Estimation of the traffic in the binary channel for data networks

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1 Estmto of the tffc the b che fo dt etwoks Sde Steov sdesteov@hoo.com Abstct It s mossbe to ovde effectve utzto of commucto etwoks wthout the ss of the qutttve chctestcs of the tffc e tme. The costt suevso of ches of the dt ctc s mctcbe becuse eques tsfe of the sgfct ddto fomto o etwok d ge esouces exeses fo devces of the coto. Thus the tsk o tffc estmto wth sm exeses e tme s the uget. Itoducto The dmc mgemet of etwok s bsed o use o e of the fomto o the tffc of the uses of etwok. Routg ezto of mets cogesto coto ezto of tffc mgemet sstem - d m othe fuctos dt etwoks so eque kowedge of the e tme sttstc chctestcs of voume of the tffc. Ths wok s devoted to the decso of the cotdcto betwee ecesst of the costt coto of ots of the cosumes of etwok d deess of ts ezto. We ssume tht the outut of the che c be codto ckge s tsfeed d codto the ckge s ot tsfeed the b che d we kow egth of ckge got ude the coto. Ths ssumto c be used s smfcto f we e teested the tffc of vous souces of the fomto oe che of commucto. I.e. t s ossbe to dvde the che o some vtu ches. Ad fo exme f hve ued out ckge we egste esece of ckge fo the ote vtu che d bsece of ckge fo othe ches. The dom ocesses sstem of commucto e ssumed stto. The bsc tsk s the defto of the ckges tsfe tme s wth t s ossbe wth the gete ccuc s soo s ossbe t the sm tme of suevso of the

2 Sde_Steov_tfc_estmto_3_oct_26 Pge 2 of 29 che. Phsc t s ecess whe the devce of estmto of the tffc c ot costt obseve the che fo exme owg to sevce of seve ches se. O whe the coto s ced out b mes of tsfe b the cosume to the devce of estmto of the tffc of the fomto bout the codto o the che of commucto. Ce s ths cse costt to tsfe the sevce fomto s exesve eve f to tsfe the fomto o the chctestcs of ckge f thee ws ckge coto ot d to ot tsfe thg f coto ot thee ws o ckge.e. to mke the decso o bsece of ckge b defut d cosequet we e teested s sm s ossbe to occu the che of commucto. The gothm of estmto shoud c out the foowg:. To edct otet ccuc of ccuto of the tffc. It ows befoe ezto of estmto to kow how m esouces t s ecess to sed o estmto fo obbe szes of the tffc. 2. To ccute ccuc of estmto dug ccutos. It ows to oete ocess of estmto oetg tme of gothm. Fo exme t s ecess to decde to cotue suevso of the che o to sto. Bckgoud We sh use mode of suevso of the tffc whe smes tke out dom ots o xs of tme o outut of souce of ckges. Fo coveece of the ss s the chctestc of souce we sh use the sttstc chctestc of ts bt to tsfe ckges. It s obbt of esece of ckge o outut of souce t the momet of the coto we sh desgte t b smbo U utzto fcto. Thus f we sh ccute U d fte tht the tme t tht hs ssed t s ossbe to cosde tht U*t tme uts the ckges wee tsfeed. It w be sm ossbe to edct tht dug the futue t 2 tme uts to be tsfeed ckges U*t 2 tme uts. We tteto tht sted of sech of the tffc tsfeed dug wok we sech fo the chctestc of bt of souce to tsfe ckges.e. we ssume

3 Sde_Steov_tfc_estmto_3_oct_26 Pge 3 of 29 esece of such hothetc chctestc tht mthemtc sttstcs d theo of obbt the wdesed ssumto. Fo exme bom exemets. Fom bove-stted foows tht us shoud ot cofuse f s esut of wok w s mde method of defto of the tffc d so method of ccuto of ccuc of defto of the tffc. Ad f we sh ook tht w gve these methods t costt suevso of souce otwthstdg wht we sh obseve tme d shoud kow ow tffc ecse but these methods w gve eos defto U t becuse mode ukow ot the tffc but U. Oe of the most owefu sttstc methods s the method Mxmum kehood estmto MLE. Accodg to ths method the ccout of deedece of suevso s comex theefoe t fst we sh cete method fo deedet smes d the we sh deveo method of ezto of deedece. The deedece of smes mkes so ot of the fomto bout the tffc the mted qutt of smes comso wth cse of deedet smes d cosequet ovdes educto of tme of estmto. Let - qutt of ots of the coto - qutt of ots whch the ckges wee obseved. The obbt of suevso of ckges ots. P C U U. Let's fd exesso fo U ovdg the getest obbt of ckges ots t s equvet U U g C U U.2 U g [ U U ].3. U Sovg.3 we c wte the obt d[ U + U ] d U.4 U.5.

