# Okumura-Hata Model Based on 1960's measurements ## Parameters d - distance between transmit and receive antennas f - carrier frequency (Unit is MHz) $h_t$, $h_r$ - [Tx](Transmitter.md) and [Rx](receiver.md) heights The geographic environment. ## Parameter ranges $150MHz \leq f \leq 1500 MHz$ $1m \leq h_t \leq 200m$ $1m \leq h_r \leq 10m$ $1km \leq d \leq 20km$ ## Urban model $P_L^{Urban}\;=\;69.55\;+\;26.16\;\log _{{10}}f\;-\;13.82\;\log _{{10}}h_{B}\;-\;C_{H}\;+\;[44.9\;-\;6.55\;\log _{{10}}h_{B}]\;\log _{{10}}d$ ## Medium sized city ![C_{H}\;=\;0.8\;+\;(\;1.1\;\log _{{10}}f\;-\;0.7\;)\;h_{M}\;-\;1.56\;\log _{{10}}f](https://wikimedia.org/api/rest_v1/media/math/render/svg/85df8ca401617adda011891c7461dafefbcecc17) ## Large urban city: $C_{H}\;={\begin{cases}\;8.29\;(\;\log _{{10}}({1.54h_{M}}))^{2}\;-\;1.1\;{\mbox{ , if }}150\leq f\leq 200\\\;3.2\;(\log _{{10}}({11.75h_{M}}))^{2}\;-\;4.97\;{\mbox{ , if }}200<f\leq 1500\end{cases}}$ ## Suburban ![{\displaystyle L_{SU}\;=\;L_{U}\;-\;2{\big (}\log _{10}{\frac {f}{28}}{\big )}^{2}\;-\;5.4}](https://wikimedia.org/api/rest_v1/media/math/render/svg/098d823fc1dff434a685d374a219c53d1930f3d8) Useful for cell planning. ## Rural ("Open") Environments ![{\displaystyle L_{O}\;=\;L_{U}\;-\;4.78{\big (}\log _{10}{f}{\big )}^{2}\;+\;18.33{\big (}\log _{10}{f}{\big )}-\;40.94}](https://wikimedia.org/api/rest_v1/media/math/render/svg/ea0dff7d33464a80c792841e2bf693c5a7723bfd) ## Graph ![](attachments/Okumura-Hata%20Model-attachment.png#invert) ## Remarks - Still a function of distance and frequency! - As the [transmitter](Transmitter.md) gets higher, [path loss](Path%20loss.md) at a given distance decreases. - This is because there are less obstacles in the way! [^wikipedia] ## Footnotes and References [^wikipedia]: https://en.wikipedia.org/wiki/Hata_model