1. Date Submitted: [March 2007]
Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: [Suggestions to CWPAN from IEEE c Study Group]
Date Submitted: [March 2007]
Source: [Bob Heile, Clint Powell, Kuor-Hsin Chang, Phil Beecher, Michael Schmidt] Company: [ZigBee Alliance, Freescale Semiconductor, Integration Associates, Atmel]
Address: [11 Louis Road, Attleboro, MA USA; 2100 E. Elliot Rd, MD: EL542, Tempe, AZ 85284, USA; West Street, Reigate, Surrey RH2 9BS, United Kingdom; Königsbrücker Strasse 61, Dresden, Germany]
Voice:[ , , , , ],
Re: [ IEEE c ]
Abstract: [Document suggestions to the CWPAN standard so that harmonizing between CWPAN and IEEE standard can be achieved.]
Purpose: [To encourage discussion.]
Notice: This document has been prepared to assist the IEEE P 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 P
Submission
Bob Heile, Clint Powell, Kuor-Hsin Chang, Phil Beecher, Michael
Schmidt (ZigBee Alliance, Freescale, Integration, Atmel)

2. Motivation
Compatibility with will result in more choices and lower cost.
Submission
Bob Heile, Clint Powell, Kuor-Hsin Chang, Phil Beecher, Michael
Schmidt (ZigBee Alliance, Freescale, Integration, Atmel)

3. Suggestions to CWPAN in PHY
PN Code:
Suggested modifications:
Circular shift by 2 instead of by 1
PN Code 8-15 are complex conjugate of PN Code 0-7
Change the PN Code from floating-point numbers to binary numbers
The PN code should lead to a DC free signal.
Advantage
Harmonize the PN Code generating process between CWPAN and so that it can share most of the PN code generation HW
The correlator structure could be shared between CWPAN and
DC free signal offers simpler transceiver design.
Disadvantage:
The orthogonality of PN code under ideal condition is compromised. But this could be offset in implementation. Also, the orthogonality of the Chinese PN code is compromised under non-ideal channel condition anyway.
Submission
Bob Heile, Clint Powell, Kuor-Hsin Chang, Phil Beecher, Michael
Schmidt (ZigBee Alliance, Freescale, Integration, Atmel)

4. Suggestions to CWPAN in PHY (cont’d.)
Mapping data to PN Code:
Suggested Change:
For preamble, SFD, data payload using the same mapping method. This can be feasible after PN code generation process in CWPAN is changed.
Modulation:
Suggested Changes:
From MPSK type to OQPSK type
Change the pulse shaping filter from raise-cosine to half-sine
Advantages:
Constant envelope modulation simplifies power amplifier design.
DAC is not required in the transmitter for OQPSK+half-sine.
At the receiver, the resolution requirements for ADC is relaxed.
Half-sine pulse shaping+OQPSK can achieve the spectral requirement yet with simpler implementation.
Submission
Bob Heile, Clint Powell, Kuor-Hsin Chang, Phil Beecher, Michael
Schmidt (ZigBee Alliance, Freescale, Integration, Atmel)

5. MAC Questions / Comments / Clarifications
MAC layer differences - Document
QoS: we understand this is no longer required, please confirm.
security procedure – is this compatible with ?
Distributed Contention Access Scheme - document
Confirm that this can be implemented by the NHL?
Confirm that the necessary hooks are already provided by the MAC?
Clarification of non-persistent CSMA - document
Step 4 of slides 8 and 9 shows BE incremented based on retries – is this correct?
slide 7 - What is the calculation? Which PIB parameters are adjusted?
slide 12 – please show values of relevant PIB parameters and their effect.
GTS enhancement – document
Clarify applications and confirm that these applications cannot be implemented with current MAC/GTS.
Confirm interoperability with current superframe structure
Suggest new GTS command and GTS specification field rather than redefinition of existing command and spec field
Submission
Bob Heile, Clint Powell, Kuor-Hsin Chang, Phil Beecher, Michael
Schmidt (ZigBee Alliance, Freescale, Integration, Atmel)

6. General Comment in MAC
If additional MAC functionality is required to support the additional features proposed in CWPAN (e.g. E-GTS), it is recommended that CWPAN specifies this functionality as optional and ensures that it is interoperable with MAC.
Motivation – implementers may wish to only implement MAC functionality, but still be compliant with CWPAN.
Submission
Bob Heile, Clint Powell, Kuor-Hsin Chang, Phil Beecher, Michael
Schmidt (ZigBee Alliance, Freescale, Integration, Atmel)