Hata´S Empirical Formula And Cell Size Estimation

Hata Model is applied for GSM Link Budget,here i write about its formula and Cell Size Estimation.

Hata´S Empirical Formula

PL = 69.55 +26.6log₁₀f_c– 13.82log₁₀h_b + (44.9 – 6.55log₁₀h_b)log₁₀R – a(h_m) -CF

Where ,

f_c – Frequency in MHZ

h_b – Transmitter antenna height

h_m – Receiver antenna height

R – Radius in Km

a(h_m) is the correction factor for effective mobile antenna height

Solving backwards the cell radius is given by

log₁₀R = MAPL +CF – 69.55 +26.6log₁₀f_c+ 13.82log₁₀h_b+ a(h_m) / (44.9 – 6.55log₁₀h_b)

Cell Size/Count Estimation

Once the Maximum allowable path loss is known, the achievable cell size can be evaluated.
Cell radius is calculated using MAPL and Hata’s empirical formula.
Cell radius is the distance from base station where the path loss equals MAPL. Beyond this radius, the signal is too weak to be acceptable.
Each area has a different correction factor.
Also the coverage objectives are usually different for Urban, Suburban and Rural areas.
Therefore MAPL has to be calculated for each area and then cell size determined separately.
Once the cell radius is calculated, cell count estimates can be made.
Once the cell radius for each area is calculated, then the minimum number of cells required to provide coverage can be determined.
For each area

A = 2.6R²

Where,