doc.: IEEE g Submission May 11, 2011 Steve Jillings, SemtechSlide 1 Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Comment Resolution for LB#70 ACR CID #84, #118, #119] Date Submitted: [17 March 2011] Source: [Steve Jillings,] Company: [Semtech] Re: [] Abstract:[] Purpose:[To assist with comment resolution for LB #70 for ACR related comments] 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

doc.: IEEE g Submission May 11, 2011 Steve Jillings, SemtechSlide 2 BACKGROUND Section of D4 of the 15.4g Standard states: –The adjacent channel rejection shall be measured as follows: the desired signal shall be a compliant MRFSK PHY signal, as defined in , of pseudo-random data at the center frequency of the desired channel. –The desired signal is input to the receiver at a level 3 dB above the receiver sensitivity given in In either the adjacent or the alternate channel, an un-modulated carrier in the center of that channel is input at the following level relative to the level of the desired signal: The adjacent channel rejection shall be greater than or equal to 10 dB. The alternate channel rejection shall be greater than or equal to 30 dB. –The test shall be performed for only one interfering signal at a time. The receiver shall meet the error rate criteria defined in under these conditions.

doc.: IEEE g Submission May 11, 2011 Steve Jillings, SemtechSlide 3 CID #84, #118 Proposal: –Paragraph 2 of should be amended to read…In either the adjacent or the alternate channel, an IEEE signal is input at the required min performance level Assumption: IEEE signal implies a IEEE g MR-FSK signal commensurate with the PHY operating mode of the wanted signal

doc.: IEEE g Submission May 11, 2011 Steve Jillings, SemtechSlide 4 CID #84, #118 Question: What is a MR-FSK signal? Answer: “Filtered” FSK Question: What is “Filtered” FSK? Answer: ??? Assumption: For 15.4g, “Filtered FSK” describes the MR- FSK signal as defined in of the current draft: –The modulation for the MR-FSK PHY is either 2 or 4 level filtered FSK that meets the transmit spectral mask, as defined in GFSK with a BT value of 0.5 should be used in the 950 MHz band.

doc.: IEEE g Submission May 11, 2011 Steve Jillings, SemtechSlide 5 CID #84, # Transmit Spectral Mask The transmit spectral content is the ratio of the total transmitted out-of- channel power to the total transmitted in-channel power in a given integration bandwidth. The frequency interval shall be equal to 1.5 x R, where R is the symbol rate, expressed in units of hertz. Out-of-channel power shall be measured at two offset frequencies relative to the carrier frequency. The offset frequencies M1 and M2 are defined as follows: –M1 = 1.5 x R x (1+h) Where h is the modulation index for 2-level modulation and three times the modulation index for 4-level modulation –M2 = 3 x R x (1+h) The transmit spectral content at M1 and M2 shall be less than –25 dB and –35 dB, respectively. The modulated signal shall use a PN data pattern of 511 bits or longer. The spectrum analyzer settings for this measurement shall be as follows: the resolution bandwidth is 1 kHz, the video bandwidth is 1 kHz or greater, and the detector is RMS

doc.: IEEE g Submission May 11, 2011 Steve Jillings, SemtechSlide 6 For MR-FSK PHY operating mode #1 BR = 50 kb/s, h = 1, channel spacing = 200 kHz –R = 25 kHz –M1 = 1.5*R*(1+h) = 1.5*25*(1+1) = ±75 kHz –M2 = 3*R*(1+h) = 3*25*(1+1) = ±150 kHz For MR-FSK PHY operating mode #3 BR = 200 kb/s, h = 0.5, channel spacing = 400 kHz –R = 100 kHz –M1 = 1.5*R*(1+h) = 1.5*100*(1+0.5) = ±225 kHz –M2 = 3*R*(1+h) = 3*100*(1+0.5) = ±450 kHz CID #84, #118

doc.: IEEE g Submission May 11, 2011 Steve Jillings, SemtechSlide 7 CID #84, #118

doc.: IEEE g Submission May 11, 2011 Steve Jillings, SemtechSlide 8 CID #84, #118

doc.: IEEE g Submission May 11, 2011 Steve Jillings, SemtechSlide 9 CID #84, # g spectral mask and regulatory requirements for license-exempt frequency bands (as of 05/11/2011): Regulatory compliance –It is the responsibility of the implementer to verify and ensure that the device is in compliance with all regulatory requirements in the geographic region where the device is deployed or sold. Conformance with this standard does not guarantee compliance with the relevant regulatory requirements which may apply. Band (MHz)Regulatory BodyDocumentCompliance 863 – 870ETSIEN v2.3.1  902 – 928FCCCFR  ARIBT-96 v1.1 

doc.: IEEE g Submission May 11, 2011 Steve Jillings, SemtechSlide 10 CID #84, #118 Question: Just because the transmit spectral mask is as defined, do we expect a MR-FSK “Filtered” FSK signal to occupy all of the mask (potentially out to ±  )? Answer: ??? But there exist in the standard specifications that are meant – for a reason - to address the concerns of the support of legacy products: –Transmitter: Symbol rate tolerance (±300 ppm) –Preamble: Up to 1000 octets Assumption: A MR-FSK “Filtered” FSK may need to occupy the available spectrum allowed by the spectral mask

doc.: IEEE g Submission May 11, 2011 Steve Jillings, SemtechSlide 11 CID #84, #118 Proposed Resolution: Reject –Analysis of ACR and AACR performance for a given MR-FSK PHY operating mode should allow for an apples-to-apples comparison to be made –The definition of the transmit spectral mask allows for many different filtering schemes resulting in significantly varied occupied bandwidths that make this direct comparison difficult –The definition of an un-modulated carrier for the adjacent and alternate channel interferer allows for a relative figure of merit of.4g receiver interference rejection to be obtained Note: –Should the task group decide to revisit the transmit spectral mask this would be encouraged by both the original commentators and the owner of this document

doc.: IEEE g Submission May 11, 2011 Steve Jillings, SemtechSlide 12 CID #119 Proposal: –Change text to read a min of 30 dB ACR is required in both adjacent and alternate channels

doc.: IEEE g Submission May 11, 2011 Steve Jillings, SemtechSlide 13 CID #119 Proposed Resolution: Reject –The group has discussed at length the ACR and AACR values for the MR-FSK PHY at length –The ACR and AACR receiver interference rejection of 15.4g are more stringent than those of existing 15.4 standards –In a mixed signal mode environment, blocking (non-linear) interference rejection is as important, if not more so, than the linear interference rejection performance of the receiver Note –Should the task group decide to revisit the transmit spectral mask which would allow for the receiver interference rejection specification to be revisited this would be encouraged by both the original commentators and the owner of this document