doc.: IEEE 802.15-<doc#> <month year> doc.: IEEE 802.15-<doc#> May 2004 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [ Two Problems on MAC] Date Submitted: [12 May, 2004] Source: [Liang Li] Company [Helicomm. Inc] Address [1947 Camino Vida Roble, Carlsbad, CA92008] Voice:[+1 760 918 0856], FAX: [+1 760 918 0338], E-Mail:[liang.li@helicomm.com] Re: [802.15.4 – 2003, DCN 15-04-0093-00-004b ] Abstract: [] Purpose: [Informational - This is a introduction to DCN 15-04-0093-00-004b ] 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. Liang Li <author>, <company>

Questions regarding 802.15.4-MAC May 2004 Questions regarding 802.15.4-MAC Liang Li

doc.: IEEE 802.15-<doc#> <month year> doc.: IEEE 802.15-<doc#> May 2004 Question 1 According to the message sequence chart of page 185, the Rx should be turned on before the end of the backoff period. And the Section 7.5.1.3 mentioned that "Although the receiver of the device is enabled during the channel assessment portion of this algorithm, the device shall discard any frames received during this time."(Page 143, First Para.) Liang Li <author>, <company>

doc.: IEEE 802.15-<doc#> <month year> doc.: IEEE 802.15-<doc#> May 2004 Question 1 The questions is whether the Rx shall be turned on during the backoff period or only be turned on before the CCA? We think the Rx shall be off in the backoff period but not sure. If the Rx is on when the backoff period, how about the frames that it received during the backoff? Discard it or reserve it? Liang Li <author>, <company>

doc.: IEEE 802.15-<doc#> <month year> doc.: IEEE 802.15-<doc#> May 2004 Question 2 According to Section 6.2.2.7.3, the PHY should return BUSY_RX when MAC commands to turn off the Rx and Rx has received a valid SFD at that time. The CSMA/CA algorithm will turn off the Rx and turn on the Tx before the transmission But what should the CSMA algorithm do when it received a BUSY_RX return value? Liang Li <author>, <company>