RSCP,RSSI,RTWP 1. RSCP and RSSI 1. RSSI is Rx level before descrembling. It’s just RxLev of UARFCH. CPICH_RSCP is Rx level after descrembling. CPICH_Ec/No is result of filtering after dechanalization. In dBm is: RSCP=RSSI+EcNo
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1. RTWP stands for Received Total Wideband Power and its a measurement in the cell radio unit. RTWP is the signal strenght received in the 5MHz uplink frequency. This measurement is the total addition of the equipment thermal noise level(-105 dBm +/0.5 dB sometimes more) plus signal of users connected to the cell plus signal of users connected to other cells and other type of radio signals(GSM,CDMA,MW,TV) in that range of frequencies that the cell measure(5MHz). RSSI stands for Received Signal Strenght Indicator and its a general term for RF signals, its used in downlink and uplink in different mobile technologies. In WCDMA (uplink) is said to be equivalent to RTWP because is the signal strenght in UL this means the sum of all signals that the cell measure. In DL is just like the guy down here said, i will put the formula in power levels so it can get a bit more clear. Ec/Io=RSCP/RSSI So pretty much RSSI is the signal that contains the usefull and not usefull part. The usefull part is decoded and then its RSCP in downlink. The nonusefull part is the downlink signal, is the signal from the same cell which is sent to other users and the signal from other cell sent to other users. In Huawei the counter is RTWP, in Ericsson the counter is RSSI thats the difference. Hope you got it! 1. UL RSSI is represented as the average of RTWP (Received Total Wideband Power) in the uplink. RTWP is used to configure the initial power of P-RACH and is part of Open Loop power control. In Ericsson RTWP is calculated as pmSumUlRssi/pmSamplesUlRssi. UL RSSI = -112 + ((pmSumUlRssi / pmSamplesUlRssi) /10) Theoretically ideal value of UL RSSI = Thermal Noise + ASC Noise Unloaded Network = -174 dBm/Hz + 2dB = -172 + 10*log(3.84*10^6) = -106.2dBm (Typical ASC Noise = 1.3dB, Guaranteed = 2.0dB, different for different ASC, RRU etc) So, for 50% System Load = -106.2dBm + 3dB = -103.2dBm
