To establish the size of a cellular network, we need to know the:

 Network topology: base-station transceiver- base station controller mobile switching center (BTS-BSC-MSC).

 Link capacity: BTS-BSC, BSC-MSC.

 BSC sizing.

 MSC sizing.

Cell & frequency planning in cellular networks requires initial traffic estimation, a traffic growth plan, the selection of an initial design, an initial cell plan, a network expansion plan, a selection of reuse pattern, the development of an initial theoretical plan, computer simulation, localized performance measurements, & final network design. We need the following data to develop a traffic plan for a cellular network.

 The number of users.

 User’s behavior, i.e. heavy or light users.

 Busy-hour traffic as a percentage of the total traffic.

 User’s distribution over the service area.

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A cellular network growth plan involves time to roll out the network, requirements of additional cells, requirements of microwave link sites, & the cost to rework network versus initial deployment costs. Basic traffic engineering of a cellular network is based on coverage. In this case, the maximum cell radius based on the required in-building coverage criterion is used. Often a maximum cell radius of less than 10km is used to determine the required numbers of cells in thecoverage area. For some in-building coverage in large urban areas, cell radius may be 1km or even less to achieve good in-building coverage.

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PROGRAM:

%GSM 1800 network calculation to find average busy hour traffic/subscriber,Traffic capacity/cellrequired base stations/zone and hexagonal cell radius.

% GSM 1800 network

cch = input('Enter control channels per cell = ');

tch = input('Enter traffic channels per cell = ');

nc = input('Enter number of per cell per bit = ');

Subs = input('Enter subscriber usage per month = ');

dpm = input('Enter busy days per month = ');

bhr = input('Enter busy hrs per month = ');

B = input('Enter spectrum = ');

Bch = input('Enter channel width = ');

nos = input('Enter number of subscribers = ');

g = input('Enter growth = ');

area = input('Enter area = ');

planyrs = input('Enter plan years = ');

cap = input('Enter capacity in erlangs = ');

erlang_er_subscriber = 1370;

% Calculations

erlang_er_subscriber = Subs/(dpm*bhr*60);

Carriers = B/Bch;

Traffic_cap_cell = 8.2;

traffic_cap_BTS = Traffic_cap_cell*nc;

Pb_trunk = 14;

GOS = 0.02;

Max_Subscribers_BS = traffic_cap_BTS/erlang_er_subscriber;

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BE(EXTC) SEM VIII (RCOE) Page 5 no_of_Bs = sub_initial/(Max_Subscribers_BS);

average_hex_radius = sqrt(area/(no_of_Bs*2.6));

RESULT:

Enter control channels per cell = 2. Enter traffic channels per cell = 4. Enter number of per cell per bit = 3. Enter subscriber usage per month = 150. Enter busy days per month = 24.

Enter busy hrs per month = 6. Enter spectrum = 4800000. Enter channel width = 200000. Enter number of subscribers = 50000. Enter growth = 5.

Enter area = 500. Enter plan years = 4.

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OUTPUT:

erlang_er_subscriber = 1370. erlang_er_subscriber = 0.0174. Carriers = 24.

Traffic_cap_cell = 8.2000. traffic_cap_BTS = 24.6000. Pb_trunk = 1.

GOS = 0.0200.

Max_Subscribers_BS = 1.4170e+003. sub_initial = 6.0775e+004.

no_of_Bs = 42.8913.