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Nitinder Mohan

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Conference paper (2026) - Rohan Bose, Jinwei Zhao, Tanya Shreedhar, Jianping Pan, Nitinder Mohan
Low Earth Orbit (LEO) satellite ISPs promise universal Internet connectivity, yet their interaction with content delivery remains poorly understood. We present the first comprehensive measurement study decomposing Starlink's web content delivery performance decomposed across Point of Presence (PoP), DNS, and CDN layers. To quantify how satellite architecture disrupts terrestrial CDN assumptions, we conduct a measurement study spanning two years. We identify three distinct performance regimes based on infrastructure density. Regions with local content-rich PoPs achieve near-terrestrial latencies with the satellite segment dominating 80-90% of RTT. Infrastructure-sparse regions suffer cascading penalties: remote PoPs force distant resolver selection, which triggers CDN mislocalization, pushing latencies beyond 200 ms. Dense-infrastructure regions show minimal sensitivity to PoP changes. Leveraging Starlink's infrastructure expansion in early 2025 as a natural experiment, we demonstrate that relocating PoPs closer to user location reduces median page-fetch times by 60%. Our findings reveal that infrastructure proximity, not satellite coverage, influences web performance, requiring fundamental changes to CDN mapping and DNS resolution for satellite ISPs. ...
Book chapter (2026) - Benjamin Finley, Nitinder Mohan, Peng Yuan Zhou
Networking is critical to a holistic metaverse system given the high-throughput and low-latency requirements and often distributed nature of metaverses. This chapter discusses several important aspects and directions that can enhance the networking performance in the metaverse, including user experienced delay, edge computing, multimodal networking, semantic and goal/deadline-aware networking, multipath networking, CDN, etc. ...

Understanding and Predicting Global Starlink Performance

Starlink has deployed over 7,800 satellites serving millions of subscribers, yet predicting its performance remains an open challenge. Rapid orbital dynamics, frequent handovers, and weather-induced signal attenuation create variability that existing models, built on a handful of instrumented terminals in limited regions, cannot capture at global scale. We present Horizon, the first global-scale machine learning system for predicting LEO satellite Internet performance. Our key insight is that crowdsourced measurement platforms, while noisier than controlled experiments, provide the geographic diversity necessary to build globally generalizable models. Horizon integrates 11 months of measurements from M-Lab and Cloudflare spanning 90+ countries with meteorological data and satellite orbital propagation features. On a fully held-out one-week temporal window, Horizon achieves mean absolute errors of 17.76 ms for latency and 25.63 Mbps for throughput; on a standard 80/20 split it outperforms all baselines, including adaptations of state-of-the-art architectures. Feature importance analysis reveals that geographic position dominates prediction, with latitude alone contributing 42-46%, while weather features account for 14-15%, quantifying the impact of atmospheric conditions on Ku/Ka-band links. Leave-one-location-out experiments confirm that Horizon generalizes to regions absent from training, enabling performance estimation where measurement infrastructure does not yet exist. Our dataset and pipeline are publicly available, providing a foundation for global LEO network performance visibility. ...
Conference paper (2025) - Giovanni Bartolomeo, Patrick Sabanic, Nitinder Mohan, Jorg Ott
Microservice architectures allow developers to decompose their applications into independently deployable functional blocks, each with its own requirements. In order to support a wide range of constraints, service virtualization can be customized across microservices but is typically homogeneous within a cluster. As there is no clear one size fit all approach, we can improve resource utilization and performance by using virtualization as a new dimension in orchestration, especially in edge computing environments. For instance, Unikernels represent a lightweight virtualization technology that offers a performant alternative to traditional containers. While we find different studies analyzing and comparing these virtualization technologies, (a) the performance results might vary when including the overhead of the orchestration platform, and (b) it's not trivial to select the perfect virtualization technology for an entire cluster. In this paper, we explore the benefits of hybrid container-unikernel deployments by extending an orchestration framework for edge computing to allow for seamless mixing and matching of both technologies. Our evaluation shows how hybrid deployments can lead up to 44% CPU reduction cluster-wide while there are scenarios where containers are still preferable. ...
Conference paper (2025) - Wei Geng, Oguz Kagan Altas, David Guzman, Giovanni Bartolomeo, Nitinder Mohan, Joerg Ott
Edge computing orchestration faces significant challenges due to resource constraints, highly distributed topologies, and dynamic network conditions. The discrepancy between theoretical and actual runtime performance often leads to suboptimal deployment decisions. This discrepancy is severe in clustered deployments, as existing tools either saturate network links during testing or lack proactive assessment capabilities. None of these approaches accurately predicts service co-locating compatibility in real-world scenarios. We present KUT (Konnectivity Under Test), a lightweight network assessment framework designed specifically for edge environments, combining service-specific traffic simulation with periodical monitoring to provide accurate compatibility assessments without starving co-located services. KUT enables periodic background assessments that inform orchestration decisions while consuming minimal resources. ...
Conference paper (2025) - Jörg Ott, Jussi Kangarharju, Nitinder Mohan
Emerging Low Earth Orbit (LEO) satellite constellations have been considered for uses beyond plain Internet access, including content caching and edge computing. Assuming satellites are equipped with inter-satellite links, we propose using these links and thus the space in-between satellites, paired with a dedicated satellite queuing system, to "store"data and provide access by keeping data in constant flux around the globe. We describe the properties and explore the capabilities of such a system and discuss some potential uses. ...
Preprint (2024) - Leonardo Tonetto, Pauline Kister, Nitinder Mohan, Jörg Ott
Networking research, especially focusing on human mobility, has evolved significantly in the last two decades and now relies on collection and analyzing larger datasets. The increasing sizes of datasets are enabled by larger automated efforts to collect data as well as by scalable methods to analyze and unveil insights, which was not possible many years ago. However, this fast expansion and innovation in human-centric research often comes at a cost of privacy or ethics. In this work, we review a vast corpus of scientific work on human mobility and how ethics and privacy were considered. We reviewed a total of 118 papers, including 149 datasets on individual mobility. We demonstrate that these ever growing collections, while enabling new and insightful studies, have not all consistently followed a pre-defined set of guidelines regarding acceptable practices in data governance as well as how their research was communicated. We conclude with a series of discussions on how data, privacy and ethics could be dealt within our community. ...

