Dependence of transfer time of bluetooth payload packets on the surroundings and distance

INFORMATION AND COMMUNICATION TECHNOLOGIES AND SERVICES VOLUME: 12 |NUMBER: 2 |2014 |JUNE Dependence o T ans e Time o Blue oo h Payload Packe s on he Su oundings and Dis ance P emysl MER Depa men o Telecommunica ions, Facul y o Elec ical Enginee ing and Compu e Science, VSB–Technical Uni e si y o Os a a, 17. lis opadu 15/2172, 708 33 Os a a-Po uba, Czech Republic p em[email p o ec ed] Abs ac . This pape deals wi h he Blue oo h ech- nology in elecommunica ion ne wo ks. The basis o he da a ansmission is a packe which has i s own speci ics in he wi eless communica ion. The signal le el is o highe impo ance, bu o he pa ame e s like ans e ime and a numbe o ans e ed packe s a e in e es ing oo. The ou pu o his pape is a p oposed ma hema ical model, which desc ibes dependencies o his ou pu pa ame e s on he dis ance be ween com- munica ing de ices and on he en i onmen , in which hese de ices a e placed. Some inpu c i e ia and con- di ions a e de ined o he unc ionali y o he p oposed design. The ile ans e speed be ween he de ices de- pends on he dis ance be ween hem and on he su - oundings, whe e he sla e de ice is placed. Fo ou pu poses some possible su oundings ha migh be en- coun e ed we e selec ed. I is ee-space, pape wi h a iable hickness, PVC o lea he and wood wi h hei espec i e densi y. Thanks o he applica ion o he log- a i hmic eg ession on he ou pu da a he equa ion o ma hema ical model was ound. Keywo ds Blue oo h, en i onmen , ma hema ical model, eg ession, ans e ime. 1. In oduc ion The basic pa ame e s in in o ma ion echnologies a e ansmission pa ame e s. T ansmission pa ame e s in- luence he ways o usage o his echnology in spe- ci ic applica ions. The Blue oo h echnology belongs o PAN (Pe sonal A ea Ne wo k) ne wo ks. Thei co - e age and u iliza ion a e de e mined o applica ions as he da a ansmission among pe sonal e minals o he con igu a ion and con ol o a ious pe iphe als. In he in oduc ion a e sho ly p esen ed he Blue- oo h echnology ea u es. The basic o he da a ans- mission is a packe which has i s own speci ics in he wi eless communica ion. Some packe s ca y payload da a, some packe s synch onize and con ol he com- munica ion. This a icle is ocused on da a ansmis- sion ea u es o he packe s ha ca y use ul da a. The possibili ies and he u iliza ion o he p oposed model a e es ed in he nex pa o he pape by com- pa ing esul s om a ma hema ical model and he ex- pe imen al measu emen s. Rela ed wo ks [6], [7], desc ibes basic pa ame e s o Blue oo h echnology and p esen s measu emen o ile ans e delay wi h a iable ile size and a iable dis- ance wi h and wi hou physical obs acle. This a i- cle is disco e ed speci ic pa ame e – ans e ime o payload packe s (i means packe s wi h use ul in o ma- ion no synch onize and se ice packe s) – o Blue oo h echnology in de ined condi ion depend on su ound- ings and dis ance by ansmi ing he same ile size da a. 2. Fea u e o Blue oo h The basic ea u es o Blue oo h echnology a e e- quency ange, TX powe and RX sensi i i y. We o e iew some speci ic ea u e o Blue oo h echnology in his chap e . 