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  • 1.
    Andersson, Karl
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Elkotob, Muslim
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    A new MIP-SIP interworking scheme2008In: MUM'08 Proceedings: 7th ACM International Conference on Mobile and Ubiquitous Multimedia, December 3 - 5, 2008, Umeå, Sweden, New York: ACM Digital Library, 2008, p. 117-120Conference paper (Refereed)
    Abstract [en]

    Mobility management is today handled at various layers in the network stack including the datalink layer, the network layer, the transport layer and the application layer. Also, cross-layer designed solutions exist and the most known example is the work performed by IEEE currently standardizing media-independent handover services under the name of IEEE 802.21.This paper proposes a new interworking scheme for Mobile IP and the Session Initiation Protocol being the most popular solutions for mobility management at the network and application layers respectively. The goal is to deliver seamless mobility for both TCP-based and UDP-based applications taking the best features from each mobility management scheme. In short, this paper proposes that TCP connections are handled through Mobile IP while UDP-based connection-less applications may use the Session Initiation Protocol for handling mobility. The two mobility management solutions are integrated into one common solution.

  • 2.
    Andersson, Karl
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Granlund, Daniel
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Elkotob, Muslim
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Bandwidth efficient mobility management for heterogeneous wireless networks2010In: 2010 7th IEEE Consumer Communications and Networking Conference: Las Vegas, Nevada, USA : 9-12 January, 2010, Piscataway, N.J: IEEE Communications Society, 2010Conference paper (Refereed)
    Abstract [en]

    An important feature of the upcoming fourth generation wireless networks is support for heterogeneous radio access technologies in combination with an all-IP type of overall architecture. Operators and users will benefit from a smooth technology transition leveraging existing investments and use a variety of access technologies simultaneously. This paper describes and evaluates an innovative mobility management scheme in such an environment. It does not require any changes to the IP stack in the mobile node and does not introduce any additional overhead to the payload traffic over air interfaces. Furthermore, it does not add any signaling overhead and outperforms existing mobility management schemes for heterogeneous environments in terms of bandwidth consumption. The architecture uses a make-before-break principle for vertical handovers and bidirectional tunneling using various tunneling mechanisms connecting mobile nodes through access networks to a home network. Also, it proposes a packet inspection routine for timely handover execution in the home network. The architecture is evaluated both through analytical calculations and experiments using a voice over IP traffic model.

  • 3.
    Andersson, Karl
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Granlund, Daniel
    Åhlund, Christer
    M4: MultiMedia Mobility Manager: a seamless mobility management architecture supporting multimedia applications2007In: Proceedings of the 6th International Conference on Mobile and Ubiquitous Multimedia: December 12 - 14, 2007, Oulu, Finland / [ed] Timo Ojala, Red Hook, NY: Curran Associates, Inc., 2007, p. 6-13Conference paper (Refereed)
    Abstract [en]

    In this paper, a proof-of-concept and a software architecture, M4 (MultiMedia Mobility Manager), is presented. In short, M4 is offering seamless mobility management to multimedia appli­cations using a variety of wireless access networks. First, M4 is built on multihomed Mobile IP building on the principle of soft handovers. Second, network selection in M4 is based on a network layer metric combining round-trip times and jitter in round-trip times. Third, the end-user can enter its own preferences on network selection through a policy-based extension to the proposed network selection algorithm.The proposed architecture is evaluated in a live heterogeneous networking environment where handover performance is studied in detail. In addition, user-perceived quality of experience for Voice over IP using the M4 software architecture has been studied. Last, downloads of large amount of data using a combination of high and low capacity wireless networks in M4 were studied.Results indicate that the architecture as a whole and the proposed algorithms perform well. M4 can thus be seen as an imple­mentation of the "Always Best Connected" vision.

  • 4.
    Andersson, Karl
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Sarker, ANM. Zaheduzzaman
    Luleå University of Technology.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Multihomed mobile IPv6: OPNET simulation of network selection and handover timing in heterogeneous networking environments2007In: Proceedings of the Eleventh Annual OPNET Technology Conference: OPNETWORK 2007, 2007Conference paper (Refereed)
  • 5.
    Andersson, Karl
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    A mobility management scheme for heterogeneous environments supporting vehicular speeds using a policy-based approach2008In: Proceedings of the 5th International Workshop Conference on Performance Modelling and Evaluation of Heterogeneous Networks: (HET-NETs), 2008Conference paper (Refereed)
    Abstract [en]

    Today, handsets and terminals are typically equipped with multiple radio interfaces. Meanwhile, various types of access networks using different radio technologies are being deployed all over the world. Also, there is a strong trend towards All-IP-Networks following the principle "Everything over IP", and "IP over everything". This development is leading researchers into the area of heterogeneous networking and overlay topologies.This paper focuses on mobility management issues related to such an environment supporting vehicular speeds of users using a policy-based approach and a network-layer metric for access network selection.A Mobile IP-based architecture is proposed where mobility bindings are sent periodically at a frequency depending on the speed of the user also taking variations in the network-layer metric into account and the overall signaling cost. The architecture is designed with a focus on minimizing packet losses and timely handling of vertical hand-overs.

  • 6.
    Andersson, Karl
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    An architecture for seamless mobility management in various types of applications using a combination of MIP and SIP2006In: Proceedings of Swedish National Computer Networking Workshop 2006: sponsored by IEEE VT/COM Sweden : October 26-27, 2006, Luleå University of Technology, Luleå: Luleå tekniska universitet, 2006, p. 33-36Conference paper (Refereed)
    Abstract [en]

    In the future, mobile users will have the possibility to use a variety of wireless access networks simultaneously making the vision "Always best connected" come true. The Internet Protocol (IP) will most likely be the least common divisor allowing service providers to deploy services in a unified way regardless of access network type (being wired or wireless). The 3GPP-led development of the IP Multimedia Subsystem (IMS) is a promising step towards the vision. However, there are a number of obstacles along this way forward. Various deployment difficulties related to already installed base of user and infrastructure equipment and service providers protecting their old investments are the most common obstacles. In addition to those reasons, somewhat conservative regulatory authorities, short-comings in digital rights management, multiple standardization bodies proposing non-aligned solutions, as well as non-uniformed and non-optimized use of radio spectrum do not improve the speed of change.Our research is performed within the area of seamless real-time multimedia distribution in heterogeneous wireless access networks with a user-centric and end-to-end system approach. Having proposed various extensions to Mobile IP (MIP) including multihoming and port-based handling of flows, as well as solutions for global connectivity in ad hoc networks we now present a combined architecture using both MIP and Session Initiation Protocol (SIP) for mobility management where MIP is used for TCP connections and SIP is used for UDP traffic carrying real-time multimedia streams of data.

