@techreport{ElsayedRizk2022,
  type      = {Working Paper},
  author    = {Elsayed, Karim and Rizk, Amr},
  title     = {Response Times in Time-to-Live Caching Hierarchies under Random Network Delays},
  series = {W{\"u}rzburg Workshop on Next-Generation Communication Networks (WueWoWas'22)},
  journal   = {W{\"u}rzburg Workshop on Next-Generation Communication Networks (WueWoWas'22)},
  doi       = {10.25972/OPUS-28084},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-280843},
  pages     = {4},
  year      = {2022},
  abstract  = {Time-to-Live (TTL) caches decouple the occupancy of objects in cache through object-specific validity timers. Stateof- the art techniques provide exact methods for the calculation of object-specific hit probabilities given entire cache hierarchies with random inter-cache network delays. The system hit probability is a provider-centric metric as it relates to the origin offload, i.e., the decrease in the number of requests that are served by the content origin server. In this paper we consider a user-centric metric, i.e., the response time, which is shown to be structurally different from the system hit probability. Equipped with the state-of-theart exact modeling technique using Markov-arrival processes we derive expressions for the expected object response time and pave a way for its optimization under network delays.},
  subject      = {Datennetz},
  language  = {en}
}
@techreport{AlfredssonKasslerVestinetal.2022,
  type      = {Working Paper},
  author    = {Alfredsson, Rebecka and Kassler, Andreas and Vestin, Jonathan and Pieska, Marcus and Amend, Markus},
  title     = {Accelerating a Transport Layer based 5G Multi-Access Proxy on SmartNIC},
  series = {W{\"u}rzburg Workshop on Next-Generation Communication Networks (WueWoWas'22)},
  journal   = {W{\"u}rzburg Workshop on Next-Generation Communication Networks (WueWoWas'22)},
  doi       = {10.25972/OPUS-28079},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-280798},
  pages     = {4},
  year      = {2022},
  abstract  = {Utilizing multiple access technologies such as 5G, 4G, and Wi-Fi within a coherent framework is currently standardized by 3GPP within 5G ATSSS. Indeed, distributing packets over multiple networks can lead to increased robustness, resiliency and capacity. A key part of such a framework is the multi-access proxy, which transparently distributes packets over multiple paths. As the proxy needs to serve thousands of customers, scalability and performance are crucial for operator deployments. In this paper, we leverage recent advancements in data plane programming, implement a multi-access proxy based on the MP-DCCP tunneling approach in P4 and hardware accelerate it by deploying the pipeline on a smartNIC. This is challenging due to the complex scheduling and congestion control operations involved. We present our pipeline and data structures design for congestion control and packet scheduling state management. Initial measurements in our testbed show that packet latency is in the range of 25 μs demonstrating the feasibility of our approach.},
  subject      = {Datennetz},
  language  = {en}
}
@techreport{OPUS4-20232,
  type      = {Working Paper},
  title     = {White Paper on Crowdsourced Network and QoE Measurements - Definitions, Use Cases and Challenges},
  editor    = {Hoßfeld, Tobias and Wunderer, Stefan},
  doi       = {10.25972/OPUS-20232},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-202327},
  pages     = {24},
  year      = {2020},
  abstract  = {The goal of the white paper at hand is as follows. The definitions of the terms build a framework for discussions around the hype topic 'crowdsourcing'. This serves as a basis for differentiation and a consistent view from different perspectives on crowdsourced network measurements, with the goal to provide a commonly accepted definition in the community. The focus is on the context of mobile and fixed network operators, but also on measurements of different layers (network, application, user layer). In addition, the white paper shows the value of crowdsourcing for selected use cases, e.g., to improve QoE or regulatory issues. Finally, the major challenges and issues for researchers and practitioners are highlighted. This white paper is the outcome of the W{\"u}rzburg seminar on "Crowdsourced Network and QoE Measurements" which took place from 25-26 September 2019 in W{\"u}rzburg, Germany. International experts were invited from industry and academia. They are well known in their communities, having different backgrounds in crowdsourcing, mobile networks, network measurements, network performance, Quality of Service (QoS), and Quality of Experience (QoE). The discussions in the seminar focused on how crowdsourcing will support vendors, operators, and regulators to determine the Quality of Experience in new 5G networks that enable various new applications and network architectures. As a result of the discussions, the need for a white paper manifested, with the goal of providing a scientific discussion of the terms "crowdsourced network measurements" and "crowdsourced QoE measurements", describing relevant use cases for such crowdsourced data, and its underlying challenges. During the seminar, those main topics were identified, intensively discussed in break-out groups, and brought back into the plenum several times. The outcome of the seminar is this white paper at hand which is - to our knowledge - the first one covering the topic of crowdsourced network and QoE measurements.},
  subject      = {Crowdsourcing},
  language  = {en}
}
@techreport{Metzger2020,
  type      = {Working Paper},
  author    = {Metzger, Florian},
