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Skip to 0 minutes and 9 secondsAs our next topic, we would like to discuss a few aspects of protocol message geo-location. Geo-location is the process of leveraging the measurement information contained in a radio resource protocol (or RRC) message to estimate the UE position at the time the protocol message was sent. Remember from the previous video, that such measurement information

Skip to 0 minutes and 28 secondsincludes: the serving cell identifier, the time of arrival, the time delay of arrival, and the receive power from the serving cell and neighboring cells. The geo-location process then uses some mathematical algorithms to estimate the UE’s position. These algorithms include a position estimation, based on the time of arrival. This can be used for 3G radio technology, where a propagation delay is contained in some RRC messages. Also, some 2G, so GSM, messages contain timing information called timing advance, which can be leveraged. Another algorithm estimates the position from a reported time difference of arrival. This algorithm can be applied to the 3G system only, where necessary synchronization offsets are reported in RRC messages.

Skip to 1 minute and 16 secondsThe most powerful algorithm uses the reported receive signal strength from the serving and neighboring cells. These measurement values are correlated with a path loss prediction in order to estimate the UE position. Other algorithms use the identifiers of the serving and neighboring cells, which are also contained in the RRC messages, in order to estimate the UE position from overlapping cell serving areas. Depending on the vendor of the geo-location solution, further heuristics or specific signatures might also be used in estimating the UE position. The pictures on the right illustrate some of the algorithms graphically. The black polygons highlight target zones for a UE position estimate. For higher accuracy of the position estimate, the results of multiple such algorithms might be combined.

Skip to 2 minutes and 4 secondsThe purpose of associating the protocol message with a position estimate in this geo-location process is the creation of a so-called “cell footprint”, which is a map of the measured receive power of a cell. Such a map is created by aggregating and averaging measurement values from protocol messages. The accuracy of such a map is determined again by geographical bins. All measurement values, that have a position estimate from the geo-location process and that fall within a geographical bin are averaged. This average is then used as the representative receive power in this bin of the cell footprint. Customer Experience Cell footprints generate geographical KPIs to identify issues concerning network health. Geo-located protocol message trace

Skip to 2 minutes and 49 secondsdata enable the following types of analyses: coverage, interference, and pilot pollution. This customer experience type of network analytics then allows for customer experience optimization. Before we finish this lesson, we would like to stress the importance of the geographic user experience analytics. A network analysis based on aggregated and averaged network management measurements only can identify, diagnose and resolve problems at a network level, by looking at the performance at a cell-level only. The result is all green network statistics that paint a convincing picture of network quality at all cells, but with persistent customer experience issues. Such a network-centric approach in network analytics

Skip to 3 minutes and 33 secondsand optimization misses out in crucial areas: no visibility into indoor performance, inability to identify problem locations, inability to identify coverage holes and areas of low throughput, inability to measure impact on key customer segments. On the other hand, geo-located customer experience data identify, diagnose and resolve more problems at geographic, customer and network levels. The Customer Experience Analytics generates geographical KPIs that allow engineers to assess the real customer’s experience of the network. We can clearly identify problems like pilot pollution, overshooters, or areas with any problems.

Geo-Location of User Measurements

Finally, we dive in to the topic of geo-location, which is the process of leveraging the measurement information contained in a radio resource protocol message.

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This video is from the free online course:

Introduction to Radio Network Optimization