1. doc.: IEEE 802.15-<doc#>
<month year>
doc.: IEEE <doc#>
Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: Peer Aware Communication MAC Final-proposal to Call for Contributions
Date Submitted: 2 May, 2014
Source: Seong-Soon Joo, In-Hwan Lee, Hyo-Chan Bang
Company: ETRI
Address: 161 Gajeong-dong, Yuseong-gu, Daejeon, KOREA
Voice: , FAX: ,
Re:
Abstract: As a final contribution proposal for the IEEE TG8 standards, the PAC MAC specification is proposed.
Purpose: Response to the IEEE TG8 call for contribution
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
<author>, <company>

2. Peer Aware Communication MAC Final-proposal to Call for Contributions
<month year>
doc.: IEEE <doc#>
Peer Aware Communication MAC Final-proposal to Call for Contributions
Seong-Soon Joo*,
In-Hwan Lee, Hyo-Chan Bang
ETRI
<author>, <company>

3. MAC Primitives PDME-START.request/confirm
request : PeerServiceType, PeerGroupId
confirm : PeerGroupList
PDME-DISCOVER.request/indication/response/confirm
request : PeerServiceType, PeerId/PeerList,
PDME-ADVERTISE.request/indication/response/confirm
request : PeerServiceType, PeerId, msduLength, msdu, CapablePeerServiceList
PDME-PEER.request/indication/response/confirm
request : PeerId, PeerLinkType
PDME-DEPEER.request/indication/response/confirm
request : PeerId
PDME-REPEER.request/indication/response/confirm
PD-DATA.request/indication/confirm
request : PeerId, PeerLinkType, msduLength, msdu
PD-DATA-Group.request/indication/response/confirm

4. PDME-START start peer group or join a peer group Start Peer Group
(PeerServiceType, PeerList)
set superframe structure
listen neighbor for
n-times superframe interval
report peer group list
find peer group ? N Y
PDME-DISCOVER
PDME-PEER

5. PDME-DISCOVER
invite peers. if found, setup peering or start data comm.
Discover Peers
(PeerServiceType, PeerList)
initiator
participant1
participant2
set superframe structure
Discover req.
Advertise req.
select starting time
send Discovery frame
Discover req.
receive from peers ?
need peer link setup ? Y N
Peering request N Y
Peering response
initial discovery times up ? N
PDME-PEER
PD-DATA Y
no peers found ?
fail

6. PDME-ADVERTISE
request to advertise PD. Or search peer with sending data.
initiator
participant1
participant2
Advertise Peer
(PeerServiceType, CapPeerServ, PeerId, Data)
Advertise req.
Advertise req.
listen neighbor
select advertising time
Advertise req. (data)
send Advertise frame
Advertise resp (ACK)
send with data ?
receive ACK ? Y N N Y
complete
complete
fail

7. PDME-PEER request to setup peer link with QoS parameters. initiator
participant1
participant2
Request Peering
(PeerId, PeerLinkType)
Peering request
Peering response
send Peering request frame
receive response ?
Peering request N
Peering response Y
complete
fail

8. PD-DATA request to send data with QoS parameters. initiator
participant1
participant2
Req. to send data
(PeerId, PeerLinkType, msdu)
Advertise req. (data)
Advertise resp (ACK)
select sending slot
Data request
which slot ?
Groupcast
CFP
Data response
CAP
send Advertise req. command with data
send Data req. command with data
send Data req. command with data
complete
complete
complete

9. MAC Command Frame Discovery request command Advertise request command
Advertise response command
Peering request command
Peering response command
De-peering request command
De-peering response command
Re-peering request command
Re-peering response command
Data request command
Data response command

