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  • 1.
    Ahlgren-Moritz, Charlotte
    et al.
    Malmö högskola, Sweden.
    Alm, Anna-Karin
    Malmö högskola, Sweden.
    Christersson, Cecilia
    Malmö högskola, Sweden.
    Eikelboom Sällström, Anette
    Enheten för externa relationer, Umeå universitet, Sweden.
    Esbjörnsson, Mattias
    Malmö högskola, Sweden.
    Jacobsson, Andreas
    Fakulteten för teknik och samhälle, Malmö högskola, Sweden.
    Marell, Agneta
    Samverkan och innovation, Umeå universitet, Sweden.
    Persson, Jeanette
    Innovation och utveckling, Malmö högskola, Sweden.
    Ramsten, Anna-Carin
    Linköping University, REMESO - Institute for Research on Migration, Ethnicity and Society. Linköping University, Department of Social and Welfare Studies. Linköping University, Faculty of Arts and Sciences.
    Rehme, Jakob
    Linköping University, Department of Management and Engineering, Industrial Economics. Linköping University, Faculty of Science & Engineering.
    Reinhold, Mats
    Enheten för externa relationer, Umeå universitet, Sweden.
    Sjögren, Karin
    Malmö högskola, Sweden.
    Sörensson, Victoria
    Enheten för externa relationer, Umeå universitet, Sweden.
    Värbrand, Peter
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Vägen till samverkanssäkrad utbildning. [1]: Metoder och strategier2016Book (Other academic)
    Abstract [sv]

    Universitet och högskolor bidrar till samhällsutvecklingen genom att forskningsbaserad kunskap tillämpas av olika aktörer i samhället. För att möta dagens och morgondagens samhällsutmaningar utgör således kunskapsutbyte och samverkan mellan lärosäten och samhället en värdefull möjlighet. Att ha starka relationer med samhällets aktörer identifieras också som viktigt i utvecklingen av ett internationellt starkt lärosäte.

    Samverkan i högre utbildning främjar samhällets förändringsförmåga och stärker utbildningens kvalitet, men samverkan förbereder också studenterna för ett livslångt lärande och underlättar övergången mellan utbildning och arbetsliv. Ett lärosäte i nära samverkan med aktörer i samhället är ett relevant lärosäte, det vill säga ett lärosäte som är till nytta för sin omvärld och för sina medarbetare och studenter.

    Ett grundläggande problem vad gäller möjligheterna att integrera samverkan i akademisk utbildning står att finna i statens fördelning av medel till lärosätena. De statliga medlen utgår nämligen i två separata anslag, ett vardera för de båda huvuduppdragen utbildning och forskning. Samverkan kan sägas ingå i bägge uppdragen. Till skillnad från forskningssamverkan finns det för utbildningssamverkan ingen särskild uppföljning och inte heller några ekonomiska incitament. Utvärdering av forskning och utbildning bör således breddas så att kvalitetsstärkande samverkansinslag också inkluderas i resursfördelningsprinciperna. Statens bristande strukturer för fördelning och uppföljning återspeglas i hur lärosätena fördelar resurser till och följer upp samverkan: lärare ges sällan resurser (i form av särskild tid) för att på ett pedagogiskt genomtänkt sätt kunna inkludera samverkansinslag i undervisningen; samverkan är sällan meriterande eller lönegrundande; och den utbildningssamverkan som bedrivs följs sällan upp – varken på institutions-, fakultets- eller lärosätesnivå. Samma sak kan sägas gälla på nationell nivå – det samverkande lärosätet erhåller inga extra anslag och det bestraffas ej heller för försummelse av detsamma. Att göra samverkan till en integrerad del av utbildningen innebär att samverkan bör ingå i de pedagogiska modeller som lärare använder för att leda studenternas kunskapsutveckling mot de mål som finns angivna i kurs- och utbildningsplaner. Det betyder också att arbetet med samverkan bör inkluderas i processer för styrning, planering och uppföljning av utbildning och undervisning på såväl kurs- och programnivå som på institutions-, fakultets- och lärosätesnivå. Att göra samverkan till en integrerad del av utbildningen är att sträva mot att externa aktörer ska bli en självklar del i den dagliga verksamheten – för studenter såväl som för medarbetare och för de organisationer man samverkar med. För att svenska lärosäten ska ges en realistisk möjlighet att göra samverkan till en integrerad del av utbildningsverksamheten krävs det framför allt följande:

    • att politiker och departement utformar ett fördelningssystem där framgångsrika samverkansinsatser inom utbildningen leder till en förstärkning av resursbasen på lärosätena;
    • att lärosätesledningar tar tydlig ställning för samverkansfrågan i sina strategiska styrdokument och att samverkan införs i lärosätenas kvalitetssäkringssystem för utbildning, samt att lärosätena inför system för att styra och följa upp samverkan i utbildningen på lärosätesövergripande nivå;
    • att ledningen för fakulteter, institutioner eller motsvarande omsätter lärosätets strategiska åtaganden i handlingsplaner och lokala styrdokument samt utformar system för dokumentation, styrning och uppföljning av samverkan i utbildningsprogram;
    • att lärare samt kurs- och programansvariga inför samverkan i utbildningens styrande dokument (t.ex. kurs- och utbildningsplaner) samt i den ordinarie undervisningsverksamheten.

    Dessutom bör lärosätena – både gemensamt men också vart och ett för sig – införa system och karriärvägar där medarbetares insatser i det vardagliga samverkansarbetet uppmärksammas och belönas.

    Mot bakgrund av detta kan man konstatera att det är angeläget att lärosätenas strategiska arbete avseende utveckling och uppföljning av samverkan i utbildningen vidareutvecklas. Men, med vilka verktyg, var i verksamheten och på vilka sätt?

