May 2009 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Flexible DSSS Proposal] Date Submitted: [01 March 2009] Source: [Kuor Hsin Chang, Clint Powell, & Rick Enns] Company [Freescale & Consultant] Address [KC: 890 N. McCarthy Blvd, Suite 120, Milpitas, CA 95035 USA] Voice:[KC:+1 (408) 904-2705, RE:+1.650.327.9708] E-Mail:[Kuor-Hsin.Chang@freescale.com, cpowell@ieee.org ,enns@stanfordalumni.org] Re: [] Abstract: Proposal for a 802.15.4 radio based on a flexible DSSS Purpose: Presented to the 802.15.4g SUN Task Group for consideration 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.

Flexible Direct Sequence Spread Spectrum (DSSS) Proposal May 2009 Flexible Direct Sequence Spread Spectrum (DSSS) Proposal Kuor Hsin Chang - Freescale Clint Powell - Consultant Rick Enns - Consultant May, 2009 at Montreal CA

Flexible DSSS Proposal May 2009 Flexible DSSS Proposal Provide configuration options for the number of chips per symbol and bits per symbol while keeping the chip rate constant at 2 Mcps Optimize performance for range and data rate – long range at reduced data rate and short range at high data rate

Flexible DSSS Examples for 2.4 GHz May 2009 Flexible DSSS Examples for 2.4 GHz Chip rate (cps) Chips per symbol Bits per symbol Data rate (bps) Coding gain (dB) Notes 2 M 32 1 62.5 K 15.05 rural application 2 125 K 12.04 4 250 K 9.03 16 500 K 6.02 Urban application

PN Codes & Chip to Symbol Mapping: Data Rate of 62.5 kbps Data Rate of 125 kbps Data Rate of 250 kbps (2.4 GHz PHY in IEEE 802.15.4-2006) Data symbol (decimal) (binary) (b0) Chip values (c0 c1 … c30 c331) Note 1 1 0 1 1 0 0 1 1 1 0 0 0 0 1 1 0 1 0 1 0 0 1 0 0 0 1 0 1 1 1 0 PN Code 0 in Table 24 1 1 0 0 0 1 1 0 0 1 0 0 1 0 1 1 0 0 0 0 0 0 1 1 1 0 1 1 1 1 0 1 1 PN Code 8 in Table 24 Data symbol (decimal) (binary) (b0 b1) Chip values (c0 c1 … c30 c331) Note 00 1 1 0 1 1 0 0 1 1 1 0 0 0 0 1 1 0 1 0 1 0 0 1 0 0 0 1 0 1 1 1 0 PN Code 0 in Table 24 1 10 0 1 0 1 0 0 1 0 0 0 1 0 1 1 1 0 1 1 0 1 1 0 0 1 1 1 0 0 0 0 1 1 PN Code 4 in Table 24 2 01 1 0 0 0 1 1 0 0 1 0 0 1 0 1 1 0 0 0 0 0 0 1 1 1 0 1 1 1 1 0 1 1 PN Code 8 in Table 24 3 11 0 0 0 0 0 1 1 1 0 1 1 1 1 0 1 1 1 0 0 0 1 1 0 0 1 0 0 1 0 1 1 0 PN Code 12 in Table 24

PN Codes & Chip to Symbol Mapping (cont’d.) Data Rate of 500 kbps Data symbol (decimal) (b0 b1 b2 b3) Chip values (c0 c1 … c14 c15) 0 0 0 0 0 0 1 1 1 1 1 0 0 0 1 0 0 1 0 1 1 1 0 0 0 0 1 0 0 1 1 1 1 1 0 0 0 1 0 0 1 2 0 1 0 0 0 1 0 1 0 0 1 1 1 1 1 0 0 0 1 0 3 1 1 0 0 1 0 0 1 0 1 0 0 1 1 1 1 1 0 0 0 4 0 0 1 0 0 0 1 0 0 1 0 1 0 0 1 1 1 1 1 0 5 1 0 1 0 1 0 0 0 1 0 0 1 0 1 0 0 1 1 1 1 6 0 1 1 0 1 1 1 0 0 0 1 0 0 1 0 1 0 0 1 1 7 1 1 1 0 1 1 1 1 1 0 0 0 1 0 0 1 0 1 0 0 8 0 0 0 1 0 1 1 0 1 0 1 1 0 1 1 1 0 0 0 0 9 1 0 0 1 0 0 0 1 1 0 1 0 1 1 0 1 1 1 0 0 10 0 1 0 1 0 0 0 0 0 1 1 0 1 0 1 1 0 1 1 1 11 1 1 0 1 1 1 0 0 0 0 0 1 1 0 1 0 1 1 0 1 12 0 0 1 1 0 1 1 1 0 0 0 0 0 1 1 0 1 0 1 1 13 1 0 1 1 1 1 0 1 1 1 0 0 0 0 0 1 1 0 1 0 14 0 1 1 1 1 0 1 1 0 1 1 1 0 0 0 0 0 1 1 0 15 1 1 1 1 1 0 1 0 1 1 0 1 1 1 0 0 0 0 0 1

Packet Structure Extend the Frame Length Field (PHR) of 802.15.4 packet from one byte to two bytes in order to support the packet length to be up to 1500 bytes. Use bit 15 (bit 7 of the Frame Control Field) of the PHR to determine long packet (≥127 bytes) or short packet (≤127 bytes)

Packet Length Field Maximum packet length of 2047 bytes. Parity Check bit for packet length to avoid unnecessary receiver power consumption due to errors in packet length

Compliance to the PAR PAR requirement Comments May 2009 Compliance to the PAR PAR requirement Comments Operation in license exempt bands  DSSS can be applied to the radios for the 868/915/2.4 GHz bands Data rate between 40 and 1,000 kbps Adjustable data rates available in this range Optimal link margins for rural and urban environments Coding trades off data rate for range Principally outdoor Basic radio proven 1500 octet frame size An extension to the radio synchronization At least 3 co-located networks Supported At least 1,000 neighbors

Advantages of Making DSSS Flexible May 2009 Advantages of Making DSSS Flexible Easy chip design – keeps the chip rate set at what 802.15.4-2006 uses. The design of the front end of the current chips can be used. Simple- we know the radio and this is well understood extension to only the digital side. Known coexistence properties – transmissions look the same to other radios.