  • 7.
    Andersson, Karl
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Mobile mediator control function: an IEEE 802.21-based mobility management and access network selection model2009In: Proceedings of the 18th ICT-Mobile Summit / [ed] Paul Cunningham; Miriam Cunningham, IIMC International Information Management Corporation , 2009Conference paper (Refereed)
    Abstract [en]

    This paper proposes a combined network and application layer access network decision model for multimedia applications in heterogeneous networking environments. It builds on previous work of a network layer based metric used in combination with multihomed Mobile IP and introduces a mechanism for applications to interact with the mobility management system in the mobile node. This way, applications executing in the mobile node can decide either to take access network decisions on their own or to let the network layer handle mobility management tasks automatically based on default decision criterion decided by the end-user.An extended architecture based on previous work and the upcoming IEEE 802.21 standard for media-independent handover services is presented. The control plane, named "Mobile Mediator Control Function", offers a set of events and commands through an additional service access point. Results from a scenario with a Voice over IP application running in the proposed environment simulated in OPNET Modeler are presented.

  • 8.
    Andersson, Karl
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Optimized access network selection in a combined WLAN/LTE environment2011In: Wireless personal communications, ISSN 0929-6212, E-ISSN 1572-834X, Vol. 61, no 4, p. 739-751Article in journal (Refereed)
    Abstract [en]

    Multimode terminals equipped with multiple radio access technologies are becoming increasingly popular. At the same time, network operators and service providers seek opportunities to deliver seamless services cost effectively, leveraging a variety of radio access technologies using both licensed and unlicensed spectrum. In order to standardize the operations of such complex environments 3GPP is currently working on IP flow mobility and mobile data offload solutions. This article proposes and evaluates a new access network selection procedure in such a combined WLAN/LTE environment. The proposed solution takes not only parameters available in the mobile node and its current and candidate access networks into account, but performs an optimization on the heterogeneous wireless network level as well. An optimization model based on an approximate solution to the well-known bin packing problem is presented. Also, there is a signaling scheme for distribution handling presented. Results from simulations performed in OPNET Modeler show improvements compared to basing handover decisions on locally available information only.

  • 9.
    Andersson, Karl
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Projekt: Hybrinet@Skellefteå2007Other (Other (popular science, discussion, etc.))
    Abstract [sv]

    Projektet Hybrinet@Skellefteå studerar effektiv multimediedistribution i heterogena nätverksmijöer

  • 10.
    Andersson, Karl
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Gukhool, Balkrishna Sharma
    Electrical and Computer Engineering Department, Sherbrooke University.
    Cherkaoui, Soumaya
    Electrical and Computer Engineering Department, Sherbrooke University.
    Mobility management for highly mobile users and vehicular networks in heterogeneous environments2008In: 2008 IEEE 33rd Conference on Local Computer Networks: [LCN 2008] ; Montreal, AB, Canada, 14 - 17 October 2008, Piscataway, NJ: IEEE Communications Society, 2008, p. 593-599Conference paper (Refereed)
    Abstract [en]

    With the recent developments in wireless networks, different radio access technologies are used in different places depending on capacity in terms of throughput, cell size, scalability etc. In this context, mobile users, and in particular highly mobile users and vehicular networks, will see an increasing number and variety of wireless access points enabling Internet connectivity. Such a heterogeneous networking environment needs, however, an efficient mobility management scheme offering the best connection continuously. In this paper, a mobility management architecture focusing on efficient network selection and timely handling of vertical and horizontal hand-overs is proposed. The solution is based on Mobile IP where hand-over decisions are taken based upon calculations of a metric combining delay and delay jitter. For efficiency reasons, the frequency of binding updates is dynamically controlled, depending on speed and variations in the metric. The dynamic frequency of binding updates helps the timely discovery of congested access points and cell edges so as to allow efficient hand-overs that minimize packet drops and hand-over delays.Results show that the overall signaling cost is decreased and changes in networking conditions are detected earlier compared to standard Mobile IP.

  • 11.
    Araujo, Victor
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Mitra, Karan
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Saguna, Saguna
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Performance evaluation of FIWARE: A cloud-based IoT platform for smart cities2019In: Journal of Parallel and Distributed Computing, ISSN 0743-7315, E-ISSN 1096-0848, Vol. 132, p. 250-261Article in journal (Refereed)
    Abstract [en]

    As the Internet of Things (IoT) becomes a reality, millions of devices will be connected to IoT platforms in smart cities. These devices will cater to several areas within a smart city such as healthcare, logistics, and transportation. These devices are expected to generate significant amounts of data requests at high data rates, therefore, necessitating the performance benchmarking of IoT platforms to ascertain whether they can efficiently handle such devices. In this article, we present our results gathered from extensive performance evaluation of the cloud-based IoT platform, FIWARE. In particular, to study FIWARE’s performance, we developed a testbed and generated CoAP and MQTT data to emulate large-scale IoT deployments, crucial for future smart cities. We performed extensive tests and studied FIWARE’s performance regarding vertical and horizontal scalability. We present bottlenecks and limitations regarding FIWARE components and their cloud deployment. Finally, we discuss cost-efficient FIWARE deployment strategies that can be extremely beneficial to stakeholders aiming to deploy FIWARE as an IoT platform for smart cities.

  • 12.
    Bezerra, Nibia Souza
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Wang, Min
    Network Architecture and Protocols Research, Ericsson .
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Nordberg, Mats
    Network Architecture and Protocols Research, Ericsson .
    Schelén, Olov
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    RACH performance in massive machine-type communications access scenario2018Conference paper (Refereed)
    Abstract [en]

    With the increasing number of devices performing Machine-Type Communications (MTC), mobile networks are expected to encounter a high load of burst transmissions. One bottleneck in such cases is the Random Access Channel (RACH) procedure, which is responsible for the attachment of devices, among other things. In this paper, we performed a rich-parameter based simulation on RACH to identify the procedure bottlenecks. A finding from the studied scenarios is that the Physical Downlink Control Channel (PDCCH) capacity for the grant allocation is the main limitation for the RACH capacity rather than the number of Physical Random Access Channel (PRACH) preambles. Guided by our simulation results, we proposed improvements to the RACH procedure and to PDCCH.

  • 13.
    Bezerra, Nibia Souza
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Saguna, Saguna
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    de Sousa Jr., Vicente A.
    Federal University of Rio Grande do Norte.
    Propagation Model Evaluation for LoRaWAN: Planning Tool Versus Real Case Scenario2019In: 2019 IEEE 5th World Forum on Internet of Things (WF-IoT) / [ed] IEEE, https://ieeexplore.ieee.org/document/8767299, 2019, p. 1-6Conference paper (Refereed)
    Abstract [en]

    LoRa has emerged as a prominent technology for the Internet of Things (IoT), with LoRa Wide Area Network (LoRaWAN) emerging as a suitable connection solution for smartthings. The choice of the best location for the installation of gateways, as well as a robust network server configuration, are key to the deployment of a LoRaWAN. In this paper, we present an evaluation of Received Signal Strength Indication (RSSI) values collected from the real-life LoRaWAN deployed in Skellefteå, Sweden, when compared with the values calculatedby a Radio Frequency (RF) planning tool for the Irregular Terrain Model (ITM), Irregular Terrain with Obstructions Model (ITWOM) and Okumura-Hata propagation models. Five sensors are configured and deployed along a wooden bridge, with different Spreading Factors (SFs), such as SF 7, 10 and 12. Our results show that the RSSI values calculated using the RF planning tool for ITWOM are closest to the values obtained from the real-life LoRaWAN. Moreover, we also show evidence that the choice of a propagation model in an RF planning tool has to be made with care, mainly due to the terrain conditions of the area where the network and the sensors are deployed.

