Traditionally, until the end of 20-th century, wireless systems could be subdivided in three broad categories, namely point-to-point, point-to-multipoint and area systems. The three categories are rather distinct from each other. Point-to-point links are generally bidirectional and symmetrical, providing the same transmission capacity at both ends of the link, while the two terminals usually are identical. Point-to-multipoint systems, on the other hand, are intrinsically hierarchical, inasmuch as there is one central terminal which is in charge of communication with all the other peripheral terminals. The individual links can be either symmetrical or asymmetrical, and they can also be unidirectional. Finally, area systems (such as mobile radio and broadcasting) are characterised by one station providing service to all the terminals within its coverage area. Mobile radio links are generally bidirectional and they can be either symmetrical or asymmetrical depending from the application. On the contrary, broadcasting systems are intrinsically unidirectional, with the terminals only able to receive the signal emitted by the transmitter. Area systems in general may also support terminal mobility, allowing the terminal to interact with the central station from whichever location of the coverage area, and even to move among coverage areas of different stations. The development of new, advanced concepts and standards brought along distributed network architectures that can't be encompassed in the above taxonomy. The familiar one-to-one and one-to-many relationships cease to apply, and each terminal is immersed in a web-like network of similar elements, exchanging information and/or co-operating with each other. In this chapter we address some of the hottest topics related to the evolution of advanced wireless network systems and architectures. We start presenting the main contributions of COST 2100 to the theory of wireless networks. Then we present a thorough overview of activities regarding Wireless Sensors Networks and Mesh Networks, while the subsequent section deals with Cognitive Radio. Finally, the possibilities offered by MANET are discussed.
Advances in Wireless Ad Hoc and Sensor Networks
TRALLI, Velio;
2012
Abstract
Traditionally, until the end of 20-th century, wireless systems could be subdivided in three broad categories, namely point-to-point, point-to-multipoint and area systems. The three categories are rather distinct from each other. Point-to-point links are generally bidirectional and symmetrical, providing the same transmission capacity at both ends of the link, while the two terminals usually are identical. Point-to-multipoint systems, on the other hand, are intrinsically hierarchical, inasmuch as there is one central terminal which is in charge of communication with all the other peripheral terminals. The individual links can be either symmetrical or asymmetrical, and they can also be unidirectional. Finally, area systems (such as mobile radio and broadcasting) are characterised by one station providing service to all the terminals within its coverage area. Mobile radio links are generally bidirectional and they can be either symmetrical or asymmetrical depending from the application. On the contrary, broadcasting systems are intrinsically unidirectional, with the terminals only able to receive the signal emitted by the transmitter. Area systems in general may also support terminal mobility, allowing the terminal to interact with the central station from whichever location of the coverage area, and even to move among coverage areas of different stations. The development of new, advanced concepts and standards brought along distributed network architectures that can't be encompassed in the above taxonomy. The familiar one-to-one and one-to-many relationships cease to apply, and each terminal is immersed in a web-like network of similar elements, exchanging information and/or co-operating with each other. In this chapter we address some of the hottest topics related to the evolution of advanced wireless network systems and architectures. We start presenting the main contributions of COST 2100 to the theory of wireless networks. Then we present a thorough overview of activities regarding Wireless Sensors Networks and Mesh Networks, while the subsequent section deals with Cognitive Radio. Finally, the possibilities offered by MANET are discussed.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
