Congestion aware forwarding in delay tolerant and social opportunistic networks

Abstract

-We propose an approach for opportunistic forwarding that supports optimization of multipoint high volume data flow transfer while maintaining high buffer availability and low delays. This paper explores a number of social, buffer and delay heuristics to offload the traffic from congested parts of the network and spread it over less congested parts of the network in order to keep low delays, high success ratios and high availability of nodes. We conduct an extensive set of experiments for assessing the performance of four newly proposed heuristics and compare them with Epidemic, Prophet, Spay and Wait and Spay and Focus protocols over real connectivity driven traces (RollerNet) and with a realistic publish subscribe filecasting application. We look into success ratio of answered queries, download times (delays) and availability of buffer across eight protocols for varying congestion levels in the face of increasing number of publishers and topic popularity. We show that all of our combined metrics perform better than Epidemic protocol, Prophet, Spray and Wait, Spray and Focus and our previous prototype across all the assessed criteria.

Transfer Reliability and Congestion Control Strategies in Opportunistic Networks: A Survey

“…Congestion Aware Forwarding (CAFé) [46] aims to distribute load away from hub nodes. We illustrated the algorithm in outline form in Fig.…”

“…CAFRep [58] is a multiple-copy variant of CAFé [46] that controls the number of copies of messages forwarded to relay nodes. As with CAFé, CAFRep also considers three types of metrics: node social-network metrics, node buffer statistics and ego network statistics.…”

Exploiting social preferences for congestion control in opportunistic networks

“…Several approaches have been proposed in the literature for overcoming the problem of storage congestion in opportunistic networks [9]- [13]. They can be broadly categorized to those applicable to multi-copy routing protocols and those applicable to single-copy schemes.…”

“…This method may provide significant throughput, but unfortunately it is extremely costly in terms of packet transmissions. Another approach, called CAFé [13], utilizes buffer and network statistics to predict whether the transmission of a packet will later cause congestion or not. However, a non-trivial fine-tuning of the parameters is required for collecting statistics.…”

Using Buffer Space Advertisements to Avoid Congestion in Mobile Opportunistic DTNs

“…Radenkovic and Grundy [17] propose a congestion approach for social opportunistic networks. They suggest a combination of routing and congestion avoidance that uses heuristics to infer shorter paths to destinations from social information and use buffer information to avoid areas of the network that are congested.…”