  • 14.
    Bezerra, Nibia Souza
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Saguna, Saguna
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    de Sousa Jr., Vicente A.
    Federal University of Rio Grande do Norte (UFRN).
    Temperature Impact in LoRaWAN: A Case Study in Northern Sweden2019In: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 19, no 20, article id 4414Article in journal (Refereed)
    Abstract [en]

    LoRaWAN has become popular as an IoT enabler. The low cost, ease of installation and the capacity of fine-tuning the parameters make this network a suitable candidate for the deployment of smart cities. In northern Sweden, in the smart region of Skellefteå, we have deployed a LoRaWAN to enable IoT applications to assist the lives of citizens. As Skellefteå has a subarctic climate, we investigate how the extreme changes in the weather happening during a year affect a real LoRaWAN deployment in terms of SNR, RSSI and the use of SF when ADR is enabled. Additionally, we evaluate two propagation models (Okumura-Hata and ITM) and verify if any of those models fit the measurements obtained from our real-life network. Our results regarding the weather impact show that cold weather improves the SNR while warm weather makes the sensors select lower SFs, to minimize the time-on-air. Regarding the tested propagation models, Okumura-Hata has the best fit to our data, while ITM tends to overestimate the RSSI values.

  • 15.
    Brännström, Robert
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    E, Ruwini Kodikara
    Monash University, Melbourne, VIC.
    Åhlund, Christer
    Zaslavsky, Arkady
    Mobility management for multiple diverse applications in heterogeneous wireless networks2006In: New technologies for consumer networking and communications: eliminating boundaries: 2006 3rd IEEE Consumer Communications and Networking Conference ; CCNC 2006 ; Harrah's Las Vegas Casino & Hotel, Las Vegas, Nevada, USA, 8 - 10 January 2006, Piscataway, NJ: IEEE Communications Society, 2006, p. 818-822Conference paper (Refereed)
    Abstract [en]

    This paper presents a mobility management solution to support both applications who are mobility-aware and those who are not. Mobility management in heterogeneous network environments needs to address the double meaning of the IP address as an endpoint identifier and a location identifier. Application-layer mobility use a non-IP endpoint identifier (e.g. user @ realm) while network-layer mobility uses a fixed home IPaddress as endpoint identifier. The resolving of the endpoint identifier to a temporary unicast IP address as location identifier needs support from a mobility management system. This paper proposes a mobility support system that integrates the benefits of application-layer SIP mobility with network-layer MIP mobility. A cross-layer information system provides context for mobility adaptation. Context awareness enhances handover decisions, transport performance and media adoption. The network-layer mobility supports the application to locate the destination ondemand for the initial setup of the sessions. The paper includes an initial evaluation of the network-layer mobility part of the solution.

  • 16.
    Brännström, Robert
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Andersson, Karl
    Granlund, Daniel
    Multimedia flow mobility in heterogeneous networks using multihomed mobile IP2007In: Journal of Mobile Multimedia, ISSN 1550-4646, E-ISSN 1550-4654, Vol. 3, no 3, p. 218-234Article in journal (Refereed)
    Abstract [en]

    Communication in next generation networks will use multiple access technologies, creating a heterogeneous network environment. To enable end-user terminals to move between access networks with minimal disruption, the terminals should be able to maintain multiple active network connections. Such a multihomed mobile host will experience differences in capabilities and coverage area depending on the access technologies. This paper proposes and evaluates an extension to Mobile IP enabling multihoming, regardless of the access technology. Mobility of multimedia communication in this environment should adapt to changing conditions and be based on dynamic measurements and user preferences. The proposed architecture gives opportunities for mobile multimedia applications to use multiple access networks simultaneously and the possibility to move individual flows between access networks and between user devices. Media flows are identified by destination IP address, protocol and port number. Evaluation results are presented both from a simulation study and from a real world prototype implementation using three different wireless access technologies: 802.11, UMTS and 802.16-2004.

  • 17.
    Brännström, Robert
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Kodikara, E. Ruwini
    Zaslavsky, Arkady
    Implementing global connectivity and mobility support in a wireless multi-hop ad hoc network2006In: Proceedings of the 4th Asian International Mobile Computing Conference: AMOC 2006, 2006, article id 100-063Conference paper (Refereed)
    Abstract [en]

    Pervasive access to the Internet is driven by users who want wireless connectivity to ad hoc as well as infrastructure networks. Multi-hop wireless connectivity widens the coverage areas of access networks and enables two-way wireless traffic into previously dead-spot areas. This paper addresses network mobility issues, which are essential for roaming users who connect to the Internet through wireless access networks. We propose to support connectivity to wired infrastructure through multiple gateways with possibly different capabilities and utilization. Increased network performance can be achieved by adapting to variations in performance and coverage and by switching between gateways when beneficial. We present an efficient solution to enable ad hoc access to the Internet as well as interoperation of reactive routing protocols with Mobile IP. Our solution combines the benefits of proactive agent advertisement and reactive route discovery into a flexible multi-hop access network. We also discuss wireless network metrics that can be used for more intelligent decision making on gateway selection. The feasibility of our approach is validated by simulation and implementation.

  • 18.
    Brännström, Robert
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Zaslavsky, Arkady
    Maintaining gateway connectivity in multi-hop ad hoc networks2005In: Proceedings: the IEEE Conference on Local Computer Networks, 30th anniversary : Sydney, Australia, November 15 - 17, 2005, Los Alamitos, Calif: IEEE Computer Society Press , 2005, p. 682-689Conference paper (Refereed)
    Abstract [en]

    The need for maintaining gateway connectivity in an ad hoc access network is vital considering the 80/20 ratio of Internet traffic. There are several proposals of how to integrate gateway forwarding strategies but they all rely on the route discovery procedure of reactive routing protocols. We propose a proactive approach to avoid the delay of the route discovery process. Mobile IP is often suggested to handle macro mobility and we use the advertisements periodically sent by the gateway to update routing tables in the ad hoc network. Since advertisements may arrive to a mobile host through multiple paths, it is important to keep track of the best path to each gateway. We demonstrate the use of a proposed dynamic metric and how to handle location of correspondent hosts. A simulation study demonstrates the usefulness and efficiency of our approach.

