What is RTWP?Represents a measure of UMTS technology: the total level of noise within the UMTS frequency band of any cell. RTWP is related to uplink interference, and its monitoring helps control the call drops mainly CS. It also has importance in the capacity management, as it provides information for the Congestion Control regarding Uplink Interference. In UMTS, the uplink interference may vary due to several factors, such as the number of users in the cell, the Service, Connection Types and Conditions of Radio, etc.. As our goal is to always be as simple as possible, we will not delve in terms of formulas or concepts involved. We will then know the typical values, and know what must be done in case of problems. Typical Values Ok, we know that RTWP can help us in checking the uplink interference, then we need to know its typical values. In a network is not loaded, normal, acceptable RTWP Average value is generally around 104.5 and -105.5 dBm. But what can we do when we find bad values? If RTWP is not at acceptable levels. with strong uplink interferers. The first thing to do is check if there is a configuration issue with the RNC or NodeB. it's actually indicating the presence of interference . However. or even been forced to have a momentary value due to some algorithm i.. most vendors have an alarm: RTWP "Very High. especially in cases of new activations. the value that helps us. mainly CS Call Drops. Thus. the difference between them RTWP should not exceed 6 dB. Note: Actually. Usually we have High.e. the situation is ugly. . What happens is that when its value is 'bad'. If the value is around -85 dBm.Values around -95 dBm indicate that the cell has some uplink interferers. Low and Medium measures of RTWP. the maximum and minimum values are recommended only as auxiliary or reference. This is the most common case. it's not RTWP that causes performance degradation. Based on these typical values.the latter being responsible for degradation. and has the most accurate information is the same Mean RTWP! For cases in which cell has two carriers. " What to do in case of problems? We have seen that RTWP can cause performance degradation. since they may have been caused by a peak of access. some actions should be taken. if it carry high traffic. further worsening the problem. through the information directing the antenna and the respective values of RTWP. allowing it to make a triangulation increasing the chances of locating the source of interference.problems of interference is one of the biggest challenges in our area. the next step is the physical examination. we see different days and times . An antenna guy must gradually change the azimuth of the antenna. both internal and external. Insufficient data collected can lead to erroneous conclusions. etc. . but this is a suggestion for whoever wants to deepen the study. Note: There are many forms of interference in the uplink.. In practice to find . such as a Interferer Repeater.and eliminate . Another way to locate the source of interference is to do a test in field. The uplink interference may appear only in specific periods. It also should be checked if there is faulty transmitters. Usually this amount of data is sufficient. especially jumpers and cables. or any other problem that could generate intermodulation between the NodeB and the antenna. you can draw conclusions very good. Once verified the parameter settings. In the figure below. That is. while another professional do RTWP measurements. Data should be collected for the suspicious cell. often partially reversed. it is recommended that data be collected from at least one week (7 days) for every 24 hours. identification and elimination of interference. the chance is very high that we have external interference. major subscribers. The deepening of all possibilities is beyond the goal of being simple to teach the concepts. Thus. but also for its adjacent cells. If the parameter settings and hardware are ok.colorful . we recommend that be collected enough data for each investigation. we must begin to act after such a prioritization based on how much this is affecting the cell KPI's across the network. For being such a complex problem.a fictional example where the interference occurred. Only a few are listed above. In cases where there may be external interference. In order to improve user experience you should find the source and avoid it. I've also found several cases of external intermodulation . Conclusion In this brief tutorial. From my experience the most cases of internal intermodulation is due to improper connector fixing .corroded surface acts as a mixer. Just be careful to monitor it as if the external interference will varnish you need to set RTWPINITADJUST 0 again. performance counters and logs. Run dsp ucellchk command(RNC level) before and after to check the changes. because it has many issues area. In case of RTWP occurence in the UMTS network checking the system against intermodulation should be done in the first step.external interference reacts to the tilt change. If not you can play with RTWPINITADJUST that can be found at nodeb level MML. Setting it to -150 will add -15dbm more and in total you will go -100dbm. see what dictionary .com/ If the rtwp is -85 all the time it is external interference most of the time.by describing RTWP.it isn't rare the interference is broadband and it's difficult to see it unless the noise floor on the SA display is around -130 [dBm] or lower so preamplifier should be used along with pass band filter to avoid intermodulation in the spectrum analyzer alone and false readout in the result. User experience will increase and throughput also. using the OSS.100% of them were GSM or/and DCS repeaters with too small attenuation set. Cell level. When RTWP rises as tx power rises intermodulation is suspected. ie making is as close as possible to -105 dBm. As the RTWP is directly related to Uplink Interference . and that the ideal typical value is about -104. that help in our growth in telecom and IT http://www.and we know that interference is the main cause of performance degradation . Use automatic background noise also.5 dBm.. and tests can be made with a Yagi antenna and a Spectrum Analyzer. If you have I strongly recommend.5 dBm and -105. The test is very simple . It can be either internal or external but it's simple to differentiate it .during monitoring RTWP in the observed cell set the maximum tx power in that cell. Remember that interesting tutorial in the Tips Section..It is obvious that changing the online system may not be a good practice.finetopix. we learn what is RTWP. improving the Call Drop Rate! IMPORTANT : Seizing the opportunity. Solutions was stated at the start of this tutorial this site has been the subject of a very not visited this section of the portal yet . Vendors offer several ways to measure RTWP.have concluded that improving RTWP. Update: . Searching external interference in UMTS network with a spectrum analyzer is tricky to some extent . In case of RTWP affected cells neighbours list should be also checked. especially with lower band (eg 900 MHz) UMTS systems. UE connected to other cells can cause elevated RTWP in case of missing neighbours between these (affected and serving UE) cells. .