# Comparative Analysis of Producer Mobility Management Approaches in Named Data Networking
## 5 Results  
The resulting data retrieval delay from the producer mobility as a function of speed are shown in Figure 7 when handled by the AFIRM, Map-Me-IU, Map-Me-IN, and R-Kite schemes. As we can see, the highest delay was for R-Kite. This was due to the existence of an anchor, and all interest packets had to pass through this central entity in order to reach the producer. This was required regardless of the relative geographical location of the producer  
Figure 7: Data retrieval delay. and consumer in the network. In the worst cases, the consumer was near the producer, but both were far away from the anchor. In such situations, the interest packet must travel all the way from the consumer to the anchor, and the data packet follows the reverse of this same long path. We must note that producer mobility had little affect on the resulting data retrieval delay in the case of the R-Kite scheme, and this was because a consumer had to query the anchor about the location of the producer upon every request. Although the mobile producer needed to only propagate a mobility notification to the central anchor, the consumer interest had to go through the anchor regardless in all communications. The variations of Map-Me (Map-Me and Map-Me-IU) both caused lower data delays of about 50 ms, whereas Map-Me achieved a slightly lower delay. This was due to the fast reactivity of the Map-Me variations, which were operating on edge PoAs instead of propagating mobility notifications to a central anchor as in R-Kite. AFIRM achieved the lowest delay, indicating its having the fastest reactivity to producer mobility in addition to the advantage of the followed optimal paths. Furthermore, we noticed that the slopes of all schemes were not affected much by the mobility speed of the producer. This was because the data retrieval delay was calculated for every interest-data pair for data packets that arrived at the consumer only. Although producer mobility may cause interest loss (as we will show shortly), this does not affect the calculation of the data retrieval delay. Figure 8 shows the average hop count taken by data packets from a mobile producer to a consumer when the producer mobility was handled by the different schemes as a function of the producer mobility speed. The results shown here are in agreement with the average packet delay results in Figure 7. We can see that the hop count for the R-Kite approach was the highest, and the hop count for AFIRM was the lowest. Although Map-Me is known to generate triangular paths, the seen path stretch was not high, given that the topology was a fat tree and a producer attached to PoAs which were leaves of the tree. In Figure 9, the resulting data loss rates as a function of the producer mobility speed are shown. Although packet loss may be caused by either producer mobility, network  
Figure 8: Average hop counts. congestion, or wireless collisions, fixing the simulation parameters (streaming rate, link delay, etc.) for all producer MM schemes allowed us identify the performance of the producer MM schemes. We can observe that the loss rate for all schemes increased with the producer speed, which was due to the decreased ability of the producer MM scheme to handle the more frequent mobility events. Indeed, the producer-chasing nature of the full Map-Me variant yielded the lowest loss rate but certainly with the expense of the overhead caused by the broadcast of IN packets in scope discovery. AFIRM and Map-Me-IU resulted in higher loss rates than Map-Me, and the justification is obvious in the case of Map-Me-IU, given that scope discovery and producer chasing were not performed. However, for AFIRM, the loss rate was higher than that for Map-Me because the producer was only reachable once the recovery1 packet reached a router that resided in the path from the producer's old PoA to the consumer.