2.1. Indoo P opaga ion Mechanism When adio wa es s ike a su ace ha is nei he a pe - ec insula o no a pe ec conduc o (in o he wo ds, all p ac ical su aces), pa o he wa e ene gy passes h ough, pa is abso bed and pa is e lec ed [8]. These cha ac e is ic gi e us he ou pa hs by which a adio equency signal can a el om a ansmi e c 2014 ADVANCES IN ELECTRICAL AND ELECTRONIC ENGINEERING 98 INFORMATION AND COMMUNICATION TECHNOLOGIES AND SERVICES VOLUME: 12 |NUMBER: 2 |2014 |JUNE Fig. 1: Types o wa es [1]. o ecei e . The pa hs a e di ec , e lec ed, di ac ed and sca e ed (Fig. 1), [1], [5]. The classic ee-space link budge equa ion is gi en by: P =P ·G ·G ·λ 4πd2 ,(1) whe e P is ecei ed signal powe , P is ansmi ed powe , G is he gain o he ansmi an enna in he di ec ion o he ecei ed an enna and G is he gain o he ecei e an enna in he di ec ion o he ansmi an- enna. The ca ie wa eleng h λis 0.122 m a 2.45 GHz and dis he dis ance (m) be ween ansmi ing and e- cei ing an ennas [1], [2]. 2.2. Sys em Pa ame e s The Blue oo h echnology belongs o PAN (Pe sonal A ea Ne wo k) ne wo ks and hei co e age and u i- liza ion a e de e mined o applica ions as he da a ansmission among pe sonal e minals o as a con ig- u a ion and con ol o a ious pe iphe als. The Blue- oo h de ices a e small and hei ange is usually up o 10 me e s, o example mobile phones, PDA, mouse o keyboa d a e ypical Blue oo h de ices. Impo an ac- o o unc ionali y is su oundings whe e hese de ices a e placed [4]. Fo he ma hema ical model o da a ansmission by Blue oo h echnology a e dis ance and su ounding sys em pa ame e s. 3. Ma hema ical Model The ma hema ical model o da a ansmission de- sc ibes communica ion be ween wo de ices. Fi s mas e de ice sen da a o second sla e de ice. The ile ans e be ween bo h de ices depends on he dis ance be ween communica ing de ices and on he su ound- ings, whe e he sla e de ice is placed. Fo ou pu poses we e selec ed some possible su oundings ha migh be Fig. 2: Ma hema ical model. encoun e ed, i is ee-space (densi y 1.204 kg/m3), pa- pe wi h a ian hickness (densi y 700–1000 kg/m3), PVC o lea he (densi y 1200 kg/m3), and wood (den- si y 1000 kg/m3). The Blue oo h echnology is packe o ien ed. Du - ing a ans e he se e al ypes o Blue oo h packe s – payload packe s, synch onizing packe s, con ol pack- e s o e o packe s a e sen . This pape is o ien ed only on payload packe s – packe s wi h use ul in o - ma ion. This idea o igina ed du ing expe imen s wi h Blue oo h p o ocol analyze . Wi h ega d o complica ed ma hema ics ha de- sc ibes signal p opaga ion eg essed o m o c ea ing he ma hema ical model is used [3]. Pa ame e s o he ma hema ical model a e dis ance be ween communi- ca ing de ices and en i onmen , whe e a sla e de ice is placed. Used ma hema ical model o da a ans e in Blue oo h echnology is depic ed in Fig. 2: •inpu alue: s (MB), •pa ame e s: zd (cm) and p (kg/m3), •ou pu unc ion: Bs(cm). 3.1. Ou pu Func ion Da a ans e was used in he expe imen o compila- ion o he ou pu unc ion be ween mas e and sla e de ices. Fo all expe imen s was used he same ile, he same mas e posi ion and he same sla e de ice. Measu ed da a om Blue oo h p o ocol analyze we e so ed by di ec ion and packe s – only mas e -sla e ans e and only payload packe s. 3.2. Measu ing Wo kplace Measu ing wo kplace illus a ed in Fig. 3 shows he ba- sic con igu a ion o he expe imen . Blue oo h de ice c 2014 ADVANCES IN ELECTRICAL AND ELECTRONIC ENGINEERING 99 INFORMATION AND COMMUNICATION TECHNOLOGIES AND SERVICES VOLUME: 12 |NUMBER: 2 |2014 |JUNE Fig. 3: Measu ing wo kplace. M sends da a o de ice S