Transcript November 2001 doc.: IEEE 802.15-01/449r0 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [IEEE 802.15.4 Status] Date Submitted: [November,

November 2001
doc.: IEEE 802.15-01/449r0
Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: [IEEE 802.15.4 Status]
Date Submitted: [November, 2001]
Source: [Ed Callaway]
Company: [Motorola]
Address: [8000 W. Sunrise Blvd., M/S 2141, Plantation, FL 33322]
Voice:[(954) 723-8341], FAX: [(954) 723-3712], E-Mail:[[email protected]]
Re: []
Abstract: [This presentation describes the status of the IEEE 802.15.4 standard, with emphasis on coexistence
features.]
Purpose: [Description of 802.15.4 status to 802 COEX.]
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
Ed Callaway, Motorola
November 2001
doc.: IEEE 802.15-01/449r0
IEEE 802.15.4 Status
Ed Callaway
Florida Communication Research Lab
Motorola Labs
[email protected]
Submission
Ed Callaway, Motorola
November 2001
doc.: IEEE 802.15-01/449r0
Now in Development …
A low-rate wireless personal area network
communications protocol that:
-Supports multiple network types,
-Has long battery life (months or years from a AAA
cell)
-Is low cost
… for systems with moderate data throughput (< 250
kb/s) and QoS requirements.
Submission
Ed Callaway, Motorola
November 2001
doc.: IEEE 802.15-01/449r0
MAC Features
•Supports star & peer-peer topologies
–Master/slave, point to any point, cluster tree, etc.
•Access is slotted CSMA-CA
•Raw data rates of 250 kb/s at 2.4 GHz, lower at 868
and 915 MHz
•Optional use of network beacons
•Optional time slots for low latency transfer
•Super-frame is contention based
Submission
Ed Callaway, Motorola
November 2001
doc.: IEEE 802.15-01/449r0
Node Types

Distribution node




Controls the network topology at that node
Master/coordinator or mediation device
 Stores routing information
Talks to other distribution and slave nodes
Slave node



Cannot control the network
Very simple implementation
 Does not store routing information
Talks only to a distribution node
Submission
Ed Callaway, Motorola
November 2001
doc.: IEEE 802.15-01/449r0
Optional Super Frame Structure
Slot 3
Slot 2
Slot 1
15ms
Network
beacon
Transmitted by distribution nodes. Contains network information,
super 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
Allocated
slot
Reserved for nodes requiring guaranteed bandwidth.
Submission
Ed Callaway, Motorola
November 2001
doc.: IEEE 802.15-01/449r0
Master/Slave: Network Connection
Master
Slave
CONNECT
PERMIT-CONNECTION
BEACON
CONNECT
Tx
ACK
Rx
CONNECT-CONF
ACK
NEW-DEVICE
Submission
CONNECT-CONF
Ed Callaway, Motorola
November 2001
doc.: IEEE 802.15-01/449r0
Mediation Device Operation
Source
Node
MD
Destination
Node
Query
Tx slot
RTS
Rx slot
RTS Reply
Query Response
Timing
adjustment
CTS
DATA
ACK
… Solves synchronization problem for low cost, low
duty cycle peer-peer systems
Submission
Ed Callaway, Motorola
November 2001
doc.: IEEE 802.15-01/449r0
PHY Features



250 kb/s operation at 2.4 GHz
DSSS with low chip rate (1 MHz) for low power
operation
O-QPSK, for constant envelope modulation


Orthogonal coding


Simple, low-cost PA
Greater range for a given output power
5 MHz channel separation




Submission
16 channels in the 2.4 GHz band
5 channels in the U.S. 915 MHz band
1 channel (at lower data rates) in the European 866 MHz
band
Eases channel filter requirements to lower die size & cost
Ed Callaway, Motorola
November 2001
doc.: IEEE 802.15-01/449r0
Principle of Code Phase Shift Keying
The starting position of a single pn sequence is
modulated with the transmitted data
• Multiple bits may be sent in a single symbol
time  better battery life
Preamble
I
Q
c0 … c28
c1 … c29
Submission
Symbol 0000
c30
c31
cn cn+2
cn+1 cn+3
…
Symbol 0001
c30 c0 … cn-2 cm cm+2 …
…
c31
c1 … cn-1 cm+1
cm+3 …
Ed Callaway, Motorola
November 2001
doc.: IEEE 802.15-01/449r0
Coexistence Features
• Designed for ultra-low duty cycle operation: <
0.1% to 1%
– Node transmitters off more than 99% of the time
network is in operation
• Multiple PHYs: 868, 915 MHz, 2.4 GHz
• Devices above 16 dBm must be capable of
power reduction to below 4 dBm
• Designed for applications tolerant of message
latency; multiple retries acceptable
Submission
Ed Callaway, Motorola
November 2001
doc.: IEEE 802.15-01/449r0
For Further Information
• The IEEE 802.15.4 web site:
http://www.ieee802.org/15/pub/TG4.html
Submission
Ed Callaway, Motorola