    I följande skrift samlas erfarenheter och goda exempel gjorda inom ramen för ett flerårigt lärosätesövergripande samarbetsprojekt, Samverkanssäkrade utbildningsprogram, där utgångspunkten har varit att identifiera strategier och metoder för att integrera samverkan i utbildningsprogram. Målet har varit att undersöka och beskriva hur samverkan kan vara ett medel som bidrar till att stärka utbildningens kvalitet och relevans, samt ge förslag på hur vägen till samverkanssäkrad utbildning kan se ut.

    Den centrala slutsatsen är att samverkan, när den är en integrerad del av utbildningen, bidrar till kvalitet och säkerställer att utbildningen blir till nytta för samhället. Det finns också andra vinster med att bedriva ett systematiskt samverkansarbete, till exempel att det leder till pedagogisk utveckling för undervisande personal, att det ökar förutsättningarna för ett utmaningsbaserat lärande med studenten i centrum, att det underlättar övergången från studier till arbetsliv, och att det möjliggör fördjupade relationer med den värld lärosätet finns i. Resan mot samverkanssäkrad utbildning är, med andra ord, mödan väl värd.

  • 2.
    Ahlgren-Moritz, Charlotte
    et al.
    Malmö högskola, Sweden.
    Alm, Anna-Karin
    Malmö högskola, Sweden.
    Christersson, Cecilia
    Malmö högskola, Sweden.
    Eikelboom Sällström, Anette
    Enheten för externa relationer, Umeå universitet, Sweden.
    Esbjörnsson, Mattias
    Malmö högskola, Sweden.
    Jacobsson, Andreas
    Fakulteten för teknik och samhälle, Malmö högskola, Sweden.
    Marell, Agneta
    Samverkan och innovation, Umeå universitet, Sweden.
    Persson, Jeanette
    Innovation och utveckling, Malmö högskola, Sweden.
    Ramsten, Anna-Carin
    Linköping University, REMESO - Institute for Research on Migration, Ethnicity and Society. Linköping University, Department of Social and Welfare Studies. Linköping University, Faculty of Arts and Sciences.
    Rehme, Jakob
    Linköping University, Department of Management and Engineering, Industrial Economics. Linköping University, Faculty of Science & Engineering.
    Reinhold, Mats
    Enheten för externa relationer, Umeå universitet, Sweden.
    Sjögren, Karin
    Malmö högskola, Sweden.
    Sörensson, Victoria
    Enheten för externa relationer, Umeå universitet, Sweden.
    Värbrand, Peter
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Vägen till samverkanssäkrad utbildning. [2]: Möjligheter och utmaningar2016Book (Other academic)
    Abstract [sv]

    Universitet och högskolor bidrar till samhällsutvecklingen genom att forskningsbaserad kunskap tillämpas av olika aktörer i samhället. För att möta dagens och morgondagens samhällsutmaningar utgör således kunskapsutbyte och samverkan mellan lärosäten och samhället en värdefull möjlighet. Att ha starka relationer med samhällets aktörer identifieras också som viktigt i utvecklingen av ett internationellt starkt lärosäte.

    Samverkan i högre utbildning främjar samhällets förändringsförmåga och stärker utbildningens kvalitet, men samverkan förbereder också studenterna för ett livslångt lärande och underlättar övergången mellan utbildning och arbetsliv. Ett lärosäte i nära samverkan med aktörer i samhället är ett relevant lärosäte, det vill säga ett lärosäte som är till nytta för sin omvärld och för sina medarbetare och studenter.

    Ett grundläggande problem vad gäller möjligheterna att integrera samverkan i akademisk utbildning står att finna i statens fördelning av medel till lärosätena. De statliga medlen utgår nämligen i två separata anslag, ett vardera för de båda huvuduppdragen utbildning och forskning. Samverkan kan sägas ingå i bägge uppdragen. Till skillnad från forskningssamverkan finns det för utbildningssamverkan ingen särskild uppföljning och inte heller några ekonomiska incitament. Utvärdering av forskning och utbildning bör således breddas så att kvalitetsstärkande samverkansinslag också inkluderas i resursfördelningsprinciperna. Statens bristande strukturer för fördelning och uppföljning återspeglas i hur lärosätena fördelar resurser till och följer upp samverkan: lärare ges sällan resurser (i form av särskild tid) för att på ett pedagogiskt genomtänkt sätt kunna inkludera samverkansinslag i undervisningen; samverkan är sällan meriterande eller lönegrundande; och den utbildningssamverkan som bedrivs följs sällan upp – varken på institutions-, fakultets- eller lärosätesnivå. Samma sak kan sägas gälla på nationell nivå – det samverkande lärosätet erhåller inga extra anslag och det bestraffas ej heller för försummelse av detsamma. Att göra samverkan till en integrerad del av utbildningen innebär att samverkan bör ingå i de pedagogiska modeller som lärare använder för att leda studenternas kunskapsutveckling mot de mål som finns angivna i kurs- och utbildningsplaner. Det betyder också att arbetet med samverkan bör inkluderas i processer för styrning, planering och uppföljning av utbildning och undervisning på såväl kurs- och programnivå som på institutions-, fakultets- och lärosätesnivå. Att göra samverkan till en integrerad del av utbildningen är att sträva mot att externa aktörer ska bli en självklar del i den dagliga verksamheten – för studenter såväl som för medarbetare och för de organisationer man samverkar med. För att svenska lärosäten ska ges en realistisk möjlighet att göra samverkan till en integrerad del av utbildningsverksamheten krävs det framför allt följande:

    • att politiker och departement utformar ett fördelningssystem där framgångsrika samverkansinsatser inom utbildningen leder till en förstärkning av resursbasen på lärosätena;
    • att lärosätesledningar tar tydlig ställning för samverkansfrågan i sina strategiska styrdokument och att samverkan införs i lärosätenas kvalitetssäkringssystem för utbildning, samt att lärosätena inför system för att styra och följa upp samverkan i utbildningen på lärosätesövergripande nivå;
    • att ledningen för fakulteter, institutioner eller motsvarande omsätter lärosätets strategiska åtaganden i handlingsplaner och lokala styrdokument samt utformar system för dokumentation, styrning och uppföljning av samverkan i utbildningsprogram;
    • att lärare samt kurs- och programansvariga inför samverkan i utbildningens styrande dokument (t.ex. kurs- och utbildningsplaner) samt i den ordinarie undervisningsverksamheten.

