SMK SMK Corporation Kenji OTSUKA AV AV RF 2.4GHz ISM 2.4GHz ISM 2.4GHz RF
IEEE 802.15.4 ZigBee 2.4GHz 250kbps O-QPSK DSSS Bluetooth IEEE 802.15.1 2.4GHz 3Mbps G-FSK FHSS PC LAN IEEE 802.11b 2.4GHz 11Mbps CCK DSSS LAN LAN IEEE 802.11g 2.4GHz 54Mbps 64QAM OFDM LAN 2.4GHz ISM Industry-Science-Medical ISM FCC Part.15 RF LAN Bluetooth ZigBee IEEE 802.15.4 ISM RF RF 1 A 2 100ms 1 µa 2 100ms 300ms
1 W e... 1 2 PL = W W 2 R T T at ar T A A W λ G G W = = 2 2 2 2 d λ 16π d T 4πd 1 λ G G e at ar 2... 2 db 3 2 d PL [ db] = 10 4π log ( logg G... 3 at log ar ) 10 + 10 λ 1 4 4 d 1 2 d 1 PL0 = 2 π =... 4 1 jk l π λ exp( ) λ 2 k l sin 2 k=2π /λ l>λ/2 d 4 sin0.5 5 d PL0 = 2 2... 5 π λ d l 16 PL... 6 7 d b 0 4 d hh 2 2 2 t r hh t > 2 2π λ r 2 2... 7 h t d h r W T W A T m 2 2G a / 4 (m) A R m 2 PL G at G ar W e W m h t h r m d m l m d b = m
RF 1% 2.45GHz 3 PL = 0 ( 85) + ( 2) + ( 1) 2 3= 77[ db] 20log dm [ ] = PL 40. 22 = 77 40. 22 = 36. 78 10 36. 78 20 dm [ ] = 10 = 69. 0[ m] 7 d b =71.5m W T =0 dbm W R = 85 dbm 1% G T = 2 dbi G R = 1 dbi h t =h r =1 m RF 2 db RF 3 db 2.45GHz 2.4GHz ISM 1 2 db 0 10 20 30 40 50 60 70 80 90 100 110 120 130 m 1 10 100 1000 l 1 d l> /2
3 4 2.4GHz ISM ASK : amplitude shift keyingfsk : frequency shift keying ISM FHSS : Frequency Hopping Spread Spectrum DSSS : Direct Sequence Spread Spectrum ASK FSK FHSS Bluetooth IEEE 802.15.1 DSSS LAN IEEE802.11b IEEE 802.15.4 ZigBee QPSK 1 PA
PNPN DSSS 8 G p =... 8 8 SN = S/N S/N BW RF R info S M = G L + ( ) N j p sys out... 9 L sys (S/N) out SN RF (BW RF )=2MHz (R info )=250kbps 1% (S/N) out =6dB IEEE 802.15.4 L sys =3dB9 f f f
10 M j = 10log 2 10 250 10 ( 3[ db] + 6[ db]) = 0[ db]... 10 1% FHSS Bluetooth Bluetooth 1 2 3 1 3s FHSS Bluetooth DSSS IEEE 802.15.4 Bluetooth ms µa 6 3 DSSS IEEE 802.15.4 RF IEEE 802.15.4 RF LAN LAN LAN.11b Ch14 LAN Ch1 Ch6 Ch11 LAN LAN IEEE 802.15.4 Ch15 Ch20 Ch25 Ch26 LAN IEEE 802.15.4 CCA : clear channel assessment CCA
ARIB STD-T66 2400MHz 2483.5MHz RCR STD-33 2471MHz 2497MHz 22MHz Ch1 Ch2 Ch13 Ch14 Ch14 11b 25MHz 25MHz Ch1 Ch6 Ch11 Ch14 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 IEEE 802.15.4 2MHz 5MHz LAN 46 2450MHz 50MHz 2450MHz 10 Bluetooth
LAN Ch1 IEEE 802.15.4 Ch15 Bluetooth 2.4000 2.4835GHz 1MHz625µs 79 RF 49.4ms Payload data 8byte Bluetooth RF 11 RFBluetooth 49.4ms 50 150ms IEEE 802.15.4 byte Payload data byte18byte 250kbps11 576µs byte8 =... 11 bps IEEE 802.15.4 Ch11 Bluetooth 12 2404MHz 2405MHz 2406MHz Bluetooth RF 122.45ms Bluetooth 3 IEEE 802.15.4... 12 13
625 s 2403 2405 2402 2404 2480 Bluetooth 625 s 79 49.4ms IEEE 802.15.4 576 s 2MHz 4.96 Bluetooth 2402 2403 2404 2405 2406 IEEE 802.15.4 Ch11 100... 13 1% 4.96 1% CCA 13 on6.283ms
PER 5m RF off3.792ms 576µs 68.1% CCA CCA PER 1 5m 14 2 500W 2r 3 RFFC8602T 2405MHz 2450MHz 2480MHz PER RF 4 1000 PER 18byte 5 14
PER PER1 % 2405MHz5m 2480MHz1 RF 1% 10 2450MHz Ch20 9 40m y 2405MHz 2450MHz 2480MHz 0m 17% 76% 2% 1m 10% 58% 0% 2m 5% 50% 0% 3m 3% 45% 0% 4m 3% 41% 0% 5m 0% 35% 0% 2405MHz Ch11 5m 2480MHz Ch26 1m RF LAN Bluetooth 1% ISM ISM LAN Bluetooth CCA Ch11 Ch26
RF IEEE 802.15.4 Robert C. Dixon Bluetooth ZigBee 2.1 3.6V 10 +50 42mAtyp. / 5 Atyp. at 252.7V URAT 19200bps PWM IR 2.5mm 20 30 5mm 2400 2483.5 O-QPSK DSSS 20 MHz m Offset- Quadrature Phase Shift Keying Direct Sequence Spread Spectrum