  title     = {Crowdsensed QoE for the community - a concept to make QoE assessment accessible},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-203748},
  pages     = {7},
  year      = {2020},
  abstract  = {In recent years several community testbeds as well as participatory sensing platforms have successfully established themselves to provide open data to everyone interested. Each of them with a specific goal in mind, ranging from collecting radio coverage data up to environmental and radiation data. Such data can be used by the community in their decision making, whether to subscribe to a specific mobile phone service that provides good coverage in an area or in finding a sunny and warm region for the summer holidays. However, the existing platforms are usually limiting themselves to directly measurable network QoS. If such a crowdsourced data set provides more in-depth derived measures, this would enable an even better decision making. A community-driven crowdsensing platform that derives spatial application-layer user experience from resource-friendly bandwidth estimates would be such a case, video streaming services come to mind as a prime example. In this paper we present a concept for such a system based on an initial prototype that eases the collection of data necessary to determine mobile-specific QoE at large scale. In addition we reason why the simple quality metric proposed here can hold its own.},
  subject      = {Quality of Experience},
  language  = {en}
}
@techreport{LhamoNguyenFitzek2022,
  type      = {Working Paper},
  author    = {Lhamo, Osel and Nguyen, Giang T. and Fitzek, Frank H. P.},
  title     = {Virtual Queues for QoS Compliance of Haptic Data Streams in Teleoperation},
  series = {W{\"u}rzburg Workshop on Next-Generation Communication Networks (WueWoWas'22)},
  journal   = {W{\"u}rzburg Workshop on Next-Generation Communication Networks (WueWoWas'22)},
  doi       = {10.25972/OPUS-28076},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-280762},
  pages     = {4},
  year      = {2022},
  abstract  = {Tactile Internet aims at allowing perceived real-time interactions between humans and machines. This requires satisfying a stringent latency requirement of haptic data streams whose data rates vary drastically as the results of perceptual codecs. This introduces a complex problem for the underlying network infrastructure to fulfill the pre-defined level of Quality of Service (QoS). However, novel networking hardware with data plane programming capability allows processing packets differently and opens up a new opportunity. For example, a dynamic and network-aware resource management strategy can help satisfy the QoS requirements of different priority flows without wasting precious bandwidth. This paper introduces virtual queues for service differentiation between different types of traffic streams, leveraging protocol independent switch architecture (PISA). We propose coordinating the management of all the queues and dynamically adapting their sizes to minimize packet loss and delay due to network congestion and ensure QoS compliance.},
  subject      = {Datennetz},
  language  = {en}
}
@techreport{VomhoffGeisslerHossfeld2022,
  type      = {Working Paper},
  author    = {Vomhoff, Viktoria and Geißler, Stefan and Hoßfeld, Tobias},
  title     = {Identification of Signaling Patterns in Mobile IoT Signaling Traffic},
  series = {W{\"u}rzburg Workshop on Next-Generation Communication Networks (WueWoWas'22)},
  journal   = {W{\"u}rzburg Workshop on Next-Generation Communication Networks (WueWoWas'22)},
  doi       = {10.25972/OPUS-28081},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-280819},
  pages     = {4},
  year      = {2022},
  abstract  = {We attempt to identify sequences of signaling dialogs, to strengthen our understanding of the signaling behavior of IoT devices by examining a dataset containing over 270.000 distinct IoT devices whose signaling traffic has been observed over a 31-day period in a 2G network [4]. We propose a set of rules that allows the assembly of signaling dialogs into so-called sessions in order to identify common patterns and lay the foundation for future research in the areas of traffic modeling and anomaly detection.},
  subject      = {Datennetz},
  language  = {en}
}
@techreport{LohGeisslerHossfeld2022,
  type      = {Working Paper},
  author    = {Loh, Frank and Geißler, Stefan and Hoßfeld, Tobias},
  title     = {LoRaWAN Network Planning in Smart Environments: Towards Reliability, Scalability, and Cost Reduction},
  series = {W{\"u}rzburg Workshop on Next-Generation Communication Networks (WueWoWas'22)},
  journal   = {W{\"u}rzburg Workshop on Next-Generation Communication Networks (WueWoWas'22)},
  doi       = {10.25972/OPUS-28082},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-280829},
  pages     = {4},
  year      = {2022},
  abstract  = {The goal in this work is to present a guidance for LoRaWAN planning to improve overall reliability for message transmissions and scalability. At the end, the cost component is discussed. Therefore, a five step approach is presented that helps to plan a LoRaWAN deployment step by step: Based on the device locations, an initial gateway placement is suggested followed by in-depth frequency and channel access planning. After an initial planning phase, updates for channel access and the initial gateway planning is suggested that should also be done periodically during network operation. Since current gateway placement approaches are only studied with random channel access, there is a lot of potential in the cell planning phase. Furthermore, the performance of different channel access approaches is highly related on network load, and thus cell size and sensor density. Last, the influence of different cell planning ideas on expected costs are discussed.},