    Dessutom bör lärosätena – både gemensamt men också vart och ett för sig – införa system och karriärvägar där medarbetares insatser i det vardagliga samverkansarbetet uppmärksammas och belönas.

    Mot bakgrund av detta kan man konstatera att det är angeläget att lärosätenas strategiska arbete avseende utveckling och uppföljning av samverkan i utbildningen vidareutvecklas. Men, med vilka verktyg, var i verksamheten och på vilka sätt?

    I följande skrift samlas erfarenheter och goda exempel gjorda inom ramen för ett flerårigt lärosätesövergripande samarbetsprojekt, Samverkanssäkrade utbildningsprogram, där utgångspunkten har varit att identifiera strategier och metoder för att integrera samverkan i utbildningsprogram. Målet har varit att undersöka och beskriva hur samverkan kan vara ett medel som bidrar till att stärka utbildningens kvalitet och relevans, samt ge förslag på hur vägen till samverkanssäkrad utbildning kan se ut.

    Den centrala slutsatsen är att samverkan, när den är en integrerad del av utbildningen, bidrar till kvalitet och säkerställer att utbildningen blir till nytta för samhället. Det finns också andra vinster med att bedriva ett systematiskt samverkansarbete, till exempel att det leder till pedagogisk utveckling för undervisande personal, att det ökar förutsättningarna för ett utmaningsbaserat lärande med studenten i centrum, att det underlättar övergången från studier till arbetsliv, och att det möjliggör fördjupade relationer med den värld lärosätet finns i. Resan mot samverkanssäkrad utbildning är, med andra ord, mödan väl värd.

  • 3.
    Andersson Granberg, Tobias
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Norin, Anna
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Värbrand, Peter
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Yuan, Di
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Integrating optimization and simulation to gain more efficient airport logistics2009In: Eighth USA/Europe Air Traffic Management Research and Development Seminar (ATM2009), 2009, p. 1-10Conference paper (Refereed)
    Abstract [en]

    In this paper we present airport logistics, which is a framework of resource management in the air transportation system. Focus is on the processes supporting turn-around. A detailed simulation model of various processes involved in turn-around is developed, by which the interaction between these processes are analyzed. We show that integrating optimization and simulation is a powerful tool to demonstrate efficiency improvements in airport logistics, using scheduling de-icing trucks as an example. An optimization algorithm for scheduling de-icing trucks is developed and simulations are performed comparing different schedules. The schedule obtained when considering total airport performance in the optimization algorithm gives minimum flight delay and waiting times in the simulations.

  • 4.
    Andersson Granberg, Tobias
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Värbrand, Peter
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Decision support tools for ambulance dispatch and relocation2007In: Journal of the Operational Research Society, ISSN 0160-5682, Vol. 58, p. 195-201Article in journal (Refereed)
    Abstract [en]

    In this paper, the development of decision support tools for dynamic ambulance relocation and automatic ambulance dispatching is described. The ambulance dispatch problem is to choose which ambulance to send to a patient. The dynamic ambulance relocation problem occurs in the operational control of ambulances. The objective is to find new locations for some of the ambulances, to increase the preparedness in the area of responsibility. Preparedness is a way of evaluating the ability to serve potential patients with ambulances now and in the future. Computational tests using a simulation model show that the tools are beneficial in reducing the waiting periods for the patients.

  • 5.
    Andersson Granberg, Tobias
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Värbrand, Peter
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    The flight perturbation problem2004In: Transportation planning and technology (Print), ISSN 0308-1060, E-ISSN 1029-0354, Vol. 27, no 2, p. 91-117Article in journal (Refereed)
    Abstract [en]

    Airlines spend considerable time, effort and financial resources on planning. It is essential to create a competitive timetable and construct a fleet and a crew schedule that utilizes these resources to the maximum. Unfortunately, it is all too common that an airline is faced with the necessity of reconstructing their schedules due to some unforeseen event, for example an aircraft breakdown or a crew member that is indisposed. In this paper, an application that can help airlines solve the complex problem of reconstructing aircraft schedules is presented. A mixed integer multicommodity flow model with side constraints is developed and further reformulated into a set packing model using the Dantzig—Wolfe decomposition. Cancellations, delays and aircraft swaps are used to resolve the perturbation, and the model ensures that the schedule returns to normal within a certain time. Two column generation schemes for heuristically solving the model are tested on real problem data obtained from a Swedish domestic airline. The computational tests show that the application is capable of presenting high quality solutions in a few seconds and therefore can be used as a dynamic decision support tool by the airlines.