Third International Workshop on Negative Results in Pervasive Computing - Welcome and Committees

Journal article (2024) - Ella Peltonen, Nitinder Mohan, Peter Zdankin, Malte Josten, Tanya Shreedar, Tanya Shreedhar, Suzan Bayhan, Javier Berrocal, Aaron Yi Ding, More authors...
Conference paper (2024) - Nitinder Mohan, Andrew E. Ferguson, Hendrik Cech, Rohan Bose, Prakita Rayyan Renatin, Mahesh K. Marina, Jörg Ott
The Starlink network from SpaceX stands out as the only commercial LEO network with over 2M+ customers and more than 4000 operational satellites. In this paper, we conduct a first-of-its-kind extensive multi-faceted analysis of Starlink performance leveraging several measurement sources. First, based on 19.2M crowdsourced M-Lab speed tests from 34 countries since 2021, we analyze Starlink global performance relative to terrestrial cellular networks. Second, we examine Starlink's ability to support real-time latency and bandwidth-critical applications by analyzing the performance of (i) Zoom conferencing, and (ii) Luna cloud gaming, comparing it to 5G and fiber. Third, we perform measurements from Starlink-enabled RIPE Atlas probes to shed light on the last-mile access and other factors affecting its performance.Finally, we conduct controlled experiments from Starlink dishes in two countries and analyze the impact of globally synchronized "15-second reconfiguration intervals'' of the satellite links that cause substantial latency and throughput variations. Our unique analysis paints the most comprehensive picture of Starlink's global and last-mile performance to date. ...
Conference paper (2024) - Valentin Hartig, Marcin Bosk, Nitinder Mohan, Paulo Mendes
Low Earth Orbit (LEO) satellite constellations have highly dynamic network topologies, making conventional routing protocols inefficient. This paper presents Geographic Checkpoint Routing (GCR), a routing protocol that combines Geographic Routing and Segment Routing (SR) principles. Utilizing the structure of Walker Delta constellations, GCR eliminates the reliance on network topologies. It routes traffic through predefined geographic segments, offloads route computation to network edges, and allows traffic engineering through customizable policies without modifying satellite infrastructure. Simulations using the Starlink constellation show that GCR can match the performance of traditional source-based routing protocols without depending on network topologies. ...
Journal article (2024) - Tobias Meuser, Lauri Lovén, M Bhuyan, Shishir G. Patil, Schahram Dustdar, Atakan Aral, Suzan Bayhan, Aaron Yi Ding, Nitinder Mohan, More authors...
Edge artificial intelligence (AI) is an innovative computing paradigm that aims to shift the training and inference of machine learning models to the edge of the network. This paradigm offers the opportunity to significantly impact our everyday lives with new services such as autonomous driving and ubiquitous personalized health care. Nevertheless, bringing intelligence to the edge involves several major challenges, which include the need to constrain model architecture designs, the secure distribution and execution of the trained models, and the substantial network load required to distribute the models and data collected for training. In this article, we highlight key aspects in the development of edge AI in the past and connect them to current challenges. This article aims to identify research opportunities for edge AI, relevant to bring together the research in the fields of artificial intelligence and edge computing. ...

