High insulation of building structures for energy efficiency cause that outdoor mobile network signals do not easily penetrate through walls and windows, resulting in inadequate indoor cellular services. Today this is solved by placing active components (baseband units and/or remote radio units) within the building and connect them with the nearest outdoor cell tower via fibers. This paper describes an alternative solution, especially suited for educational and research campuses, that scales better and is more cost-effective: using the infrastructure of the national research and education network (NREN) to connect the active equipment directly with the mobile cores of communications service providers. By converting the electric signal output from the radio unit to an optical signal, the signal can be transported over the existing campus network to each individual building. By adding the output of two small cells that use private spectrum, a small private mobile network that supports multiple-input and multiple-output is created. This paper describes the setup and our accompanied search to use it to support the ICT demands of the research and education community.

The authors analyze a generalization of the classical Erlang loss model. Customers of several types contend for access to a service facility consisting of a finite number of servers. Each customer requires a fixed number of servers simultaneously during an exponentially distributed service time, and is blocked on arrival if this requirement cannot be met. Customers of each type arrive in geometrically distributed batches, while the arrival of batches of each type is governed by a Poisson process. All relevant parameters may be type-dependent. The authors obtain the steady-state distribution of the number of customers of each type in the system (which turns out to have product form) and the blocking probabilities experienced by each customer type. In addition, the authors bring to light the connection between the model at hand and a method is proposed by L.E.N. Delbrouck (1983) for estimating blocking probabilities in an incompletely specified setting.>