Using multiple unmanned aerial vehicles to maintain connectivity of MANETs

Abstract

Unmanned Aerial Vehicles (UAVs) have emerged as promising relay platforms to improve the connectivity of ground Mobile Ad Hoc Networks (MANETs). Due to the relatively high cost of UAVs, a lot of efforts have been made to optimize the deployment of UAVs so that the number of UAVs needed in maintaining the connectivity of ground nodes can be minimized. However, existing work on optimization of UAVs' deployment hasn't considered the situation that there are already some UAVs deployed in the field. In this paper, we study the problem of deploying minimum number of UAVs to maintain the connectivity of ground MANETs under the condition that some UAVs have already been deployed in the field. We formulate this problem as a Minimum Steiner Tree problem with Existing Mobile Steiner points under Edge Length Bound constraints (MST-EMSELB) and prove that the problem is NP-Complete. We also propose an Existing UAVs Aware (EUA) polynomial time approximate algorithm for the MST-EMSELB problem that uses a maximum match heuristic to compute new positions for existing UAVs. Simulation results demonstrate that the proposed EUA method has bester performance than a non-EUA method in the term of needed new UAV numbers. Compared with the non-EUA method, the EUA method can reduce at most 60% of the new UAVs number.

Modelling unmanned aerial vehicles base station in ground‐to‐air cooperative networks

“…In particular, various metrics for ad‐hoc network connectivity were investigated. In [3], under the condition that some UAVs have already been deployed in the field, the minimum number of UAVs to add to maintain connectivity among ground ad‐hoc networks was studied. In [6], considering static ground users, a multiple‐antenna UAV trajectory and heading control algorithm was proposed to maximise the link capacity of ground‐to‐air (G2A) uplink channel.…”

“…In recent years, unmanned aerial vehicles (UAVs) embedded with communication equipments have emerged as a possible way to improve connectivity and efficiency of ground‐based ad‐hoc networks [2, 3]. Owing to their elevation, UAVs have more chances of line‐of‐sight (LoS) connections toward the users.…”

Maintaining Connectivity of MANETs through Multiple Unmanned Aerial Vehicles

“…It follows from this remark and Theorem 1 that we have proved Theorem 2. Detailed proofing of Theorem 1 can be found in our previously published paper in [20].…”

“…end if (11) end for (12) if sizeof( ) > 0 then (13) ← ( − ), ← ( − ); (14) else (15) break; (16) end if (17) end while (18) for each edge ∈ do (19) if | | > then (20) if | | ≤ then spanning tree , all existing UAVs have been considered as terminals. However, existing UAV that has 1 degree in is the leaf of the tree and should not be considered in adding new UAVs in next step.…”

“…= then (9) all nodes in component changes its component to ; (10) end if (11) end for (12) while true do (13) mnn min ← −1, pair ← Φ; (14) for each edge , ∈ that ( , ) > do (15) if ! = then (16) mnn 1 ← Exist-UAV-Chain( , , , , , ); (17) mnn 2 ← New-UAV-Chain( , , , , ); (18) mnn ← min(mnn 1 , mnn 2 ); (19) if mnn < mnn min ||mnn min < 0 then (20) mnn (3) get UAV chain from 1 to 2 (4) for each UAV ∈ do (5) get left node and right node ; (6) compute three candidate positions CP 1 , CP 2 , CP 3 ; (7) choose one position CP with highest priority and satisfy dist( , CP ) ≤ , here = 1, 2, 3; (8) ← CP ; (9) end for (10) for each edge in chain do (11) test | | with and add new UAVs to ; (12) ← ∪ ; (13) end for (14) return , ;…”