  • 19.
    Brännström, Robert
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Zaslavsky, Arkady
    Port-based multihomed mobile IPv6: load-balancing in mobile ad hoc networks2007In: Proceedings: the 31st IEEE Conference on Local Computer Networks, LCN 2006 : Tampa, Florida, U.S.A., November 14 - 16, 2006, Piscataway, NJ: IEEE Communications Society, 2007, p. 269-271Conference paper (Refereed)
    Abstract [en]

    With today's heterogeneous access to the Internet, users will move between wired and wireless environments and between infrastructure mode and ad hoc mode of wireless communication. When a mobile node moves from an infrastructure connection and connects multihop to an Internet gateway, the performance will degrade and it may not be able to send all of its traffic via a single gateway. This highlights the need of load-balancing between Internet gateways, especially since the behavior of users today involves a multitude of parallel activities generating multiple flows. This paper proposes a solution that enables distribution of individual traffic flows via different Internet gateways instead of using one single gateway. The proposal includes extensions to Mobile IP in order to handle flow mobility bindings. The performance of the solution is verified by simulation studies.

  • 20.
    Cherkaoui, S.
    et al.
    Sherbrooke University.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Welcome message from the ON-MOVE 2010 co-chairs2011Other (Other academic)
  • 21.
    Elkotob, Muslim
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering.
    Granlund, Daniel
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Andersson, Karl
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Multimedia QoE optimized management using prediction and statistical learning2010In: 35th Annual IEEE Conference on Local Computer Networks: LCN 2010, Piscataway, NJ: IEEE Communications Society, 2010, p. 328-331Conference paper (Refereed)
    Abstract [en]

    In this paper, we present a scheme for flow management with heterogeneous access technologies available indoors and in a campus network such as 3G and Wi-Fi. Statistical learning is used as a key for optimizing a target variable namely video quality of experience (QoE). First we analyze the data using passive measurements to determine relationships between parameters and their impact on the main performance indicator, namely the video QoE value. The derived weights are used for performing prediction in every discrete time interval of our designed autonomic control loop to know approximately the QoE in the next time interval and be able to perform a switch to another access technology if it yields a better QoE level. This user-perspective performance optimization is in line with operator and service provider goals. QoE performance models for slow vehicular and pedestrian speeds for Wi-Fi and 3G are derived and compared as well.

  • 22.
    Granlund, Daniel
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Andersson, Karl
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Elkotob, Muslim
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    A uniform AAA handling scheme for heterogeneous networking environments2009In: 2009 IEEE 34th Conference on Local Computer Networks: LCN 2009 ; Zurich, Switzerland, 20 - 23 October 2009 ;, Piscataway, NJ: IEEE Communications Society, 2009, p. 683-687Conference paper (Refereed)
    Abstract [en]

    Starting with an efficient mobility management scheme for heterogeneous wireless networks, this paper proposes a solution for AAA handling using a common database for storing user information. Regardless of the access technology selected, user@realm identities are used for authentication, authorization, and accounting. In particular, a new function is introduced in which port-based network access control is used in combination with dynamic host configuration protocol mechanisms for IP address allocation. This way, PPP-based and Ethernet-based access technologies are handled uniformly.Advantages with the proposed solution include: using only standardized mechanisms in the mobile node, as well as in the access networks. Only an additional plug-in in the AAA server (located in the access networks) needs to be deployed.The proposed AAA architecture has been implemented and evaluated in a live experimental environment. Results show authentication and authorization to perform efficiently and seamlessly.

  • 23. Granlund, Daniel
    et al.
    Gylling, Arne
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Distance- Spanning Technology.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Osipov, Evgeny
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Brännström, Robert
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Jacquier, Anna
    Elkotob, Muslim
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Distance- Spanning Technology.
    Åhl, Anneli
    Project: BASICNET2008Other (Other (popular science, discussion, etc.))
    Abstract [en]

    Broadband Access Services In Converging NETworks

  • 24.
    Granlund, Daniel
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Holmlund, Patrik
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Opportunistic Mobility Support for Resource Constrained Sensor Devices in Smart Cities2015In: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 15, no 3, p. 5112-5135Article in journal (Refereed)
    Abstract [en]

    A multitude of wireless sensor devices and technologies are being developed and deployed in cities all over the world. Sensor applications in city environments may include highly mobile installations that span large areas which necessitates sensor mobility support. This paper presents and validates two mechanisms for supporting sensor mobility between different administrative domains. Firstly, EAP-Swift, an Extensible Authentication Protocol (EAP)-based sensor authentication protocol is proposed that enables light-weight sensor authentication and key generation. Secondly, a mechanism for handoffs between wireless sensor gateways is proposed. We validate both mechanisms in a real-life study that was conducted in a smart city environment with several fixed sensors and moving gateways. We conduct similar experiments in an industry-based anechoic Long Term Evolution (LTE) chamber with an ideal radio environment. Further, we validate our results collected from the smart city environment against the results produced under ideal conditions to establish best and real-life case scenarios. Our results clearly validate that our proposed mechanisms can facilitate efficient sensor authentication and handoffs while sensors are roaming in a smart city environment.

  • 25.
    Granlund, Daniel
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    A scalability study of AAA support in heterogeneous networking environments with global roaming support2011In: TrustCom 2011: 2011 international joint conference of IEEE TrustCom-11, IEEE ICESS-11 / FCST-11 : 16-19 November 2011, Changsha, Hunan, P. R. China / [ed] Guojun Wang, Los Alamitos, Calif: IEEE Computer Society Press , 2011, p. 488-493Conference paper (Refereed)
    Abstract [en]

    In this paper, we present a scalability study of AAA support in mobile heterogeneous access networks with respect to server and network load related to AAA processes using the RADIUS protocol. Technologies such as IEEE 802.11, CDMA 2000 and UMTS which all support the RADIUS protocol for AAA handling are discussed and analyzed. Typical performance data are gathered and complemented with a theoretical study in order to achieve an overview of what parameters will affect the performance and scalability of the network. Also, guidelines are developed for network design in order to achieve the desired performance for a given number of users. Results of this study include the conclusion that the main bottleneck of the AAA procedure is not necessarily the AAA server CPU power. Aside the cases with a high proportion of computationally intensive WiFi sign-ons with strong encryption, performance issues may be caused by AAA server network connection bandwidth, and RAM memory. In cases where a high number of users reside in the same user database, database performance becomes a significant issue. In order to achieve better performance, CPU load balancing over several servers may be performed.

  • 26.
    Granlund, Daniel
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Holmlund, Patrik
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    EAP-Swift: An Efficient Authentication and Key Generation Mechanism for Resource Constrained WSNs2015In: International Journal of Distributed Sensor Networks, ISSN 1550-1329, E-ISSN 1550-1477, article id 460914Article in journal (Refereed)
    Abstract [en]

    Technological advances within the area of wireless sensor technology allow WSNs to be used in a increasing number of measurement scenarios. As new application areas are emerging, such as infrastructure monitoring and smart cities, the need for sensor mobility handling requires efficient and secure authentication protocols. This paper presents EAP-Swift, a novel EAP based authentication protocol with a focus on lightweight processing and faster response. It supports end-to-end session encryption key generation and mutual authentication. By utilizing lightweight hashing algorithms, the challenge-response authentication mechanism uses only two round trips to the AAA server for the complete authentication procedure leading to the reduction of latency by 33% compared to the baseline protocols. Further, using extensive experimentation, we validate that the authentication time can be kept below 250 ms and the power consumption can be kept below 15 mJ. Furthermore, we show that a battery lifetime of more than four years can be achieved when running the system on a regular button cell battery. Finally, the protocol was verified in terms of security using the AVISPA tool.