Twinkle, Twinkle, Streaming Star: Illuminating CDN Performance over Starlink

Conference paper (2024) - Rohan Bose, Nitinder Mohan, Jörg Ott
Low-Earth-Orbit satellite networks (LSNs) are enabling low-latency high-bandwidth internet connectivity at a global scale. However, majority of the traffic on the Internet is currently handled by Content Delivery Networks (CDNs), which rely on geographical proximity to deliver content. In this work, we examine CDN performance for the commercial largest LSN, i.e. Starlink, by performing active measurements through our web browser plugin and passive analysis of Cloudflare speed tests globally. Comparing this to terrestrial networks, we highlight significant performance degradation for Starlink users due to the asymmetries between satellite and terrestrial infrastructure. ...

Investigating Content Delivery Networks in the LEO Satellite Networks Era

Conference paper (2024) - Rohan Bose, Saeed Fadaei, Nitinder Mohan, Mohamed Kassem, Nishanth Sastry, Jörg Ott
Content Delivery Networks (CDNs) have been pivotal in the dramatic evolution of the Internet, handling the majority of data traffic for billions of connected users. Low-Earth-Orbit (LEO) satellite networks, such as Starlink, aim to revolutionize global connectivity by providing high-speed, low-latency Internet to remote regions. However, LEO satellite networks (LSNs) face challenges integrating with traditional CDNs, which rely on geographical proximity for efficient content delivery - a method that clashes with the operational dynamics of LSNs. In this paper, we scrutinize the operation of CDNs in the context of LSNs, using Starlink as a case study. We develop a browser extension NetMet that performs extensive web browsing experiments from controlled nodes using both Starlink and terrestrial Internet access. Additionally, we analyse crowdsourced speed tests from Starlink users to Cloudflare CDN servers globally. Our results indicate significant performance issues for Starlink users, stemming from the misalignment between terrestrial and satellite infrastructures. We then investigate the potential for SpaceCDNs which integrate CDN infrastructure directly within the LSNs, and show that this approach offers a promising alternative that decreases latencies by over 50%, making them comparable with the CDN experience of users behind terrestrial ISPs. Our aim is to stimulate further research and discussion on overcoming the challenges of effective content delivery with growing LSN offerings. ...
Journal article (2023) - Ella Peltonen, Nitinder Mohan, Peter Zdankin, Tanya Shreedhar, Tri Nguyen, Suzan Bayhan, Jon Crowcroft, Jussi Kangasharju, Daniela Nicklas
Not all research leads to fruitful results; trying new ways or methods may surpass state of the art, but sometimes the hypothesis is not proven, the improvement is insignificant, or the system fails because of a design error done years ago in previous works. In a systems discipline like pervasive computing, there are many sources of errors, from hardware issues over communication channels to heterogeneous software environments. However, failure to succeed is not a failure to progress. It is essential to create platforms for sharing insights, experiences, and lessons learned when conducting research in pervasive computing so that the same mistakes are not repeated. And sometimes, a problem is a symptom of discovering new research challenges. Based on the collective input of the First International Workshop on Negative Results in Pervasive Computing (PerFail 2022), co-located with the 20th International Conference on Pervasive Computing and Communications (PerCom 2022), this article presents a comprehensive discussion on perspectives on publishing negative results, useful failures, and lessons learned in pervasive computing. ...
Journal article (2023) - Aygün Baltaci, Kaushik Chavali, Mike Kosek, Nitinder Mohan, Dominic A. Schupke, Jörg Ott
Recent industrial advancements introduce novel safety-critical applications for commercial networks. Remote Piloting (RP) Aerial Vehicles (AVs) is an example application, where reliable wireless connectivity is key to ensure safe operations in the sky. Jointly utilizing cellular and satellite networks can enable robust Multipath (MP) communications; however, their usage must be orchestrated efficiently toward application requirements. In this work, we investigate the MP communications performance of cellular and Low-Earth-Orbit (LEO) satellite links with respect to the Quality-of-Service (QoS) requirements of RP operations. Using MP-Transmission Control Protocol (MPTCP) and MP-Datagram Congestion Control Protocol (MP-DCCP), we evaluate various transport layer configurations to efficiently orchestrate both links and to support the application requirements. For this purpose, we develop an end-to-end MP emulation testbed that can provide means to realistically emulate cellular and LEO links with MPTCP and MP-DCCP. We run bi-direction al RP traffic over our testbed and measure the MP performance using different schedulers and Congestion Control (CC) algorithms. The results show that the flow size largely influences the individual path utilization due to high LEO link-layer losses. Moreover, excessive retransmissions occur on the MPTCP layer due to Head-of-Line (HoL) blocking from asymmetric link conditions. Using MP-DCCP without retransmissions helps avoid late arrivals and can meet the 99.999% communication reliability demand. ...
Conference paper (2023) - Giovanni Bartolomeo, Jacky Cao, Xiang Su, Nitinder Mohan