  • 6.
    Andersson, Henrik
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Värbrand, Peter
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    A Lagrangean Based Heuristic for the Inventory Routing Problem2006In: European Journal of Operational Research, ISSN 0377-2217Article in journal (Refereed)
  • 7.
    Andersson, Henrik
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Värbrand, Peter
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Decision Support for Distribution Chain Management: the Swedish Pulp Industry2004In: 7th International Conference on Intelligent Transport Systems, 2004, p. 1051-1056Conference paper (Other academic)
  • 8.
    Andersson, Henrik
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Värbrand, Peter
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Solving a distribution chain management problem in the Swedish pulp industry2004In: 11th World Congress on ITS - ITS for a Livable Society,2004, 2004Conference paper (Other academic)
  • 9.
    Andersson, Tobias
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Petersson, S.
    SOS Alarm AB, Stockholm, Sweden.
    Värbrand, Peter
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Calculating the preparedness for an efficient ambulance health care2004In: 7th International Conference on Intelligent Transport Systems,2004, New York, NY, USA: IEEE , 2004, p. 785-Conference paper (Refereed)
  • 10.
    Andersson, Tobias
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Petersson, S.
    SOS Alarm AB.
    Värbrand, Peter
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Dynamic ambulance relocation for a higher preparedness2004In: 35th Annual Meeting of the Decision Sciences Institute,2004, Atlanta, Georia, USA: Decision Sciences Institute , 2004, p. 3911-Conference paper (Refereed)
  • 11.
    Andersson, Tobias
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Petersson, S.
    SOS Alarm AB, Stockholm, Sweden.
    Värbrand, Peter
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    OPAL - Optimized ambulance logistics2004In: TRISTIN V: 5th Triennial Symposium on Transport Analysis,2004, 2004Conference paper (Other academic)
  • 12.
    Andersson, Tobias
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Petersson, Sverker
    SOS Alarm AB, Sweden.
    Värbrand, Peter
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Decision support for efficient ambulance logistics2007In: Operational Research for Health Policy: Making Better Decisions: Proceedings of the 31st Annual Conference of the European Working Group on Operational Research Applied to Health Services / [ed] Sally Brailsford, Paul Harper, Bern, Switzerland: Peter Lang AG , 2007, p. 107-125Conference paper (Refereed)
    Abstract [en]

    Ambulance logistics comprises everything that has to do with managing an efficient ambulance health care, which includes both emergency medical services and patient transportations. In this work, ambulance logistics is defined and discussed using the Swedish public service enterprise SOS Alarm as a basis. A number of ways of improving the ambulance logistic service provided by SOS Alarm are identified, and nine areas of improvement are defined. Two of the nine areas, -Visualisation of the preparedness- and -Decision support for efficient ambulance logistics- are described in more detail. In both of these, the main improvement lays in the development of decision support tools for the ambulance dispatchers. The tools that are developed are a preparedness calculator, an ambulance dispatch suggestion tool, a relocation tool and a simulation tool.

  • 13.
    Björklund, Patrik
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Värbrand, Peter
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Yuan, Di
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology, Communications and Transport Systems.
    A Column Generation Method for Spatial TDMA Scheduling in Ad Hoc Networks2004In: Ad hoc networks, ISSN 1570-8705, E-ISSN 1570-8713, Vol. 2, no Issue 4, p. 405-418Article in journal (Refereed)
    Abstract [en]

    An ad hoc network can be set up by a number of units without the need of any permanent infrastructure. Two units establish a communication link if the channel quality is sufficiently high. As not all pairs of units can establish direct links, traffic between two units may have to be relayed through other units. This is known as the multi-hop functionality. In military command and control systems, ad hoc networks are also referred to as multi-hop radio networks. Spatial TDMA (STDMA) is a scheme for access control in ad hoc networks. STDMA improves TDMA by allowing simultaneous transmission of multiple units. In this paper, we study the optimization problem of STDMA scheduling, where the objective is to find minimum-length schedules. Previous work for this problem has focused on heuristics, whose performance is difficult to analyze when optimal solutions are not known. We develop novel mathematical programming formulations for this problem, and present a column generation solution method. Our numerical experiments show that the method generates a very tight bound to the optimal schedule length, and thereby enables optimal or near-optimal solutions. The column generation method can be used to provide benchmarks when evaluating STDMA scheduling algorithms. In particular, we use the bound obtained in the column generation method to evaluate a simple greedy algorithm that is suitable for distributed implementations.

  • 14.
    Björklund, Patrik
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Värbrand, Peter
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Yuan, Di
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology, Communications and Transport Systems.
    A Dynamic Programming Method for Optimal Scheduling in High Speed Downlink Packet Access2006In: The 3rd International Conference on Mobile Technologies,Applications and Systems Mobility 2006,2006, 2006Conference paper (Refereed)
  • 15.
    Björklund, Patrik
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Värbrand, Peter
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Yuan, Di
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology, Communications and Transport Systems.
    A dynamic programming technique for downlink bandwidth allocation in WCDMA networks2004In: Vehicle Technology Conference,2004, New York, NY, USA: IEEE , 2004Conference paper (Refereed)
  • 16.
    Björklund, Patrik
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Värbrand, Peter
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Yuan, Di
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    A Simulated Annealing Algorithm for Frequency Assignment in Frequency Hopping GSM Networks2003In: International Conference on Computer, Communication and Control Technolgies CCCT 03,2003, Orlando: IIIS , 2003, p. 155-Conference paper (Refereed)
    Abstract [en]

    We consider the frequency assignment problem in frequency hopping GSM networks, where the task is to construct and assign lists of frequencies to blocks of transceivers, such that the total interference is minimized. We present a mathematical model and describe a simulated annealing algorithm. The algorithm explores the solution space by solving an integer program in each iteration. Computational experiments for real-life and synthesized networks show that considerable interference reduction can be achieved using the algorithm.

