Roberto Rossi

Flexible scheduling for Real-Time services in High-Speed Packet Access cellular networks

This paper presents the HYbrid Channel-Aware and Real-Time scheduler (HY-CART) for UMTS High-Speed Packet Access networks. The latter works for both downlink and uplink scheduling, with slightly different embodiments due to the different technology constraints. Its basic principle is to select users based on their channel conditions when the deadlines are far ahead: as the deadlines approach, they become progressively more important. Furthermore, resources for scheduled users are allocated sparingly, i.e. enough to serve packets whose deadline is actually near, so as to make room for a possibly larger number of simultaneous users, and keeping into account the user channel state. Simulative evaluation shows that HY-CART performs better than the previous work, allowing more users to be served with the same resources.

Efficient downlink scheduling with power boosting in mobile IEEE 802.16 networks

In current mobile broadband wireless access (BWA) technologies, which are based on orthogonal frequency division multiple access (OFDMA), terminals close to cell edge experience poor channel quality, due to severe path-loss and high interference from concurrent transmissions in nearby cells. To mitigate this problem we propose: (a) to partition the set of sub-channels into chunks, which are assigned different power levels; (b) the design of a data scheduling and allocation algorithm positioned in the medium access control (MAC) layer of the base station (BS), exploiting such a partitioning. The framework is analyzed in a multi-cell IEEE 802.16 network by means of system-level packet-based simulations, with detailed MAC and physical layer abstractions in combination with realistic models of the wireless channel and interference.