# A Service-Efficient Proxy Mobile IPv6 Extension for IoT Domain
## 5 Results and Analysis
### Signaling Efficiency (A1)  
Initially, the effect of the RSS error on the signaling cost is assessed. For this purpose, the velocity of the MN is taken constant, such as (v = 20 m/s), and the signaling cost is assessed for variations in RSS error (0.0-0.5). It is important to mention that the velocity has a direct relationship with signaling cost, in the context of increasing velocity when the signaling cost becomes high. For meaningful representation, signaling cost is plotted on the y-axis while variation in RSS error is recorded on the x-axis. The comparison is shown in two parts. First of all, the proposed extension is evaluated in comparison with non-location RSS extensions as shown in Figure 2. Furthermore, a comparison among location-based available and presented schemes is represented in Figure 3.  
Figure 2: Comparing signaling among proposed and non-location-based extensions.  
From the statistics, it is shown that RSS-based existing schemes including low latency scheme, FPMIPv6, and smart buffering, incur high signaling for different levels of RSS error. One of the main reasons for their worst performance is that these schemes are only based on the RSS measure. Therefore, when the RSS is affected by the environment, then these schemes are affected by wrong handover moment prediction, which ultimately leads to high signaling costs. In the case of location-based PMIPv6 extensions, the signaling cost is much lower than the aforementioned schemes. Among these schemes, proposed Loc-PMIPv6, and LH-PMIPv6 protocol extensions have high signaling efficiency compared to location-aware PMIPv6 extensions.  
In addition, the signaling required is directly affected by the attached number of MNs to a corresponding MAG. For this purpose, experiments are run for different numbers of MN, and the respective required signaling is assessed. The statistics of the same are represented in Figures 4 and 5, where MNs are horizontally plotted with variations in the range (20-100) in addition to the RSS error due to environment (RSS = 0.20). It is observed that the signaling cost is directly affected by the number of MN. Among the existing schemes, the schemes that do not use location information for handover moment perform much worst in comparison to the location-based extensions. Such a scheme includes a low latency scheme, FPMIPv6, and smart buffering. Among the location-based extension protocols, the proposed LH-PMIPv6 performs better compared to the location-aware PMIPv6 protocol extension. Based on the relative comparison, the proposed scheme provides promising signaling efficiency with respect to the existing location-aware and RSS-based PMIPv6 protocol extensions.  
Figure 4: Signaling comparison among proposed and non-location-based schemes.  
Figure 3: Signaling comparison among proposed and location-based extensions.  
By analyzing the results obtained from the comparison, it is observed that the proposed scheme requires less signaling by avoiding any additional communication that takes place between MNs and MAG in the presence of RSS error. Furthermore, by accurately predicting the target MAG-ID, the LMA avoids multi-casting IHR messages to the surrounding MAGs. Such enhancements significantly reduce the signaling required.