  • 17.
    Björklund, Patrik
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Värbrand, Peter
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Yuan, Di
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology, Communications and Transport Systems.
    Optimized planning of frequency hopping in cellular networks2005In: Computers & Operations Research, ISSN 0305-0548, E-ISSN 1873-765X, Vol. 32, no 1, p. 169-186Article in journal (Refereed)
    Abstract [en]

    We consider a generalization of the classical frequency assignment problem. The generalization arises when frequency hopping is used in a cellular network. The planning problem concerns assigning lists of frequencies to blocks of transceivers, such that the total interference is minimized. This problem is considerably more difficult than the classical frequency assignment problem, because of the large number of possible frequency lists. We provide the technical background that motivates our study, and present a mathematical model which includes the classical frequency assignment problem as a special case. We describe a simulated annealing algorithm. The algorithm explores the solution space by solving an integer program in each iteration. We report computational results for real-life and synthesized networks. © 2003 Elsevier Ltd. All rights reserved.

  • 18.
    Björklund, Patrik
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Värbrand, Peter
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Yuan, Di
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Resource Optimization of Spatial TDMA in Ad Hoc Radio networks : A Column Generation Approach2003In: IEEE INFOCOM 2003,2003, San Francisco: IEEE , 2003, p. 818-Conference paper (Refereed)
    Abstract [en]

    Wireless communications using ad hoc networks are receiving an increasing interest. The most attractive feature of ad hoc networks is the flexibility. The network is set up by a number of units in an ad hoc manner, without the need of any fixed infrastructure. Communication links are established between two units if the signal strength is sufficiently high. As not all pairs of nodes can establish direct links, the traffic between two units may have to be relayed through other units. This is known as the multihop functionality. Design of ad hoc networks is a challenging task. In this paper we study the problem of resource allocation with spatial TDMA (STDMA) as the access control scheme. Previous work for this problem has mainly focused on heuristics, whose performance is difficult to analyze when optimal solutions are not known. We develop, for both node-oriented and link-oriented allocation strategies, mathematical programming formulations for resource optimization. We further present a column generation approach, which, in our numerical experiments, constantly yields optimal or near-optimal solutions. Our results provide important benchmarks when evaluating heuristic on-line algorithms for resource optimization using STDMA.

  • 19. Engevall, Stefan
    et al.
    Göthe-Lundgren, Maud
    Linköping University, The Institute of Technology. Linköping University, Department of Mathematics, Optimization .
    Värbrand, Peter
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    A strong lower bound for the node weighted Steiner tree problem1998In: Networks, ISSN 0028-3045, E-ISSN 1097-0037, Vol. 31, p. 11-17Article in journal (Refereed)
  • 20.
    Engevall, Stefan
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mathematics, Optimization .
    Göthe-Lundgren, Maud
    Linköping University, The Institute of Technology. Linköping University, Department of Mathematics, Optimization .
    Värbrand, Peter
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    The heterogeneous vehicle-routing game2004In: Transportation Science, ISSN 0041-1655, E-ISSN 1526-5447, Vol. 38, no 1, p. 71-85Article in journal (Refereed)
    Abstract [en]

    In this paper, we study a cost-allocation problem that arises in a distribution-planning situation at the Logistics Department at Norsk Hydro Olje AB, Stockholm, Sweden. We consider the routes from one depot during one day. The total distribution cost for these routes is to be divided among the customers that are visited. This cost-allocation problem is formulated as a vehicle-routing game (VRG), allowing the use of vehicles with different capacities. Cost-allocation methods based on different concepts from cooperative game theory, such as the core and the nucleolus, are discussed. A procedure that can be used to investigate whether the core is empty or not is presented, as well as a procedure to compute the nucleolus. Computational results for the Norsk Hydro case are presented and discussed.

  • 21.
    Engevall, Stefan
    et al.
    Linköping University, Department of Mathematics. Linköping University, The Institute of Technology.
    Göthe-Lundgren, Maud
    Linköping University, Department of Mathematics. Linköping University, The Institute of Technology.
    Värbrand, Peter
    Linköping University, Department of Mathematics. Linköping University, The Institute of Technology.
    The traveling salesman game: An application of cost allocation in a gas and oil company1998In: Annals of Operations Research, ISSN 0254-5330, E-ISSN 1572-9338, Vol. 82, p. 203-218Article in journal (Refereed)
    Abstract [en]

    In this article, a cost allocation problem that arises in a distribution planning situation atthe Logistics Department at Norsk Hydro Olje AB is studied. A specific tour is considered,for which the total distribution cost is to be divided among the customers that are visited.This problem is formulated as a traveling salesman game, and cost allocation methods basedon different concepts from cooperative game theory, such as the nucleolus, the Shapleyvalue and the t-value, are discussed. Additionally, a new concept is introduced: the demandnucleolus. Computational results for the Norsk Hydro case are presented and discussed.

  • 22.
    Henningsson, Mathias
    et al.
    Linköping University, Department of Mathematics. Linköping University, The Institute of Technology.
    Holmberg, Kaj
    Linköping University, Department of Mathematics. Linköping University, The Institute of Technology.
    Rönnqvist, Mikael
    Linköping University, Department of Mathematics. Linköping University, The Institute of Technology.
    Värbrand, Peter
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    A column generation approach for a ring network design problem2003Report (Other academic)
    Abstract [en]

    When designing a telecommunication network, one often wish to include some kind of survivability requirement, for example that there should be at least two paths between every pair of nodes in the network. A design model who fulfills this requirement is a network build up with rings. The network design problem is to choose links from a given network, and compose them into a number of rings. The rings are connected to each other at certain transit nodes. The number of possible rings is enormous, and each possible ring is associated with a certain fixed cost. A ring has a fixed capacity, however, we model it as a linear cost depending on the traffic using the ring and the length of the ring. We describe the problem, and model it is a set covering model, where a column describes how a specific ring is used. Even with a small set of rings, number of possible columns in the model is large. Therefore, a column generation approach is used to solve the set covering model with a given set of rings. An important part of the problem is to generate new rings, were the dual solution from the set covering model gives rewards on the nodes, representing a nodes’ wish to be included in a new ring. The ring generation problem is a modification of a traveling salesman subtour problem. New rings are generated using a heuristic. We present some computational results for a real data network and a number of random generated networks.

