Esitetään Jyväskylän yliopiston informaatioteknologian tiedekunnan suostumuksella julkisesti tarkastettavaksi yliopiston Agora-rakennuksen auditoriossa 3 joulukuun 12. päivänä 2014 kello 13.Academic dissertation to be publicly discussed, by permission of the Faculty of Information Technology of the University of Jyväskylä, in building Agora, auditorium 3, on December 12, 2014 at 13 o'clock. In this thesis, the solutions for efficiently offering two types of typical services (voice based RT services and data based NRT services) were investigated for evolution of a future network system. For the voice service characterized by the low latency and the small packet size, VoIP over E-DCH associated with DPCCH gating and/or packet bundling in uplink has been investigated and proven in a compelling performance. Moreover, HS-SCCH-less operation in the downlink and the enhanced packet scheduler have been studied to further improve the user end-to-end experience. The tradeoff between reduction of CQI reports and the reliability of the link adaption has also been evaluated for consideration in performance optimization.
UNIVERSITYFor the data service, a hybrid network has been integrated using deviceto-device (D2D) communication into a LTE cellular network is envisioned and investigated as one potential solution. The various RRM schemes for mode selection, power control and resource allocation are studied, which are further complemented by a time hopping mechanism and the enhanced scheduler algorithm. Additionally, asymmetric D2D operation and semi-autonomous D2D were presented as different ways for D2D implementation. D2D based cluster operation was also studied for the potential of offering multicast services. The feedback mechanism for a multicast operation was discussed for assisting the cooperative D2D operation.In short, the VoIP based voice solutions and D2D based data solutions can be considered for future network evolution based on the studies in this thesis.