Towards collaboration in heterogeneous Wireless Networks

Piotr Gawłowicz, Technische Universität Berlin, Adam Wolisz
The wireless spectrum is getting crowded with heterogeneous technologies that are designed to satisfy various requirements of existing and emerging applications. Unfortunately, due to diverse operation principles, the channel access coordination methods that work well in homogeneous networks are not applicable or perform poorly in heterogeneous environments. Hence, coexisting networks suffer from frequent collisions and significant performance degradation. Furthermore, even homogeneous wireless
more » ... networks operate independently and are adversaries to each other, i.e., they compete for limited radio resources. This dissertation aims to improve wireless coexistence by enabling collaboration between networks that are heterogeneous concerning technology and ownership. To this end, the key challenges and opportunities of collaboration are considered in three main parts. First, we address the issue of information exchange that is needed for collaboration but missing among heterogeneous technologies due to their incompatible physical layers. We describe two cross-technology communication (CTC) schemes. LtFi enables direct over-the-air data transmission from LTE-U to WiFi, while NOTCH is a generic CTC framework that can be parametrized for any pair of wireless technologies. As a proof of concept, we use NOTCH to enable bidirectional CTC between LTE-U/LAA and WiFi. Second, having the possibility of communication, we build a common control plane and create two collaboration schemes. In XZero, an unlicensed LTE base station uses its beamforming capabilities to reduce interference at neighboring WiFi nodes. To this end, the nodes collaboratively perform the null-beam search. NxWLAN enables collaboration among separately owned WiFi networks. Specifically, it enables secure infrastructure sharing and cross-network traffic delivery to form a composite network and serve wireless clients from the access point providing the best connectivity. Finally, to move the boundaries of wireless communication, we need to make networks to ident [...]
doi:10.14279/depositonce-12218 fatcat:glihaqgw7zalxgcictlr6uicka