4 Sde_Steov_tfc_estmto_3_oct_26 Pge 4 of 29 Lets ξ - csu vbe equ whe ot of the coto thee s ckge d equ whe ot of the coto thee s o ckge Me U ξ.6. M U M * M * the chctestcs of vce U 2 M ξ U U.7 AR ξ AR U U AR U AR U U dar U 2U du.9 U AR U AR 2 U U U. AR U U.5 Fg. U d AR U du

5 Sde_Steov_tfc_estmto_3_oct_26 Pge 5 of 29 U. 5 U Fg. 2 AR U U U Fg. 3 As t s vsbe fom the. 8.9 d fgues Fg. Fg.2 fo bsoute vce sm fo sm d ge vues U d to become m t U.5. Howeve sometmes bette fo ctce to be teested etve vce. Fom the fomu. d fgue Fg.3 foows tht t sm vues U the mstke of ccuto cosdeb gows. If befoe extcto of smes to deteme the stes b the geeto of dom umbes wth ufom dstbuto gve o osectve tme tev of the ss the tsk of defto of the tffc to become sm to tsk of ccuto of the cet tegs. As the ccuted e thee w be tme dug ckges. Ths educto of tsk of defto of the tffc to the we deveoed tsk of ccuto of tegs b method Mote Co c be used whe we e ot teested b the chctestc of oductvt of souce d we gee costt to suevse outut of souce sted of defto of the chctestc of oductvt of souce d subsequet o to check t hs chged. At cto of ths smfcto the sec

6 Sde_Steov_tfc_estmto_3_oct_26 Pge 6 of 29 tteto o s ecess tht the ce of extcto of smes must coesod to method of ccuto of tegs. The comete cofomt woud be f we coud tke smes ot ude the temo ode s t defto of the tffc but b w of geeto of dom umbes s t ccuto of tegs. Fo ze we sh desgte: T- commo oetg tme of souce; T - commo tme dug whch the ckges wee tsfeed; t - me sze cket; t b - me tev betwee ckets. The obbt obsevto cket fo method Mote Co ce estmte T U MC T T. 2. we ce ccute usg.8 T T T U.3 AR T 2 AR U * T T T T /. 4. The ss of equt.4 s doe sm to equt.8 d the esuts t s sm. I cse of teest to etve vce T AR T 2 T 2 T AR U T T /. 5 Cosdeg tht whee N - e qutt of ckges. The we deduce T N t + t T Nt. 6 b T AR tb t T.. 7 Fo t b fom exoet dstbuto wth mete λ T AR t λ T.. 8 C be teestg estmto λ λ usg

7 Sde_Steov_tfc_estmto_3_oct_26 Pge 7 of 29 T T T T tb / λ N T / t.9 d so tht sted of T we c use. 3 obt / λ..2 t / The ccuc of ccutos U ocess estmtg c be suevsed b method cofdece mts. Ue cofdece mt U u stsfes to exesso γ 2 C U u U u Lowe cofdece mt U stsfes to exesso..2 γ 2 C U U.22 wee - γ ebt P U U U γ.. 23 u I fgues 6 the ossbe vts of cuve fuctos e show. It s vsbe tht t the decso of the equtos b mes of sech methods of otmzto t ge fgue 6 dffcut to execute sech of the decso becuse of sh ecesso of fuctos o shot ste. As hs show modeg sech method of dvso o hf sometmes msses b stes wth but ecesso.