  • 23.
    Henningsson, Mathias
    et al.
    Linköping University, Department of Mathematics. Linköping University, The Institute of Technology.
    Holmberg, Kaj
    Linköping University, Department of Mathematics. Linköping University, The Institute of Technology.
    Rönnqvist, Mikael
    Linköping University, Department of Mathematics. Linköping University, The Institute of Technology.
    Värbrand, Peter
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    A ring network design problem and heuristics for generating a set of feasible rings2003Report (Other academic)
    Abstract [en]

    We discuss the problem of designing a telecommunication network with the survivability requirement that the network should be composed of connected rings of links. The work design problem is then to choose links from a given network, and compose them into a number of rings. Furthermore, the rings should be connected at certain transit nodes. The traffic between rings may pass through other rings. Each ring is associated with a certain fixed cost depending on the length of the ring. We describe the problem, modeled as a linear integer programming problem. We find a feasible solution to the problem by first find good rings in the network using two heuristics, and then solve the optimization model using only these rings. Finally, we give some computational results for different networks.

  • 24.
    Henningsson, Mathias
    et al.
    Linköping University, Department of Mathematics. Linköping University, The Institute of Technology.
    Holmberg, Kaj
    Linköping University, Department of Mathematics. Linköping University, The Institute of Technology.
    Rönnqvist, Mikael
    Linköping University, Department of Mathematics. Linköping University, The Institute of Technology.
    Värbrand, Peter
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    A ring network design problem solved by a ring generation and allocation approach2003Report (Other academic)
    Abstract [en]

    The development of optical fibers in telecommunications has lead large changes in the field. When design a telecommunication network, capacity nowadays is cheap, and the minimal cost design tends to be a tree. Since such a design is very vulnerable for link or node failures, one often wish to include some kind of survivability requirement, for example that the network should be two-edge-connected or two-node-connected. Another form of design model is to prescribe that the network should be composed of connected rings of links. The network design problem is then to choose links from a give network, and compose them into a number of rings. Furthermore, the rings should be connected at certain transit nodes. Each possible ring is associated with a certain fixed cost, and all links in a certain ring are given the same capacity. Traffic between rings may pass through other rings, which is an important element of the problem. Finally, reserve capacity allocation according to certain principles is included. We describe the problem, modeled as a linear integer programming problem, and discuss different formulations and different solution methods. As the problem is quite difficult, we focus on heuristic solution methods, including elements of column generation and Lagrangean relaxation.

  • 25.
    Henningsson, Mathias
    et al.
    Linköping University, Department of Mathematics. Linköping University, The Institute of Technology.
    Holmberg, Kaj
    Linköping University, Department of Mathematics. Linköping University, The Institute of Technology.
    Rönnqvist, Mikael
    Linköping University, Department of Mathematics. Linköping University, The Institute of Technology.
    Värbrand, Peter
    Linköping University, Department of Mathematics. Linköping University, The Institute of Technology.
    Ring network design by Lagrangean based column generation2002In: Telecommunications Systems, ISSN 1018-4864, E-ISSN 1572-9451, Vol. 21, no 2-4, p. 301-318Article in journal (Refereed)
    Abstract [en]

    We discuss the problem of designing a telecommunication network with the survivability requirement that the network should be composed of connected rings of links. The network design problem is then to choose links from a given network, and compose them into a number of rings. Furthermore, the rings should be connected at certain transit nodes. The traffic between rings may pass through other rings. Each ring is associated with a certain fixed cost depending on the length of the ring. We describe the problem, modeled as a linear integer programming problem, and a heuristic solution method, based on column generation and Lagrangean relaxation.

  • 26.
    Häll, Carl Henrik
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Andersson, Henrik
    Department of Industrial Economics and Technology Management, Norwegian University of Science and Technology.
    Lundgren, Jan T.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Värbrand, Peter
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    The Integrated Dial-a-Ride Problem2009In: Public Transport, ISSN 1866-749X, E-ISSN 1613-7159, Vol. 1, no 1, p. 39-54Article in journal (Refereed)
    Abstract [en]

    In this paper we present a formulation of the Integrated Dial-a-Ride (IDARP). This problem is to schedule dial-a-ride requests, where some part of each journey may be carried out by a fixed route service. The IDARP is a generalization of the Dial-a-Ride Problem. An arc-based formulation is proposed, and it is shown how the model can be made easier to solve by arc elimination, variable substitution and the introduction of subtour elimination constraints. Small instances of the IDARP can be solved using an exact solution method, and one such instance is studied. We also describe how input and output data can be created and visualized in a geographic information system.

  • 27.
    Häll, Carl Henrik
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Lundgren, Jan T.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Värbrand, Peter
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Evaluation of an integrated public transport system: a simulation approach2008In: Archives of Transport, ISSN 0866-9546, Vol. 20, no 1-2, p. 29-46Article in journal (Refereed)
    Abstract [en]

    Integrated public transportation service is a new interesting form of service combining a fixed route service with a demand responsive service. When designing such a service, it is important to analyse and evaluate how the attractiveness and operating costs for the service depend on the type of demand responsive service used, the design parameters related to the fleet of vehicles, the structure of the transportation network and on the personal service commitments made to the passengers. In this paper, we show how simulation can be used to perform these analyses. The performed simulations also give guidelines to help operators of public transport to design the service. The evaluation is made using the LlTRES-2 public transport modelling system. The results show the importance of the design of the demand responsive part of the integrated service.

