Page 19 - ITUJournal Future and evolving technologies Volume 2 (2021), Issue 1
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ITU Journal on Future and Evolving Technologies, Volume 2 (2021), Issue 1




          ʹǤ                                                   {S i (t)}  ”‡’”‡•‡– –Š‡ …Šƒ‡Ž •–ƒ–‡ ˆ‘” ‡ƒ…Š —•‡” i
                                                                      i∈N
                                                               †—”‹‰ •Ž‘– tǤ  Ž•‘ǡ –Š‡ …Šƒ‡Ž …ƒ „‡ ‡‹–Š‡” ‹ Dz ƒ†dz •–ƒ–‡
           ‡ …‘•‹†‡” N —•‡”• –”ƒ•‹––‹‰ ’ƒ…‡–• –‘ ƒ •‹‰Ž‡ ”‡Ǧ  ȋ†‡‡’ ˆƒ†‹‰Ȍ ‘” ‹ Dz ‘‘†dz •–ƒ–‡ ȋ‹Ž† ˆƒ†‹‰ȌǤ  Š‡ ’‘••‹Ǧ
          …‡‹˜‡” ‘˜‡” ™‹”‡Ž‡•• ˆƒ†‹‰ …Šƒ‡Ž•Ǥ  ‡– N   {1,...,N}  „Ž‡ …Šƒ‡Ž •–ƒ–‡• ‘ˆ ‡ƒ…Š —•‡” i ƒ”‡ †‡•…”‹„‡† „› –Š‡ •‡–
          „‡ –Š‡ •‡– ‘ˆ –Š‡ –‘–ƒŽ —•‡”• ‹ –Š‡ •›•–‡Ǥ  ‹‡ ‹• ƒ••—‡†  S   { ,  }ǡƒ† S i (t) ∈Sǡ ∀i ∈NǤ  ‘” •‹’Ž‹…‹–›ǡ ™‡
                                        –Š
          –‘ „‡ •Ž‘––‡†ǡ ƒ† t ∈ Z †‡‘–‡• –Š‡ t •Ž‘–Ǥ         ƒ••—‡ –Šƒ– –Š‡ ”ƒ†‘ ˜ƒ”‹ƒ„Ž‡• ‘ˆ –Š‡ …Šƒ‡Ž ’”‘…‡••
                                                                (t) ƒ”‡ ‹Ǥ‹Ǥ†Ǥ ˆ”‘ ‘‡ •Ž‘– –‘ –Š‡ ‡š–Ǥ
                                                                ‡– p(t)   [p 1 (t),...,p N (t)] †‡‘–‡ –Š‡ ’‘™‡” ƒŽŽ‘…ƒ–‹‘
                                                                           –Š
                                                               ˜‡…–‘” ‹ –Š‡ t •Ž‘–Ǥ  ‡ …‘•‹†‡” ƒ •‡– ‘ˆ †‹•…”‡–‡ ’‘™‡”
                                                                         ( ‘™)  ( ‹‰Š)
              Actuation/Control                                Ž‡˜‡Ž• 0,P    ,P      Ǥ  Š‡ ”‡“—‹”‡† ’‘™‡” –‘ Šƒ˜‡ ƒ
                                VR/AR                          •—……‡••ˆ—Ž –”ƒ•‹••‹‘ —†‡” Dz ƒ†dz ƒ† Dz ‘‘†dz …Šƒ‡Ž
                                                               …‘†‹–‹‘• ‹• †‡‘–‡† „› P  ‹‰Š  ƒ† P   ‘™ ǡ ”‡•’‡…–‹˜‡Ž›Ǥ  –
