?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Fmiis.maths.ox.ac.uk%2Fmiis%2F278%2F&rft.title=Multipoint-to-multipoint+network+communication&rft.creator=Kilby%2C+Philip&rft.creator=Lun%2C+Desmond&rft.creator=Nguyen%2C+Giang&rft.subject=Information+and+communication+technology&rft.description=We+have+formulated+an+exact+ILP+model+for+the+problem+of+communicating+on+a+virtual+network.+While+this+ILP+model+was+successful+in+solving+small+problems%2C+it+is+not+recommended+to+handle+larger+instances%2C+due+to+the+fact+that+the+number+of+variables+in+the+model+grows+exponentially+as+the+graph+size+grows.+However%2C+this+ILP+model+can+provide+a+benchmark+for+heuristic+algorithms+developed+for+this+problem.%0D%0A%0D%0AWe+have+also+described+a+heuristic+approach%2C+and+explored+several+variants+of+the+algorithm.+We+found+a+solution+that+seems+to+perform+well+with+reasonable+computation+time.+The+heuristic+is+able+to+find+solutions+that+respect+the+degree+constraints%2C+but+show+a+small+number+of+violations+of+the+desired+time+constraints.%0D%0ATests+on+small+problems+show+that+heuristic+is+not+always+able+to+find+feasible+solutions%2C+even+though+the+exact+method+has+shown+they+exist.+It+would+be+interesting+in+the+future+to+look+at+whether+insights+gained+by+looking+at+exact+solutions+can+be+used+to+improve+the+heuristic.&rft.date=2009&rft.type=Study+Group+Report&rft.type=NonPeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fmiis.maths.ox.ac.uk%2Fmiis%2F278%2F1%2Fictrmisg2009.pdf&rft.identifier=++Kilby%2C+Philip+and+Lun%2C+Desmond+and+Nguyen%2C+Giang++(2009)+Multipoint-to-multipoint+network+communication.++%5BStudy+Group+Report%5D+++++