  • 28.
    Häll, Carl Henrik
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Lundgren, Jan
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Värbrand, Peter
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Simulation and evaluation of integrated public transport2005In: Advanced OR and AI Methods in Transportation, Proceedings of the 10th Jubilee Meeting of the EURO Working Group on Transportation,2005, Poznan, Poland: Publishing House of the Poznan University of Technology , 2005, p. 271-Conference paper (Refereed)
  • 29.
    Lundgren, Jan
    et al.
    Linköping University, Department of Science and Technology.
    Rönnqvist, Mikael
    Linköping University, The Institute of Technology. Linköping University, Department of Mathematics, Optimization .
    Värbrand, Peter
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Optimeringslära2003Other (Other (popular science, discussion, etc.))
  • 30.
    Norin, Anna
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Andersson Granberg, Tobias
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Yuan, Di
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Värbrand, Peter
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Airport logistics - A case study of the turn-around process2012In: Journal of Air Transport Management, ISSN 0969-6997, E-ISSN 1873-2089, Vol. 20, p. 31-34Article in journal (Refereed)
    Abstract [en]

    This paper studies the effects of different optimization objectives when scheduling de-icing services at Stockholm Arlanda airport. The optimized schedule is tested using a simulation model of the turnaround process. The results demonstrate that the schedule taking into account overall airport performance results in less delay than one targeted solely at the performance of the de-icing process.

  • 31.
    Norin, Anna
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Andersson, Tobias
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Värbrand, Peter
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Yuan, Di
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology, Communications and Transport Systems.
    A GRASP Heuristic for Scheduling De-icing trucks at Stockholm Arlanda Airport2007In: 6th Eurocontrol Innovative Research Workshop and Exhibition,2007, 2007Conference paper (Other academic)
    Abstract [en]

    It is a fact that the most delays in the Air Transportation System (ATS) today occur at the airport. One reason for this is the large number of actors operating at the airport and the scarcity of communication between them and other parts of the ATS. Airport Logistics is a concept developed to survey all the flows of ehicles, people, material and information, which can be found on and around the airport. The objective is to increase efficiency, where one part is to decrease the delays. As an initial step, the turn-around process is analysed and an optimization model for the planning of de-icing trucks is implemented. The model shows that large savings can be made both by reducing the travelling distances for the trucks and reducing the delays the de-icing process is causing the ATS. However, most important is the advantage of having a plan for how the de-icing trucks should be utilized, something that is missing today.  

  • 32.
    Norin, Anna
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Andersson, Tobias
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Värbrand, Peter
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Yuan, Di
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology, Communications and Transport Systems.
    Intelligent Air Transportation - A Resource Management Perspective2007In: 14th world congress on intelligent transport systems,2007, Beijing: Ministry of communications , 2007Conference paper (Refereed)
    Abstract [en]

    In this paper we look at the air transportation system from a resource management perspective. In particular, we introduce the concept airport logistics, with the general focus of efficiently managing all the logistic activities and processes at, or nearby, an airport. One important goal is to utilize and process the available information for intelligent resource management. Some previous research in the air transportation system area is reviewed and classified into three categories; airline operations, airport operations and air traffic management. A conceptual framework of a decision support system is presented and motivated with a clear emphasis on the airport system.

  • 33.
    Norin, Anna
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Yuan, Di
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Andersson Granberg, Tobias
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Värbrand, Peter
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Scheduling de-icing vehicles within airport logistics: a heuristic algorithm and performance evaluation2012In: Journal of the Operational Research Society, ISSN 0160-5682, E-ISSN 1476-9360, Vol. 63, no 8, p. 1116-1125Article in journal (Refereed)
    Abstract [en]

    Most delays in the air transport occur at the airport. A particular reason is the complexity of managing the large number of supporting flows in airport logistics. We consider the optimisation problem of scheduling de-icing vehicles that is one of the key supporting logistic flows in the turn-around process of aircraft. The objective is to minimise the delay of flights due to de-icing, and the travel distance of the de-icing vehicles. We study the complexity of the problem, and develop a solution algorithm using greedy randomised adaptive search. A case study of real-life data from Stockholm Arlanda Airport shows that optimised schedule leads to significantly better performance in comparison to intuitive and simple scheduling strategies. The benefit of optimisation in reducing the waiting time for de-icing is further demonstrated via dynamic simulations.

  • 34.
    Palmgren, Myrna
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mathematics, Optimization .
    Rönnqvist, Mikael
    Linköping University, The Institute of Technology. Linköping University, Department of Mathematics, Optimization .
    Värbrand, Peter
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    A near-exact method for solving the log-truck scheduling problem2004In: International Transactions in Operational Research, ISSN 0969-6016, E-ISSN 1475-3995, Vol. 11, no 4, p. 447-464Article in journal (Refereed)
  • 35.
    Palmgren, Myrna
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mathematics, Optimization .
    Rönnqvist, Mikael
    Linköping University, The Institute of Technology. Linköping University, Department of Mathematics, Optimization .
    Värbrand, Peter
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    A solution approach for log truck scheduling based on composite pricing and branch and bound2003In: International Transactions in Operational Research, ISSN 0969-6016, E-ISSN 1475-3995, Vol. 10, p. 433-447Article in journal (Refereed)
  • 36.
    Siomina, Iana
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Värbrand, Peter
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Yuan, Di
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology, Communications and Transport Systems.
    An effective optimization algorithm for configuring radio base station antennas in UMTS networks2006In: The 64th IEEE Vehicular Technology Conference 2006 Fall VTC2006-fall,2006, IEEE , 2006Conference paper (Refereed)
    Abstract [en]

    In this paper we propose an effective algorithm for configuring radio base station antennas in UMTS networks and optimizing the Primary Common Pilot Channel (CPICH) transmit power. The algorithm is based on tabu search and utilizes the advantage of a problem size reduction technique which allows us to detect the most critical parts of the service area where the coverage loss probability is very sensitive to the choice of antenna configuration in neighboring cells. We report numerical results for a test network originating from a realistic planning scenario for the city of Lisbon.  

