Abstract-Regulation will experience enormous changes in section deals with distributed resource auctioning, where a the near future resulting in seamless connectivity by bluring specific belief function is introduced that is an estimation spectrum borders. A promising approach in this context is of the cumulative distribution function. Finally, Section IV dynamic spectrum allocation which leads to a more flexible concludes the paper. access to spectral resources by employing intelligent radio devices

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Abstract-In this paper we present a requested relaying protocol that helps mitigating multipath and shadowing effects in wireless networks. In our approach it is assumed that the destined mobile station has not been able to receive information from the base station and sends a request to surrounding terminals. Those terminals able to receive the request act as relays and help to transmit information from the base station to the destination. Performance analysis with respect to probability of decoding error and outage probability have been made with the results that both can be enormously improved by exploiting diversity. Additionally, order of diversity is defined and applied to our relaying approach as well.

It is increasingly difficult to satisfy growing demands for spectrum with the conventional policy of fixed spectrum allocation. To overcome this problem, flexible/dynamic spectrum sharing methods that can significantly improve spectrum utilization of the spectrum have gained increasing interest recently. This paper presents two dynamic spectrum sharing approaches, a centralized and a decentralized one. The centralized approach is based on hierarchical trading. Each level of hierarchy is composed of "markets" that are associated with a certain spatial area and trading occurrence frequency, whereas area size and trading occurrence frequency depend on the hierarchy level. The decentralized approach is based on game-theory. There, it is assumed that the operators are averse to unequal payoffs and act unselfishly, enabling a stable and sustainable community. Numerical results show that, in the observed scenario, both proposals outperform the reference case of fixed resource allocation significantly in terms of utilized bandwidth. Whereas, negotiation costs for spectrum brokerage appear in the centralized approach, nonnegligible amounts of spectrum are lost in the decentralized approach due to collisions. Thus, a hybrid of centralized and decentralized approach that exploits the benefits of both is also considered.