LTE Drive Test Procedure for SSV Using
TEMS
Coverage Test
• The objective of this test is to check if there's swapped feeders and if the
Radio Units and Antennae are radiating as supposed to be.
• - near the site we should receive -70 and the PCI should be as planned.
• - the test is done by driving all the roads around the sites in idle mode (
just plugging in the data card and make sure it is camped on LTE without
doing any kind of browsing or download)
• - on Tems you should monitor the map and the radio levels ( RSRP, RSRQ,
SINR, PCI) >>> windows on Tems : LTE Serving /Neighbor Cell.
• Note: you activate the card and when ur in idle mode n u can see the
signals>> u start logging and then drive and when u finish driving u stop
logging.
Coverage Test radio paramters
Handover Test
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HO test is done in dedicated mode >> connecting to filezilla and downloading big file and
driving
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The objective is to know if the HO is working between the 3 sectors of the site.
>> drive clockwise and counterclockwise around the site and near, and monitor that the PCI
is changing from one sector
>>> windows on Tems : LTE Serving /Neighbor Cell and another Windows Events.
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Another drive is needed to check the HO to neighbor site.
Just check one neighbor per cell to conduct a HO test and vice versa.
Neighbors are chosen based on availability
If theres huawei and ericsson sites as neighbors two tests should be done
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Note: you activate the card and and u start downloading big file from Filezilla when ur in
connected mode n u can see the signals and download working>> u start logging and then
u drive and when u finish driving u stop logging.
Throughput test
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For each cell we should do 3 DL test and 3 UL Test >> for a
site >>18 tests >> 18 log files
The throughput test is a static test>> no drive >> just find a
location in front of the sector where radio conditions are
the best ( SINR>>22/25, RSRP>> -70/-75)
And do the tests for each sector in the location chosen
During test you make sure you are always camping on
same PCI ( the one of the sector) >> >>> windows on Tems
: LTE Serving /Neighbor Cell
And make sure that most of the time that transmission
mode is 3 ( MIMO),
RI=2, TS01 and TBS02 is 64QAM during DL for PDSCH
Modulation and PUSCH modulation is 16 QAM during UL
test. >> Windows in Tems : LTE radio paramters
DL & UL Throughput test
• For DL and UL tests, they should be done using Filezilla and connecting to
the FTP server and downloading 10 big files for DL and 10 big files for UL.
• While monitoring the throughput through netpersec and take snapshot
when we reach the target.
• For 2600 sites : target : average throughput DL= 60 Mbps and for UL = 30
Mbps
• For 1800 sites: target : throughput DL= 30 Mbps and for UL = 15 Mbps
• U should do the file transfer and when its stable on the high throughput
start logging for 2 min.
• In total you shuld have 18 log files per site and 18 snapshots.
DL & UL Throughput test graph
Latency (RTT time) test
• Open command prompt from windows and
ping the ip address of the FTP server on same
location u where doing the throughput test
and take snapshot of the blck window.
• We do it once per sector
• Kindly note that before pinging start logging
and after pinging stop logging
LTE RF conditions classification
It is common sense that the performance of any wireless system has a direct relationship
with the RF conditions at the time. To aid with performance analysis then, we typically
define some ranges of RF measurements that correspond to some typical RF conditions
one might find themselves in.
When it comes to LTE, I came across the above table that presents a good classification.
The source of this table is a EUTRAN vendor and has been complied during the RF tuning
process for a major US operator. Of course there are no rules as to how various RF
conditions are classified, so different tables will exist but to a great extent you can expect
them to align.
In this particular example, three measurement quantities are used. RSRP (Reference
Signal Received Power), RSRQ (Reference Signal Received Quality) and SINR (Signal to
Interference & Noise Ratio).
RSRP is a measure of signal strength. It is of most importance as it used by the UE for the
cell selection and reselection process and is reported to the network to aid in the
handover procedure. For those used to working in UMTS WCDMA it is equivalent to
CPICH RSCP.
The 3GPP spec description is "The RSRP (Reference Signal Received Power) is determined
for a considered cell as the linear average over the power contributions (Watts) of the
resource elements that carry cell specific Reference Signals within the considered
measurement frequency bandwidth."
In simple terms the Reference Signal (RS) is mapped to Resource Elements (RE). This
mapping follows a specific pattern (see below). So at any point in time the UE will
measure all the REs that carry the RS and average the measurements to obtain an RSRP
reading.
RSRQ is a measure of signal quality. It is measured by the UE and reported back to the
network to aid in the handover procedure. For those used to working in UMTS WCDMA is it
equivalent to CPICH Ec/N0. Unlike UTMS WCDMA though it is not used for the process of cell
selection and reselection (at least in the Rel08 version of the specs).
The 3GPP spec description is "RSRQ (Reference Signal Received Quality) is defined as the
ratio: N×RSRP/(E -UTRA carrier RSSI) where N is the number of Resource Blocks of the E-UTRA
carrier RSSI measurement bandwidth."
The new term that appears here is RSSI (Received Signal Strength Indicator). RSSI is
effectively a measurement of all of the power contained in the applicable spectrum (1.4,
3, 5, 10, 15 or 20MHz). This could be signals, control channels, data channels, adjacent
cell power, background noise, everything. As RSSI applies to the whole spectrum we
need to multiple the RSRP measurement by N (the number of resource blocks) which
effectively applies the RSRP measurement across the whole spectrum and allows us to
compare the two.
Finally SINR is a measure of signal quality as well. Unlike RSRQ, it is not defined in the
3GPP specs but defined by the UE vendor. It is not reported to the network. SINR is used
a lot by operators, and the LTE industry in general, as it better quantifies the relationship
between RF conditions and throughput. UEs typically use SINR to calculate the CQI
(Channel Quality Indicator) they report to the network.
The components of the SINR calculation can be defined as:
S: indicates the power of measured usable signals. Reference signals (RS) and physical
downlink shared channels (PDSCHs) are mainly involved
I: indicates the power of measured signals or channel interference signals from other
cells in the current system
N: indicates background noise, which is related to measurement bandwidths and receiver
noise coefficients
So that is it! I have also included a real life measurement from a Sierra Wireless card that
includes the above mentioned metrics so you can see what is the typical output from a UE.
Using that and the table above you should be able to deduce the RF condition category it is
in at the time of measurement.