8 Sde_Steov_tfc_estmto_3_oct_26 Pge 8 of 29 Fgues 6 Fgues 6b

9 Sde_Steov_tfc_estmto_3_oct_26 Pge 9 of 29 s Fgue 6. Chctestc dgms of fuctos s U C U u U u U C U U fo cse ge fgue 6 d cse sm fgue 6b. Thus the ssumto of deedece of smes the exesso fo U ws s dvced. The w of deveomet of deedece of suevso s descbed futhe.. 2. Obtg deedece of smes. 2.. Obtg deedece b Bes Theoem To obt stght PDF of tevs betwee smg ots wth deedece betwee smes s comex we sh vet theefoe decso fo the foowg exeece. We mke extcto of sme ot d the ot 2 dstce betwee ots s dstbuted o PDF ϕ t. It s vsbe tht we hve smfed tsk but howeve hsc sese bsc hve ket. The bsc eseched mechsm hs ot chged - s we s e tsk thee s deedece betwee suevso the ext ots ths deedece s doe b sze of ckges d sze of tevs the eto betwee szes of ckges both tevs betwee ckges d tevs betwee smg ots e set PDF s. I the begg we sh sove tsk fo cse of the kow sttstc chctestcs of souce of ckges. So s cosdeed kow PDF of tevs of tme betwee ckges PDF of egths of ckges. Let's desgte them ccodg b τ d f. PDF dstce betwee ots ϕ t s ukow b ts choce we shoud cheve sttstc deedece of smes. Let's cosde τ t d s deedet. τ 2 d t Fg. 4

10 Sde_Steov_tfc_estmto_3_oct_26 Pge of 29 I de cse the obbt of ht of the secod ot ckge fte the fst ot hs got ckge shoud be equ sm to obbt of ht of ot ckge. f d U 2. f d + b τ τdτ Let's cosde tht the fst ot hs got ckge thee e o esos to beeve tht ce of ckge moe efeb fo ht. Theefoe t s ossbe to use ufom PDF fo ccuto of obbt of esece of the fst ot ce of ckge. Pobbt of ht of the secod ot ckge fte the fst ot hs got ckge s equ to the sum of ot jot evets: the secod ot hs got the sme ckge we sh desgte ts obbt though P ; t tme x Fg. 5 P f / ϕ t dt dx d 2. 2 x the secod ot hs got the fst foowg ckge we sh desgte hsts obbt though P ; etc x+ τ b τ P f / f ϕ t dt d dτ dx d 2. 2b 2 x+ τ I de cse of deedet smes shoud be 2

11 Sde_Steov_tfc_estmto_3_oct_26 Pge of 29 U P 2. 3 howeve such decso s t s vsbe s ve comex. We smf de method of ccuto cosstg use of exessos b tht we sh tke to ccout cses whe the evous ot of the coto ws the begg of ckge o the begg of tev betwee ckges. Ad tht we sh sech fo mm costt vues of the og betwee ots of suevso. It s ossbe to use vbe dstce betwee suevso but wth codto to ot exceed dstce of mtece of deedece. Let's ccute dstces betwee ots of the coto ote to these cses d we sh use the vege. Coectess of the mde ssumtos g we sh check u b modeg. Let evous ot ws the begg of ckge the the cuet ot w get ckge f: egths of ckge w e moe th dstce of the coto H ths obbt s equ H e d 2. 4 f whee e e vue of vecto of metes 2 o egth of the fst ckge d tev fte t w e ess th dstce of the coto d og of the secod ckge ge eough tht t the ot of the coto hs got ths obbt s equ H H e e e f b f dd whee e e vue of vecto of metes Geezg the fomus we mke gee obbt of ht ckge f the fst ot ws the begg of ckge P H e e QF H + QF H bf d 2. 6

12 Sde_Steov_tfc_estmto_3_oct_26 Pge 2 of 29 wee z e e QF z f d e e e e bf f b f b. The gee obbt of ht ckge f the fst ot ws the begg of tev betwee ckges to be deduced sm. Actu e ot kow PDF of egths of ckges d dstces betwee ckges. If the wee e kow t s ossbe woud be to ccute U o equt 2.. The deduced bove exessos t s ossbe to t to use s foows. To ccutos b Bes theoem. I ccutos to be set the begg b o vues f d bτ the to ccute H. It s Agothm to obt H. Ste. Emc choce: kd of fucto f et's desgte ts vecto of metes d bτ et's desgte ts vecto of metes ; ges of defto fo f d bτ ; m j d m j - ows bouds of mete j fo d m j d m j ues bouds of mete j fo d m j d 2 2 m j - qutt of vues tev [ m j - m j ] d [ m j - ] of m j mete j fo d ; o obbtes fo vues ; Ste 2. P o g P f 2. 7 w q o o w q g P f 2. 8 w q o w q wee umbe of cce of gothm; mw2 mw mw + w... ;... mw 3 ; m w w3

