Topology Control in Wireless Ad Hoc Networks phần 5

Ghi chú 1: đồ thị Gabriel đã Ghi chú quyền lực tối ưu yếu tố kéo dài 2: tất cả các đồ thị định tuyến trên là thưa thớt (tức là, mức độ liên tục nút trung bình), nhưng có mức độ nút tối đa tuyến tính trong n | 5th ACM MobiHoc - Tokyo May 24 2004 The CBTC protocol 2 The CBTC protocol produces a connected communication graph if p 2n 3 The obtained communication graph is made symmetric by adding the reverse edge to every unidirectional link A set of optimizations are also proposed that prune energy-inefficient edges while not impairing connectivity and symmetry Drawback directional information required Several variants of CBTC have been introduced Bahramgiri et Huang et Istituto di g Kg Inform atica TC protocols 8 12 e Telematica 5th ACM MobiHoc - Tokyo May 24 2004 Neighbor-based TC Other class of TC protocols based on the k-neighbors graph . the graph in which every node is connected to its k closest neighbors First neighbor-based TC protocol the LINT protocol of RamanathanRosales-Hain00 - Basic idea try to keep the number of neighbors of every node within a low and high threshold centered around an optimal value - Number of neighbors estimated overhearing control and data messages - Drawbacks the optimal value is not characterized the estimation of the number of neighbors might be inaccurate silent neighbors are not detected connectivity is not guaranteed KNeigh Blough et - Goal maintain the number of physical neighbors equal to or slightly below k - k is chosen in such a way that the graph generated is connected . - The graph produced is symmetric - On the average it is 20 more energy-efficient than CBTC - Drawback based on distance estimation connectivity only . Istituto di Informatica e Telematica TC protocols 9 12 5th ACM MobiHoc - Tokyo May 24 2004 The optimal value of k Optimal value of k for increasing n Optimal value Optimal value of k for increasing values of n from Blough et al. 03 Remark setting k 9 guarantees connectivity . for values of n ranging from 50 to 500 Istituto di g Ịg Inform atica TC protocols 10 12 B n e .