Transcript doc.: IEEE 802.15-03/0xxr0> Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [TG4 Review] Date Submitted: [15 January 2003] Source:

<January 2003>
doc.: IEEE 802.15-03/0xxr0>
Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: [TG4 Review]
Date Submitted: [15 January 2003]
Source: [Pat Kinney] Company [Kinney Consulting]
Address [4097 Manor Oaks Ct, Export, PA, 15632]
Voice:[724-733-8650], FAX: [724-733-8650], E-Mail:[[email protected]]
Re: [In response to the UWB call for interest.]
Abstract: [Overview of IEEE 802.15.4.]
Purpose: [To provide an informative TG4 baseline to the UWB call for interest.]
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) reserve(s) 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 may be made publicly available by P802.15.
Submission
Slide 1
<Pat Kinney>, <Kinney Consulting>
<January 2003>
doc.: IEEE 802.15-03/0xxr0>
IEEE 802.15.4
Overview
Submission
Slide 2
<Pat Kinney>, <Kinney Consulting>
<January 2003>
doc.: IEEE 802.15-03/0xxr0>
802.15.4 Applications Space
• Home Networking
• Automotive Networks
• Industrial Networks
• Interactive Toys
• Remote Metering
Submission
Slide 3
<Pat Kinney>, <Kinney Consulting>
<January 2003>
doc.: IEEE 802.15-03/0xxr0>
802.15.4 Applications Topology
Cable replacement - Last meter connectivity
Virtual Wire
Mobility
Wireless Hub
Ease of installation
Stick-On Sensor
Submission
Slide 4
<Pat Kinney>, <Kinney Consulting>
<January 2003>
doc.: IEEE 802.15-03/0xxr0>
Some needs in the sensor networks
Thousands of sensors in a small space  Wireless
but wireless implies Low Power!
and low power implies Limited Range.
Of course all of these is viable is a Low Cost
transceiver is required
Submission
Slide 5
<Pat Kinney>, <Kinney Consulting>
<January 2003>
doc.: IEEE 802.15-03/0xxr0>
802.15.4 General Characteristics
Data rates of 250, 40, and 20 kbps.
Star or Peer-to-Peer operation.
Support for low latency devices.
CSMA-CA channel access.
Dynamic device addressing.
Fully handshaked protocol for transfer reliability.
Low power consumption.
16 channels in the 2.4GHz ISM band, 10 channels in the 915MHz
ISM band and one channel in the European 868MHz band.
Extremely low duty-cycle (<0.1%)
Submission
Slide 6
<Pat Kinney>, <Kinney Consulting>
<January 2003>
doc.: IEEE 802.15-03/0xxr0>
802.15.4 Architecture
Upper Layers
IEEE 802.2
LLC, Type I
IEEE 802.15.4 LLC
IEEE 802.15.4 MAC
IEEE 802.15.4
868/915 MHz
PHY
Submission
IEEE 802.15.4
2400 MHz
PHY
Slide 7
<Pat Kinney>, <Kinney Consulting>
<January 2003>
doc.: IEEE 802.15-03/0xxr0>
IEEE 802.15.4
PHY Overview
Paul Gorday
Submission
Slide 8
<Pat Kinney>, <Kinney Consulting>
<January 2003>
doc.: IEEE 802.15-03/0xxr0>
IEEE 802.15.4 PHY Overview
Operating Frequency Bands
868MHz/
915MHz
PHY
2.4 GHz
PHY
Channel 0
Channels 1-10
868.3 MHz
902 MHz
Channels 11-26
2.4 GHz
Submission
2 MHz
928 MHz
5 MHz
2.4835 GHz
Slide 9
<Pat Kinney>, <Kinney Consulting>
<January 2003>
doc.: IEEE 802.15-03/0xxr0>
IEEE 802.15.4 PHY Overview
Packet Structure (Both PHY’s)
PHY Packet Fields
•
•
•
•
Preamble (32 bits) – synchronization
Start of Packet Delimiter (8 bits) – specifies one of 3 packet types
PHY Header (8 bits) – Sync Burst flag, PSDU length