                    Tactile Internet
                                                               ‡ƒ…Š –‹‡ •Ž‘–ǡ –Š‡ •‡– ‘ˆ •‡Ž‡…–ƒ„Ž‡ ’‘™‡” Ž‡˜‡Ž• P i (t) ˆ‘”
                                                               ‡ƒ…Š —•‡” ‹• …‘†‹–‹‘‡† ‘ –Š‡ …Šƒ‡Ž •–ƒ–‡ S i (t)Ǥ ‘”
                                                               ‡šƒ’Ž‡ǡ ‹ˆ –Š‡ …—””‡– …Šƒ‡Ž •–ƒ–‡ ‹• Dz ƒ†dzǡ –Š‡ P ȋ ‘™Ȍ
                                                               …ƒ‘– „‡ •‡Ž‡…–‡†Ǥ  Š—•ǡ ™‡ Šƒ˜‡


                                                                                ȋ ‹‰ŠȌ
                                                                            0,P      ǡ‹ˆ S i (t)=
                                                                   p i (t) ∈                      ǡ ∀i ∈NǤ   ȋͷȌ
                                                                            0,P  ȋ ‘™Ȍ  ǡ‹ˆ S i (t)=
                                                                ‡– μ i (t) „‡ –Š‡ ’‘™‡” ƒŽŽ‘…ƒ–‹‘ǡ ‘” ’ƒ…‡– •‡”˜‹‰ǡ ‹†‹Ǧ
           ‹‰Ǥ ͳ Ȃ  šƒ’Ž‡ ‘ˆ –Š‡ •›•–‡ ‘†‡Ž ™‹–Š –‹‡Ǧ…”‹–‹…ƒŽ —•‡”• ™‹–Š ’ƒ…Ǧ    –Š
          ‡–• ™‹–Š †‡ƒ†Ž‹‡• ƒ† —•‡”• ™‹–Š ‹‹—Ǧ–Š”‘—‰Š’—– ”‡“—‹”‡‡–•Ǥ  …ƒ–‘” ˆ‘” –Š‡ —•‡” i ‹ –Š‡ t •Ž‘–ǡ ™‡ Šƒ˜‡

           ‡ …‘•‹†‡” –Š‡ —•‡”• –‘ „‡ •›…Š”‘‹œ‡† ƒ† …‘–”‘ŽŽ‡†        μ i (t)    1ǡ‹ˆ p i (t) > 0  ǡ ∀i ∈NǤ  ȋ͸Ȍ
          „› ƒ •…Š‡†—Ž‡”Ǥ   ‘—” •›•–‡ ‘†‡Žǡ ƒ– ‘•– ‘‡ —•‡” …ƒ              0ǡ ‘–Š‡”™‹•‡
          –”ƒ•‹– ƒ– ‡ƒ…Š –‹‡ •Ž‘–Ǥ  ‡ …‘•‹†‡” –™‘ •‡–• ‘ˆ —•‡”•Ǥ
           Š‡ ϐ‹”•– •‡– ‹…Ž—†‡• —•‡”• –Šƒ– Šƒ˜‡ ƒ””‹˜ƒŽ• ‘ˆ ’ƒ…‡–•   – ‘•– ‘‡ ’ƒ…‡– …ƒ „‡ –”ƒ•‹––‡† ‹ ƒ –‹‡•Ž‘– tǡ ‹Ǥ‡Ǥǡ
          ™‹–Š †‡ƒ†Ž‹‡•Ǥ  ‡ †‡‘–‡ –Š‡ •‡– ‘ˆ —•‡”• ™‹–Š ’ƒ…Ǧ  –Š‡ ˜‡…–‘” ’(t) Šƒ• ƒ– ‘•– ‘‡ ‘Ǧœ‡”‘ ‡Ž‡‡–Ǥ  Š‡ •‡–
          ‡–• ™‹–Š †‡ƒ†Ž‹‡• „› R⊆NǤ  Š‡ •‡…‘† •‡– ‘ˆ —•‡”•ǡ  ‘ˆ ’‘™‡” …‘•–”ƒ‹–• ˆ‘” p(t) ‹• –Š‡ †‡ϐ‹‡† „›
          U⊆ N ǡ …‘–ƒ‹• –Š‡ —•‡”• –Šƒ– Šƒ˜‡ –Š”‘—‰Š’—– ”‡“—‹”‡Ǧ                     N
