Cognitive methods in multimedia communications

In this thesis; it is aimed to improve the multimedia throughput of IEEE 802.16j network by improving the performances of route life time, amount of disconnected periods, average hop count and packet loss rate, using cognitive methods. For this purpose, first the base relaying strategies are compared by simulations and the evaluated results are used to develop the novel proposed AEABR (Alternative Enhancement of Associativity Based Routing) and ATAABR (Associativity Tick Averaged Associativity Based Routing) routing algorithms which are the extensions of ABR (ABR Associativity Based Routing) algorithm. It is shown that the proposed routing algorithms provide longer route life and less number of disconnected time than ABR and the relaying strategies. On the other hand, a novel access method called Most Congested Access First (MCAF) is proposed to decrease the packet loss rate and improve the system throughput. It is shown that, MCAF, which is used in addition to OFDMA and TDMA methods, improves the system throughput by working together with other proposed Spectral Aids (SA) and Buffer Management (BM) methods. It is finally shown that, more throughput improvement is provided when the proposed MCAF, BM and SA methods are used together with AEABR and ATAABR algorithms even for different vehicular velocities and different number of nodes. The novel proposed methods work with an ad-hoc signaling channel that can be sustained by the mobile nodes for distributed network management.