Advances, Systems and Applications
Table 1 Summary of key notations
From: Joint task offloading and resource allocation in mobile edge computing with energy harvesting
Notation | Description |
|---|---|
I | number of SMDs |
\(\mathcal {I}\) | set of SMDs |
ci | number of CPU-cycle required to accomplish task i |
si | input computation file size of task i |
oi | output computation result size of task i |
\(t_{i}^{\text {max}}\) | maximal delay requirement of task i |
λi | offloading ratio variable of task i |
T | total EH and task offloading time |
α | time switching factor |
bi | bandwidth between eNodeB and SMD i |
hi | uplink channel gain from SMD i to eNodeB |
\(p_{i}^{u}\) | uplink transmission power of SMD i to eNodeB |
\(r_{i}^{u}\) | uplink transmission rate of task i |
\(t_{i}^{u}\) | uplink transmission time of the partial task i |
\(E_{i}^{u}\) | uplink transmission energy consumption of partial task i |
\(f_{i}^{\text {loc}}\) | CPU-cycle frequency of SMD i allocated to the task |
\(F_{i}^{\text {max}}\) | maximal CPU-cycle frequency of SMD i |
\(t_{i}^{\text {loc}}\) | local computation time |
\(E_{i}^{\text {loc}}\) | local computation energy consumption of SMD i |
\(\kappa _{i}^{\text {loc}}\) | conversion coefficient of SMD i |
\(F_{\text {mec}}^{\text {max}}\) | maximal CPU-cycle frequency of MEC server |
\(f_{i}^{\text {mec}}\) | CPU-cycle frequency of MEC server allocated to the task i |
\(t_{i}^{\text {mec}}\) | MEC server computation time of task i |
\(E_{i}^{\text {mec}}\) | MEC server computation energy consumption of task i |
κmec | conversion coefficient of MEC server |
\(p_{i}^{d}\) | downlink transmission power of eNodeB to SMD i |
\(r_{i}^{d}\) | downlink transmission rate from eNodeB to SMD i |
\(t_{i}^{d}\) | downlink transmission time from eNodeB to SMD i |
\(E_{i}^{d}\) | downlink transmission energy consumption of eNodeB to SMD i |
\(E_{i}^{\text {har}}\) | total energy harvested by SMD i |
ηi | energy conversion efficiency |