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Advances, Systems and Applications

Table 1 Notations and definitions

From: Collaborative task offloading and resource allocation with hybrid energy supply for UAV-assisted multi-clouds

Notion

Definition

\(d_{i}(t)\)

The number of arrived requests of IoT device j in time slot t

\(D_{j}(t)\)

The total number of arrived requests of IoT devices \(A_j\) in time slot t

\(D_{l,j}(t)\)

The number of tasks locally executed by IoT devices set \(A_j\) in time slot t

\(D_{r,j}(t)\)

The number of tasks offloaded by IoT devices set \(A_j\) in time slot t

\(D_{u,j}(t)\)

The number of tasks that executed the UAV j in time slot t

\(S_{j}(t)\)

Queue backlog of IoT devices set \(A_j\) in time slot t

\(M_{j}(t)\)

Queue backlog of UAV j in time slot t

\(H_j(t)\)

The remaining battery capacity of UAV j in time slot t

\(W_j(t)\)

The size of obtained energy of UAV j in time slot t

\(E_H\)

The capacity of battery of UAV

\(E_{safe}\)

the minimum battery energy level

\(E_{u,j}\)

The energy consumption of UAV j in time slot t

\(f_{l,i}(t)\)

The CPU-cycle frequency of the IoT device i in time slot t

\(f_{max,i}\)

The maximum CPU-cycle frequency of the IoT device i

\(L_i\)

The CPU cycles of IoT device i when executing 1 bit task in time slot t

\(p_{l,i}(t)\)

The CPU power consumption of IoT device i in time slot t

\(k_{mod,i}\)

The effective switched capacitance of the CPU of IoT device i

\(r_{i,j}(t)\)

The transmission rate between the IoT device i and the UAV j in time slot t

\(p_{r,i}(t)\)

The transmission power of the IoT device i in time slot t

\(p_{max,i}\)

The maximum transmission power of IoT device i

\(B_i\)

The channel bandwidth of IoT device i

\(G_i\)

The channel power gain at a reference distance 1m of IoT device i

\(d_{i,j}(t)\)

The distance between IoT device i and the UAV j in time slot t