          ‡–•Ǥ  ‡ …‘•‹†‡” –Šƒ– ‡ƒ…Š —•‡” u ∈U ‹• •ƒ–—”ƒ–‡†           P(t)    p(t):     ͳ {μ i (t)=1} ≤ 1 ǡ  ȋ͹Ȍ
          ƒ† –Š‡”‡ˆ‘”‡ǡ ‹– Šƒ• ƒŽ™ƒ›• ’ƒ…‡– –‘ –”ƒ•‹–Ǥ  ‘–‡ –Šƒ–                 i=1
          U∪ R = N ƒ† U∩ R = ∅Ǥ   ‡šƒ’Ž‡ ‘ˆ ‘—” •›•–‡      ™Š‡”‡ ͳ {·} †‡‘–‡• –Š‡ ‹†‹…ƒ–‘” ˆ—…–‹‘Ǥ  ‘” ‡ƒ…Š —•‡”
          ‘†‡Ž ‹• •Š‘™ ‹  ‹‰Ǥ ͳǤ                            r ∈Rǡ ƒ ’ƒ…‡– ‹• †”‘’’‡† ‹ˆ ‹–• †‡ƒ†Ž‹‡ Šƒ• ‡š’‹”‡†Ǥ
           ‘” –Š‡ †‡ƒ†Ž‹‡Ǧ…‘•–”ƒ‹‡† —•‡”•ǡ ‡ƒ…Š ’ƒ…‡– –Šƒ– ƒ”Ǧ   ‹…‡ –Š‡ “—‡—‡ ˆ‘ŽŽ‘™• –Š‡      †‹•…‹’Ž‹‡ǡ ƒ ’ƒ…‡– ‹•
          ”‹˜‡• ‹ –Š‡ “—‡—‡ ‘ˆ –Š‡ —•‡”• Šƒ• ƒ †‡ƒ†Ž‹‡ „› ™Š‹…Š –Š‡  †”‘’’‡† —†‡” –Š‡ ˆ‘ŽŽ‘™‹‰ …‘†‹–‹‘•ǣ ͳȌ ‹– ‹• ƒ– –Š‡
          ’ƒ…‡– —•– „‡ –”ƒ•‹––‡†Ǥ  –Š‡”™‹•‡ǡ ‹– ‹• †”‘’’‡† ƒ†  Š‡ƒ† ‘ˆ –Š‡ “—‡—‡Ǣ ʹȌ –Š‡ ”‡ƒ‹‹‰ —„‡” ‘ˆ –Š‡ •Ž‘–•
          ”‡‘˜‡† ˆ”‘ –Š‡ •›•–‡Ǥ  ‡ ƒ••—‡ –Šƒ– –Š‡ †‡ƒ†Ž‹‡•  –‘ •‡”˜‡ –Š‡ ’ƒ…‡– ‹• 1Ǣ ƒ† ͵Ȍ ’‘™‡” ‹• ‘– ƒ••‹‰‡† –‘
          ‘ˆ–Š‡’ƒ…‡–• ‹ –Š‡•ƒ‡“—‡—‡ ƒ”‡–Š‡•ƒ‡Ǥ  ‘™‡˜‡”ǡ    —•‡” r ƒ– –Š‡ …—””‡– •Ž‘–Ǥ  ‡– D r (t) „‡ –Š‡ ‹†‹…ƒ–‘” ‘ˆ –Š‡
          †‡ƒ†Ž‹‡• ‘ˆ †‹ˆˆ‡”‡– “—‡—‡• ƒ› ˜ƒ”›Ǥ  ‡ †‡‘–‡ –Š‡  ’ƒ…‡– †”‘’ ˆ‘” —•‡” r ƒ– –‹‡ tǤ  Š‡ “—‡—‡ ‡˜‘Ž—–‹‘ ˆ‘”
                              –Š
          ’ƒ…‡– †‡ƒ†Ž‹‡ ‘ˆ –Š‡ r “—‡—‡ ™‹–Š m r ∈ Z + ǡ ∀r ∈RǤ  ‡ƒ…Š —•‡” r ∈R ‹• †‡•…”‹„‡† ƒ•
           ‡– d r (t) „‡ –Š‡ —„‡” ‘ˆ •Ž‘–• Ž‡ˆ– ‹ –Š‡ t –Š  •Ž‘– „‡Ǧ
          ˆ‘”‡ –Š‡ ’ƒ…‡– –Šƒ– ‹• ƒ– –Š‡ Š‡ƒ† ‘ˆ “—‡—‡ r ‡š’‹”‡•Ǥ  ‡–  Q r(t +1) = ƒš [Q r(t) − μ r(t), 0] + α r(t) − D r(t)ǡ ∀i ∈RǤ
                                                    –Š
          Q r (t) „‡ –Š‡ —„‡” ‘ˆ ’ƒ…‡–• ‹ “—‡—‡ r ‹ –Š‡ t •Ž‘–Ǥ                                         ȋͺȌ
            ’ƒ…‡– ƒ””‹˜‡• ™‹–Š ’”‘„ƒ„‹Ž‹–› π r ƒ– ‡˜‡”› –‹‡ •Ž‘–
                                                   ǡ ™Š‡”‡
          ‹ –Š‡ “—‡—‡ ‘ˆ —•‡” rǤ ‡– α(t)   {α r (t)}           ‡ †‡ϐ‹‡ –Š‡ ’ƒ…‡– †”‘’ ”ƒ–‡ ˆ‘” ‡ƒ…Š —•‡” r ∈Rǡ–Š‡