  subject      = {Datennetz},
  language  = {en}
}
@techreport{SertbasBuelbuelErgencFischer2022,
  type      = {Working Paper},
  author    = {Sertbas B{\"u}lb{\"u}l, Nurefsan and Ergenc, Doganalp and Fischer, Mathias},
  title     = {Evaluating Dynamic Path Reconfiguration for Time Sensitive Networks},
  series = {W{\"u}rzburg Workshop on Next-Generation Communication Networks (WueWoWas'22)},
  journal   = {W{\"u}rzburg Workshop on Next-Generation Communication Networks (WueWoWas'22)},
  doi       = {10.25972/OPUS-28074},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-280743},
  pages     = {5},
  year      = {2022},
  abstract  = {In time-sensitive networks (TSN) based on 802.1Qbv, i.e., the time-aware Shaper (TAS) protocol, precise transmission schedules and, paths are used to ensure end-to-end deterministic communication. Such resource reservations for data flows are usually established at the startup time of an application and remain untouched until the flow ends. There is no way to migrate existing flows easily to alternative paths without inducing additional delay or wasting resources. Therefore, some of the new flows cannot be embedded due to capacity limitations on certain links which leads to sub-optimal flow assignment. As future networks will need to support a large number of lowlatency flows, accommodating new flows at runtime and adapting existing flows accordingly becomes a challenging problem. In this extended abstract we summarize a previously published paper of us [1]. We combine software-defined networking (SDN), which provides better control of network flows, with TSN to be able to seamlessly migrate time-sensitive flows. For that, we formulate an optimization problem and propose different dynamic path configuration strategies under deterministic communication requirements. Our simulation results indicate that regularly reconfiguring the flow assignments can improve the latency of time-sensitive flows and can increase the number of flows embedded in the network around 4\% in worst-case scenarios while still satisfying individual flow deadlines.},
  subject      = {Datennetz},
  language  = {en}
}
@techreport{LeGrossmannKrieger2022,
  type      = {Working Paper},
  author    = {Le, Duy Thanh and Großmann, Marcel and Krieger, Udo R.},
  title     = {Cloudless Resource Monitoring in a Fog Computing System Enabled by an SDN/NFV Infrastructure},
  series = {W{\"u}rzburg Workshop on Next-Generation Communication Networks (WueWoWas'22)},
  journal   = {W{\"u}rzburg Workshop on Next-Generation Communication Networks (WueWoWas'22)},
  doi       = {10.25972/OPUS-28072},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-280723},
  pages     = {4},
  year      = {2022},
  abstract  = {Today's advanced Internet-of-Things applications raise technical challenges on cloud, edge, and fog computing. The design of an efficient, virtualized, context-aware, self-configuring orchestration system of a fog computing system constitutes a major development effort within this very innovative area of research. In this paper we describe the architecture and relevant implementation aspects of a cloudless resource monitoring system interworking with an SDN/NFV infrastructure. It realizes the basic monitoring component of the fundamental MAPE-K principles employed in autonomic computing. Here we present the hierarchical layering and functionality within the underlying fog nodes to generate a working prototype of an intelligent, self-managed orchestrator for advanced IoT applications and services. The latter system has the capability to monitor automatically various performance aspects of the resource allocation among multiple hosts of a fog computing system interconnected by SDN.},
  subject      = {Datennetz},
  language  = {en}
}
@techreport{HoewelerXiangHoepfneretal.2022,
  type      = {Working Paper},
  author    = {H{\"o}weler, Malte and Xiang, Zuo and H{\"o}pfner, Franz and Nguyen, Giang T. and Fitzek, Frank H. P.},
  title     = {Towards Stateless Core Networks: Measuring State Access Patterns},
  series = {W{\"u}rzburg Workshop on Next-Generation Communication Networks (WueWoWas'22)},
  journal   = {W{\"u}rzburg Workshop on Next-Generation Communication Networks (WueWoWas'22)},
  doi       = {10.25972/OPUS-28077},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-280770},
  pages     = {4},
  year      = {2022},
  abstract  = {Future mobile communication networks, such as 5G and beyond, can benefit from Virtualized Network Functions (VNFs) when deployed on cloud infrastructures to achieve elasticity and scalability. However, new challenges arise as to managing states of Network Functions (NFs). Especially control plane VNFs, which are mainly found in cellular core networks like the 5G Core (5GC), received little attention since the shift towards virtualizing NFs. Most existing solutions for these core networks are often complex, intrusive, and are seldom compliant with the standard. With the emergence of 5G campus networks, UEs will be mainly machine-type devices. These devices communicate more deterministically, bringing new opportunities for elaborated state management. This work presents an emulation environment to perform rigorous measurements on state access patterns. The emulation comes with a fully parameterized Markov model for the UE to examine a wide variety of different devices. These measurements can then be used as a solid base for designing an efficient, simple, and standard conform state management solution that brings us further towards stateless core networks.},
  subject      = {Datennetz},
  language  = {en}
}