502 citations · 648 across the 20 of their papers we have counts for
22 papers
Embedding Delay-Constrained VNF Forwarding Graphs into Reconfigurable WDM Optical Networks -- Extended Version
Valentin Kirchner, Holger Karl
Operators of reconfigurable wavelength-division multiplexed (WDM) optical networks adapt the lightpath topology to balance load and reduce transmission delays. Such an adaption gen…
Reinforcement Learning for Admission Control in Wireless Virtual Network Embedding
Haitham Afifi, Fabian Sauer, Holger Karl
Using Service Function Chaining (SFC) in wireless networks became popular in many domains like networking and multimedia. It relies on allocating network resources to incoming SFCs…
Practical sufficient conditions for convergence of distributed optimisation algorithms over communication networks with interference
Adrian Redder, Arunselvan Ramaswamy, Holger Karl
Information exchange over networks can be affected by various forms of delay. This causes challenges for using the network by a multi-agent system to solve a distributed optimisati…
The Softwarised Network Data Zoo
Manuel Peuster, Stefan Schneider, Holger Karl
More and more management and orchestration approaches for (software) networks are based on machine learning paradigms and solutions. These approaches depend not only on their progr…
Deep Reinforcement Learning for Wireless Sensor Scheduling in Cyber-Physical Systems
Alex S. Leong, Arunselvan Ramaswamy, Daniel E. Quevedo +2
In many Cyber-Physical Systems, we encounter the problem of remote state estimation of geographically distributed and remote physical processes. This paper studies the scheduling o…
Specifying and Analyzing Virtual Network Services Using Queuing Petri Nets
Stefan Schneider, Arnab Sharma, Holger Karl +1
For optimal placement and orchestration of network services, it is crucial that their structure and semantics are specified clearly and comprehensively and are available to an orch…
DeepCAS: A Deep Reinforcement Learning Algorithm for Control-Aware Scheduling
Burak Demirel, Arunselvan Ramaswamy, Daniel E. Quevedo +1
We consider networked control systems consisting of multiple independent controlled subsystems, operating over a shared communication network. Such systems are ubiquitous in cyber-…
Joint Orchestration of Cloud-Based Microservices and Virtual Network Functions
Hadi Razzaghi Kouchaksaraei, Holger Karl
Recent studies show the increasing popularity of distributed cloud applications, which are composed of multiple microservices. Besides their known benefits, microservice architectu…
MARVELO: Wireless Virtual Network Embedding for Overlay Graphs with Loops
Haitham Afifi, Sebastien Auroux, Holger Karl
When deploying resource-intensive signal processing applications in wireless sensor or mesh networks, distributing processing blocks over multiple nodes becomes promising. Such dis…
JASPER: Joint Optimization of Scaling, Placement, and Routing of Virtual Network Services
Sevil Dräxler, Holger Karl, Zoltán Ádám Mann
To adapt to continuously changing workloads in networks, components of the running network services may need to be replicated (scaling the network service) and allocated to physica…
Understand Your Chains: Towards Performance Profile-based Network Service Management
Manuel Peuster, Holger Karl
Allocating resources to virtualized network functions and services to meet service level agreements is a challenging task for NFV management and orchestration systems. This becomes…
MeDICINE: Rapid Prototyping of Production-Ready Network Services in Multi-PoP Environments
Manuel Peuster, Holger Karl, Steven van Rossem
Virtualized network services consisting of multiple individual network functions are already today deployed across multiple sites, so called multi-PoP (points of presence) environ-…
SONATA: Service Programming and Orchestration for Virtualized Software Networks
Sevil Dräxler, Manuel Peuster, Holger Karl +6
In conventional large-scale networks, creation and management of network services are costly and complex tasks that often consume a lot of resources, including time and manpower. N…
Response-Time-Optimized Distributed Cloud Resource Allocation
Matthias Keller, Holger Karl
A current trend in networking and cloud computing is to provide compute resources over widely dispersed places exemplified by initiatives like Network Function Virtualisation. This…
Response-Time-Optimised Service Deployment: MILP Formulations of Piece-wise Linear Functions Approximating Non-linear Bivariate Mixed-integer Functions
Matthias Keller, Holger Karl
A current trend in networking and cloud computing is to provide compute resources at widely dispersed places; this is exemplified by developments such as Network Function Virtualis…
HybridTE: Traffic Engineering for Very Low-Cost Software-Defined Data-Center Networks
Philip Wette, Holger Karl
The size of modern data centers is constantly increasing. As it is not economic to interconnect all machines in the data center using a full-bisection-bandwidth network, techniques…
Dynamic Backhaul Network Configuration in SDN-based Cloud RANs
Martin Dräxler, Holger Karl
The coordination of base stations in mobile access networks is an important approach to reduce harmful interference and to deliver high data rates to the users. Such coordination m…
Specification of Complex Structures in Distributed Service Function Chaining Using a YANG Data Model
Sevil Mehraghdam, Holger Karl
While services benefit from distributed cloud centers running in isolation, allowing multiple centers to cooperate on implementing services unlocks the full power of distributed cl…
Adding Geographical Embedding to AS Topology Generation
Arne Schwabe, Holger Karl
To study large-scale effects on the Internet various mod- els have been introduced to generate Internet-like autono- mous system (AS) topologies. The models for large-scale AS topo…
DCTGen: A Versatile TCP Traffic Generator for Data Centers
Philip Wette, Holger Karl
Only little is publicly known about traffic in non-educational data centers. Recent studies made some knowledge available, which gives us the opportunity to create more realistic t…
Specifying and Placing Chains of Virtual Network Functions
Sevil Mehraghdam, Matthias Keller, Holger Karl
Network appliances perform different functions on network flows and constitute an important part of an operator's network. Normally, a set of chained network functions process netw…
Anticipatory Buffer Control and Quality Selection for Wireless Video Streaming
Martin Dräxler, Johannes Blobel, Philipp Dreimann +2
Video streaming is in high demand by mobile users, as recent studies indicate. In cellular networks, however, the unreliable wireless channel leads to two major problems. Poor chan…