  • 27.
    Idowu, Samuel
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Saguna, Saguna
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Schelén, Olov
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Applied Machine Learning: Forecasting Heat Load in District Heating System2016In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 133, p. 478-488Article in journal (Refereed)
    Abstract [en]

    Forecasting energy consumption in buildings is a key step towards the realization of optimized energy production, distribution and consumption. This paper presents a data driven approach for analysis and forecast of aggregate space and water thermal load in buildings. The analysis and the forecast models are built using district heating data unobtrusively collected from ten residential and commercial buildings located in Skellefteå, Sweden. The load forecast models are generated using supervised machine learning techniques, namely, support vector machine, regression tree, feed forward neural network, and multiple linear regression. The model takes the outdoor temperature, historical values of heat load, time factor variables and physical parameters of district heating substations as its input. A performance comparison among the machine learning methods and identification of the importance of models input variables is carried out. The models are evaluated with varying forecast horizons of every hour from 1 up to 48 hours. Our results show that support vector machine, feed forward neural network and multiple linear regression are more suitable machine learning methods with lower performance errors than the regression tree. Support vector machine has the least normalized root mean square error of 0.07 for a forecast horizon of 24 hour.

  • 28.
    Idowu, Samuel
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Saguna, Saguna
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Schelén, Olov
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Forecasting Heat Load for Smart District Heating Systems: A Machine Learning Approach2014In: 2014 IEEE International Conference on Smart Grid Communications (SmartGridComm 2014): Venice, 3-6 Nov. 2014, Piscataway, NJ: IEEE Communications Society, 2014, p. 554-559Conference paper (Refereed)
    Abstract [en]

    The rapid increase in energy demand requires effective measures to plan and optimize resources for efficient energy production within a smart grid environment. This paper presents a data driven approach to forecasting heat load for multi- family apartment buildings in a District Heating System (DHS). The forecasting model is built using six and eleven weeks of data from five building substations. The external factors and internal factors influencing the heat load in substations are parameters used as our model’s input. Short-term forecast models are generated using four supervised Machine Learning (ML) techniques: Support Vector Regression (SVR), Regression Tree, Feed Forwards Neural Network (FFNN) and Multiple Linear Regression (MLR). Performance comparison among these ML methods was carried out. The effects of combining the internal and external factors influencing heat load at substations was studied. The models are evaluated with varying horizon up to 24-hours ahead. The results show that SVR has the best accuracy of 5.6% MAPE for the best-case scenario.

  • 29.
    Idowu, Samuel
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Schelén, Olov
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Machine learning in district heating system energy optimization2014In: 2014 IEEE International Conference on Pervasive Computing and Communications workshops: PERCOM WORKSHOPS 2014, Budapest, Hungary; 24-28 March 2014, Piscataway, NJ: IEEE Communications Society, 2014, p. 224-227, article id 6815206Conference paper (Refereed)
    Abstract [en]

    This paper introduces a work in progress, where we intend to investigate the application of Reinforcement Learning (RL) and online Supervised Learning (SL) to achieve energy optimization in District-Heating (DH) systems. We believe RL is an ideal approach since this task falls under the control-optimization problem where RL has yielded optimal results in previous work. The magnitude and scale of a DH system complexity incurs the curse of dimensionalities and model, hereby making RL a good choice since it provides a solution for the problem. To assist RL even further with the curse of dimensionalities, we intend to investigate the use of SL to reduce the state space. To achieve this, we shall use historical data to generate a heat load sub-model for each home. We believe using the output of these sub-models as feedback to the RL algorithm could significantly reduce the complexity of the learning task. Also, it could reduce convergence time for the RL algorithm. The desired goal is to achieve a realtime application, which takes operational actions when it receives new direct feedback. However, considering the dynamics of DH system such as large time delay and dissipation in DH network due to various factors, we hope to investigate things such as the appropriate data sampling rate and new parameters / sensors that could improve knowledge about the state of the system, especially on the consumer side of the DH network.

  • 30.
    Idowu, Samuel
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Schelén, Olov
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Brännström, Robert
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Machine Learning in Pervasive Computing2013Report (Other academic)
    Abstract [en]

    Increase in data quantities and number of pervasive systems has resulted in many decision-making systems. Most of these systems employ Machine Learning (ML) in various practical scenarios and applications. Enormous amount of data generated by sensors can be useful in decision-making systems. The rising number of sensor driven pervasive systems presents interesting research areas on how to adapt and apply existing ML techniques effectively to the domain of pervasive computing. In the face of data deluge, ML has proved viable in many application areas such as data mining and self-customizing programs and could bring about great impact in the field of pervasive computing.The objective of this study is to give the underlying concepts of ML techniques that can be applied to problems in the domain of pervasive and mobile computing. The scope of this study covers the three primary types of ML, supervised, unsupervised and reinforcement learning methods. In the process of providing the fundamental knowledge of ML, we present some conceptual terms of ML and the steps required in developing ML system with a great impact on domains outside ML scope.Our findings show that previous works in the area of ubiquitous computing have successfully applied supervised learning and reinforcement learning methods. Hence, this study focuses more on supervised learning and reinforcement learning. In conclusion, we discuss some basic performance evaluation metrics and methods for obtaining reliable classifiers estimates, such as cross-validation and leave-one-out validation.

  • 31.
    Jimenez, Lara Lorna
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Simon, Miguel Gomez
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Schelén, Olov
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Kristiansson, Johan
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Synnes, Kåre
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    CoMA: Resource Monitoring of Docker Containers2015In: Proceedings of the 5th International Conference on Cloud Computing and Services Science (CLOSER 2015), SCITEPRESS Digital Library , 2015, Vol. 1, p. 145-154Conference paper (Refereed)
    Abstract [en]

    This research paper presents CoMA, a Container Monitoring Agent, that oversees resource consumption of operating system level virtualization platforms, primarily targeting container-based platforms such as Docker. The core contribution is CoMA, together with a quantitative evaluation verifying the validity of the measurements reported by the agent for three metrics: CPU, memory and block I/O. The proof-of-concept is implemented for Docker-based systems and consists of CoMA, the Ganglia Monitoring System and the Host sFlow agent. This research is in line with the rising trend of container adoption which is due to the resource efficiency and ease of deployment. These characteristics have set containers in a position to topple virtual machines as the reigning virtualization technology in data centers.

  • 32.
    Johansson, Dan
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Andersson, Karl
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science. Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Distance- Spanning Technology.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Supporting user mobility with peer-to-peer-based application mobility in heterogeneous networks2013In: Proceedings of the 38th IEEE Conference on Local Computer Networks Workshops (LCN Workshops): 7th IEEE Workshop On User MObility and VEhicular Networks / [ed] Damla Turgut; Nils Aschenbruck; Jens Tölle, Piscataway, NJ, 2013, p. 150-153Conference paper (Refereed)
    Abstract [en]

    When migrating applications between devices during runtime, one has achieved application mobility. In this paper we present the XAM system, providing application mobility through a peer-to-peer based solution over heterogeneous networks. Our architecture takes into consideration established requirements of application mobility, being application identification and distribution; context-awareness and context quality; seamlessness; heterogeneity support; and usability. Our system differs from traditional systems as it provides application mobility in a decentralized manner over heterogeneous networks, using different communication technologies. Following the evaluation of our system, we also discuss major challenges and possibilities for the continuing evolution of application mobility systems.

