Smart management of D2D constructs: an experiment-based approach

This article considers the concept of device-to- device communications for the resolution of persistent issues in mobile networks. Specifically, two scenarios are described, the opportunistic coverage expansion of the infrastructure, where an access point transits to offline mode (and hence its terminals shall exploit the presence of neighboring devices in order to reroute their traffic to alternative APs), as well as the opportunistic capacity expansion scenario where an AP faces congestion issues due to the excessive traffic of its terminals or the use of an obsolete RAT with low capacity. In the same manner, part of the traffic shall be offloaded to alternative APs through the creation of D2D links with neighboring devices. In order to realize the proposed solutions, the network elements exchange information regarding their capabilities and their status so as to identify the best path from all the potential ones. Therefore, control channels for cognitive radio systems will be utilized since the information that is conveyed through them comprises information from all the layers of the protocol stack. Furthermore, the article focuses on the coverage expansion scenario, which is implemented at the w.iLab-t testbed. In order to realize the D2D constructs, the devices of the testbed will be configured to communicate through WiFi technology, and specifically the 802.11s standard for wireless mesh networks, in order to enable multihop communications. In this respect, the D2D constructs that will be created are mesh networks that comprise the problematic terminals, their neighboring terminals that offload their traffic, and the APs that receive the traffic. In order to evaluate the proposed solution, the signaling loads of the conveyed messages are measured, as well as the performance of the mesh network that is created after the solution enforcement through the use of a ping, a file transfer, and a video streaming application.