The most common performance indicator of LTE network is the downlink throughput because it straightforwardly represents the end user satisfaction towards the data downloading speeds of the various packet applications – streaming, File Transfer Protocol (FTP) file downloading, HTTP web browsing, etc. For this reason, most of the LTE network operators regularly perform the field tests to measure the throughput of their network to compare it against the competitor’s as the performance benchmarking purpose. The benchmarking through the extensive drive tests using several User Equipment (UE) simultaneously is considered a standard method for a long while as it provides the throughput quantity directly from the network speed testing applications installed on the UE.
However, the benchmarking test using the UE has inherited flaws to become a reliable reference to judge which network is superior to others. Many mobile network operators own multi-layers of LTE network nowadays, which is necessary to accommodate the increasing number of subscribers with more network resource, e.g. natural spectrum and with more satisfied throughput. Under the multi-layer LTE network circumstances, the UE may transit from one layer to another via Inter-frequency handover according to the instantaneous RSRP or RSRQ at the given time and location. Therefore, the UE may stay in e.g. layer 1 today but may stay in e.g. layer 2 tomorrow.
In order to grasp the overall performance of the set of all RF layers that an operator runs, the benchmarking test needs to be repeated many times but still the UE is not under control which RF layers they will camp on during the individual benchmarking and as a result the benchmarking test becomes significantly inefficient.
Moreover UE based benchmarking is too much result oriented so that it is not possible to tell the reason or root cause if an operator’s throughput performance is superior to other network or vice versa. There can be several important reasons if an operator’s performance is better such as the RF layer has better RSRP coverage, better G-factor profile, less traffic load or a certain layer is less loaded but another layer is more loaded due to unbalanced traffic distribution and so on. The current benchmarking method cannot tell any of this so that it is really hard for the operators to take any action to improve their network just from the benchmarking reports.
As a breakthrough, we use LTE RF scanner to replace the UE as test device for the benchmarking. The LTE RF scanner is a LTE signal measurement instrument collecting the RF coverage quantities such as RSRP, RSRQ, and SINR of the LTE cells identified from the scanning the PCIs in multiple RF layers in sequence. This method can get rid of all the above-mentioned problems of UE based benchmarking and furthermore we can provide detailed analytic benchmarking report, which will open the operator’s eyes by showing all RF layers’ traffic loads and the potential downlink throughput together with the performance limiting factors automatically.