OWP112010 WCDMA Radio Network Coverage Dimensioning ISSUE1.21

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WCDMA radio network coverage

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<ul><li><p>WCDMA Radio Network Coverage Planning </p><p>Confidential Information of Huawei. No Spreading Without Permission </p><p>N-0 </p></li><li><p>WCDMA Radio Network Coverage Planning </p><p>Confidential Information of Huawei. No Spreading Without Permission </p><p>N-1 </p></li><li><p>WCDMA Radio Network Coverage Planning </p><p>Confidential Information of Huawei. No Spreading Without Permission </p><p>N-2 </p></li><li><p>WCDMA Radio Network Coverage Planning </p><p>Confidential Information of Huawei. No Spreading Without Permission </p><p>N-3 </p><p> Capacitycoverage (typical case: downlink load balance) </p><p> Capacityquality (typical case: lowering BLER through outer loop power control) </p><p> Coveragequality (typical case: lowering the data rate of the connections with much path </p><p>loss through AMRC) </p></li><li><p>WCDMA Radio Network Coverage Planning </p><p>Confidential Information of Huawei. No Spreading Without Permission </p><p>N-4 </p><p> 3G radio network planning can be divided into three phases. They are shown in above </p><p>figure, and consist of dimensioning, pre-planning and cell planning. </p><p> According to the above figure, the output result of radio network dimensioning stage </p><p>serves as the input condition of the pre-planning, and the pre-planning is based on the </p><p>network dimensioning and also checks the network dimensioning result. The site quantity </p><p>can be adjusted according to the pre-planning result in order to obtain the reasonable sites. </p><p>If the existing sites are considered in the selection of theoretical sites during the pre-</p><p>planning, the pre-planning result will be more practical, thus facilitating the cell planning. </p></li><li><p>WCDMA Radio Network Coverage Planning </p><p>Confidential Information of Huawei. No Spreading Without Permission </p><p>N-5 </p><p> Radio Network Dimensioning is a simplified analysis for radio network </p><p> Dimensioning provides the first and most rapid evaluation of the network element number </p><p>as well as the associated capacity of those elements. The target of dimensioning phase is </p><p>to estimate the required site density and site configurations for the area of interest. </p><p>Dimensioning activities include radio link budget and coverage analysis, capacity evaluation </p><p>and final estimation of the amount of NodeB hardware and E1, cell average throughput </p><p>and cell edge throughput. </p><p> Objective: </p><p> To obtain the network scale ( approximate NodeB number and configuration) </p><p> Method: </p><p> Select a proper propagation model, traffic model and subscriber distribution, and </p><p>then estimate the NodeB number, coverage radius, E1 number per site, cell </p><p>throughput, cell edge throughput and so on. </p></li><li><p>WCDMA Radio Network Coverage Planning </p><p>Confidential Information of Huawei. No Spreading Without Permission </p><p>N-6 </p><p> The service distribution, traffic density, traffic growth estimates and QoS requirements are </p><p>already essential elements in dimensioning phase. Quality is taken into account here in </p><p>terms of blocking and coverage probability. </p></li><li><p>WCDMA Radio Network Coverage Planning </p><p>Confidential Information of Huawei. No Spreading Without Permission </p><p>N-7 </p><p> Wireless network dimensioning intends to obtain the approximate UTRAN scale. Based on </p><p>the network dimensioning, geography and traffic distribution, the network is pre-planned </p><p>in detail by using planning software and digital map. </p><p> Based on the network dimensioning and site information, the initially selected WCDMA </p><p>site is imported into the planning software, and coverage is estimated by parameters </p><p>setting. Then an analysis is made to check whether the coverage of the system meet the </p><p>requirements. If necessary, the height and tilt of the antenna and the NodeB quantity are </p><p>adjusted to optimize the coverage. And then the system capacity is analyzed to check </p><p>whether it meets the requirement. </p><p> Implementation parameters, such as antenna type / azimuth / tilt / altitude / feeder type / </p><p>length </p><p> Cell parameters, such as transmission power of traffic channel and common channel, </p><p>orthogonal factor, primary scrambling code </p></li><li><p>WCDMA Radio Network Coverage Planning </p><p>Confidential Information of Huawei. No Spreading Without Permission </p><p>N-8 </p><p> Based on the network dimensioning and site information, the initially selected WCDMA BS </p><p>is imported into the planning software, and coverage is estimated by setting the cell </p><p>parameters and engineering parameters. Then an analysis is made to check whether the </p><p>coverage of the system meet the requirements. Then the system capacity is analyzed to </p><p>check whether it meets the requirement. If necessary, the height and tilt angle of the </p><p>antenna and the BS quality are adjusted to optimize the coverage. </p></li><li><p>WCDMA Radio Network Coverage Planning </p><p>Confidential Information of Huawei. No Spreading Without Permission </p><p>N-9 </p><p> These graphs are prediction results of Huawei planning tool: U-Net </p><p> For the result of coverage prediction, focus on the distribution of best servers and pilot </p><p>level. For the small areas with unqualified level, adjust the azimuth