Wireless Communications 2007 CNIT Thyrrenian Symposium e-bog

The 18th Tyrrhenian Workshop on digital communications is devoted to wi- less communications. In the last decade, wireless communications research boosted launching new standards and proposing new techniques for the - cess technology. We moved from the UTRA standard capable to transmit 0. 5bit/s/Hz to WLAN which is promising 2. 7bit/s/Hz. Now wireless c- munication systems are facing a ?ourishing of new proposal moving from multiple antennas at transmitter and receiver side (MIMO systems), to new powerfulForwardErrorCorrectionCodes,toadaptiveradioresourcemana- mentalgorithms. Thenewchallenge,however,isthemovetowardsmultimedia communications and IP technology. This move implies e?orts in several new aspects. First of all an open network, as IP is, imposes the necessity of a - cure network, to guarantee the privacy of the ongoing communications, avoid the use of the networks by unauthorized customers, avoid the misuses and the charge to third parties of the cost of the connection. Also, quality of service (QoS) of the communications is becoming a must in IP networks which are carrying services which need a guaranteed QoS as telephony, real time s- vices, etc. To get this new target some form of access control to the network must be setup. Recently, new form of communication networks has appeared to collect data for several applications (sensor networks, ad hoc networks, etc. ) and they need a connection with a backbone network which could be a wireless one with a larger range than the sensor or ad hoc networks.