Signalling overhead Clause Samples

Signalling overhead. The investigated D2D communication links can be categorized into two groups: inner and outer links. The first one includes those D2D links that their paired nodes are both located in a single cell, far from its edges, and are being con- trolled by the same BS. The second group corresponds to those links that are located in the edge of a cell and their nodes might belong to two different serv- ing geographical areas, as mentioned before. Considering the latter, we presume that the two DUEs could be associated with different BSs. However, this will eventually increase latency and signaling overhead due to the need of the two involved BSs to coordinate the communication (Figure 3.3a). Thus, in order to limit these impeding factors, we assume that the overall signaling overhead for D2D data/forwarding plane D2D control plane BS intercommunication (a) BS1 BS2 DUE2 DUE1 (b) Figure 3.3: Signalling exchange for the control of a cell-edge D2D pair: (a) Disjoint DUE association, (b) Joint DUE association (no exchange).