1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: [Distributed Channel Hopping (DCH) over EGTS Structure]
Date Submitted: [May 12, 2009]
Source: [Wun-Cheol Jeong, Seong-Soon Joo, Chang-Sub Shin, Anseok Lee]
Address []
Voice:[ ], FAX: [],
Re: [IEEE P e]
Abstract: [This document describes operational description of DCH over EGTS structure.]
Purpose: [Discussion in e Task Group]
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. doc.: IEEE 802.15-<doc#>
<11 January, 2008r>
<11 January, 2008r>
doc.: IEEE <doc#>
doc.: IEEE <doc#>
Distributed Channel Hopping (DCH) over EGTS structure
Wun-Cheol Jeong, Seong-Soon Joo, Chang-Sub Shin, Anseok Lee
ETRI
Page 2
<author>, <company>
<author>, <company>

3. doc.: IEEE 802.15-<doc#>
<11 January, 2008r>
<11 January, 2008r>
doc.: IEEE <doc#>
doc.: IEEE <doc#>
Table of Contents
Channel Diversity Subgroup Report
Merging DCH over EGTS structure
Initialization
Channel Hopping Sequence & Hopping Sequence Offset Selection
EGTS Slot allocation
Required Changes
Page 3
<author>, <company>
<author>, <company>

4. Channel Diversity Subgroup Contributors
<11 January, 2008r>
<11 January, 2008r>
doc.: IEEE <doc#>
doc.: IEEE <doc#>
Channel Diversity Subgroup Contributors
ETRI: Wun-Cheol Jeong, Changsub Shin, Anseok Lee, Seong-Soon Joo
Dust Networks: Chol Su Kang, Kris Pister (UC Berkeley)
Freescale: Kuor-Hsin Chang, Clinton Powell
Emerson: José A. Gutierrez
Siemens: Ludwig Winkel
Rick Enns: Consultant
CUNY
Huawei
Arch Rock
SIMIT
Vino
USTB
SIA
Page 4
<author>, <company>
<author>, <company>

5. Channel Diversity Subgroup Report
<11 January, 2008r>
<11 January, 2008r>
doc.: IEEE <doc#>
doc.: IEEE <doc#>
Channel Diversity Subgroup Report
Description of Channel Diversity
Channel hopping
Channel adaptation
Proposals for Channel Diversity
Distributed Channel Hopping (DCH)
Time Slotted Channel Hopping (TSCH)
Enhanced GTS (EGTS) Channel Adaptation
Page 5
Page 5
<author>, <company>
<author>, <company>

6. Channel Diversity Subgroup Report
<11 January, 2008r>
<11 January, 2008r>
doc.: IEEE <doc#>
doc.: IEEE <doc#>
Channel Diversity Subgroup Report
Two different structures
EGTS
TSCH
Merging Activity
DCH over EGTS
nonbeacon-enabled PAN
beacon-enabled PAN
E-GTS
TSCH
Contention Access
Contention-Free
ISA, HCF
ZigBee,
Overhead Reduction/Security
Low Energy
Channel Diversity
Page 6
Page 6
<author>, <company>
<author>, <company>

7. Initiation of DCH Operation
<11 January, 2008r>
<11 January, 2008r>
doc.: IEEE <doc#>
doc.: IEEE <doc#>
Initiation of DCH Operation
During association process, a node device scans channel to locate beacon frames.
If a beacon frame is found and ‘EGTS Flag’ is True, a device shall operate in a EGTS mode. Otherwise, the PAN is not in EGTS mode.
If ‘Channel Diversity Mode’ is ‘1’, a device shall operate in a EGTS-DCH mode. Otherwise, the PAN is in EGTS-CA mode.
By listening beacon frames, a node device shall update channel hopping information.
A node shall send a Association frame to join the network.
Page 7
<author>, <company>
<author>, <company>

8. Channel Hopping Sequence & Hopping Sequence Offset Management
If a PAN is found to be operating in EGTS-DCH mode, a node device shall update channel hopping offset information by listening ‘Channel Diversity Specification’ field in the received beacon frame.
‘Channel Offset Bitmap’ sub field in ‘Channel Diversity Specification’ field shall inform which offset values used among 2 hop-distance nodes at the perspective of the reference node.
Updates macChannelOffset attribute in PIB.
NHL shall select channel offset value and inform MAC sub layer using primitive. MAC entity send a Association request frame with the selected channel offset value and channel hopping sequence request using ‘Channel Sequence Request’.
Upon the reception of a Association request frame, the corresponding node informs channel hopping sequence using ‘Channel Hopping Sequence’ field in a Association response frame.

