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HUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Security Level: www.huawei.com RTWP Troubleshooting uide Zhang Junjie (employee ID: 00107307)Liu Qiong (employee ID: 54780) HUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential Contents ã RTWP Concept and Impacts on the System ã Overview of RTWP Sampling Points ã Common RTWP Problems and Troubleshooting Procedure Traffic statistics decision RTWP problem description and handling suggestions 2 ms RTWP analysis ã Overview Troubleshooting Methods Configuration problems Interference detection (intermodulation problems, external problems) Network planning problems Traffic capacity and improvement measures Appendix 1: Method of Collecting Tracing Logs Routinely Page 2 HUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential RTWP ã What is RTWP? RTWP is short for received total wideband power, which is used in UMTS. Itspecifies the total energy in the uplink 3.84 MHz band, including the availablesignals, noise, and interference. ã Normal range of RTWP Thermal noise is the noise floor in the nature. The actual noise is greater than or equal to thermal noise. Therefore, thermal noise is also called background noise. The thermal noise in the 3.8 4 MHz band is -108 dBm. The thermal noise on theantenna connector deteriorates and becomes -106 dBm after being amplified by thereceiver. As specified in 3GPP protocols, the RTWP accuracy is +/-4 dB. That is, when there are no uses and no external interference, the RTWP should be -106 dBm +/-4 dB. When there are uses, the RTWP increases. PN = KTB + NF, where,K = Boltzmann constant, T = 290 K (room temperature)B = RF carrier bandwidth (Hz) = 3.84 MHzNF: noise factor of the RF systemThe PN is about -106 dBm at room temperature. Page 3 HUAWEI TECHNOLOGIES CO., LTD.Huawei Confidential RTWP Measurement ã RTWP is defined as the energy on the antenna connector. However, the energy istoo weak. The energy can be measured only after being amplified by the receiver. ã RTWP = energy amplified by the receiver – amplified multiples (gain) ã If the configurations and use methods are correct, the actual amplified multiples(actual gain) is consistent with the preset amplified multiples (theoretical gain).Therefore, even on the DSP port, the RTWP can be measured correctly. ã If the configurations and use methods are incorrect, the actual gain is differentfrom the theoretical gain. As a result, the RTWP is incorrect. Page 4 MRF Ur e c ei v er ar c h i t e c t ur e RTWP=P_in=P_out - Gain P_outP_in
