Title :
Cross-Layer Design of Multicast in Fading: Network Coding and Asynchronous Subgradients
Author :
Rajawat, Ketan ; Gatsis, Nikolaos ; Giannakis, Georgios B.
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of Minnesota, Minneapolis, MN, USA
Abstract :
A cross-layer design along with an optimal resource allocation framework is formulated for wireless fading networks, where the nodes perform network coding. The aim is to jointly optimize end-to-end multicast rates, network code design variables, broadcast link flows, link capacities, average power consumption, and short-term power allocation policies. As in the conventional routing paradigm, the cross-layer optimization problem with network coding is non-convex in general. It is proved however, that dual decomposition is optimal so long as the fading at each wireless link is a continuous random variable. This result is leveraged to develop a subgradient algorithm for network control. The algorithm is asynchronous, whereby the dual updates at the physical layer can be affordably performed with a certain delay with respect to the resource allocation tasks in upper layers. Moreover, the long-term average values of multicast end-to-end rates, virtual flows, broadcast link flows, link capacities, and power consumption are shown to converge to near-optimal ones.
Keywords :
Broadcasting; Cross layer design; Design optimization; Energy consumption; Fading; Multicast algorithms; Network coding; Random variables; Resource management; Routing;
Conference_Titel :
Wireless Network Coding Conference (WiNC), 2010 IEEE
Conference_Location :
Bostn, MA, USA
Print_ISBN :
978-1-4244-7978-8
DOI :
10.1109/WINC.2010.5507936