Advances, Systems and Applications
Table 1 Notation and description
From: Optimizing task offloading and resource allocation in edge-cloud networks: a DRL approach
Symbol | Definitions |
|---|---|
\(\mathcal{T}\) | A set of tasks generated by edge devices |
\({t}_{n}\) | Each task generated by the end device \(n\) |
\(z_n\)Â Â | The input data size of the task \({t}_{n}\) |
\({c}_{n}\) | Computation resource size required for the task \({t}_{n}\) |
\({\tau }_{n}\) | Maximum tolerable latency of the task \({t}_{n}\) |
\(y_n\)Â Â | The resultant data of the task \({t}_{n}\) |
\({x}_{n}\) | A binary variable to indicate whether the task \({t}_{n}\) is assigned to edge or cloud, (0 indicates edge and 1 indicates cloud) |
\(\varsigma\) | CPU unit to process the one byte of data |
\(\mathcal{B}\) | Set of base stations (BS),\(\mathcal{B}=\{{b}_{1}, {b}_{2},\dots ,{b}_{W}\}\) |
\({\mathcal{U}}_{B}\left(t\right)\) | The bandwidth utilization of all BSs at time step \(t\) |
\({H}_{w}\) | Set of wireless channels related to the BS \({b}_{w}\) |
\({\beta }_{h}^{w}\) | The bandwidth of each channel \(h\) \({b}_{w}\) |
\({\sigma }_{h}^{w}\) | Remaining bandwidth of the BS \({b}_{w}\) |
\(\mathcal{P}\) | The set of computing servers at the edge |
\(p\) | Computing server at the edge \((p\in \mathcal{P})\) |
\({c}_{p}\) | The available computing capacity of server \(p\) |
\({T}_{n}^{{proc}_{e}}\) | The processing time for the task \({t}_{n}\) at the edge |
\(\mathcal{M}\) | The set of computing servers in the cloud |
\(m\) | Computing server at the edge \((m\in \mathcal{M})\) |
\({T}_{n}^{{proc}_{c}}\) | The processing time for the task \({t}_{n}\) at the cloud server |
\({c}_{m}\) | \(\mathrm{T}\) he computing capacity of a cloud server \(m\) |
\({C}_{c}\) | \(\mathrm{T}\) he total computing capacity of cloud servers |
\({T}_{n}^{{proc}_{c}}\) | The total computation time for the task \({t}_{n}\) at cloud |
\({\mathcal{U}}_{M}\left(t\right)\) | The computational resources utilization of cloud servers at time step \(t\) |
\({T}_{n}^{{trans}_{e}}\) | Transmission time for the task \({t}_{n}\) data sent to the edge server |
\({T}_{n}^{{trans}_{c}}\) | Transmission time for the task \({t}_{n}\) data to the cloud server |
\({T}_{n}^{{prop}_{e}}\) | The propagation time of the link between the nodes and edge servers |
\({T}_{n}^{{prop}_{c}}\) | The propagation delay of the link between the edge and cloud |
\({rtt}_{n}^{e}\) | The total round-trip time to the edge for a task \({t}_{n}\) |
\({rtt}_{n}^{c}\) | The total round-trip time to the cloud for a task \({t}_{n}\) |