Offloading: Where and When Iwan Setiawan 

Iwan Setiawan Categories of Edge Nodes[1] ● Cloudlets ● Micro data centers ● Base stations ● Other types of edge nodes – Vehicles with onboard computers – IoT gateways – Smartphones Lin, et al., 2019 

Iwan Setiawan Categories of Edge Nodes[1] ● Cloudlets ● Micro data centers ● Base stations ● Other types of edge nodes – Vehicles with onboard computers – IoT gateways – Smartphones Lin, et al., 2019 Fog MEC 

Iwan Setiawan Offloading: Why ● Limited computing resources ● Energy consumption ● Cost? Time Energy Offload or not to offload Money 

Iwan Setiawan Wu, 2018 

Iwan Setiawan Offloading: Major Challenges ● Resource, related to resources from device to cloud ● Component, related to program complexity ● Intermittence, related to network connectivity ● Data, related to the amounts of data – Input data, when the task is offloaded to the cloud – Communication data, between device and remote cloud – Output data, generated from remote execution 

Iwan Setiawan Offloading: Where[2] ● Target: Cloud service selection +edge and fog ● Criteria – Performance: Speed, accuracy, response time – Cost: virtual machine, data, storage, communication – Security: Data integrity, privacy, loss – Bandwidth – Availability 

Iwan Setiawan Offloading: Where[2] ● Multi-criteria decision making – Matching: finding a matched (cloud) services – Ranking: evaluate (cloud) services, qualitative/quantitative – Selecting: choosing the optimal (cloud) service ● Cloudlet-based decision making[2][3] – Two-level offloading: offload to a cloud – Three-level offloading: offload to nearby cloudlet (edge) ● Hybrid offloading decision making – Using mobile edge and cloud computing – Taking advantages of both (cloud-edge) (Edge) 

Iwan Setiawan Offloading: Where[2] Wu, 2018 

Iwan Setiawan Offloading: Where[2] ● Multi-criteria decision making – Matching: finding a matched (cloud) services – Ranking: evaluate (cloud) services, qualitative/quantitative – Selecting: choosing the optimal (cloud) service ● Cloudlet-based decision making[2][3] – Two-level offloading: offload to a cloud – Three-level offloading: offload to nearby cloudlet (edge) ● Hybrid offloading decision making – Using mobile edge and cloud computing – Taking advantages of both (cloud-edge) (Edge) 

Iwan Setiawan Offloading: Where ● Two-tier model – Cloud – Device ● Three-tier model – Cloud – Edge – Device ● Directions – Vertical offloading – Horizontal offloading Cloud Edge Device 1 2 3 3 1 3 1 2 

Iwan Setiawan Offloading: Where ● Two-tier model – Cloud – Device ● Three-tier model – Cloud – Edge – Device ● Direction – Vertical offloading: to higher tier – Horizontal offloading Cloud Edge Device 1 2 3 D1 D2 E1 E2 C1 C2 

Iwan Setiawan Offloading: Where ● Two-tier model – Cloud – Device ● Three-tier model – Cloud – Edge – Device ● Directions – Vertical offloading: to higher tier, to lower tier? – Horizontal offloading: same tier, federation Cloud Edge Device 1 2 3 D1 D2 E1 E2 C1 C2 

Iwan Setiawan Offloading: Where ● Two-tier model – Cloud – Device ● Three-tier model – Cloud – Edge – Device ● Directions – Vertical offloading: to higher tier, to lower tier? – Horizontal offloading: same tier, federation Cloud Edge Device 1 2 3 D1 D2 E1 E2 C1 C2 Limited resources Limited capacity Limited energy 

Iwan Setiawan Offloading: Where ● Two-tier model – Cloud – Device ● Three-tier model – Cloud – Edge – Device ● Directions – Vertical offloading: to higher tier, to lower tier? – Horizontal offloading: same tier, federation Cloud Edge Device 1 2 3 D1 D2 E1 E2 C1 C2 Limited resources Limited capacity Limited energy Compute Storage Network 

Iwan Setiawan Offloading: Where ● Two-tier model – Cloud – Device ● Three-tier model – Cloud – Edge – Device ● Directions – Vertical offloading: to higher tier, to lower tier? – Horizontal offloading: same tier, federation Cloud Edge Device 1 2 3 D1 D2 E1 E2 C1 C2 

Iwan Setiawan Offloading: Where ● Two-tier model – Cloud – Device ● Three-tier model – Cloud – Edge – Device ● Directions – Vertical offloading: to higher tier, to lower tier? – Horizontal offloading: same tier, federation Cloud Edge Device 1 2 3 D1 D2 E1 E2 C1 C2 