  • 33.
    Johansson, Dan
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Andreas
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    A MIP-P2P based architecture for application mobility2011In: Proceedings of the 10th International Conference on Mobile and Ubiquitous Multimedia: MUM '11, New York: ACM Digital Library, 2011, p. 85-93Conference paper (Refereed)
    Abstract [en]

    Mobility exists in many shapes; when migrating a running application (code, states and data) from one device to another, one has achieved application mobility. In this article we combine this mobility type with context awareness, defiining context awareness supported application mobility (CASAM) as when using context in the act of moving an application between hosts during its execution, to provide relevant information and/or services, where relevancy depends on the user's task. We identify and present five CASAM challenges, that are used to create requirements for a CASAM architecture. A proposal for an architecture, building on peer-to-peer (P2P) technology in combination with mobile IP, is then presented, addressing the identified challenges, providing a decentralized framework for global application mobility. As such, our architecture differs from earlier centralized and/or locally bound solutions for application mobility.

  • 34. Johansson, Dan
    et al.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Brännström, Robert
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Andersson, Karl
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Projekt: MOSA - mobil och öppen tjänste-access2009Other (Other (popular science, discussion, etc.))
    Abstract [sv]

    Projektet ämnar till att möjliggöra uppkoppling av fler hushåll och företag till bredbandsnät, utveckla en teknisk plattform som ökar tillgång till tjänster och möjliggör mobilitet mellan olika accessnätverk. Genom att möjliggöra mobilitet kommer tjänster att vara nåbara på flera platser, mobiliteten skapar också utrymme för nya tjänster.

  • 35. Kodikara, E. Ruwini
    et al.
    Brännström, Robert
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Zaslavsky, Arkady
    APM: Adaptive Performance Metric2006Conference paper (Other academic)
  • 36.
    Kodikara, R.E
    et al.
    Caulfield School of Information Technology, Monash University.
    Zaslavsky, Arkady
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    ConEx: context exchange in MANETs for real time multimedia2006In: International Conference on Networking: ICN 2006 ; Morne, Mauritius, 23 - 28 April, 2006 ; bonus: International Conference on Mobile Communications and Learning Technologies (MCL 2006), International Conference on Systems (ICONS 2006) ; proceedings / [ed] Pascal Lorenz, Los Alamitos, Calif: IEEE Computer Society Press , 2006, p. 70-Conference paper (Refereed)
    Abstract [en]

    MANETs are important and integral part of next generation wireless networking. Real time multimedia communication over MANETs is challenging due to reasons like network topology changes, limitations of wireless links and demanding requirements of multimedia. Channel adaptivity is adopting applications to the dynamic and unpredictable network conditions. QoS adaptivity is adopting lower layers to multimedia application requirements. The novel cross layer context exchange approach called ConEx, presented in this paper improves the efficiency of this two-way information exchange. This paper focuses on adaptive multimedia applications over mobile ad hoc networks, which addresses the challenges of multimedia applications. ConEx uses publish-subscribe event notification system for vertical context exchange across layers of the mobile host and horizontal context exchange across the MANET. ConEx architecture and implementation issues are discussed in this paper.

  • 37.
    Kodikara, Ruwini E.
    et al.
    Centre for Distributed Systems and Software Engineering, Monash University.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Zaslavsky, Arkady
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Towards context aware adaptation in wireless networks2008In: Proceedings: The Second International Conference on Mobile Ubiquitous Computing, Systems, Services and Technologies, UBICOMM 2008 : 29 September - 4 October 2008, Valencia, Spain / [ed] Jaime Lloret Mauri, Piscataway, NJ: IEEE Communications Society, 2008, p. 245-250Conference paper (Refereed)
    Abstract [en]

    Next generation ubiquitous computing will comprise of context aware adaptive applications and protocols. There is a need of a generic architecture to cater for the adaptation requirements of increasingly demanding real-time applications and increasing dynamic wireless networks. This paper discusses the adaptive approach supported by CA3RM-Com architecture. CA3RM-Com is the context aware architecture proposed for real-time communication in wireless networks. It addresses the context representation, context acquisition, context exchange,and context management. Specific details of the architecture and referring adaptations that CA3RM-Com can support are discussed. Moreover the extended simulation results of adaptive multi-homed Mobile IP are presented in this paper.

  • 38.
    Kodikara, Ruwini
    et al.
    Monash University, Melbourne, VIC.
    Zaslavsky, Arkady
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Context modelling for crosslayer context aware adaptations2009In: International Journal On Advances in Networks and Services, ISSN 1942-2644, E-ISSN 1942-2644, Vol. 2, no 1, p. 63-75Article in journal (Refereed)
    Abstract [en]

    Demand for real-time services over the Internet while moving, is growing rapidly. This necessitates efficient delivery of wireless real-time traffic. Limitations of existing layered protocol stack for wireless networks lead to the proposal of cross-layer interactions as an alternative solution. At the same time, next generation ubiquitous computing drives wireless applications and protocols to be context aware. A generic context aware architecture with context modeling can aid increasingly demanding realtime applications over highly dynamic wireless networks to be cross-layer context aware and adaptive. Moreover, a generic architecture can make lower layer protocols to be context aware and adaptive to various situations dynamically. This article discusses the adaptive approach supported by proposed cross layer context aware architecture called CA3RM-Com. The scope of this article is to discuss context modeling specifically and address the issue of context representation of multi-layer context for various adaptive situations. Various single layer and multi-layer crosslayer adaptations and the representation of context parameters with respect to each layer of the protocol stack is discussed. We discuss how these adaptations can be operated in the proposed CA3RM-Com architecture. Context aware adaptive multi-homed Mobile IP is discussed as an example adaptation that the architecture can support. Moreover, the extended simulation of context aware adaptive multi-homed Mobile IP is discussed.