  • 37.
    Siomina, Iana
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Värbrand, Peter
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Yuan, Di
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology, Communications and Transport Systems.
    Automated optimization of service coverage and base station antenna configuration in UMTS networks2006In: IEEE wireless communications, ISSN 1536-1284, E-ISSN 1558-0687, Vol. 13, no 6, p. 16-25Article in journal (Refereed)
    Abstract [en]

    Deployment and maintenance of UMTS networks involve optimizing a number of network configuration parameters in order to meet various service and performance requirements. In this article we address automated optimization of service coverage and radio base station antenna configuration. We consider three key configuration parameters: transmit power of the common pilot channel (CPICH), antenna tilt, and antenna azimuth. CPICH power greatly influences coverage. From a resource management point of view, satisfying the coverage requirement using minimum CPICH power offers several performance advantages. In particular, less CPICH power leads to less interference and higher system capacity. Optimal CPICH power, in its turn, is highly dependent on how the other two parameters, tilt and azimuth, are configured at radio base station antennas. Optimizing antenna tilt and azimuth network-wise, with the objective of minimizing the CPICH power consumption, is a challenging task. The solution approach in this article adopts automated optimization. Our optimization engine is a simulated annealing algorithm. Staring from an initial configuration, the algorithm searches effectively in the solution space of possible configurations in order to find improvements. The algorithm is computationally efficient, thus, we can optimize large networks without using excessive computing resources. We present a case study for a UMTS planning scenario in Lisbon. For this network, automated optimization saves up to 70 percent of the CPICH power used in the reference network configuration. In addition, the optimized network configuration offers significant performance improvement in terms of fewer overloaded cells and lower downlink load factor. © 2006 IEEE.

  • 38.
    Siomina, Iana
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Värbrand, Peter
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Yuan, Di
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology, Communications and Transport Systems.
    Pilot power optimization and coverage control in WCDMA mobile networks2007In: Omega: The International Journal of Management Science, ISSN 0305-0483, E-ISSN 1873-5274, Vol. 35, no 6, p. 683-696Article in journal (Refereed)
    Abstract [en]

    In mobile networks using wideband code division multiple access (WCDMA), common pilot channel (CPICH) signals are used by mobile terminals for channel quality estimation, cell selection, and handover. The strength of the CPICH signal determines the coverage area of the cell, impacts the network capacity, and thereby the quality of service, and is therefore a crucial parameter in network planning and optimization. Pilot power is the most important parameter that allows us to control the strength of the CPICH signal. The more power is spent for pilot signals, the better coverage is obtained. On the other hand, a higher value of the pilot power level in a cell means higher pilot pollution in the network and less power available to serve user traffic in the cell. In this paper, we consider the problem of minimizing the total amount of pilot power subject to a coverage constraint. Our modeling and solution approaches are based on mathematical programming techniques. We present a basic model for pilot power optimization subject to a full coverage constraint as well as its extended version which allows us to study various coverage levels and to consider user traffic distribution over the network. We also propose an efficient algorithm that gives near-optimal solutions to the problem within a reasonable amount of time. We report our numerical experiments for three WCDMA networks of various sizes based on realistic planning scenarios and examine the effect of different levels of the required coverage degree on the total amount of pilot power. © 2006 Elsevier Ltd. All rights reserved.

  • 39.
    Siomina, Iana
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Värbrand, Peter
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Yuan, Di
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Two mathematical programming approaches for pilot power optimization in WCDMA networks2004In: 8th World Multi-Conference on Systematics, Cybernetics and Informatics,2004, Orlando, FL, USA: The International Institute of Informatics and Systematics , 2004, p. 412-Conference paper (Refereed)
  • 40.
    Yuan, Di
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Brunetta, F.
    University of Milan.
    Maucelli, P.
    University of Milan.
    Värbrand, Peter
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Joint optical network design, routing and wavelength assignment by integer programming2004In: Telecommunications Systems, ISSN 1018-4864, E-ISSN 1572-9451, Vol. 26, p. 53-67Article in journal (Refereed)
  • 41.
    Yuan, Di
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology, Communications and Transport Systems.
    Värbrand, Peter
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Resource allocation of spatial time division multiple access in multi-hop radio networks2005In: Resource Management in Wireless Networking / [ed] Mihaela Cardei, Ionut Cardei, Ding-Zhu Du, New York: Springer , 2005, 1, p. -695Chapter in book (Other academic)
    Abstract [en]

    This is the first book that provides readers with a deep technical overview of recent advances in resource management for wireless networks at different layers of the protocol stack. The subject is explored in various wireless networks, such as ad-hoc wireless networks, 3G/4G cellular, IEEE 802.11, and Bluetooth personal area networks.

    Survey chapters give an excellent introduction to key topics in resource management for wireless networks, while experts will be satisfied by the technical depth of the knowledge imparted in chapters exploring hot research topics.

    The subject area discussed in this book is very relevant today, considering the recent remarkable growth of wireless networking and the convergence of wireless personal communications, Internet technologies and real-time multimedia.

    This volume is a very good companion for practitioners working on implementing solutions for multimedia and Quality of Service – sensitive applications over wireless networks.

1 - 41 of 41
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