PSDU (0 to 127 bytes) – Data field
Preamble
Start of
Packet
Delimiter
PHY
Header
PHY Service
Data Unit (PSDU)
6 Bytes
Submission
0-127 Bytes
Slide 10
<Pat Kinney>, <Kinney Consulting>
<January 2003>
doc.: IEEE 802.15-03/0xxr0>
IEEE 802.15.4 PHY Overview
Modulation/Spreading
2.4 GHz PHY
•
•
•
•
250 kbps (4 bits/symbol, 62.5 kBaud)
Data modulation is 16-ary orthogonal modulation
16 symbols are ~orthogonal set of 32-chip PN codes
Chip modulation is MSK at 2.0 Mchips/s
868MHz/915MHz PHY
•
•
•
•
Submission
40/20 kbps (1 bit/symbol, 40/20 kBaud)
Data modulation is BPSK with differential encoding
Spreading code is a 15-chip m-sequence
Chip modulation is BPSK at 0.6/0.3 Mchips/s
Slide 11
<Pat Kinney>, <Kinney Consulting>
<January 2003>
doc.: IEEE 802.15-03/0xxr0>
IEEE 802.15.4 PHY Overview
Common Parameters
Transmit Power
• Capable of at least –3dBm
Transmit Center Frequency Tolerance
•  40 ppm
Receiver Sensitivity
• -85 dBm (1% Packet Error Rate)
RSSI Measurements
• Packet strength indication
• Clear channel assessment
• Dynamic channel selection
Submission
Slide 12
<Pat Kinney>, <Kinney Consulting>
<January 2003>
doc.: IEEE 802.15-03/0xxr0>
IEEE 802.15.4 PHY Overview
PHY Primitives
PHY Data Service
• PD-DATA – exchange data packets between MAC and PHY
PHY Management Service
•
•
•
•
Submission
PLME-CCA – clear channel assessment
PLME-GET – retrieve PHY parameters
PLME-RX-ENABLE – enable/disable receiver
PLME-SET – set PHY parameters
Slide 13
<Pat Kinney>, <Kinney Consulting>
<January 2003>
doc.: IEEE 802.15-03/0xxr0>
IEEE 802.15.4
MAC/LLC Overview
Phil Jamieson
Submission
Slide 14
<Pat Kinney>, <Kinney Consulting>
<January 2003>
doc.: IEEE 802.15-03/0xxr0>
Protocol Drivers
 Extremely low cost
 Ease of installation
 Reliable data transfer
 Short range operation
• Reasonable battery life
Simple but flexible protocol
Submission
Slide 15
<Pat Kinney>, <Kinney Consulting>
<January 2003>
doc.: IEEE 802.15-03/0xxr0>
Example Network
Network
coordinator
Node 1
Node 4
Node 5
Node 2
Node 6
Node 3
Submission
Slide 16
<Pat Kinney>, <Kinney Consulting>
<January 2003>
doc.: IEEE 802.15-03/0xxr0>
Device Classes
• Full function device (FFD)
– Any topology
– Network coordinator capable
– Talks to any other device
• Reduced function device (RFD)
– Limited to star topology
– Cannot become a network coordinator
– Talks only to a network coordinator
– Very simple implementation
Submission
Slide 17
<Pat Kinney>, <Kinney Consulting>
<January 2003>
doc.: IEEE 802.15-03/0xxr0>
Example Network
FFD
RFD
FFD
RFD
RFD
RFD
FFD
Submission
Slide 18
<Pat Kinney>, <Kinney Consulting>
<January 2003>
doc.: IEEE 802.15-03/0xxr0>
Star Topology
Network
coordinator
Master/slave
Full function device
Communications flow
Reduced function device
Submission
Slide 19
<Pat Kinney>, <Kinney Consulting>
<January 2003>
doc.: IEEE 802.15-03/0xxr0>
Peer-Peer Topology
Point to point
Cluster tree
Full function device
Submission
Communications flow
Slide 20
<Pat Kinney>, <Kinney Consulting>
<January 2003>
doc.: IEEE 802.15-03/0xxr0>
Combined Topology
Clustered stars - for example,
cluster nodes exist between rooms
of a hotel and each room has a
star network for control.