in ele en dis ances, bo h de- ices mas e and sla e a e on class 3 (powe 1 mW, 0 dB). T ans e ed da a was ile (digi al pic u e) wi h size o 1247 kB (1.217 MB). The expe imen was imple- men ed in eal condi ions o o dina y used Blue oo h applica ions. As a su oundings pa ame e we e cho- sen ai wi hou obs uc ion, pape ( hickness 2 and 4 mm), plas ic obs uc ion (PVC) and wood. E e y obs uc ion was in he box shape a ound sla e de ice and expe imen oom was wi hou special adjus men (obs uc ion, noise). Inpu in o he ma hema ical model was da a ile in MB, pa ame e s we e dis ance zd (cm) and su ound- ings p (kg/m3). The densi y o he ai a 20 ◦C is 1.204 kg/m3, pape wi h a hickness o 2 mm ha e densi y o 700 kg/m3, pape wi h 4 mm ha e densi y o 900 kg/m3, wood ha e densi y o 1000 kg/m3 and plas ic (PVC) ha e abou 1200 kg/m3. Ou pu o he ma hema ical model calcula es a e age ans e ime (s) in he dependence on he dis ance and obs uc ion su oundings. 4. Expe imen A able o measu ed da a is needed o acqui e a de e - mina ion o dependencies (Tab. 1). Fi s se o mea- su emen s was achie ed wi h cons an su oundings pa- ame e – dependence o da a ans e ime on dis ance be ween Blue oo h de ices. The second se o measu e- men s was achie ed wi h cons an dis ance pa ame e – dependence o da a ans e ime on su oundings o sla e Blue oo h de ice. Measu ed da a was used o c ea e o pa ial ma he- ma ical equa ion by pa ame ic eg ession analyse [3]. Fo g aphical da a ou pu o ime o ans e ed packe s we e es ablished unc ions B1and B2, whe e B1(Fig. 4) is a unc ion o dis ance wi h en i onmen pa ame e (5 colou cu es) and B2(Fig. 5) is a unc ion o su - Tab. 1: Table o measu emen da a. p (kg/m3) zd (cm) 1.204 700 900 1200 1000 25 77.06 72.74 77.96 80.17 77.54 70 78.26 81.41 90.54 84.64 79.13 120 82.49 88.58 80.20 87.37 81.40 170 92.86 90.57 89.27 86.97 86.48 220 89.16 94.38 88.47 90.43 102.30 270 92.99 91.84 94.47 103.00 89.51 320 98.75 101.15 103.00 103.13 100.16 270 99.16 93.98 93.65 105.67 97.17 450 95.50 105.46 96.98 109.10 108.06 510 96.80 101.09 104.30 108.06 110.35 610 104.22 98.90 104.99 111.96 94.10 Fig. 4: Time o ans e ed packe s depending on dis ance. oundings wi h dis ance pa ame e (11 colou cu es): B1 = ( zd)p B2 = (p ) zd. (2) Equa ion o ou pu unc ion o da a ans e ime is: Bs= s 1.217 ·ks·B1·B2,(3) whe e Bsis ou pu alua ion o ime o ans e ed packe om ma hema ical model and ksis coe icien o he ma hema ical model. Fig. 5: Time o ans e ed packe s depending on su oundings. c 2014 ADVANCES IN ELECTRICAL AND ELECTRONIC ENGINEERING 100 INFORMATION AND COMMUNICATION TECHNOLOGIES AND SERVICES VOLUME: 12 |NUMBER: 2 |2014 |JUNE Fig. 6: Rela i e e o . 4.1. Equa ion o Ma hema ical Model Thanks o he applica ion o loga i hmic eg ession analysis on g aphical ou pu was ound ou he equa- ion o a ou pu unc ion o he ma hema ical model. Because pa ial equa ions we e mul iplying, i is mul- iplica i e (addi i e) eg ession model. Fo a c ea ion o equa ion i was needed o selec e e en ial poin om g aphical ou pu om he middle o he g aph – pa ame e zd is 270 cm and pa ame e p is 900 kg/m3. Dis ance abou 270 cm seemed as a ypical dis ance o Blue oo h applica ions. I was he same in case o su oundings pa ame e , selec ed om he middle. Equa ion o B1(B2) was c ea ed om e e en ial poin and unc ion by loga i hmic eg ession analysis: B1 = 7.9938 ·ln ( zd) + 50.329,(4) B2=0.3287 ·ln (p ) + 92.552.(5) The cons an kswe e needed o calcula e om he ma hema ical model: ks=B(270.900) B1·B2= 0.010482,(6) whe e B(270.900) is 94.47. In Fig. 6 is shown he inal o m o he ma hema ical model o Blue oo h echnol- ogy da a ansmission. Final ou pu equa ion: Bs= s 1.217 ·0.010482 (7.9938 ·ln ( zd) + 50.329) · ·(0.3287 ·ln (p ) + 92.552) .(7) 5. Conclusion C ea ed ma hema ical model desc ibes dependencies o he ou pu pa ame e s – ans e ime o payload pack- e s – on he dis ance be ween communica ing de ices and on he su oundings, whe e hese de ices we e placed. Some inpu c i e ia and equi emen s we e necessa y o de ine he unc ionali y o he p oposed model. Fo e i ica ion o he ma hema ical model o Blue- oo h echnology da a ansmissions he ou pu equa- ion was applied o all measu emen s and alues om expe imen al measu emen we e compa ed wi h alues om he ma hema ical model. The ela i e e o δs was also de e mined: δs=∆x x=Bm−Bs Bm,(8) whe e Bmis alue om expe imen measu emen . To al e alua ion o issues o he ma hema ical model can be conside ed accep able, because expe imen s and ma hema ical model we e c ea ed o eal condi ions. The esul s o ela i e e o s we e abou 5 %. I means ha measu emen da a can be in luenced by o dina y in e e ences and noises. The ma hema ical model does wo k he bes o Blue oo h de ices in class 3 in he ange om 100 o 500 cm. Blue oo h unc ions and applica ions se ices we e con o med o his ange. Acknowledgmen The esea ch leading o hese esul s has ecei ed und- ing om he Eu opean Communi y’s Se en h F ame- wo k P og amme (FP7/2007-2013) unde g an ag ee- men no. 218086. Re e ences [1] MORROW, Robe . Blue oo h ope a ion and use. New Yo k: McG awHill, 2002. ISBN 00-713-8779- X. [2] SIEP, Tom. An IEEE guide: how o ind wha you need in he Blue oo h Spec. New Yo k: IEEE, 2001. ISBN 07-381-2636-5. [3] BUDIKOVA, Ma ie, Tomas LERCH a S epan MIKOLAS. Zakladni s a is icke me ody. B no: Masa yko a uni e zi a, 2005. ISBN 80-210-3886- 1. [4] BRAY, Jenni e and Cha les F. STURMAN. Blue- oo h: connec wi hou cables. Uppe Saddle Ri e , N.J.: P en ice Hall, 2002. ISBN 01-306-6106-6. [5] MORROW, Robe . Wi eless ne wo k coexis ence. New Yo k: McG aw-Hill, 2004. ISBN 00-713- 9915-1. [6] HIPOLITO, Juan, No ma Candol i ARBALLO, Jose An onio MICHEL-MACARTY and Eli- ania Jimenez GARCIA. Blue oo h Pe o - mance Analysis in Wi eless Pe sonal A ea Ne wo ks. Elec onics, Robo ics and Au omo- i e Mechanics Con e ence. Cue na aca, Mexico: c 2014 ADVANCES IN ELECTRICAL AND ELECTRONIC ENGINEERING 101 INFORMATION AND COMMUNICATION TECHNOLOGIES AND SERVICES VOLUME: 12 |NUMBER: 2 |2014 |JUNE IEEE, 2009, pp. 38–43. ISBN 978-142-4453-412. DOI: 10.1109/CERMA.2009.48. [7] RASHID, Rozeha A. and Rohaiza YUSOFF. Blue oo h Pe o mance Analysis in Pe sonal A ea Ne wo k (PAN). In e na ional RF and Mic owa e Con e ence. Pu ayaja, Malaysia: IEEE, 2006, pp. 393–397. ISBN 0-7803-9745-2. DOI: 10.1109/RFM.2006.331112. [8] Blue oo h Speci ica ion Ve sion 2.0 + EDR. Speci- ica ion o he Blue oo h Sys em: Wi eless connec- ions made easy. Blue oo h SIG, 2004. A ailable a : www.blue o h.com. Abou Au ho s P emysl MER was bo n in Os a a. He ecei ed his M.Sc. om Uni e si y o Zilina in 1994. His esea ch in e es s include access ne wo ks and mul imedia. He ecei ed his Ph.D. om VSB–Technical Uni e si y o Os a a in 2010. c 2014 ADVANCES IN ELECTRICAL AND ELECTRONIC ENGINEERING 102