Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Channel Numbering Proposals] Date Submitted: [3 January 2011] Source: [Matt Boytim, Khurram Waheed] Company [Sensus , Freescale] Address [USA] E-Mail:[Matt.Boytim@sensus.com , B30612@freescale.com] Re: [802.15.4g LB59 Comment Resolution CID’s 34, 569, 570, 649, 650, 651] Abstract: [This spreadsheet reviews the formulae for channel numbering in Draft 2 of IEEE 802.15.4g and suggests changes to accommodate overlapping channels] Purpose: [Draft 2 Comment Resolution. CID’s 34, 569, 570, 649, 650, 651] 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. Boytim (Sensus), Waheed (Freescale)

2. Channel Numbering Comments • CID 34 • As written GL is not defined for the 2.4GHz band. • CID 569 • For uniformity, it is best to use the same terminology and the parameters for defining channel numbering for all PHYs • CID 570 • To avoid confusion, it is best to include a table of parameters such as BandEdge, GL, GH, Chan Spacing, etc. for all bands in this section • CID 649 • Specifying the GL and GH parameters in text is clumsy. • CID 650 • GL and GH need to be specified for the dedicated use bands to arrive at the proper first channel center frequency. • CID 651 • The numbering scheme assumes channel width and channel spacing are the same, but they need not be; this might complicate future standard amendments if the numbering scheme has to change again. It would be better if the scheme were more flexible from the outset. The original 15.4 case of 2MHz channel with 5MHz spacing is one example. Boytim (Sensus), Waheed (Freescale)

3. Executive Summary • This document suggests modifications to the formulae used for the computation of channel center frequency and total number of channels in a frequency band as per Draft 2 of IEEE 802.15.4g. It is intended to accommodate the following: • It is proposed to modify the equation to use two parameters, namely channel width and channel spacing to provide clear definitions of channel edges and center • Current formulae are directed towards continuous non-overlapping channels, only • SUN applications in allocated frequency bands can have overlapping non-FH channels. • A unified flexible equation is proposed such that it can be used for channel numbering for all possible SUN bands Boytim (Sensus), Waheed (Freescale)

4. Change History • Rev1 • Introduced option 3 for MR-FSK and MR-OFDM channel numbering consistent with MR-OQPSK • Withdraw recommendation for option 1 since complexity for discontinuous channels is not needed and little support demonstrated for this added flexibility • Recommend option 2 or 3 as resolution to comments Boytim (Sensus), Waheed (Freescale)

5. Existing Definition: Assumes Non-overlapping Continuous Channel Assignment The channel center ChanCenterFreq frequency shall be derived using Equation 0a: where BandEdge is the start of the Frequency band in MHz NumChan = 0,…, TotalNumChan-1 ChanSpacing is the separation between adjacent channels in MHz GL is guard band on the lower frequency side of the band in MHz GH is guard band on the higher frequency side of the band in MHzThe total number of channels is given by Equation: where W is width of band in MHz Boytim (Sensus), Waheed (Freescale)

6. Interpretation of Equations ChanSpacing * GL ChanSpacing 2 ChanSpacing BandEdge ChanCenterFreq ChanCenterFreq NumChan=0 NumChan=1 W f GH ChanCenterFreq NumChan=TotanNumChan-1 * Assumes the channel width equals ChanSpacing Boytim (Sensus), Waheed (Freescale)

7. Overlapping and Discontinuous channels can be obtained through a misuse of GL, ChanSpacing, and GH(cases where channel width does not equal ChanSpacing) Hypothetical example of Overlapping Case (channel width > ChanSpacing): “Specified” Channel Channel Width “Intended” Channel ChanSpacing GL ChanSpacing 2 ChanSpacing BandEdge ChanCenterFreq ChanCenterFreq NumChan=0 NumChan=1 Boytim (Sensus), Waheed (Freescale)

8. Hypothetical example of Discontinuous Case (channel width < ChanSpacing): “Specified” Channel Channel Width “Intended” Channel ChanSpacing GL ChanSpacing 2 ChanSpacing BandEdge ChanCenterFreq ChanCenterFreq NumChan=0 NumChan=1 Conclusion: You can just specify GL to be whatever it takes to make Equation 0a work, and GH to be whatever it takes to make the TotalNumChan equation work. Boytim (Sensus), Waheed (Freescale)

