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Project: IEEE 802.15 Study Group for Wireless Personal Area Networks (WPANs) Submission Title: [Codes, PRFs and Scans] Date Submitted: [May 2006] Source: [P Orlik]: Company1 [Mitsubishi Electric Research Labs, Inc.] Address [201 Broadway, 8 th floor, Cambridge, MA 02139]
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Project: IEEE 802.15 Study Group for Wireless Personal Area Networks (WPANs) Submission Title: [Codes, PRFs and Scans] Date Submitted:[May 2006] Source: [P Orlik]: Company1 [Mitsubishi Electric Research Labs, Inc.] Address [201 Broadway, 8th floor, Cambridge, MA 02139] Voice: [(617) 621 7570] Re: [802.15.4a] Abstract: [] Purpose: [discuss preamble options] 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.
Only nominal PRF of 16 and 4 MHz are required At all center frequencies the use of length 31 and 127 preamble codes is allowed Length 127 codes have higher PRF
Questions • How do we handle a scan when looking for a network to join? • Currently need to scan each channel and the allowed preamble codes. • The two mandatory PRFs (4 or 16 MHz) do not require additional scan time since a correlation at the 4MHz can be done with samples from the 16MHz correlator. • Methodology adopted -- limit the search space • Assigned 2 length 31 codes to each channel • Length 31 codes need two scans per channel. • For length 127, intention was to assign 4 codes per channel? • What happened to length 127 assignments and 31 assignments?
Only assigned codes to channels 1-4 RESOLUTION: Complete Assignments in Table 39d and Table 39e: CID 77, 10
Resolution • Add scan parameters to scan for length 127 AND 64 MHz PRF codes – current 7.5.2.1.2 doesn’t make mention of scanning optional codes or PRF.
Resolution 2 • Change scan procedure to allow the MAC and PHY to scan optional code lengths. (page 80 Line 13). • “For UWB and CSS PHY, the scan process shall be repeated for each mandatory preamble code, setting the phyCurrentCode appropriately.” • Change to “…, the scan process shall be repeated for each supported codes appropriate to the channel being scanned as specified in tables 39d and 39e.” • Additionally, we wish to ensure that the capability of the NHLE can issue a scan for a center frequency, with a particular code or set of codes to be scanned is retained and the correct PHY PIB parameters and MLME.scan.request parameters are specified.
One additional problem • While searching through the Table 39a we noticed some very high chipping rates. • No Comments on this but we should consider changing this so that the chipping rate is 499.2 MHz as was the case in D1 of the draft where all channels had uniform chipping rates • Will make these the same rate as the 500MHz UWB bands, Specifically, 499.2MHz