## 5 Results
### Simulation Parameters  
The simulation considered a real network topology running in an urban scenario. We used real traces from the CRAWDAD [39] project that were acquired from a wireless mesh network operating in Portland, Oregon, USA, depicted by Figure 5. This network covers an outdoor scenario with urban buildings between some nodes. The network consists of 70 nodes, and some of them are geographically separated by a river. The reason for choosing this network was related to the number of nodes and their positions. Nodes are densely concentrated in some areas while in other areas, nodes are barely sparse. Such different densities provided an opportunity to evaluate our mechanism in a realistic scenario. Producer nodes were fixed on the edge of the network, while the consumer nodes were  
Figure 4: Neighbors discover flowchart.  
randomly distributed. To simulate this scenario, which is urban and outdoor, the following parameters for the link and physical layers were defined. The network technology was the IEEE 802.11a standard in ad-hoc mode with OFDM (Orthogonal Frequency-Division Multiplexing) modulation and the transmission rate was 24 Mb/s. The propagation model used was the Shadowing Deviation with 5 dBm of transmission power.  
We varied the transmission rate of interest packets. Consumers sent from 10 to 50 interest packets per second. The interest packets carried the required content names. Every item of content had a size of 1000 bytes and was encapsulated in one data packet. The cache size was equal to 10,000 kB in all nodes and the cache replacement policy was the Least Recently Used (LRU). Depending on the scenario analyzed, content chunks were requested sequentially or based on their popularity levels, defined by a Zipf-like distribution with the parameter \(\alpha=0.7\).  
We defined the following parameters for the proposed mechanisms. Both PIF and ReCIF+PIF were evaluated for \(p=0.2\). The reason for this value is explained in Section 5.3.1. The centrality threshold (\(G\)) was equal to 8. Based on preliminary experiments, this is the average number of neighbors of nodes that are placed in high-density areas of Portland Network. Finally, with ReCIF-hard, the retransmission threshold used was \(C=7\). This value was also defined according to preliminary tests to determine the average number of hops traversed by interest packets sent by a given consumer to reach the producers in the Portland Network. ReCIF-Soft used \(\alpha=0.9\) and \(P=10\).  
The metrics considered in the simulation were the number of content packets delivered, the average delivery delay, and the number of interest transmitted by contents received. The rate of content packets delivered was calculated using the number of requested contents delivered on each consumer node. The content delivery delay is the time between the transmission of an interest packet and the reception of the corresponding data packet by a consumer. For each configuration of our mechanisms, described in Section 4, we performed 50 simulation runs of 100 s each. Confidence intervals were calculated at the 95% confidence level and were represented by vertical bars in figures in the following sections.  
Figure 5: Geographical location of Portland network nodes.