13 Sde_Steov_tfc_estmto_3_oct_26 Pge 3 of 29 mq2 mq q mq + q... Q;... mq 3 ; m q3 umbe of metes of f; Q - umbe of metes of bτ ; Ste 3 H m g m P P 2. 9 H de whee H ox m g m [ P P K] 2. H de < P de - de exct obbtes ccuted b mes of 2. o ste ; P - Pobbt beg vege betwee obbt fo cse whe the fst ot the begg of ckge d fo cse whe the fst ot the begg of tev betwee ckges o ste ; H - dstce betwee ots of the coto K - emc umbe t c be ed to smfcto of otmzto t fdg of the decso 2. 2 becuse thee s mt of ccuc of ccuto 2. 2 fte whch cese of ccuc s ot mott.e. the eo t ccuto 2. 2 shoud be ot ess eos of othe stes of gothm. Secod t the eft "m" the fomus mes tht t s ecess to sech H mkg fo the sme obbt to get ckge b the secod ot s obbt to get ckge b oe soted ot. Fst t the eft "m" mes tht s ecess to sech fo the mm H stsfg to the secod codto. Ths secod "m" ovdes educto of commo tme of suevso behd the che. Fo udestdg of comutg comext the equt 2. 9 s show the comete fom

14 Sde_Steov_tfc_estmto_3_oct_26 Pge 4 of 29 f d H m g m H f d + b τ τdτ QF 2 H + H QF H bf d* 2. * H QF H b d + H QF H bf 2 d wee z QF z f d bf f b f b - Assumed obbt 2 of ht ckge ude codto of ht of the fst ot begg of ckge; bf 2 b f b f b - Assumed obbt of ht ckge ude codto of ht of the fst ot begg of tev betwee ckges. 2+ Fo > 6 t s ossbe to use om oxmto PDF sums of fuctos the bf o M * + M 2 * * + 2 * 2. 2 bf2 o M * + M 2 * + * + 2 * e e Whee M M 2 mes d 2 vces f d b ccodg. At use >6 we ose f exst sme H ote sme tht we sh mss them. Whe the beeft fom educto of tme of estmto of the tffc ge the s ecess to ccute H b moe comex but so moe effectve w s s descbed beow. λτ fo f o M b τ λ e - exoet PDF deduce

15 Sde_Steov_tfc_estmto_3_oct_26 Pge 5 of 29 z e dz e z M z o e M o bf! * *! * * λ λ λ λ λ λ 2. 4 z e dz e z M z o e M o bf! * *! * * λ λ λ λ λ λ 2. 5 The esuts of ccutos of obbtes of ht ckge e beow show whe the evous ot ws the begg of ckge sx d the begg of tev betwee ckges s2x Fg. 7 Fg d ogm the executed. The esech of exessos shows tht t ccutos of eough sm vues so fo exme fgue the vues of exesso 2. 4 fo 2 5 e show whe b t t > M3. λ d whe b t t < M3 λ. It s vsbe wht eough to tke to ccout sgfct qutt comosed.

16 Sde_Steov_tfc_estmto_3_oct_26 Pge 6 of 29 Fg. 7 Fg. 7b

17 Sde_Steov_tfc_estmto_3_oct_26 Pge 7 of 29 Fg. 7. Fg. 7 Pobbtes of ht ckge whe the evous ot ws the begg of ckge sx d the begg of tev betwee ckges s2x t the ge dstce betwee ckges M < / λ. be L fgue coesods λ. be x fgue coesods H. Fg. 7b The deedece of sze of exesso 2. 4 fom d H. s vsbe wht eough to tke to ccout sm The deedece mde b modeg of obbt of ht ut fom dstce of estmto obbt of ut detectg umbe of ste N umbe of ste N2 MEAN 3 ARIANCE. Lmbd. Pteo dstce of suevso Fg. 8 The Smuted obbtes of ht ckge whe the evous ot ws the begg of ckge t the ge dstce betwee ckges M < / λ λ. two dmesos

18 Sde_Steov_tfc_estmto_3_oct_26 Pge 8 of 29 Fg. 9 The Smuted obbtes of ht ckge whe the evous ot ws the begg of ckge t the ge dstce betwee ckges M < / λ λ. thee dmesos

