The UrBan Interactions (UBI) research program, coordinated by the University of Oulu, has created a middleware layer on top of the panOULU wireless network and opened it up to ubiquitous-computing researchers, offering opportunities to enhance and facilitate communication between citizens and the government.

Global optimization of access point (AP) assignment to user terminals requires efficient monitoring of user behavior, fast decision algorithms, efficient control signaling and fast access point reassignment mechanisms. In this scenario, Software Defined Networking (SDN) technology may be suitable for network monitoring, signaling and control. We recently proposed embedding virtual switches in user terminals for direct management by an SDN controller, further contributing to SDN-oriented access network optimization. However, since users may restrict terminal-side traffic monitoring for privacy reasons (a common assumption by previous authors), in this work we infer user traffic classes at the access points. On the other hand, since handovers will be more frequent in dense small-cell networks (e.g. mmWave based 5G deployments will require dense network topologies with inter-site distances of ∼150–200 meters), the delay to take assignment decisions should be minimal. To this end, we propose taking fast decisions based exclusively on extremely simple network-side application flow-type predictions based on past user behavior. Using real data we show that a centralized allocation algorithm based on those predictions achieves network utilization levels that approximate those of optimal allocations. We also test a distributed version of this algorithm. Finally, we quantify the elapsed time since a user traffic event takes place until its terminal is assigned an access point, when needed.

Radio Frequency Identification (RFID) systems are one of the enabling technologies for the ubiquitous computing paradigm. At the moment, the EPCglobal organization leads the development of industry-driven standards for this field and has settled the EPC "Gen 2" as a reference standard. In this paper, we analyze the anti-collision procedure of EPC "Gen 2" to find the time needed to identify a population of tags, by means of the finite Markov-chain of the system. In addition, a UHF multi-reader prototype based on time division multiple access (TDMA) scheme is evaluated in this work. In this TDMA scheme, the reader time-slot duration is allocated according to the computations obtained from our analytical study. The main conclusions derived from this implementation are summarized in this work.

Packet switches with optical fabrics can potentially scale to higher capacities. It is also potentially possible to improve their reliability, and reduce both their footprint and power consumption. A well-known alternative for implementing hardwired switches is Arrayed Waveguide Grating (AWG). Ideally, AWG insertion losses do not depend on the number of input-output ports, meaning that scalability is theoretically infinite. However, accurate second-order assessment has demonstrated that in-band crosstalk exponentially increases the power penalty, limiting the realistic useful size of AWG commercial devices to about 10-15 ports (13-18 dB). On the other hand, the in-band crosstalk at AWG outputs depends on the connection pattern set by the scheduling algorithm and this port count limitation is calculated for worst-case scenarios. In this paper, we show that distributed schedulers with predetermined connection patterns can be used to avoid these harmful arrangements. We also show that the probability of worst-case patterns is very low, allowing us to set a more realistic port limit for general centralized schedulers and very small losses. With these results, we calculate more realistic port count limits for both scheduler types.