Page 16 - ITU Journal Future and evolving technologies Volume 2 (2021), Issue 5 – Internet of Everything
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ITU Journal on Future and Evolving Technologies, Volume 2 (2021), Issue 5




                                                 Table 1 – Literature contributions

                Standard Literature  Paper contribution
                [36, 37, 38]         Proposal of a revenue maximization framework based on data information elab‑
                                     orated locally on the users’ devices, avoiding the typical privacy concerns of the
                                     other approaches.
                [40, 8, 39, 20, 41, 42]  Contextualization of the application of the FL to the VFs deployment problem, by
                                     exploiting the FL framework to properly predict the application network demand,
                                     in order to maximize the SP revenue.


                         Table 2 – Main symbols

            Notation  Description                                                 0,              = 0,
                                                                           (   ) = {                         (1)
                                                                              
                                                                                                
            CN        Computation node                                                 ,    +       ,     > 0,
                                                                                                   
                                                                                          ,     
            VF        Virtual function
            FL        Federated learning                       in which    ,    ,    are real valued parameters whose
                                                                               ,  
                                                                           ,  
                                                                                  
            SRB       Storage resource block                   value changes on the basis of the request type.
            SR        Service request                          Similarly, the provision cost for providing    SRs of type   
                                                                                                      
            S         Number of SRBs per CN                    follows the rule [46]
            U         Cloud SRBs
            ECN       Edge computing network                               (   ) = { 0,            = 0,      (2)
                                                                                                   
                      High priority requests                                           ,    +       ,    > 0,
                                                                                                
                                                                                           ,     
                                                                                                   
            ℳ         Low priority requests
                      Time deadline                            where    ,    ,    are, also in this case, real valued pa‑
                                                                                
                                                                         ,  
                                                                             ,  
                      Number of req. demanding for service     rameters.
                      Number of req. demanding for service     Moreover, for each service type with high priority, the SP
              (   ,    )  SP revenue for the high priority req.  revenue results ruled by the following relation
                 
                    
              (   ,    )  SP revenue for the low priority req.
                 
                   
                      Service accomplishment time                              (   ,    ) =  log(1 +    )  ,  (3)
                                                                                                 
                                                                                     
                                                                                   
                 ,ℎ   Waiting time on the CN                                                    
                 ,    Waiting time on the cloud
                                                               with    = |   −    |, where    is the number of SRs for
                                                                                           
                                                                       
                                                                                 
                                                                             
                                                                        
                          1
          any CN to the cloud . Furthermore, we guess that the ECN   which    has been respected. Then, the SP revenue for the
                                                               low priority SRs is given by
          is able to support    different high priority service types,
          which are characterized by different provision costs and                      log(1 +    )
          selling prices.  Each service type     ∈     has associated a        (   ,    ) =          ,       (4)
                                                                                     
                                                                                   
            lev  expressed             befor  which                                           
                                               
          the type    service accomplishment has to be completed.   where    is the number of SRs among    accepted by the
                                                                        
                                                                                                   
          In addition, we consider the presence of ℳ service type   network for their service. Hence, the SP revenue, corre‑
          requests with lower priority and without any time dead‑   sponding to the provision of the   ‑th and the   ‑th service
          line constraint. The number of requests belonging to this   type, can be expressed as
          class is indicated hereafter with    , with    ∈ ℳ.
                                        
          Periodically, the SP updates the service demand and we             (   ,    ) =   (   ,    ) −   (   ),  (5)
                                                                                 
                                                                                           
                                                                                             
                                                                                                    
                                                                                   
          assume that any new request does not arrive between two
          SP updates.                                          and
          Let    be the number of SRs demanding for service     We           (   ,    ) =   (   ,    ) −   (   ),  (6)
                                                                                                    
                                                                                             
                                                                                          
                                                                                
                                                                                   
                
            that        originat  b        that
                                                               respectively.
          an EU requires only one SR. Therefore, as a direct conse‑
                                                               Both the SRs with high and low priority, in order to be
          quence, hereafter we assume interchangeable the SR and
                                                               accomplished, require the presence of a VF in set    which
          EU   Then, as regards the SP, the provision of a ser‑   has to be preliminary loaded on at least one CN of the net‑
          vice has a cost mainly depending on    and following the  work or on the far cloud. The loading process requires the
                                            
          model given by [46]                                  CN or cloud availability in terms of SRBs, since each VF
                                                                  ∈    requires a number    of SRBs, different for each VF.
         1 We have assumed that the connection towards the cloud is performed           
          throughout the CN nearest to the SRs needing computation. Conse‑  Consequently, the time required for the service accom‑
          quently, the communication latency cost between SRs and their nearest  plishment (TSA) of a generic SR   , independently by its
          CN has no impact on the overall SR completion time and hence it has  priority, is given by
          been neglected in de ining (7).
        4                                    © International Telecommunication Union, 2021
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