Full function device
Communications flow
Reduced function device
Submission
Slide 21
<Pat Kinney>, <Kinney Consulting>
<January 2003>
doc.: IEEE 802.15-03/0xxr0>
Device Addressing
• All devices have IEEE addresses
• Short addresses can be allocated
• Addressing modes:
– Network + device identifier (star)
– Source/destination identifier (peer-peer)
– Source/destination cluster tree + device
identifier (cluster tree)
Submission
Slide 22
<Pat Kinney>, <Kinney Consulting>
<January 2003>
doc.: IEEE 802.15-03/0xxr0>
General Data Packet Structure
Preamble sequence
Start of Packet Delimiter
PRE
SPD
LEN
PC
ADDRESSING
DSN
Link Layer PDU
CRC
CRC-16
Data sequence number
Addresses according to specified mode
Flags specify addressing mode
Length for decoding simplicity
Submission
Slide 23
<Pat Kinney>, <Kinney Consulting>
<January 2003>
doc.: IEEE 802.15-03/0xxr0>
Optional Frame Structure
GTS 3
GTS 2
GTS 1
15ms * 2n
where 0  n  14
Network
beacon
Transmitted by network coordinator. Contains network information,
frame structure and notification of pending node messages.
Beacon
extension
period
Space reserved for beacon growth due to pending node messages
Contention
period
Access by any node using CSMA-CA
Guaranteed
Time Slot
Reserved for nodes requiring guaranteed bandwidth [n = 0].
Submission
Slide 24
<Pat Kinney>, <Kinney Consulting>
<January 2003>
doc.: IEEE 802.15-03/0xxr0>
Traffic Types
• Periodic data
– Application defined rate (e.g. sensors)
• Intermittent data
– Application/external stimulus defined rate
(e.g. light switch)
• Repetitive low latency data
– Allocation of time slots (e.g. mouse)
Submission
Slide 25
<Pat Kinney>, <Kinney Consulting>
<January 2003>
doc.: IEEE 802.15-03/0xxr0>
Data Service
Originator
LLC
Originator
MAC
Recipient
MAC
Recipient
LLC
MD-DATA.request
Channel
access
DATA
MD-DATA.confirm
Packet
validation
MD-H/S.indication
Submission
HANDSHAKE
MD-DATA.indication
Slide 26
<Pat Kinney>, <Kinney Consulting>
<January 2003>
doc.: IEEE 802.15-03/0xxr0>
Management Service
•
•
•
•
•
•
Access to the PIB
GTS allocation
Message pending
Node notification
Network scanning/start
Network synchronization/search
Submission
Slide 27
<Pat Kinney>, <Kinney Consulting>
<January 2003>
doc.: IEEE 802.15-03/0xxr0>
MAC Summary
•
•
•
•
•
•
•
•
Star and peer-to-peer topologies
Optional frame structure
CSMA-CA channel access mechanism
Packet validation and message rejection
Handshake generation (for speed)
Optional guaranteed time slots
Guaranteed packet delivery
Frame fragmentation/reconstitution
Submission
Slide 28
<Pat Kinney>, <Kinney Consulting>
<January 2003>
doc.: IEEE 802.15-03/0xxr0>
802.15.4 PHY Specs/Values
Standard Typical
Units
Xmit PO
>-3
0
dBm
Sens.
-85/-92
-95/-97
dBm
Channels
1,10,16
Data Rate
250/
40/20
250/
40/20
Kb/s
Battery life --------
.5 - 2
years
Location
no
Awareness
no
Submission
Slide 29
<Pat Kinney>, <Kinney Consulting>