19 Sde_Steov_tfc_estmto_3_oct_26 Pge 9 of 29 Fg. Fg. b Fg. Fg..Pobbtes of ht ckge whe the evous ot ws the begg of ckge sx d the begg of tev betwee ckges s2x t the sm dstce betwee ckges M > / λ. be L fgue coesods λ. be x fgue coesods H. Fg. b The deedece of sze of exesso 2. 4 fom d H. s vsbe wht eough to tke to ccout sm

20 The deedece mde b modeg of obbt of ht ut fom dstce of estmto Sde_Steov_tfc_estmto_3_oct_26 Pge 2 of obbt of ut detectg umbe of ste N umbe of ste N2 MEAN 3 ARIANCE. Lmbd Pteo dstce of suevso Fg. Resuts of defto of obbtes of ht ckge whe the evous ot ws the begg of ckge t the sm dstce betwee ckges M > / λ b mes of modeg λ two dmesos. Fg. 2 Resuts of defto of obbtes of ht ckge whe the evous ot ws the begg of ckge t the sm dstce betwee ckges M > / λ b mes of modeg λ thee dmesos.

21 Sde_Steov_tfc_estmto_3_oct_26 Pge 2 of 29 Fom fgues t s vsbe.. Suffcet ccuc of modeg to be mde b use tetos o oe ot of the dgm. 2. Theoetc esuts w we be coodted to exemet esuts. x 2.. f x j x. k M 3. L j 2.. N om x. k M k N z M. j j. e. L. e L. z L.. z j dzd. j. 2. j! π f2 x j x. k om x. k M z M. j j. e. L. e L. z L. z j. dzd. j. 2. j! π f4 x om x. k M x k f3 x om x. k M. L. e L. d M M.75 L N N s2 x f3 x f2 x j s x f4 x f x j j j Fg. 3 ogms of ccuto of obbt of ht ckge whe the evous ot ws the begg sx of ckge d the begg of tev betwee ckges s2x t the sm dstce betwee ckges. be L fgue coesods λ. Fom fgues Fg. 7 - Fg 2 t s vsbe tht the vous emc smfctos of exesso 2. e ossbe. Fo exme to ccute exesso H QF H + QF H bf d 2. 6

22 Sde_Steov_tfc_estmto_3_oct_26 Pge 22 of 29 fo gowg sequece vbe H ut the whe dffeece fo the ext megs of exesso 2. 6 does ot become sgfct. If befoehd t s kow tht the qutt of kds of egths of ckges does ot exceed NLP t s exedet to fo f PDF wee j - ogs of ckets; f j j NLP Aj - obbt of cket wth og j. A δ 2. 7 The tegs o f to be eced wth the sums tht s t s vsbe cosdeb w smf ccutos. j j

23 Sde_Steov_tfc_estmto_3_oct_26 Pge 23 of 29 Ste Q Q Q q q w w Q Q Q Q s s s o m m m m s H s s o ost d b d f d f d b d f d f P P d b d f d f d b d f d f P P P * *... * * *... * τ τ τ τ τ τ τ τ τ τ τ τ fo w ; 3 m w ; q Q; 3 m q ; wee s f cket s detected s f cket s t detected b ot ; s P... kehood estmto of f s.

24 The smfctos descbed o ste 3 d hee w gve sgfct ecoom ccutos Ste 5 + Ste 6 P P ; o w q ost w q fo w ; m w ; q Q; m q ; 3 Ste 7. Checks o chevemet H d - mkg deedece of smes. Tht hee c be ed wth wht esobe method of detecto H d. Fo exme use of oet of vce of obbtes of both kds of smes. I.e. t use H d vue of exesso. 5 dug estmto shoud chge sgfct. At the momet of ccuto H d stos of gothm. 3 go to Ste 2. Lcks of gothm. Agothms s deduced ot stct b mthemtcs but the ssumto tht hvg ccuted kowedge ecse to ccute H we wth the he t moe o ess exct H c secf kowedge bout f d b τ tht tu w ow moe H. Thus the oo of feedbck w be mde whch w ow quck d w ecse be djusted to motog sstem. I bss of djustmet of the motog sstem the oo of feedbck s. As s kow sefexctto s ecu to oo of feedbck. Theefoe t oeto of ths gothm t s ecess to ovde the coto d eveto of sef-exctto. The cto of ths gothm togethe wth othe ess exct but stede gothm w be ossbe b the good cocto oos. Fo exme so: othe gothm soves to tsk ough d fte tht the Agothm moves the decso. It s ecess to ote tht the estmto of the tffc c be ccuted usg vectos of metes d. Howeve t such estmto t s mossbe to the fomus. 2 d. 22 fo ccuto of ccuc of estmto U. It s ossbe fo ccuto of ccuc of estmto to use osteo obbt. Howeve ebt of such chctestc of ccuc s dffcut fo defg theoetc. I exemets wth modeg of estmto U b mes of osteo the obbt hs show good sevcebt.