9. Channel Hopping Sequence & Hopping Sequence Offset Management
CAP
CFP
Channel
Time
Illustration of Channel Hopping over EGTS multi-superframe structure

10. Channel Hopping Sequence & Hopping Sequence Offset Management
Hopping Sequences are manages in tables in MAC PIBs which have following properties:
One or more hopping sequences can be stored as parameters for PIBs.
Hopping sequences in PIBs can be modified by higher layer.
Newly joined node may request for the transmission of hopping sequences if those are not in PIBs.
NHL monitors channel status. That is, channels with bad quality can be blacked out, and channels with good quality can be marked as white channels. Channels in poor quality can be excluded during the EGTS slot allocation process.

11. EGTS Slot Allocation
EGTS slots are scheduled by exchanging EGTS handshake command frames.
However, nodes exchange Timeslot Allocation Bitmaps (TABs) only. Note that the size of TAB simply represents the availability of corresponding EGTS slots. Thus, it is much smaller than EGTS ABT sub-block which represents the availability of corresponding EGTS slots and channels as well.
Since there may be links using the same channel offset value within interfering distances, there would be collision if same slots are used among the links using same channel offset value.
To avoid collision, three-way handshaking is used. 11

12. EGTS Slot Allocation Node 1 assigns slots (3), (4) for node 3
Note: Timeslot Allocation Bitmap is exchanged, not ABT!
Every node that hears the broadcasts updates its allocation bitmap table (ABT)
2. DCH reply, broadcast
Payload :
Dst addr (3)
Timeslots Allocation Bitmap(TAB)
3. DCH notify, broadcast
Payload :
Dst addr (1)
Timeslots Allocation Bitmap(TAB)
DCH slot request, unicast
Payload :
Dst addr (1)
Number of request slots: 2
Timeslots Allocation Bitmap(TAB)
Assuming slots (2), (5) are already
Assigned from node 4 for transmitting
Frames to node 3. 12

13. Required Changes Primitives MLME-START.request MLME-GTS.request
<11 January, 2008r>
<11 January, 2008r>
doc.: IEEE <doc#>
doc.: IEEE <doc#>
Required Changes
Primitives
MLME-START.request
MLME-GTS.request
MLME-GTS.confirm
MAC command frames
Beacon frame
Association request
Association respond
MAC PIBs
Page 13
Page 13
<author>, <company>
<author>, <company>

14. Required Changes MLME-START.request ( …. EGTSFlag,
<11 January, 2008r>
<11 January, 2008r>
doc.: IEEE <doc#>
doc.: IEEE <doc#>
Required Changes
MLME-START.request ( ….
EGTSFlag,
ChannelDiversityMode,
DCHDescriptor )
Name
Type
Valid Range
Description
EGTSFlag
Boolean
TRUE or FALSE
If this value is FALSE, the operation of this primitive is the same way defined in IEEE (definition of the GTSCharacteristics parameter see ).
If this value is TRUE, indicate that the request is for EGTS, the GTSCharacteristics parameter will use the definition of EGTSCharacteristics .
ChannelDiversityMode
Integer
0x00 – 0x01
Indicates the type of channel diversity mode:
0x00 = Channel Adaptation (default)
0x01 = Channel Hopping (optional)
This value is not valid for a non-beacon enabled PAN.
DCHDescriptor
DCHDescriptor Value
See next slide.
Page 14
Page 14
<author>, <company>
<author>, <company>

15. Required Changes MLME-START.request ( …. EGTSFlag,
<11 January, 2008r>
<11 January, 2008r>
doc.: IEEE <doc#>
doc.: IEEE <doc#>
Required Changes
MLME-START.request ( ….
EGTSFlag,
ChannelDiversityMode,
DCHDescriptor )
Name ID
Type
Range
Description
Default
CurrentChannelpage
Integer
0-31
The value of this attribute is set by the next higher layer.
CommonChannel
ChannelHoppingSequenceLen gth
ChannelHoppingSequece
Set of Octetets
ChannelOffset
ChannelOffsetBitmapLength
ChannelOffsetBitmap
Set of Octets
NULL
Elements of DCHDescriptor
Page 15
Page 15
<author>, <company>
<author>, <company>

