terms of shadowing, number of reflected paths etc. It has turned out that the signal strength variations are quite well described by a lognormal distribution. Hence, provides the mean excess path loss in Lexcess dB while is the standard deviation of the normal distributed signal strength in dB, known as the σL location variability. In fact, depends on the frequency and the environment. is modelled according σL σL to with = 5.2 for urban and = 6.6 for suburban environments, respectively. SE SE Since the TG4m systems are supposed to be fixed located, this equation will in fact not be exercised. Modified Hata Model for Propagation Prediction Used for ERC Report 68 The modified Hata model adopted in ERC Report 68 is available for outdoor-outdoor path loss calculations. The total path loss is where: = median propagation loss (in dB) L = frequency (in MHz) f = antenna height of the transmitter antenna (in m) h1 = antenna height of the receiver antenna (in m) h2 = min{} Hm = max{} Hb = distance (in km), preferably less than 100 km. d = parameter for the environments of the transmitter and receiver: (outdoor/indoor), (rural, urban env or suburban), (propagation above or below roof) If and/or are below 1 m, a value of 1 m should be used instead. Antenna heights above 200 m Hm Hb might also lead to significant errors. Propagation below roof means that both and are below the Hm Hb height of roofs. Propagation is above roof in other cases (Hb is above the height of roofs). Calculation of the median path loss L Case 1: 0.04 km d ≤ The median path loss is L Case 2: 0.1 km d ≥ Let be defined and the median path loss is equated for each case of urban, a(Hm), a(Hm),and α L suburban and open areas as defined in three subcases in the below.
terms of shadowing, number of reflected paths etc. It has turned out that the signal strength variations are quite well described by a lognormal distribution. Hence, Lexcess provides the mean excess path loss in dB while σL is the standard deviation of the normal distributed signal strength in dB, known as the location variability. In fact, σL depends on the frequency and the environment. σL is modelled according to with SE = 5.2 for urban and SE = 6.6 for suburban environments, respectively. Since the TG4m systems are supposed to be fixed located, this equation will in fact not be exercised. Modified Hata Model for Propagation Prediction Used for ERC Report 68 The modified Hata model adopted in ERC Report 68 is available for outdoor-outdoor path loss calculations. The total path loss is where: L = median propagation loss (in dB) f = frequency (in MHz) h1 = antenna height of the transmitter antenna (in m) h2 = antenna height of the receiver antenna (in m) Hm = min{} Hb = max{} d = distance (in km), preferably less than 100 km. env = parameter for the environments of the transmitter and receiver: (outdoor/indoor), (rural, urban or suburban), (propagation above or below roof) If Hm and/or Hb are below 1 m, a value of 1 m should be used instead. Antenna heights above 200 m might also lead to significant errors. Propagation below roof means that both Hm and Hb are below the height of roofs. Propagation is above roof in other cases (Hb is above the height of roofs). Calculation of the median path loss L Case 1: d ≤ 0.04 km The median path loss L is Case 2: d ≥ 0.1 km Let a(Hm), a(Hm),and α be defined and the median path loss L is equated for each case of urban, suburban and open areas as defined in three subcases in the below.
15-11-0684-10-004m-tg4m-technical-guidance-document.docx