  • 39.
    Kodikara, Ruwini
    et al.
    Centre for Distributed Systems and Software Engineering, Monash University.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Zaslavsky, Arkady
    Supporting adaptive real-time mobile communication with multilayer context awareness2008In: Wireless and Mobile Networking: IFIP Joint Conference on Mobile and Wireless Communications Networks (MWCN'2008) and Personal Wireless Communications (PWC'2008), Toulouse, France, September 30 - October 2, 2008 / [ed] Zoubir Mammeri, Berlin: Encyclopedia of Global Archaeology/Springer Verlag, 2008, p. 435-446Conference paper (Refereed)
    Abstract [en]

    Real time mobile communication is challenging due to the inherent limitations of mobile networks. On the other hand the stringent quality of service requirements of real time traffic is highly in demand. Our first contribution is the generic context aware architecture for adaptive real time applications. Adaptation is based on the awareness of context parameters from different layers of the existing protocol stack which involves context exchange among the neighboring layers as well as non-neighboring layers. The architecture comprises of context representation, context acquisition, cross-layer context exchange and context management. Our second contribution is the mobility aware, adaptive Multi-homed Mobile IP. Simulation of adaptive M-MIP was carried out as a proof of concept. Simulation demonstrated that adaptation to mobility was able to decrease Mobile IP handover latency. Further, the results show that the quality of service of real time traffic can be enhanced by using context aware adaptive MIP. The simulation involved with various speeds ranging from pedestrian scenarios to vehicular scenarios. Results are analyzed with variable data rates. The evaluations show that performance of the proposed solution is better compared to conventional MIP in terms of packet loss and throughput of real time traffic.

  • 40.
    Lindgren, Anders
    et al.
    Kungliga tekniska högskolan, KTH.
    Phanse, Kaustubh
    Johansson, Tomas
    Brännström, Robert
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Future directions in ad hoc networking research2005In: 5th Scandinavian Workshop on Wireless Ad-hoc Networks: ADHOC ´05, Stockholm: Wireless at KTH, Royal institute of technology , 2005Conference paper (Other academic)
    Abstract [en]

    Much effort has gone into mobile ad-hoc network (MANET) research over the past decade. Yet, even today, mobile ad-hoc networking is seen as a relatively new area of research. The reason for this can be traced to the fact that the maturity in truly understanding these networks is still alarmingly low and actual deployment of these networks rare. In this paper, we investigate the reasons for this lack and suggest ways for overcoming the shortcomings. We then describe four sub-topics in ad hoc networking that have not received much attention, but are crucial for making real deployment of MANETs feasible.

  • 41. Louis, Baptiste
    et al.
    Mitra, Karan
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Saguna, Saguna
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    CloudSimDisk: Energy-Aware Storage Simulation in CloudSim2015In: 2015 IEEE/ACM 8th International Conference on Utility and Cloud Computing (UCC): Limassol, 7-10 Dec. 2015, Piscataway, NJ: IEEE Communications Society, 2015, p. 11-15, article id 7431390Conference paper (Refereed)
    Abstract [en]

    The cloud computing paradigm is continually evolving, and with it, the size and the complexity of its infrastructure. Assessing the performance of a cloud environment is an essential but an arduous task. Further, the energy consumed by data centers is steadily increasing and major components such as the storage systems need to be more energy efficient. Cloud simulation tools have proved quite useful to study these issues. However, these simulation tools lack mechanisms to study energy efficient storage in cloud systems. This paper contributes in the area of cloud computing by extending the widely used cloud simulator CloudSim. In this paper, we propose CloudSimDisk, a scalable module for modeling and simulation of energy-aware storage in cloud systems. We show how CloudSimDisk can be used to simulate energy-aware storage, and can be extended to study new algorithms for energy-awareness in cloud systems. Our simulation results proved to be in accordance with the analytical models that were developed to model energy consumption of hard disk drives in cloud systems. The source code of CloudSimDisk is also made available for the research community for further testing and development.

  • 42.
    Minovski, Dimitar
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Mitra, Karan
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Johansson, Per
    InfoVista Sweden AB.
    Analysis and Estimation of Video QoE in Wireless Cellular Networks using Machine Learning2019In: 2019 Eleventh International Conference on Quality of Multimedia Experience (QoMEX), IEEE, 2019Conference paper (Refereed)
    Abstract [en]

    The use of video streaming services are increasing in the cellular networks, inferring a need to monitor video quality to meet users' Quality of Experience (QoE). The so-called no-reference (NR) models for estimating video quality metrics mainly rely on packet-header and bitstream information. However, there are situations where the availability of such information is limited due to tighten security and encryption, which necessitates exploration of alternative parameters for conducting video QoE assessment. In this study we collect real-live in-smartphone measurements describing the radio link of the LTE connection while streaming reference videos in uplink. The radio measurements include metrics such as RSSI, RSRP, RSRQ, and CINR. We then use these radio metrics to train a Random Forrest machine learning model against calculated video quality metrics from the reference videos. The aim is to estimate the Mean Opinion Score (MOS), PSNR, Frame delay, Frame skips, and Blurriness. Our result show 94% classification accuracy, and 85% model accuracy (R 2 value) when predicting the MOS using regression. Correspondingly, we achieve 89%, 84%, 85%, and 82% classification accuracy when predicting PSNR, Frame delay, Frame Skips, and Blurriness respectively. Further, we achieve 81%, 77%, 79%, and 75% model accuracy (R 2 value) regarding the same parameters using regression.

  • 43.
    Mitra, Karan
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Saguna, Saguna
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    A Mobile Cloud Computing System for Emergency Management2014In: I E E E Cloud Computing, ISSN 2325-6095, Vol. 1, no 4, p. 30-38, article id 7057583Article in journal (Refereed)
    Abstract [en]

    Emergency management systems deal with the dynamic processing of data, where response teams must continuously adapt to the changing conditions at the scene of the emergency. Response teams must make critical decisions in highly demanding situations using large volumes of sensor data. Mobile devices have limited processing, storage, and battery resources; therefore, the sensed data from the scene of the emergency must be transmitted and processed quickly using the best available networks and clouds. Mobile cloud computing (MCC) is expected to play a critical role in the computation and storage offloading of sensor data to the best available clouds. However, applications running on mobile devices using clouds and heterogeneous access networks such as Wi-Fi and 3G are prone to unpredictable cloud workloads, network congestion, and handoffs. This article presents M2C2, a system for mobility management in MCC, that supports mechanisms for multihoming, cloud and network probing, and cloud and network selection. Through a prototype implementation and experiments, the authors show that M2C2 supports mobility efficiently in MCC scenarios such as emergency management.

  • 44.
    Mitra, Karan
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Saguna, Saguna
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Granlund, Daniel
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    M2C2: A Mobility Management System for Mobile Cloud Computing2015In: IEEE Wireless Communications and Networking Conference, 2015: WCNC 2015, 9-12 Mars 2015, New Orleans, LA, Piscataway, NJ: IEEE Communications Society, 2015, p. 1608-1613Conference paper (Refereed)
    Abstract [en]

    Mobile devices have become an integral part of our daily lives. Applications running on these devices may avail storage and compute resources from the cloud(s). Further, a mobile device may also connect to heterogeneous access networks (HANs) such as WiFi and LTE to provide ubiquitous network connectivity to mobile applications. These devices have limited resources (compute, storage and battery) that may lead to servicedisruptions. In this context, mobile cloud computing enables offloading of computing and storage to the cloud. However, applications running on mobile devices using clouds and HANs are prone to unpredictable cloud workloads, network congestion and handoffs. To run these applications efficiently the mobile device requires the best possible cloud and network resources while roaming in HANs. This paper proposes, develops and validates a novel system called M2C2 which supports mechanismsfor: i.) multihoming, ii.) cloud and network probing, and iii.) cloudand network selection. We built a prototype system and performed extensive experimentation to validate our proposed M2C2. Our results analysis shows that the proposed system supports mobility efficiently in mobile cloud computing.