                                                r∈R
          α r (t) ∈{0, 1}ǡ ”‡’”‡•‡–• –Š‡ ’ƒ…‡– ƒ””‹˜ƒŽ ’”‘…‡•• ˆ‘”  ƒ˜‡”ƒ‰‡ ’‘™‡” …‘•—’–‹‘ ˆ‘” ‡ƒ…Š —•‡” i ∈Nǡƒ† –Š‡
                          –Š
          ‡ƒ…Š —•‡” r ‹ –Š‡ t •Ž‘–Ǥ  Š‡ ”ƒ†‘ ˜ƒ”‹ƒ„Ž‡• ‘ˆ –Š‡  –Š”‘—‰Š’—– ˆ‘” ‡ƒ…Š —•‡” u ∈U ƒ•
          ’ƒ…‡– ƒ””‹˜ƒŽ ’”‘…‡•• ƒ”‡ ‹†‡’‡†‡– ƒ† ‹†‡–‹…ƒŽŽ›
          †‹•–”‹„—–‡† ȋ‹Ǥ‹Ǥ†ǤȌǤ  ‡– λ r †‡‘–‡–Š‡ƒ””‹˜ƒŽ”ƒ–‡ˆ‘” —•‡”         D r   Ž‹ D r (t)ǡ ∀r ∈Rǡ       ȋͻȌ
          r ƒ† E{α r (t)} = λ r Ǥ  —”–Š‡”‘”‡ǡ ƒ– ‘•– ‘‡ ’ƒ…‡–                t→∞
          …ƒ „‡ –”ƒ•‹––‡† ƒ– ‡ƒ…Š –‹‡ •Ž‘– ƒ† ‘ …‘ŽŽ‹•‹‘• ƒ”‡          p   Ž‹ p (t)ǡ ∀i ∈Nǡ          ȋͼȌ
                                                                                       i
                                                                               i
                                                                                  t→∞
          ƒŽŽ‘™‡†Ǥ   ‡ƒ…Š “—‡—‡ ‘ˆ ‡˜‡”› —•‡” r ∈Rǡ ’ƒ…‡–• ƒ”‡             μ = Ž‹ ¯μ u (t)ǡ ∀u ∈Uǡ        ȋͽȌ
          •‡”˜‡† ‹ –Š‡ ‘”†‡” –Šƒ– –Š‡› ƒ””‹˜‡ ˆ‘ŽŽ‘™‹‰ –Š‡  ‹”•–           u   t→∞
           ‹”•–  —– ȋ    Ȍ †‹•…‹’Ž‹‡Ǥ                                                         t−1
                                                               ”‡•’‡…–‹˜‡Ž›ǡ ™Š‡”‡ǡ D r (τ)  =  1     D r (t)ǡ p (t)  =
           ‡ ƒ••—‡ –Šƒ– –Š‡ …Šƒ‡Ž •–ƒ–‡ ƒ– –Š‡ „‡‰‹‹‰ ‘ˆ ‡ƒ…Š                          t  τ=0      i
          –‹‡ •Ž‘– ‹• ‘™Ǥ  Š‡ …Šƒ‡Ž •–ƒ–‡ ”‡ƒ‹• …‘•–ƒ–  1  t−1              1  t−1


          ™‹–Š‹ ‘‡ •Ž‘– „—– ‹– …Šƒ‰‡• ˆ”‘ •Ž‘– –‘ •Ž‘–Ǥ  ‡–  (t)    t  p i (τ)ǡƒ† ¯μ u (t)=  t  μ u (τ)Ǥ  Š‡ ’ƒ…‡– †”‘’
                                                                 τ=0                   τ=0

                                             © International Telecommunication Union, 2021                     3
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