Mobile Augmented Reality (AR) is gaining traction as a compelling application due to recent advancements in hardware and software. Previous studies have suggested that distributing AR services on an edge computing infrastructure can offer significant performance benefits, especially for consolidating concurrent clients. In this study, we shed light on several research challenges directly impacting the effective integration of distributed AR and edge computing. Specifically, we conduct extensive experiments by deploying our distributed stream processing-based AR pipeline, scAtteR, on a representative edge-cloud infrastructure managed by the Oakestra framework. We uncover several unapparent challenges that inhibit the effective marriage of distributed AR when deployed on edge and demonstrate the potential improvements through scAtteR++. We offer valuable insights and best practices to the growing AR research community, specifically those interested in leveraging edge and public cloud technologies for large-scale AR operations. ...
Conference paper (2023) - Alba Jano, Mehmet Mert Bese, Nitinder Mohan, Wolfgang Kellerer, Jörg Ott
Researchers have already begun experimenting with next-generation cellular technologies and algorithms to enable use cases that lie beyond the scope of the current 5G standard, e.g. XR, smart factories, AI networks ops, etc. The common denominator requirement of such scenarios is the joint (coupled) operation of radio channel and edge computing resources within the core network. While there are numerous tools that allow experimenting with various aspects of radio resource management and computing resource management individually, there is a lack of solutions that enable researchers to prototype and evaluate applications and technologies dependent on both aspects simultaneously. In this work, we present nextGSIM, a 5G and beyond network simulator that realistically models the radio access network and edge network jointly to provide an end-to-end service to various user devices running microservice-based application workloads. We detail our design decisions and modular architecture of nextGSIM which resembles real-world setup of cellular networks, enabling effective and detailed simulations of resource management algorithms. We demonstrate the effectiveness and capabilities of nextGSIM through indoor factory case study wherein we evaluate widely regarded radio and edge resource management algorithms. We compare these against a joint radio-compute scheduler which emphasizes the need and benefits of joint resource allocation decision making, which is only possible through tools such as nextGSIM. ...
Conference paper (2022) - Simon Bäurle, Nitinder Mohan
Edge computing is an attractive platform where applications, previously hosted in the cloud, shift parts of their workload on resources closer to the users. The field is still in its nascent stages with significant ongoing innovation in small form-factor hardware designed to operate at the edge. However, the increased hardware heterogeneity at the edge makes it difficult for application developers to determine if their workloads will operate as desired. Simultaneously, edge providers have to make expensive deployment choices for the "correct" hardware that will remain suitable for the near future. We present ComB, an application-oriented benchmarking suite for edge that assists early adopters in evaluating the suitability of an edge deployment. ComB is flexible, extensible, and incorporates a microservice-based video analytics pipeline as default workload to measure underlying hardware's compute and networking capabilities accurately. Our evaluation on a heterogeneous testbed shows that ComB enables both providers and developers to understand better the runtime capabilities of different hardware configurations for supporting operations of applications designed for the edge. ...
Conference paper (2022) - Uthra Ambalavanan, Dennis Grewe, Naresh Nayak, Liming Liu, Nitinder Mohan, Jörg Ott
Application domains such as automotive and the Internet of Things may benefit from in-network computing to reduce the distance data travels through the network and the response time. Information Centric Networking (ICN) based compute frameworks such as Named Function Networking (NFN) are promising options due to their location independence and loosely-coupled communication model. However, unlike current operations, such solutions may benefit from orchestration across the compute nodes to use the available resources in the network better. In this paper, we adopt the State Vector Synchronization (SVS), an application dataset synchronization protocol in ICN, to enhance the neighborhood knowledge of in-network compute nodes in a distributed fashion. As such, we design distributed coordination for in-network computation (DICer) that assists the service deployments by improving the resolution of compute requests. We evaluate the performance of DICer against NFN and observe an increase in the resource utilization at the edge and a reduction in the request completion time. ...
Conference paper (2022) - Giovanni Bartolomeo, Simon Bäurle, Nitinder Mohan, Jörg Ott
Edge computing enables developers to deploy their services on compute resources deployed closer to the users. The abstraction requires powerful orchestration capabilities and the resolution of complex optimization problems. While edge computing is a consistently growing trend, the community (research and industry) still largely embraces adaptations and extensions of existing cloud technologies that have been proven ineffective on edge (e.g. Kubernetes). In this work, we present Oakestra, a novel hierarchical orchestration framework specifically designed for supporting service operation over heterogeneous edge infrastructures. In this demonstration, we showcase the various features and operations of Oakestra using our latency-critical augmented reality (AR) application. ...