Iwan Setiawan Offloading: Where ● Two-tier model – Cloud – Device ● Three-tier model – Cloud – Edge – Device Fog ● Directions – Vertical offloading: to higher tier, to lower tier? – Horizontal offloading: same tier, federation Cloud Edge Fog 1 2 3 F1 F2 E1 E2 C1 C2 D1 D2 D3 

Iwan Setiawan Offloading: Where[2] ● Multi-criteria decision making – Matching: finding a matched (cloud) services – Ranking: evaluate (cloud) services, qualitative/quantitative – Selecting: choosing the optimal (cloud) service ● Cloudlet-based decision making[2][3] – Two-level offloading: offload to a cloud – Three-level offloading: offload to nearby cloudlet (edge) ● Hybrid offloading decision making – Using mobile edge and cloud computing – Taking advantages of both (cloud-edge) (Edge) 

Iwan Setiawan Offloading: Where[2] Wu, 2018 Latency Capacity Cloud Assisted Mobile Edge 

Iwan Setiawan Offloading: When[2] ● Computation vs communication – Time-saving: the computation on cloud better than local – Energy-saving: the energy needs to be less when offload ● Interrupted vs uninterrupted – Connection failures: depend on the connection to the cloud – Cloud failures: depend on the cloud reliability ● On-the-spot vs delayed offloading – On-the-spot: any wireless network available – Delayed: waiting for a high-quality network 

Iwan Setiawan Offloading: When[2] ● Time-saving tm > tm /F + D/B ● Energy-saving pm tm > pidle (tm /F) + ptr (D/B) Wu, 2018 tm = Computation time on device F = Speedup factor D = Data exchanged B = Network bandwidth pm = Power on device when compute pidle = Power on device when idle ptr = Power when transfering data 

Iwan Setiawan Offloading: When[2] ● Computation vs communication – Time-saving: the computation on cloud better than local – Energy-saving: the energy needs to be less when offload ● Interrupted vs uninterrupted – Connection failures: depend on the connection to the cloud – Cloud failures: depend on the cloud reliability ● On-the-spot vs delayed offloading – On-the-spot: any wireless network available – Delayed: waiting for a high-quality network 

Iwan Setiawan Offloading: When[2] Wu, 2018 

Iwan Setiawan Offloading: When[2] ● Computation vs communication – Time-saving: the computation on cloud better than local – Energy-saving: the energy needs to be less when offload ● Interrupted vs uninterrupted – Connection failures: depend on the connection to the cloud – Cloud failures: depend on the cloud reliability ● On-the-spot vs delayed offloading – On-the-spot: any wireless network available – Delayed: waiting for a high-quality network 

Iwan Setiawan Offloading: When[2] Wu, 2018 Energy cost Data queue backlog Estimated rate 

Iwan Setiawan Offloading: How[2] Wu, 2018 λ = rate of offloadable jobs λ0 = rate of unoffloadable jobs π = probability to offload α = job dispatcher 

Iwan Setiawan Offloading System Architecture[2][4] Cloud-edge-fog discovery Metrics Profiling Offloading decision Querying across cloud-edge-fog Where Program partitioning What When Offloading Device Remote partition Program Energy Network Time Energy ... Cloud-edge-fog Remote partition Cloud-edge-fog federation Network +Data Why Query service Profiling Remote execution Metrics Energy Storage Cost Perform. How Matching Selecting Ranking 

Iwan Setiawan References [1] L. Lin, X. Liao, H. Jin and P. Li, "Computation offloading toward edge computing," in Proceedings of the IEEE, vol. 107, no. 8, pp. 1584- 1607, Aug. 2019. [2] H. Wu, "Multi-objective decision-making for mobile cloud offloading: a survey," in IEEE Access, vol. 6, pp. 3962-3976, 2018. [3] J. Wang, J. Pan, F. Esposito, P. Calyam, Z. Yang, and P. Mohapatra, “Edge cloud offloading algorithms: issues, methods, and perspectives,” in ACM Comput. Surv., vol. 52, no. 1, Feb. 2019. [4] K. Yang, S. Ou and H. Chen, "On effective offloading services for resource-constrained mobile devices running heavier mobile Internet applications," in IEEE Commun. Magazine, vol. 46, no. 1, pp. 56-63, Jan. 2008. 

Iwan Setiawan Offloading Decisions ● Where question related to the right place for offloading ● When question related to the right time for offloading