Table 7.12 draws the summary from the CDF in Figure 7.41 for both bands. The mini-
age area as well. The mean throughput for LTE 800 is 13.8 Mbps while that for LTE
deviation in throughputs measured in 12.3 Mbps for LTE 800 while that for LTE 1800
is 11.4 Mbps. This huge deviation in both cases is because the test network consists of
only one site and as the coverage deteriorates moving towards the cell edge, the
throughput degrades. The measurements were taken from the cell center towards the
Figure 7.41: CDF comparison of throughputs for Singerjärvi LTE 1800 and LTE 800
MEASUREMENTS AND ANALYSIS
72
cell edge in different directions. Thus, the presence of lower throughput in the cell edge
region for both of the bands causes the throughput deviate in large proportion.
Figure 7.42 shows a scatter plot of application downlink throughput vs. SNR for LTE
1800 band. The Shannon bounds for Rayleigh and AWGN channels are given in Figure
5.2. The measurement points are for all of the measurement routes. SNR in the meas-
urement routes ranges from -12 dB to 24 dB. The throughput reaches to 47 Mbps ap-
prox. supported by the peak SNR. The curve swing is similar to the ones in
Figure 7.24
plotted for LTE 800. As the SNR decreases, the downlink throughput decreases and
vice versa which is fairly predictive. The median of the data which falls at 14.7 Mbps
approx. and 9.4 dB SNR divides the data into 4 quadrants marked by black line. The
blue colored line marks the cell edge defined by SNR and throughput thresholds of -
11.4 dB and 1 Mbps respectively (as calculated in Equation 6.9).
The blue circles in the figure fall in the region where SNR is above -11.4 dB but the
throughput is below 1 Mbps. 10.1% samples of LTE 1800 fall under this region. There
are no samples that are above 1 Mbps threshold having SNR below -11.4 dB. With the
operator’s requirement of providing 1 Mbps throughput limit at the cell edge, approxi-
mately 90% of samples have met the operator’s performance requirement.
The results when compared with that of LTE 800 results for both Singerjärvi and
Kumpuvaara sites (refer to Figure 7.24) show that LTE 800 has outperformed LTE 1800
in terms of service quality provided within its coverage limits. Of all, the Kumpuvaara
LTE 800 has best performed with site meeting the requirement 98% of sample time.
Do'stlaringiz bilan baham: