Contact: Jaehwan Kim, ETRI, Korea Nov. 2008 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: In-body Channel modeling for WBAN with various frequency bands Date Submitted: [7 Nov., 2008] Source: Jaehwan Kim[ETRI], HyungSoo Lee[ETRI], Jae-Young Kim[ETRI], Jeong Ki Pack[CNU], and Tae Hong Kim[CNU] Contact: Jaehwan Kim, ETRI, Korea Voice: +82-42-860-5338, E-mail: kimj@etri.re.kr Re: [n/a] Abstract: Provide channel modeling for in-body communication communication system Purpose: To provide basic channel characteristics for the manufacture of in-body communication system Notice: This document has been prepared to assist the IEEE P802.15. It is offered as a basis for discussion and is not binding on the contributing individual's or organization's. The material in this document is subject to change in form and content after further study. The contributor's reserves the right to add, amend or withdraw material contained herein. Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE and maybe made publicly available by P802.15.

Contents Channel models for BAN Simulation Scenario Nov. 2008 Contents Channel models for BAN Simulation Scenario Channel modeling for MICS Channel modeling for ISM band Conclusion

Channel models for WBAN Nov. 2008 Channel models for WBAN Scenario Description Frequency Band Channel Model S1 Implant to Implant 402-405 MHz CM1 S2 Implant to Body Surface CM2 S3 Implant to External S4 Body Surface to Body Surface (LOS) TBD (f1,… fn) CM3 S5 Body Surface to Body Surface (NLOS) S6 Body Surface to External (LOS) CM4 S7 Body Surface to External (NLOS) .

Simulation scenario Transmitter location : 17 positions Nov. 2008 Simulation scenario Transmitter location : 17 positions Near surface implants : 9 Deep tissue implants : 8 16 15 1 2 Location Device Deep tissue Capsule endoscope, Capsule for drug delivery(1-4, 6-9) Near surface Glucose-Insulin(10-11), Insulin pump(12-13) Pacemaker(14) Deep brain stimulator, Parkinson’s disease, Cortical stimulator, Visual neuro-stimulator, Audio-neuro stimulator(15-16) Central-nerve stimulator(11) Healthcare shoes (17) 14 3 11 4 12 7 13 6 5 8 10 9 Receiver location : 286 points Implants(in-body) : 148 Body surface : 138 17

Channel modeling Path loss model Nov. 2008 Channel modeling Path loss model - Path loss model used in IEEE P802.15-08-0033-05-0006 - PL(d)=PL(d0)+10nlog10(d/d0)+S [dB] d0 : reference distance, 50 mm n : path loss exponent S : random scatter around the regression line, N(0, σs)

Path Loss vs. Distance Scatter Plot(CM1) <MICS> Nov. 2008 Path Loss vs. Distance Scatter Plot(CM1) <MICS> Deep tissue implant to another implant Near surface implant to another implant ( n=5.39, PL(d0)=39.30, σs=7.11 ) (n=4.00, PL(d0)=44.87, σs=9.01)

Path Loss vs. Distance Scatter Plot(CM2) <MICS> Nov. 2008 Path Loss vs. Distance Scatter Plot(CM2) <MICS> Deep tissue implant to body surface Near surface implant to body surface (n=4.58, PL(d0)=43.6, σs=6.18) (n=3.58, PL(d0)=46.5, σs=8.85)

Implant to body surface Nov. 2008 <Implant to Implant CM1 (Scenario S1)> <Implant to Body surface CM2 (Scenario S2)> Implant to Implant PL(d0) n σs Deep tissue 39.30 5.39 7.11 Near surface 44.87 4.00 9.01 Implant to body surface PL(d0) n σs Deep tissue 43.60 4.58 6.18 Near surface 46.50 3.58 8.85

Path Loss vs. Distance Scatter Plot(CM1) <ISM (900 MHz)> Nov. 2008 Path Loss vs. Distance Scatter Plot(CM1) <ISM (900 MHz)> Deep tissue implant to another implant Near surface implant to another implant ( n=6.34, PL(d0)=38.22, σs=10.52 ) (n=4.39, PL(d0)=42.59, σs=12.59)

Path Loss vs. Distance Scatter Plot(CM2) <ISM (900 MHz)> Nov. 2008 Path Loss vs. Distance Scatter Plot(CM2) <ISM (900 MHz)> Deep tissue implant to body surface Near surface implant to body surface (n=5.12, PL(d0)=45.24, σs=8.38) (n=3.91, PL(d0)=43.58, σs=11.97)

Implant to body surface Nov. 2008 <Implant to Implant CM1 (Scenario S1)> <Implant to Body surface CM2 (Scenario S2)> Implant to Implant PL(d0) n σs Deep tissue 38.22 6.34 10.52 Near surface 42.59 4.39 12.59 Implant to body surface PL(d0) n σs Deep tissue 45.24 5.12 8.38 Near surface 43.58 3.91 11.97

Path Loss vs. Distance Scatter Plot(CM1) <ISM(2.4 GHz)> Nov. 2008 Path Loss vs. Distance Scatter Plot(CM1) <ISM(2.4 GHz)> Deep tissue implant to another implant Near surface implant to another implant ( n=9.28, PL(d0)=50, σs=20.02 ) (n=2.57, PL(d0)=83.81, σs=19.69)

Path Loss vs. Distance Scatter Plot(CM2) <ISM(2.4 GHz)> Nov. 2008 Path Loss vs. Distance Scatter Plot(CM2) <ISM(2.4 GHz)> Deep tissue implant to body surface Near surface implant to body surface (n=4.62, PL(d0)=83.94, σs=12.75) (n=2.74, PL(d0)=71.59, σs=17.04)

Implant to body surface Nov. 2008 <Implant to Implant CM1 (Scenario S1)> <Implant to Body surface CM2 (Scenario S2)> Implant to Implant PL(d0) n σs Deep tissue 50.00 9.28 20.02 Near surface 83.81 2.57 19.69 Implant to body surface PL(d0) n σs Deep tissue 83.94 4.62 12.75 Near surface 71.59 2.74 17.04

Modified Channel Model Nov. 2008 Modified Channel Model Path loss model - PL(d)=PL(d0)+10nlog10(d/d0)+ a*d +S [dB] d0 : reference distance, 50 mm a : coefficient for absorption loss n : path loss exponent, N(0, σs) S : random scatter around the regression line - The absorption loss of biological tissues is very large. Because the absorption loss is a linear term in a log scale, we tried a modified path loss model by adding the first order term to WBAN channel more accurately.

Path loss vs. Distance Scatter Plot(CM1) <403.5 MHz> Nov. 2008 Path loss vs. Distance Scatter Plot(CM1) <403.5 MHz> Deep tissue implant to another implant Near surface implant to another implant (n=6.75, PL(d0)=33.04, a=-25.31, σs=8.30) (n=8.49, PL(d0)=29.06, a=-36.81, σs=5.96)

Path loss vs. Distance Scatter Plot(CM2) <403.5 MHz> Nov. 2008 Path loss vs. Distance Scatter Plot(CM2) <403.5 MHz> Deep tissue implant to body surface Near surface implant to body surface (n=5.83, pl=36.45, a=-19.81, σs=8.33) (n=7.99, PL(d0)=28.99, a=-32.97, σs=5.19)

Implant to body surface Nov. 2008 The modified pass loss model seems to be better, in terms of the modeling accuracy (i. e. standard deviation σs). <Implant to Implant CM1 (Scenario S1)> <Implant to Body surface CM2 (Scenario S2)> Implant to Implant PL(d0) n a σs Deep tissue 29.06 8.49 -36.81 5.96 Near surface 33.04 6.75 -25.31 8.30 Implant to body surface PL(d0) n a σs Deep tissue 28.99 7.99 -32.97 5.19 Near surface 36.45 5.83 -19.81 8.33

Path loss vs. Distance Scatter Plot(CM1) <900 MHz> Nov. 2008 Path loss vs. Distance Scatter Plot(CM1) <900 MHz> Deep tissue implant to another implant Near surface implant to another implant (n=7.75, PL(d0)=28.13, a=-30.95, σs=11.8) (n=10, PL(d0)=26.53, a=-44.49, σs=9.12)

Path loss vs. Distance Scatter Plot(CM2) <900 MHz> Nov. 2008 Path loss vs. Distance Scatter Plot(CM2) <900 MHz> Deep tissue implant to body surface Near surface implant to body surface (n=6.45, pl=32.21, a=-22.4, σs=11.49) (n=9.64, PL(d0)=25.9, a=-43.64, σs=7.11)

Implant to body surface Nov. 2008 <Implant to Implant CM1 (Scenario S1)> <Implant to Body surface CM2 (Scenario S2)> Implant to Implant PL(d0) n a σs Deep tissue 26.53 10.00 -44.49 9.12 Near surface 28.13 7.75 -30.95 11.80 Implant to body surface PL(d0) n a σs Deep tissue 25.90 9.64 -43.64 7.11 Near surface 32.21 6.45 -22.40 11.49

Path loss vs. Distance Scatter Plot(CM1) <2.4 GHz> Nov. 2008 Path loss vs. Distance Scatter Plot(CM1) <2.4 GHz> Deep tissue implant to another implant Near surface implant to another implant (n=7.53, PL(d0)=62.50, a=-45.58, σs=18.59) (n=10, PL(d0)=66.31, a=-46.79, σs=16.32)

Path loss vs. Distance Scatter Plot(CM2) <2.4 GHz> Nov. 2008 Path loss vs. Distance Scatter Plot(CM2) <2.4 GHz> Deep tissue implant to body surface Near surface implant to body surface (n=6.17, pl=56.27, a=-30.17, σs=16.43) (n=9.98, PL(d0)=61.01, a=-51.74, σs=11.62)

Implant to body surface Nov. 2008 <Implant to Implant CM1 (Scenario S1)> <Implant to Body surface CM2 (Scenario S2)> Implant to Implant PL(d0) n a σs Deep tissue 66.31 10.00 -46.79 16.32 Near surface 62.50 7.53 -45.58 18.59 Implant to body surface PL(d0) n a σs Deep tissue 61.01 9.98 -51.74 11.62 Near surface 56.27 6.17 -30.17 16.43

Comparison of Path Loss (30 cm distance) Nov. 2008 Comparison of Path Loss (30 cm distance) MICS 900 MHz 2.4 GHz Path loss Std. CM1 Deep tissue 88.35 7.11 98.07 10.52 142.23 20.02 Near surface 76.01 9.01 89.34 12.59 123.50 19.69 CM2 85.42 6.18 83.46 8.38 132.64 12.75 83.21 8.85 85.97 11.97 109.95 17.04 <Modified model> MICS 900 MHz 2.4 GHz Path loss Std. CM1 Deep tissue 90.04 5.96 100.12 9.12 118.78 16.32 Near surface 86.27 8.30 90.95 11.8 125.73 18.59 CM2 86.46 5.19 94.93 7.11 134.77 11.62 84.20 8.33 87.17 11.49 111.66 16.43

Conclusion The attenuation loss is increased since not only Nov. 2008 Conclusion When radio frequency increases The attenuation loss is increased since not only radiation loss but also conductivity rise. Finally, the path loss will be increased, too. The channel model in 2.4GHz is worse than in 400MHz or 900MHz in Accuracy. (larger σs)

Thank you for your attention! Nov. 2008 Thank you for your attention! Q & A.