We investigate the benefits of migrating from a call center, where all agents are pooled and customers are treated indifferently by any agent, toward a call center where customers are grouped into clusters with dedicated teams of agents. Each cluster is referred to as a portfolio. Customers of...

European telecommunication firms have spent billions of dollars in the last year to get a license for UMTS, a third generation standard for mobile phone net-works. Already in GSM networks today, congestion in transmission stations is com-mon...

We present an approach to the admission control, resource allocation and routing problem in connection-oriented networks that offer multiple services to users. Users' preferences are summarized by means of their utility functions, and each user is allowed to request more than one type of...