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Standard Solutions Data-rate RFID 20 cm, 10-200 kbps 100m, 11-100 Mbps 10-100m, 750 kbps 802.15.4 100m, 250 kbps IEEE802.15.6 Range 2
The IEEE 802.15.4 3
IEEE 802.15.4 - Main Features Thought for low-cost, low-rate, low-power consumption wireless communications Used for Low Rate W-PAN composed of battery charged devices Standard de-facto for WSNs It defines the PHY and MAC Layers protocols
Protocol Stack Architecture / 1
Protocol Stack Architecture / 2 Application Objects End Manufacturer Application Layer Network Layer Zigbee Alliance MAC Layer IEEE 802.15.4 Physical Layer
Protocol Stack Architecture / 3
IEEE 802.15.4 / 1 IEEE 802.15.4 2003, 2006, 2011 IEEE 802.15.4a Different PHY (UWB) IEEE 802.15.4c Alternative PHY to support Chinese bands IEEE 802.15.4e MAC Enhancements for Industrial Applications - Time Synchronized Channel Hopping (TSCH) MAC protocol, IEEE 802.15.4f Active Radio Frequency Identification (RFID) IEEE 802.15.4g Smart Utility Networks (SUN) - PHY amendment (OFDM)
IEEE 802.15.4 / 2 IEEE 802.15.4j Medical Body Area Networks IEEE 802.15.4k Low Energy Critical Infrastructure Monitoring (LECIM) IEEE 802.15.4m Operations in TV White Space IEEE 802.15.4n China Medical Band IEEE 802.15.4p Positive Train Control (PTC) IEEE 802.15.4q Ultra Low Power (ULP) Alternative PHY to support Japanese bands
The IEEE 802.15.4 PHY 10
Protocol Stack Time Synchronization Energy Management Localization Application Layer Network Layer MAC Layer PHY Layer
Outline 1. 802.15.4 PHY 2. 802.15.4a (UWB)
Outline 1. 802.15.4 PHY 2. 802.15.4a (UWB)
PHY Layer PHY is responsible for: Activation and deactivation of the radio transceiver Data Transmission and Reception Channel Frequency selection ED within the current channel CCA for CSMA/CA PAN Formation (Handouts 5) MAC Layer (Handouts 4)
IEEE 802.15.4 - Bands PHY Frequency Band Channels Chip rate parameters Modulation Bit rate parameters Symbol rate From bits to symbols 800/915 MHz 868-870 MHz 902-928 MHz 0 From 1 to 10 300 kchip/s 600 kchip/s BPSK BPSK 20 kb/s 40 kb/s 20 kbaud 40 kbaud Binary Binary 2.4 GHz 2.4-2.4835 GHz From 11 to 26 2.0 Mchip/s O-QPSK 250 kb/s 62.5 kbaud 16-ary Orthogonal 16 channels, 5 MHz each 80 MHz 2.45 GHz ISM Band 11 12 26 5 MHz frequency
IEEE 802.15.4 - PHY PHY Frequency Band Channels Chip rate parameters Modulation Bit rate parameters Symbol rate From bits to symbols 800/915 MHz 868-870 MHz 902-928 MHz 0 From 1 to 10 300 kchip/s 600 kchip/s BPSK BPSK 20 kb/s 40 kb/s 20 kbaud 40 kbaud Binary Binary 2.4 GHz 2.4-2.4835 GHz From 11 to 26 2.0 Mchip/s O-QPSK 250 kb/s 62.5 kbaud 16-ary Orthogonal
IEEE 802.15.4 PHY - Modulation MSK Modulation
IEEE 802.15.4 - PHY
IEEE 802.15.4 - PHY Hamming distance between each pair of 32-chip sequences Probability of error on a symbol when n chips are wrong (n errors on chips)
IEEE 802.15.4 PHY - Performance 802.15.4
IEEE 802.15.4 PHY - Performance 802.15.4 8 db
IEEE 802.15.4 PHY - Band 80 MHz 2.45 GHz ISM Band 5 MHz frequency 5 MHz 3 MHz
IEEE 802.15.4 Data Packet n bytes Preamble (4) SFD (1) FLI (1) MHR (3 + (4 to 20)) FCS (2) Start of Frame Delimiter Frame Length MAC Header Data Payload Frame Check Sequence PHY Payload (PSDU) Max 127 bytes PHY Layer Protocol Data Unit (PPDU)
Outline 1. 802.15.4 PHY 2. 802.15.4a (UWB)
Alternative PHYs Since 2004, the IEEE 802.15.4a task group has been working on an alternative PHY layer to allow both high-rate data transmission and accurate ranging capability. Two optional PHY layers have been proposed: - chirp spread spectrum (CSS) and - ultra wideband (UWB). Only the latter unites transmission capacity and acute radar resolution. For the former, visit www.nanotron.com
IR-UWB According to Federal Communications Commission (FCC), a UWB system is defined as any radio system that has a fractional bandwidth equal to or greater than 0.20 or has a UWB bandwidth equal to or greater than 500 MHz.
IR-UWB
IR-UWB Time-hopping sequence In the example above: [..., 2, 8, 4,...] One time-hopping sequence/user
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