# Effects of Transport Network Slicing on 5G Applications
## 6 Impact of Network Slicing on 5G Applications
### The Baseline/Non-Slicing Applications  
In graphs (a), (c), and (e), all baseline applications experience significant performance degradation when the total demand is higher than the link capacity. When the volume of background traffic increases up to 6 Gb/s, the total demand exceeds the link capacity. In this case, an insufficiency of available bandwidth results in building up the low-priority queue, growing latencies, and packet loss occurrences. The reason is that the P4 switches forward all packets from baseline applications with the best effort and dispatch them to the low-priority queue, where these packets contend with the background traffic for the remaining available bandwidth. In graph (c), the baseline sensor fusion observed a loss rate of 0% with less than 6 Gb/s background traffic volumes; a series of positive loss rates of 1.69%, 4.08%, and 7.64% can be observed respectively when background traffic volumes increase to 6 Gb/s, 8 Gb/s, and 10 Gb/s. From graphs (a) and (c), we observed that the measured throughput for baseline sensor fusion is adversely affected by the packet loss, deteriorating once the loss rate rises above 0%. The reason is that when a packet loss occurs, the sender will receive multiple duplicate acknowledgments (ACKs) or encounter a retransmission timeout (RTO) for the loss; TCP congestion control will take both instances as an indication of network congestion and reduce the sending rate. The baseline smart switch and MapTalk have the same phenomenon because of the same reason. Nevertheless, the baseline UDP video keeps sending packets, regardless of congestion. Therefore, it encounters severe packet losses, and the packet losses account for reducing throughput for the video with UDP.  
Graphs (c) and (e) demonstrate that latency is an advanced indicator for congestion. The steepest part of the dashed curve for baseline sensor fusion in graph (e) occurs before a positive loss rate occurs, as seen in graph (c). This result indicates that the low-priority queue builds up rapidly when the total demand for available bandwidth is about to reach the link capacity and stays in a near-overflow level when the link is saturated.  
The dashed curves in graphs (a), (c), and (e) reveal that network congestion has a more significant impact on the baseline sensor fusion than on the baseline smart switch and baseline MapTalk. Note that these connections of sensor fusion are long-lived TCP elephant flows, whereas those of the smart switch and MapTalk are short-lived TCP mice  
Figure 7: Effects of network slicing on applications’ output measures of throughput, loss rate, and latency. Dashed curves represent the baseline applications’ output measures; solid curves show the slicing applications’ output measures. In graphs (a), (c), and (e), a slice with a CIR ratio of 100% is created and configured for each slicing application. Note that, in graphs (b), (d), and (f), the dots at the CIR ratio of 0% represent the output measures of baseline applications. In contrast, the dots at the positive CIR ratios represent the output measures of slicing applications. **(a)** Throughput percentages at different background traffic volumes. **(b)** Throughput percentages at different CIR ratios with the background traffic volume of 10 Gb/s. **(e)** Loss rates at different background traffic volumes. **(d)** Loss rates at different CIR ratios with the background traffic volume of 10 Gb/s. **(e)** One-way Latencies at different background traffic volumes. **(f)** One-way latencies at different CIR ratios with the background traffic volume of 10 Gb/s.  
flows. The diversity of traffic patterns between these applications makes the impact of network congestion on applications different.  
From the above discussion, we conclude that the performance degradation in the baseline applications is due to network congestion, leading to a severe impact on the baseline applications with TCP or UDP elephant flows and a minor effect on the baseline applications with TCP mice flows.