and down tilt to </p><p>improve the coverage. For the large areas with weak coverage, analyze whether the site </p><p>distance is over large: </p><p> If yes, add sites to improve coverage. </p><p> If no, check whether the configuration of parameters related to coverage </p><p>prediction is correct. </p></li><li><p>WCDMA Radio Network Coverage Planning </p><p>Confidential Information of Huawei. No Spreading Without Permission </p><p>N-10 </p><p> We should consider other factors when we select the backup sites </p><p> Commercial factor: rent </p><p> Radio propagation factor: situation / height / surrounding / </p><p> Implementation factor: space / antenna installation / transmission / power supply </p></li><li><p>WCDMA Radio Network Coverage Planning </p><p>Confidential Information of Huawei. No Spreading Without Permission </p><p>N-11 </p><p> Simulation is oriented to simulate the running situation of networks under the current </p><p>network configuration so as to facilitate decision-making adjustment. Now there are two </p><p>system simulation classes: static simulation and dynamic simulation. </p><p> Static simulation focus on user behavior such as browsing Internet, call. It would gain the </p><p>performance of radio network based on snapshot. </p><p> Dynamic simulation focus on detail of user behavior such as duration and data rate of </p><p>browsing. It would gain the performance of radio network based on analysis of mobile </p><p>subscribers. But it requires higher precision of e-map. </p><p> At present, Static simulation is in common use. Monte Carlo simulation is one type of </p><p>static simulation. </p></li><li><p>WCDMA Radio Network Coverage Planning </p><p>Confidential Information of Huawei. No Spreading Without Permission </p><p>N-12 </p></li><li><p>WCDMA Radio Network Coverage Planning </p><p>Confidential Information of Huawei. No Spreading Without Permission </p><p>N-13 </p><p> Some UEs or terminals are distributed based on a certain rule (such as random even </p><p>distribution) at each snapshot </p><p> It is required to consider the possibility of multiple connection failure (uplink/downlink </p><p>traffic channel maximum transmit power, unavailable channels, low Ec/Io and </p><p>uplink/downlink interference </p></li><li><p>WCDMA Radio Network Coverage Planning </p><p>Confidential Information of Huawei. No Spreading Without Permission </p><p>N-14 </p><p> These graphs are prediction results (based on simulation) of Huawei planning tool: U-Net </p><p> The previous predictions (Coverage by transmitter, Coverage by signal level, Overlapping </p><p>zones) are based on coverage, the predictions in this slide are based on simulation. </p></li><li><p>WCDMA Radio Network Coverage Planning </p><p>Confidential Information of Huawei. No Spreading Without Permission </p><p>N-15 </p></li><li><p>WCDMA Radio Network Coverage Planning </p><p>Confidential Information of Huawei. No Spreading Without Permission </p><p>N-16 </p></li><li><p>WCDMA Radio Network Coverage Planning </p><p>Confidential Information of Huawei. No Spreading Without Permission </p><p>N-17 </p><p> In the coverage dimensioning, the link is estimated according to elements such as planned </p><p>area, network capacity, and equipment performance in order to obtain the allowed </p><p>maximum path loss. The maximum cell radius is obtained according to the radio </p><p>propagation model and allowed maximum path loss. And then the site coverage area is </p><p>calculated. Finally, the site quantity is calculated. Of course, the site quality is only for the </p><p>ideal cell status, and some additional sites will be needed in actual terrain environment. </p></li><li><p>WCDMA Radio Network Coverage Planning </p><p>Confidential Information of Huawei. No Spreading Without Permission </p><p>N-18 </p></li><li><p>WCDMA Radio Network Coverage Planning </p><p>Confidential Information of Huawei. No Spreading Without Permission </p><p>N-19 </p><p> Link dimensioning intends to estimate the system coverage by analyzing the factors of the </p><p>propagation channels of the uplink signal and downlink signal. It is the link analysis model. </p><p> If the parameters such as transmit signal power, gain and loss of the transmitter and </p><p>receiver, and quality threshold of received signal are known or estimated, the allowed </p><p>maximum path loss used for ensuring the quality of received signal can be calculated. </p></li><li><p>WCDMA Radio Network Coverage Planning </p><p>Confidential Information of Huawei. No Spreading Without Permission </p><p>N-20 </p><p> In network planning, the value should be set according to the UE capacity with lowest </p><p>power grade in the commercial network of the operator. </p><p> Note that it is possible that a UE supporting high-speed uplink data service (higher than </p><p>64kbps) has a higher power grade than a UE supporting only voice and low-speed data </p><p>services, for example, power grade 3dBm 24dBm. </p><p> With a higher maximum power rating, the maximum path loss is increased accordingly. This allows </p><p>the operator to plan cells with a relatively larger coverage. </p><p> The UE cable loss, connector loss, and combiner loss are quite negligible, hence a 0 dB loss </p><p>is assumed here </p></li><li><p>WCDMA Radio Network Coverage Planning </p><p>Confidential Information of Huawei. No Spreading Without Permission </p><p>N-21 </p><p> The 0 dBi antenna gain is considered here with respect to the internal antenna of mobile </p><p>phones. </p></li><li><p>WCDMA Radio Network Coverage Planning </p><p>Confidential Information of Huawei. No Spreading Without Permission </p><p>N-22 </p><p> The penetration loss is related to building type, incidence angle of the radio </p><p>wave and so on. In the link budget, assume that the penetration loss obey </p><p>the Log-Normal distribution. The penetration loss is related to mean value of </p><p>penetration loss and standard deviation </p><p> When indoor coverage is required to coverage by outdoor macro NodeBs, building </p><p>penetration loss needs to be considered. Building penetration loss is related to such factors </p><p>as incidence angle of the radio wave, the building construction (the construction materials </p><p>and number and size of windows), the internal building layout and frequency. Building </p><p>penetration loss is highly dependent on specific environment and morphology and varies </p><p>greatly. For instance, the wall thickness in Siberian tends to be larger than that of </p><p>Singapore in order to resist coldness and hence the formers building penetration loss is </p><p>correspondingly larger. </p><p> In addition, sometimes vehicular coverage may be required and consequently vehicular </p><p>penetration loss also needs to be included in link budget process. typical vehicular </p><p>penetration loss is around 8dB. </p></li><li><p>WCDMA Radio Network Coverage Planning </p><p>Confidential Information of Huawei. No Spreading Without Permission </p><p>N-23 </p><p> Antenna gain: It refers to the ratio of the square of the actual field of an antenna at a </p><p>point in the space to the square of the field of an ideal radiation unit at the same point in </p><p>the space, namely power ratio. It is the gain in the main transmit direction. In general, the </p><p>gain is related to the antenna pattern. If the central lobe is narrow and the back lobe and </p><p>side lobe are small, the gain is high. If the transmit direction is centralized, the antenna </p><p>gain is high. For an omnidirectional antenna, the gain in all the directions is the same. </p><p> Front-to-back ratio: It refers to the ratio of the maximum gain in the principal direction to </p><p>the gain in the reverse direction. It describes the directing feature. If it is high, the directed </p><p>receive performance of the antenna is high. </p><p> Beam width: It refers to the separation angle between the main transmit direction of the </p><p>power and the point with 3 dB of transmit power reduced, and the area is called an </p><p>antenna lobe. Tilt: It refers to the tilt angle of a directional plate antennal. It is used to </p><p>control interference and improve coverage. </p><p> Polarization: The vector direction of the electrical field in the direction with the highest </p><p>radiation. A dual polarized antenna can provide diversity over a single antenna, thus saving </p><p>one antenna. </p><p> In general, there are two or more lobes in an antenna pattern. The largest lobe is the </p><p>central lobe, and others are side lobes. The separation angle between the two half-power </p><p>points of the central lobe is the lobe width of the antenna pattern, namely, half-power </p><p>(angle) lobe width. If the central lobe is narrow, the directivity is high, and the anti-</p><p>interference capability is high. </p></li><li><p>WCDMA Radio Network Coverage Planning </p><p>Confidential Information of Huawei. No Spreading Without Permission </p><p>N-24 </p><p> Radio propagation in the land mobile channel is characterized by multiple reflections, </p><p>diffractions and attenuation of the signal energy. These are caused by natural obstacles </p><p>such as buildings, hills, and so on, resulting in so-called multi-path propagation. </p><p>Furthermore, with the moving of a mobile station, the signal amplitude, delay and phase </p><p>on various transmission paths vary with time and place. Therefore, the levels of received </p><p>signals are fluctuating and unstable and these multi-path signals, if overlaid, will lead to </p><p>fading i.e. short term fading. The mid-value field strength of Rayleigh fading has relatively </p><p>gentle change and is called Slow fading i.e. long term fading. And it conforms to </p><p>lognormal distribution. </p><p> Long term fading the variation of signal level is slow and smooth. </p><p> Short term fading the variation of signal level is fast and poignant </p></li><li><p>WCDMA Radio Network Coverage Planning </p><p>Confidential Information of Huawei. No Spreading Without Permission </p><p>N-25 </p><p> Slow Fading --- Signal levels obey Log-Normal distribution </p><p> Propagation models predict only mean values of signal strength , the mean value of signal strength </p><p>fluctuates. The deviation of the mean values has a nearly normal distribution in dB, The variation in </p><p>mean values is called log-normal fading. </p><p> Probability that the real signal strength will exceed the average one on the cell border is around </p><p>50%,for higher than 50% coverage probability an additional margin has to be introduced. The </p><p>margin is called slow fading margin. </p><p> Slow Fading Margin (SFM) is related with coverage probability in cell edge and standard deviation of </p><p>slow fading. The equation is described as following: </p></li><li><p>WCDMA Radio Network Coverage Planning </p><p>Confidential Information of Huawei. No Spreading Without Permission </p><p>N-26 </p><p> The standard deviation is a measured value that is obtained from various clutter types. It basically </p><p>represents the variance (log-normally distributed around the mean value) of the m...</p></li></ul>