Karl-Johan Grinnemo

My research primarily considers transport-level solutions for IP-based applications with soft real-time requirements in both data communication and telecommunication networks. Currently, I am involved in the Knowledge Foundation founded research profile, ”High Quality Networked Services in a Mobile World” (HITS), and the EU HORIZON 2020 project, "The Fifth Generation End-to-End Network, Experimentation, System Integration, and Showcasing.

As part of our research profile, HITS, I am researching scalable and efficient transport-level communication solutions for current and future mobile networks. One of our key objectives is to find ways to optimize the battery consumption of Machine Type Communication (MTC) devices while at the same time assure that transport quality requirements, e.g., latency, are met. Constrained sensor devices often communicate periodically to notify their measurements. Even though individual devices typically create small amounts of data, the large number of communicating devices can be a cause of network congestion. In view of this, we investigate congestion control schemes for MTC devices that work in close cooperation with available energy consumption optimization schemes.

As a third activity, we are as part of HITS studying ways in which MTC could provide real-time control and automation of dynamic processes in various fields, e.g., energy distribution. This activity entails studying transport solutions in 5G suitable for critical MTC applications such as traffic and industrial control, clinical remote monitoring, and, not least, teleprotection of smart grids. For example, in power distribution automation, so-called switchgear interlocking across bays is of paramount importance. Substation wide switchgear interlocking must be performed in a distributed way through the exchange of messages, in the same or similar way as in the IEC-618508, Generic Object Oriented Substation Events (GOOSE) smart grid control model. In this way, static wiring between bay control units can be replaced by the reliable transmission of GOOSE messages.

Finally, as a fourth activity in HITS, we are studying scalable and efficient signaling solutions for the 5G core. Since the 5G core needs to support control signaling from billions of devices, it has to be designed to avoid congestion, offer low latency, and, at the same time, provide a flexible framework that is able to adapt to a variety of different use cases. We consider ways to design an SDN/NFV-based 5G core architecture that meets these requirements. For example, we study ways to efficiently and scalable load balance signaling traffic between base stations and virtualized Mobility Management Entities (vMMEs), key network functions, in a 5G core.

The 5GENESIS project aims to validate 5G Key Performance Indexes (KPIs) for various 5G use cases, in both controlled set-ups and large-scale events. As part of this project, we intend to validate and extend our work in HITS on optimizing the battery consumption of MTC devices in 5G. Moreover, we plan to further our previous work in the EU HORIZON 2020 project, NEAT, on "de-ossifying" the Internet transport-layer interface by conducting live experiment campaigns of the NEAT system in the controlled set-ups of 5GENESIS.

Karlstad University

• Lecturer in undergraduate course "Computer Networking I" (DVAE11), Spring 2019.
• Lecturer in undergraduate course "Degree Project for Master of Science in Engineering, Computer Engineering" (DVAE11), Fall 2018.
• Lecturer in undergraduate course "Computer Engineering Project" (DVAE08), Fall 2018.
• Lecturer in undergraduate course "Operating Systems" (DVGB01), Fall 2018.
• Examiner in undergraduate course "Degree Project for Master of Science in Engineering, Computer Engineering" (DVAE11), Spring 2018.
• Examiner in undergraduate course "Computer Science Bachelor's Project" (DVGC25), Spring 2018.
• Temporary lecturer in undergraduate course "Programming Techniques" (DVGA01), Fall 2017.
• Course responsible for Ph.D. course "Computer Networking Seminar", Fall 2017.
• Examiner in undergraduate course "Computer Science Bachelor's Project" (DVGC25), Spring 2017.
• Course responsible for undergraduate course "Computer Engineering Project" (DVAE08), Fall 2015.
• Assistant in Ph.D. course "Individual Themes", Spring 2014 and Fall 2015.
• Assistant in Ph.D. course "Classic Papers", Fall 2013.
• Lab assistant in undergraduate course "Programming Techniques for Engineers" (DVGA15), Fall 2013.
• Lab assistant in undergraduate course "Software Development and Design" (DVGA09), Spring 2013.
• Lab assistant in undergraduate course "Operating Systems" (DVGB01), Fall 2012 and Fall 2013.
• Lecturer in graduate course "Perspectives in Computer Science" (DVAD07), Fall 2011 - Fall 2015.
• Thesis advisor in undergraduate course "Bachelor's Project" (DVGC25), Fall 2011 - 2013.
• Lecturer in Ph.D. course "Current Advances in Computer Networking", Spring 2011.
• Course responsible for undergraduate course "Distributed Systems and Applications" (DVGC15), Fall 2010 - Fall 2017.