25 Sde_Steov_tfc_estmto_3_oct_26 Pge 25 of Obtg deedece b ccuto of codto obbtes Moe sme w of mtece of deedece s the dect ccuto of deedece of smes. If w e tht smes e deedet the t w be ecess to ccute dstces betwee ots of the coto b Sech Methods of otmzto fo fucto of oe vbe. The veso of the decso wth decto o ctct futhe s stted. Hf-hosohc questos s fo exme. Whee the deedece begs? O whee the deedece comes to ed? To be cosdeed s t d ws ee w ot be. Though t the ed s t ws hes ctce dug tsto fom the theo to ctce t s ecess to gve o them the swes. Howeve ths o the oe hd dffcut d o the othe hd sme wok w be tsfeed o the. As we s stted ee o these dffcut questos equg emc decso so-ced egeeg decsos w be d tteto d the emc chcte w be emhszed. The deedece of smes c be eched b ccuto of ucodto obbtes of detecto d ot detecto of ckge wth the subsequet comso wth codto d jot obbtes. Let us desgte evet of ht ckge though evet ot hts ckge though the fo deedet smes P x/ - mes obbt to u out x f befoe x hve ued out ; P x - mes obbt to u out x d the ext ots P P/ P/ P P / P/ 2. 7 P P P; P P P; 2. 8 P P P; P P P; The ccuc of ccutos c be suevsed usg exessos Thus thee s dge of wog wok exessos becuse of deedece of smes. If t to be foud out the t s ecess to deveo gothms of the coto of ccuc of ccuto of obbtes tkg ce exessos

26 Sde_Steov_tfc_estmto_3_oct_26 Pge 26 of 29 We sh cosde o exme of det of ccuto O Fg. 4 the tc stuto o outut of souce s show. Fo bd extcto of smes the smes e deedet of ot of the coto e desgted though - fo good extcto of smes the smes e deedet of ot of the coto e desgted though +. Let's desgte the extcto d extcto +. O Fg. 5 d Fg. 6 s show wht ctue sees extcto d extcto +. Accouts fo extcto es d ot desgte cofomt o ot cofomt to theoetc execttos. P 9/5 P/ / P/ 8/9; es P 6/5 P/ /9 P/ 4/6; es P 8/4 P P.36; P /4 P P.24; es P 4 /4 P P.6; ot P /4.7 P P.24; es Accouts fo extcto +. P 5/5.3 P/ 3/.3 P/ / 5.2; es P /5.7 P/ 4 / 5.8 P/ 6 /.6; es P /4.7 P P; P 3/4.2 P P; es P 6/4.4 P P; P 3/4.2 P P; es As t s vsbe fom exme fo eveg deedece t s ecess to tke to ccout ossbe combtos d. The cocuso.. The offeed estmto of the tffc ccutes the chctestcs of ccuc of estmto of the tffc befoe estmto d dug ocess of estmto. A tte of tme of estmto s cheved b: deedet smes get tht ovdes et of the fomto bout the eseched tffc; b tevs of tme betwee the ext smes e mmzed wth esevto of the deedece tht esuts mmzto of commo tme of suevso.

27 Sde_Steov_tfc_estmto_3_oct_26 Pge 27 of The ebt of the cheved esuts s ovded theoetc d exemet modeg. 3. The dvced theo c be used fo estmto s ed of tsfeed tffc d fo edcto of the futue tffc. 3. Offeed och c be ed

28 Fg. 4 Fg. 5 Fg. 6

29 Sde_Steov_tfc_estmto_3_oct_26 4//6