1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: [Channel Bands Update]
Date Submitted: [10 February, 2010]
Source: [Larry Taylor] Company [DTC (UK)]
Address [UK]
Voice:[], FAX: [],
Re: [Draft 15.4g draft FSK text]
Abstract: [Update on Channel Bands – corrects a duplicate PHY PIB attribute name in ]
Purpose: [This presentation supports updated Channel Bands draft text in ]
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

2. Separate Standard Channel Page & Generic PHY Channel Page structures
Channel Bands Update
Separate Standard Channel Page & Generic PHY Channel Page structures
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3. Focus of the Update
The general form of the Channel Band Descriptor provides a very powerful generic PHY description mechanism
However, the Standard PHYs don’t need the general form of the descriptor
This update separates the standard channel page description (Channel Page 7) from the Generic PHY description (Channel Page 8) and defines a channel numbering scheme for standard 15.4g operation
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4. Part I – Standard Operation
Channel Numbering

5. Reminder – The Problem 15.4g defines
A large number of frequency bands (~20)
A large number of PHY Modes (~50)
Different data rates, channel separation, modulation
Any PHY Mode may operate over a frequency band
Not all combinations are defined, but in general all are possible
This results in a very large number of distinct channels – far more than can be represented using the 32-bit Channel Page/Channel Number structure

6. Existing Constraints
Many MAC Management primitives and MAC Commands use Channel Page and Channel Number parameters
To maintain consistency with existing specifications the extended channel numbering model must retain Channel Page and Channel Number structure
In addition, the MLME-SCAN primitive has an explicit ScanChannels parameter defined as a 27-bit field
Needs re-definition for 15.4g
Field size is PHY Mode & frequency band dependent

7. 15.4g Channel Page 7 Structure
Define Channel Page 7 for 15.4g
Bit positions index into the table of standard frequency bands
A device sets the corresponding bit to 1 for each standard frequency band supported
It is a convenient way of avoiding defining a PHY PIB attribute phyFrequencyBandsSupported
Page 7

8. Page 7 Bit Index
Each bit position in Page 7 corresponds to an index in the Standard Frequency Band Table
Bit are unused and reserved for future use

9. Current Frequency Band
Add a PHY PIB attribute phyCurrentFrequencyBand
Value is an index into the standard frequency band table
Must correspond to a bit set to 1 in Channel Page 7 bits 0..26
Identifies which of the supported standard frequency bands is currently being used

10. PHY Mode Add a PHY PIB attribute phyPHYModesSupported
A bit mask of supported PHY Modes (bit set to 1) with each bit corresponding to an index into the table of standard PHY Modes
Size is determined by the number of standard PHY Modes
Add PHY PIB attribute phyCurrentPHYMode
Its value is an index into the table of standard PHY Modes and must correspond to a bit set to 1 in phyPHYModesSupported

11. Channels Supported
The current 15.4 channel bit mask in bits of the Channel Page indicate which channels are supported
Allows a subset of possible channels to be supported
Also used for channel scanning
Add a PHY PIB attribute phyCurrentChannelsSupported to hold the channel bit mask for the current frequency band
Size is frequency band and PHY Mode dependent

12. Number of Channels Add a PHY PIB attribute phyNumberChannels
Identifies the number of channels for phyCurrentPHYMode in phyCurrentFrequencyBand
Also identifies the number of significant bits in phyChannelsSupported

13. Current Channel The current channel is therefore determined by:
phyCurrentChannel
A number in the range 0..phyNumberChannels-1
Corresponding bit position in phyCurrentChannelsSupported must be set to 1
phyCurrentFrequencyBand
A bit position in Page 7 set to 1
Indexes table of standard frequency bands
phyCurrentPHYMode
An index into the table of standard PHY Modes

14. Standard Canonical Name
To support negotiation of mode of operation by higher layers
Index values of standard frequency bands and PHY Modes
Channel number is qualified by
standard frequency band phyCurrentFrequencyBand
PHY Mode phyCurrentPHYMode
Channels supported phyChannelsSupported

15. PHY PIB Attributes New PHY PIB Attributes Modified PHY PIB Attributes
phyCurrentFrequencyBand
Value is an index into the table of standard frequency bands and must correspond to a bit position in Channel Page 7 set to 1
phyPHYModesSupported
Bit mask of PHY Modes supported. Each bit corresponds to an index into the standard table of PHY Modes
phyCurrentPHYMode
Value is an index into the table of standard PHY Modes and must correspond to a bit set to 1 in phyPHYModesSupported
phyNumberChannels
Value is the number of channels in phyCurrentFrequencyBand for phyCurrentPHYMode
phyCurrentChannelsSupported
Channel bit mask of size phyNumberChannels identifying which channels may be used in the current freqency band
Modified PHY PIB Attributes
phyCurrentChannel
Requires amended definition since range will be >27 for some SUN frequency bands and is frequency band and PHY Mode dependent
phyCurrentChannel must correspond to a bit position in phyCurrentChannelsSupported set to 1
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16. The Channel Band Descriptor
Part II – Generic PHY
The Channel Band Descriptor

17. The Problem
To allow 15.4g compliant systems to declare vendor specific modes of operation in a standard way
Permit exchange and negotiation of operating parameters (frequency band and PHY Mode)
Provide efficient short canonical name suitable for use in commands

18. 15.4g Channel Page 8 Structure
Define Channel Page 8 for 15.4g
Each bit (set to 1) identifies a Generic PHY descriptor

19. Generic PHY Descriptor
Generic PHY Descriptors are only in Channel Page 8
Page 8 + ID forms a canonical name
Frequency descriptor part based on band agnostic representation
Parametric PHY part is PHY Type dependent
Parameters for FSK PHY are suggested

20. PHY PIB Attributes
Add PHY PIB attribute phyNumberGenericPHYDescriptors
Add PHY PIB attribute phyGenericPHYDescriptors
Array of phyNumberGenericPHYDescriptors elements each one containing a Generic PHY Descriptor
Elements are uniquely identified by ID in the local system
Add PHY PIB attribute phyCurrentGenericPHYDescriptor
Value is the ID of a Generic PHY Descriptor and must correspond to a bit set to 1 in bits of Channel Page 8

21. Part III – Mode Switch Support

22. Mode Switch PPDU
Flag in the PHY Header identifies a frame PPDU variant for Mode Switching
The Frame needs a parameter to identify the operating mode of the subsequent PPDU
The canonical name serves as this parameter

23. Canonical Name (1) The canonical name is made up of two parts
Frequency Band part
PHY Mode part
Channel Page 7
Frequency Band part is the bit index in channel page 7 and is the value of phyCurrentFrequencyBand
PHY Mode is the value of phyCurrentPHYMode and is an index into the PHY Mode table
Channel Page 8
phyCurrrentGenericPHYDescriptor holds the ID of a generic PHY descriptor
Both Frequency Band & PHY Mode are identified in the generic PHY descriptor

24. Canonical Name (2) The canonical name is therefore
Channel Page (7) : Frequency Band Index : PHY Mode index
Channel Page (8) : Generic PHY Descriptor ID
An encoding in 16 bits (or less) is possible
The Mode Switch also needs a target Channel Number field

25. Questions
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