  • 45.
    Mitra, Karan
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Saguna, Saguna
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Ranjan, Rajiv
    Newcastle University.
    ALPINE: A Bayesian System For Cloud Performance Diagnosis And Prediction2017In: 2017 IEEE International Conference on Services Computing (SCC), Piscataway, NJ: IEEE, 2017, p. 281-288, article id 8034996Conference paper (Refereed)
    Abstract [en]

    Cloud performance diagnosis and prediction is a challenging problem due to the stochastic nature of the cloud systems. Cloud performance is affected by a large set of factors such as virtual machine types, regions, workloads, wide area network delay and bandwidth. Therefore, necessitating the determination of complex relationships between these factors. The current research in this area does not address the challenge of modeling the uncertain and complex relationships between these factors. Further, the challenge of cloud performance prediction under uncertainty has not garnered sufficient attention. This paper proposes, develops and validates ALPINE, a Bayesian system for cloud performance diagnosis and prediction. ALPINE incorporates Bayesian networks to model uncertain and complex relationships between several factors mentioned above. It handles missing, scarce and sparse data to diagnose and predict stochastic cloud performance efficiently. We validate our proposed system using extensive real data and show that it predicts cloud performance with high accuracy of 91.93%.

  • 46.
    Mitra, Karan
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Zaslavsky, Arkady
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    A probabilistic context-aware approach for quality of experience measurement in pervasive systems2011In: Proceedings of the 26th Annual ACM Symposium on Applied Computing 2011: Taichung, Taiwan, March 21 - 24, 2011, New York: ACM Digital Library, 2011, p. 419-424Conference paper (Refereed)
    Abstract [en]

    In this paper, we develop a novel context-aware approach for quality of experience (QoE) modeling, reasoning and inferencing in mobile and pervasive computing environments. The proposed model is based upon a state-space approach and Bayesian networks for QoE modeling and reasoning. We further extend this context model to incorporate influence diagrams for efficient QoE inferencing. Our approach accommodates user, device and quality of service (QoS) related context parameters to determine the overall QoE of the user. This helps in user-related media, network and device adaptation. We perform experimentation to validate the proposed approach and the results verify its modeling and inferencing capabilities.

  • 47.
    Mitra, Karan
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Zaslavsky, Arkady
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Context-Aware QoE Modelling, Measurement and Prediction in Mobile Computing Systems2015In: IEEE Transactions on Mobile Computing, ISSN 1536-1233, E-ISSN 1558-0660, Vol. 14, no 5, p. 920-936Article in journal (Refereed)
    Abstract [en]

    Quality of Experience (QoE) as an aggregate of Quality of Service (QoS) and human user-related metrics will be the key success factor for current and future mobile computing systems. QoE measurement and prediction are complex tasks as they may involve a large parameter space such as location, delay, jitter, packet loss and user satisfaction just to name a few. These tasks necessitate the development of practical context-aware QoE models that efficiently determine relationships between user context and QoE parameters. In this paper, we propose, develop and validate a novel decision-theoretic approach called CaQoEM for QoE modelling, measurement and prediction. We address the challenge of QoE measurement and prediction where each QoE parameter can be measured on a different scale and may involve different units of measurement. CaQoEM is context-aware and uses Bayesian networks and utility theory to measure and predict users' QoE under uncertainty. We validate CaQoEM using extensive experimentation, user studies and simulations. The results soundly demonstrate that CaQoEM correctly measures range-defined QoE using a bipolar scale. For QoE prediction, an overall accuracy of 98.93\% was achieved using 10-fold cross validation in multiple diverse network conditions such as vertical handoffs, wireless signal fading and wireless network congestion.

  • 48.
    Mitra, Karan
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Zaslavsky, Arkady
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Dynamic Bayesian networks for sequential quality of experience modelling and measurement2011In: Smart Spaces and Next Generation Wired/Wireless Networking: 11th International Conference, NEW2AN 2011, and 4th Conference on Smart Spaces, ruSMART 2011, St. Petersburg, Russia, August 22-25, 2011. Proceedings / [ed] Sergey Balandin; Yevgeni Koucheryavy; Honglin Hu, Encyclopedia of Global Archaeology/Springer Verlag, 2011, p. 135-146Conference paper (Refereed)
    Abstract [en]

    This paper presents a novel context-aware methodology for modelling and measuring user-perceived quality of experience (QoE) over time. In particular, we create a context-aware model for QoE modelling and measurement using dynamic Bayesian networks (DBN) and a context-aware state-space approach. The proposed model is then used to infer and determine users’ QoE in a sequential manner. We performed experimentation to validate the proposed model. The results prove thatit can efficiently model, reason and measure QoE of the users’.

  • 49.
    Mitra, Karan
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Zaslavsky, Arkady
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Measuring quality of experience in pervasive systems using probabilistic context-aware approach2012In: Mobile and Ubiquitous Systems: Computing, Networking, and Services: 7th International ICST Conference, MobiQuitous 2010, Sydney, Australia, December 6-9, 2010, Revised Selected Papers, Heidelberg: Encyclopedia of Global Archaeology/Springer Verlag, 2012, p. 330-331Conference paper (Refereed)
    Abstract [en]

    In this paper, we pioneer a context-aware approach for quality of experience (QoE) modeling, reasoning and inferencing in mobile and pervasive computing environments. The proposed model is based upon Context Spaces Theory (CST) and influence diagrams (IDs) to handle uncertain and hidden complex inter-dependencies between user-perceived and network level QoS and to calculate overall QoE of the users. This helps in user-related media, network and device adaptation, creating user-level SLAs and minimizing network churn. We perform experimentation to validate the proposed approach and the results verify its modeling and inferencing capabilities.

  • 50.
    Mitra, Karan
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Zaslavsky, Arkady
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Åhlund, Christer
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    PRONET: proactive context-aware support for mobility in heterogenous access networks2010In: 2009 IEEE 34th Conference on Local Computer Networks: LCN 2009 ; Zurich, Switzerland, 20 - 23 October 2009, Piscataway, NJ: IEEE Communications Society, 2010, p. 675-676Conference paper (Refereed)
    Abstract [en]

    This paper presents a blueprint for proactive context-aware mobility support architecture for heterogeneous access networks called PROET. In particular, we leverage upon the principles of cognitive networking to support proactive contextawareness for user-centric application adaptation via quality-ofexperience (QoE) provisioning. Our proposed architecture is built upon Port-based Multi-homed Mobile IPv6 (PM-MIPv6) solution to support several applications via path diversity. In this paper our contributions are two-fold. Firstly, we identify and present gaps in our research domain related to mobility, QoE, cognitive networks and cross-layer design. We then present our architecture for providing seamless mobility in heterogeneous access networks. Currently, we are in the process of collecting results via our test bed and prototype implementation for 802.11g and HSDPA wireless networks

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