KTH Royal Institute of Technology

• Project assistant in graduate course "Communication System Design" (IK2200), Spring 2010.
• Course responsible for undergraduate course "Networks and Communication" (IK1203), Spring 2010.
• Lecturer and lab assistant in graduate course "Advanced Internetworking" (IK2215), Fall 2009 and Fall 2010.
• Lecturer and lab assistant in graduate course "Internet Security and Privacy" (IK1206), Fall 2009.

• Cooperates with Ericsson AB in the KKS HITS project.

I completed my Ph.D. studies in June 2006, and worked half a year as a post doctor at the former Department of Computer Science at Karlstad University. During that time, I continued my research from my Ph.D. studies on telephone signaling over IP and SCTP together with Ericsson Research in Aachen. I was also involved in a cooperative research effort on using SCTP in mobile networks together with Universitat Politècnica de Catalunya (UPC) in Barcelona. In January 2007, my post doctoral position at Karlstad University ended, and I resumed my position as consultant at Tieto in Karlstad. My work at Tieto was in many ways aligned with my research, and covered a broad range of activities including pre-studies, system design, and implementation. For example, I was involved in the implementation of an alarm function in Ericsson’s Connectivity Packet Platform (CPP), and conducted a pre-study together with colleagues from Tieto’s Beijing office on how to build an SCTP traffic offload engine for SCTP in CPP. Moreover, I continued to have a foot in research. As an adjunct researcher, I was actively participating in an on-going research effort between Tieto and Karlstad University. I took part in more or less all research project phases including planning, grant seeking, and execution.

Between the fall of 2009 and the fall of 2010, I was on leave from Tieto in Karlstad and worked as an acting associate professor at the School of Information and Communication Technology at the KTH Royal Institute of Technology. As an associate professor, I initiated a research project, ”Smart Session Management for Multi-homed SCTP” (SCTP Smartswitch), together with Karlstad University and Ericsson Research in Kista. The “SCTP Smartswitch” project aimed at extending the failover/changeover mechanism of SCTP with smart session management so that it would be able to manage everything from real-time applications, such as interactive games, which require fast failovers/changeovers, to roaming mobile terminals which sometimes experience long disconnection periods, i.e., long failover/changeover periods. In the fall of 2010, I acquired a four-year, tenure-track position at Karlstad University, and during the first two years as associate senior lecturer at their computer science department, the ”SCTP SmartSwitch” project was a major part of my research work. Notably, it resulted in about ten publications, an SCTP-based mobility management framework for smartphones and tablets that offered sub-second vertical handover between 3G and WiFi networks, and a generic SCTP-based session layer for mobility support in mobile delay-tolerant networks.

I became a Senior Lecturer at Karlstad University in the Fall of 2014 and an Associate Professor (swe. Docent) in the Fall 2016. In recent years, my research has to a large degree focused on the use of multi-path transport protocols such as Multipath TCP and CMT-SCTP to increase reliability and throughput and decrease latency in IP networks. I have also, as part of the HITS project, initiated studies on energy-efficient transport solutions for Cellular IoT technologies such as NB-IoT. I have authored and co-authored around fifty conference and journal papers, and is a Senior member of IEEE.