Mobile connectivity has become so pervasive that humanity takes it for granted similar to a basic utility like electricity or water. However, making this utility available to a significant chunk of the world's population in several developing and rural parts of the world, is still not economically viable. In addition, even in places, where such a connectivity infrastructure exists, one cannot completely rely on it in times of natural calamities and disasters, where it can be significantly compromised. Thus, while mobile cellular networks have ushered in an era of abundant data-rates, their 5G vision to deliver true "ubiquitous" connectivity still remains unfulfilled.

With recent significant advances in autonomous systems (both unmanned aerial vehicles, UAVs and terrestrial autonomous ground vehicles, AGVs) and their proliferation in various everyday applications (delivery, transportation, etc.), one can now envision dynamic connectivity infrastructures that can be deployed and torn down "on-demand" by leveraging such platforms. This has the potential to change the landscape of wide-area wireless connectivity brought about by a new dimension – “mobility” of the cellular network infrastructure itself. The goal of this project is to architect and deploy an end-to-end system that addresses the various technical challenges in the deployment of a network of low-altitude, self-organizing, autonomous UAVs that can provide optimized mobile connectivity and sensing capabilities over a desired geographic region. 

While Google’s Project Loon is an example of high-altitude, long-endurance UAV-based connectivity effort in this direction, the telecom operators have been exploring low-altitude UAV-based LTE solutions for on-demand deployments as well. By deploying base stations on each of the UAVs, service providers can now deploy and tear-down these cellular networks “in the sky” in an on-demand and flexible manner.  This allows them to supplement static mobile networks in areas where additional connectivity is needed, or provide stand-alone connectivity in areas where existing mobile networks are either absent or compromised. Understandably, these projects are in their very early stages -- realizing this vision of deploying heavy-weight cellular networks (e.g. LTE or 5G-NR) on light-weight, resource-constrained platforms such as UAVs, faces several formidable challenges both in design and deployment. This is complicated by the complex nature of cellular networks that involve multiple interacting components – radio access network (RAN), evolved packet core (EPC) network and backhaul transport network.

Our goal is to explore the end-to-end design space of such UAV-based connectivity networks particularly in the context of low-altitude UAV networks providing cellular connectivity. As a first step in this direction, we need to understand both the challenges as well as the potential offered by these unconventional connectivity solutions. Specifically, we need to unravel the challenges that span across multiple layers (access, core network, backhaul) in an inter-twined manner as well as the richness and complexity of the design space itself. To help network practitioners navigate this complex design space towards a solution, we have architected the end-to-end design of such a system called SkyLiTE – a self-organizing network of low-altitude UAVs that aim to provide optimized cellular (e.g. LTE) connectivity in a desired region.

Check this page for updates on SkyLiTE's progress and various articles relating to its design and deployment. A short demo of some of the applications enabled by SkyLiTE can be found below.

• "SkyLiTE: End-to-End Design of Low-altitude UAV Networks for Providing LTE Connectivity." K. Sundaresan, E. Chai, A. Chakraborty, and S. Rangarajan, NEC Technical Report, Dec 2017 (On Arxiv).

• "SkyCore: Moving Core to the Edge for Un-tethered and Reliable UAV-based LTE Networks", M. Moradi, K. Sundaresan, E, Chai, S. Rangarajan, M. Mao, Best paper award, ACM MobiCom, Oct 2018. 

• "SkyRAN: A Self-Organizing LTE RAN in the Sky", A. Chakraborty, E. Chai, K. Sundaresan, A. Khojasptepour, S. Rangarajan, ACM CoNEXT, Dec 2018. (Online)

• "SkyHaul: A Self-Organizing Gigabit Network in the Sky", R. Seshadri, E. Chai, K. Sundaresan, S. Rangarajan, ACM MobiHoc 2021. 

Applications