9. It is better to introduce a parameter for the channel width (ChanWidth) so that ChanWidth and ChanSpacing can be specified separately Overlapping Case (ChanWidth > ChanSpacing): “Specified” Channel equals the “Intended” Channel ChanWidth GL ChanWidth 2 ChanSpacing BandEdge ChanCenterFreq ChanCenterFreq NumChan=0 NumChan=1 Boytim (Sensus), Waheed (Freescale)

10. Option 1: Handles Non-overlapping, Overlapping and Discontinuous Channel Assignments (proposed resolution by CID 651) The channel center frequency ChanCenterFreq shall be derived using Equation: where BandEdge is the start of the Frequency band in MHz max(a, b) is the larger of a and b NumChan = 0,…, TotalNumChan-1 ChanSpacing is the separation between adjacent channels in MHz ChanWidth is the width of the allocated channel in MHz GL is guard band on the lower frequency side of the band in MHz GH is guard band on the higher frequency side of the band in MHzChange total number of channels to Equation: where W is width of band in MHz Boytim (Sensus), Waheed (Freescale)

11. Option 2: Handles Non-overlapping and Overlapping Channel Assignments (cannot handle discontinuous channels) The channel center frequency ChanCenterFreq shall be derived using Equation: where BandEdge is the start of the Frequency band in MHz NumChan = 0,…, TotalNumChan-1 ChanSpacing is the separation between adjacent channels in MHz ChanWidth is the width of the allocated channel in MHz GL is guard band on the lower frequency side of the band in MHz GH is guard band on the higher frequency side of the band in MHzChange total number of channels to Equation: where W is width of band in MHz Boytim (Sensus), Waheed (Freescale)

12. ChanCenterFreq = ChanCenterFreq0 + ChanSpacing*k Option 3: Handles Arbitrary Uniformly Spaced Channel Assignments The channel center frequency ChanCenterFreq shall be derived using Equation: where ChanCenterFreq0 is the center of the first (lowest frequency) channel in MHz ChanSpacing is the separation between adjacent channels in MHz k = 0,…, TotalNumChan-1 ChanCenterFreq0 , ChanSpacing , and TotalNumChan are determined via any means. This proposal mimics the channel numbering scheme proposed for the MR-OQPSK PHY instead of that proposed for the MR-FSK and MR-OFDM PHY’s. It completely omits the rationale behind the channelization (i.e. GL, GH, etc) but is probably more ‘standards appropriate’. Boytim (Sensus), Waheed (Freescale)

13. Recommended Resolution • Adopt Option 1 if Overlapping and Discontinuous channel accommodation is desired, or Option 2 if only Overlapping accommodation is desired • Define and specify a ChanWidth for each MR-FSK and MR-OFDM PHY mode and change Equation 0a to Option 1 or 2 described above • Update text and figures accordingly • Add Channel Width to Table 1. • Add 'channel width' to tables 22b-k, 22t-w (in most cases channel width = channel spacing). • Add 'Channel Width' to the Generic PHY descriptor and Figure 22x. • Page 29 after line 48 add "Channel Width is the occupied bandwidth of the channel in hertz. • Add Channel width to Table 6a (Channel width = Channel spacing). • Add Channel width to Table 75a-b (in most cases Channel width = Channel spacing). • Add 'channel width' to tables 125c-d (in most cases channel width = channel spacing). • Add 4 octet Channel Width value to Figure 103g. • Page 130 after line 15 add "Channel Width is an unsigned integer representing the occupied bandwidth of the channel extent in hertz. • Adopt Option 3 • Delete unnecessary channelization parameters • Update text and figures accordingly • (Details TBD) Boytim (Sensus), Waheed (Freescale)

14. BACKUP SLIDES Boytim (Sensus), Waheed (Freescale)

15. Discontinuous Channel Case (ChanWidth < ChanSpacing): “Specified” Channel equals the “Intended” Channel ChanWidth GL ChanWidth 2 ChanSpacing BandEdge ChanCenterFreq ChanCenterFreq NumChan=0 NumChan=1 Not Applicable to SUN Boytim (Sensus), Waheed (Freescale)