16. Required Changes MLME-GTS.request ( …. EGTSFlag, EGTSCharacteristics )
<11 January, 2008r>
<11 January, 2008r>
doc.: IEEE <doc#>
doc.: IEEE <doc#>
Required Changes
MLME-GTS.request ( ….
EGTSFlag,
EGTSCharacteristics )
Name
Type
Valid Range
Description
EGTSCharacteristics
See
The characteristics of the EGTS request, including whether the request is for the allocation of a new EGTS or the deallocation / reallocation / change of an existing EGTS.
Bit: 0 1
2-9
9-11
12-13 14
15-30
31-46
47-50
51-66
Variable
Channel Diversity Mode
EGTS Flag
EGTS Length
EGTS Characte ristics Type
EGTS Handsha ke Type
Priotized Channel Access
Destination Address
EGTS slot identifier
EGTS ABT sub-block length
EGTS ABT sub-block index
EGTS ABT sub-block
Page 16
Page 16
<author>, <company>
<author>, <company>

17. Required Changes MLME-GTS.confirm ( …. EGTSFlag, EGTSCharacteristics )
<11 January, 2008r>
<11 January, 2008r>
doc.: IEEE <doc#>
doc.: IEEE <doc#>
Required Changes
MLME-GTS.confirm ( ….
EGTSFlag,
EGTSCharacteristics )
Name
Type
Valid Range
Description
EGTSCharacteristics
See
The characteristics of the EGTS request, including whether the request is for the allocation of a new EGTS or the deallocation / reallocation / change of an existing EGTS.
Bit: 0 1
2-9
9-11
12-13 14
15-30
31-46
47-50
51-66
Variable
Channel Diversity Mode
EGTS Flag
EGTS Length
EGTS Characte ristics Type
EGTS Handsha ke Type
Priotized Channel Access
Destination Address
EGTS slot identifier
EGTS ABT sub-block length
EGTS ABT sub-block index
EGTS ABT sub-block
Page 17
Page 17
<author>, <company>
<author>, <company>

18. Required Changes Beacon Frame <11 January, 2008r>
doc.: IEEE <doc#>
doc.: IEEE <doc#>
Required Changes
Beacon Frame
Octets: 2 1
4/10
0/5/6/10/14 2
variable
Variable 4
Frame Control
Seque nce Numbe r
Addressing Fields
Auxiliary Security Header
Superframe Specificiation
GTS
Pending address fields
Channel Diversity Specificatio n
EGTS Superframe Specificatio n
Beacon Bitmap)
Beacon Payload
FCS
MHR
MAC Payload
MF R
Beacon Frame Format
Bits: 0
1-7
8-15
16-23
variable
Channel Diverstiy Mode
Reserved
Channel Offset
ChannelOffset Bitmap Length
ChannelOffset Bitmap
Channel Diversity Specification Field
Page 18
Page 18
<author>, <company>
<author>, <company>

19. Required Changes Association Request Command
<11 January, 2008r>
<11 January, 2008r>
doc.: IEEE <doc#>
doc.: IEEE <doc#>
Required Changes
Association Request Command
Octets: 1
MHR fields
Command Frame Identifier
Capability Information
Channel Offset
Association Request Command Frame
bits: 0 1 2 3 4 5 6 7
Alternate PAN Coordinator
Device Type
Power Source
Receiver On When Idle
Channel Sequence Request
Reserved
Security Capability
Allocate Address
Capability Information Field Formant
Page 19
Page 19
<author>, <company>
<author>, <company>

20. Required Changes Association Respond Command
<11 January, 2008r>
<11 January, 2008r>
doc.: IEEE <doc#>
doc.: IEEE <doc#>
Required Changes
Association Respond Command
octets: 1 2
Variable
MHR fields
Command Frame Identifier
Short Address
Association Status
Channel Hopping Sequence Length
Channel Hopping Sequence
Association Respond Command Frame
Page 20
Page 20
<author>, <company>
<author>, <company>

21. Required Changes New MAC PIBs
<11 January, 2008r>
<11 January, 2008r>
doc.: IEEE <doc#>
doc.: IEEE <doc#>
Required Changes
New MAC PIBs
macEGTSFlag : will use the definition of EGTS Characteristics
macChannelDiversityMode : indicate the type of channel diversity mode
macTAB : timeslot allocation bitmap for channel hopping mode
Page 21
Page 21
<author>, <company>
<author>, <company>