10. PAC MAC Frame Formats MAC frame header MAC frame information
frame control : version, frame type, frame length
Discover, Advertise, Peer, DePeer, RePeer, Data
peer group identifier : service type, group ID
address : unicast/groupcast/broadcast
peer group authenticator
MAC frame information
type, length, value
peer group information element : with control & management commands
multiple peer group IE can exist
MAC frame payload
MAC frame tail
frame check sequence
Octets: 2 2
0/2/8
variable
Frame Control
Peer Group Identifier
Destination Address
Source Address
Peer Group Authenticator
Peer Group Information Element
Frame Payload
Frame Check Sequence
Peer Device Addressing fields
MAC Frame Header
MAC Frame Information
MAC Frame Payload
MAC Frame Tail

11. MPDU Structure (I) peer group ID PAC device ID
service class of peer group : service priority of a peer group
PAC service profile identifier : identify the service offered by a peer group, need service profile registry
local peer group identifier : identify a peer group among peer groups in a proximity which provide the same service
PAC device ID
global device identifier : 64bit
local device identifier : 16bit
local device ID indicator : 4bit
0x0 : local device ID indication
0x1~0xe : group indication
0xf : broadcast indication
local PAC device identifier : 12bit
generated by hashing based on global device identifier, capability of device, PAC service profile identifier
reserved local peer device identifier for special purpose
0x000 : initiator of a peer group
0x001 : proxy initiator of a peer group
0xfff : broadcast (with ID indicator 0xf) or groupcast (with ID indicator 0x1~0xe)
Bits: 2 10 4
Service Class of Peer Group
PAC Service Type Identifier
Local Peer Group Identifier
Bits: 4 12
Local Device ID Indicator
Local PAC Device Identifier

12. MPDU Structure (II) peer group information elements
with discover, advertise, peer command frame, data frame
IE type : req./resp.
superframe offset : slot location from the start of superframe
superframe descriptor : structure information (optional)
align with slot appearance sequence
slot type (Group/CAP/CFP/Relay/Pause)
slot length
device advertisement information
capable service list, joined peer group
neighbor relation map
relative localization
Octet: 1 1
variable
Peer Group IE Type & Length
Superframe Offset
Superframe Descriptor
Peer Group Service List
Neighbor Relation List

13. Superframe Structure (I)
MAC superframe
unit length of a MAC slot : number of PHY unit resource
structure : sequence of MAC slot appearance, length of each MAC slot
for each PAC service, possible specific allocation of MAC slots
for each phase of a service, possible specific allocation of MAC slots
Superframe
SYNC
GROUP
(DISCOVERY)
IDLE
SYNC
GROUP
CAP
IDLE
SYNC
CFP
RELAY
MAC superframe
Superframe
SYNC
GROUP
CAP
IDLE
Sync Interval
PHY frame
SYNC
DATA
SYNC
DATA
SYNC
DATA
Superframe
discovery phase S G I C S G I C S G I C S G I C
discovery phase
data phase
Superframe 1
Superframe 2
game service S G I C S G I C S G C F I R S G C F I R

14. Superframe Structure (II)
service example : real-time short message exchange in a peer group with moving PDs
specification of service phases
peer discovery – peer-to-peer communication
specification of superframe for each phase
peer discovery phase : SYNC - GROUP – IDLE – CAP
peer-to-peer comm phase : SYNC - GROUP – CFP – IDLE – CAP – RELAY – IDLE
specification MAC slot
MAC unit slot : 2 unit PHY slots
SYNC : 1 unit PHY slot
GROUP : 3 unit MAC slots
IDLE : 2 unit MAC slots
CAP : 1 unit MAC slots
peer discovery phase
peer-to-peer communication phase
SYNC
GROUP
IDLE
CAP
SYNC
GROUP
CFP
peer group

15. Fully Distributed Interference Avoidance (I)
access control within single peer group
Groupcast slot
used for broadcasting, discovery, peer association/disassociation, relaying command frame
different backoff dependent upon the access priority of PD
initiator, relay, assigned order based on hashing of PD ID
CAP slot
used for transmitting peer-to-peer command frame, data frame
CCA with random backoff (or load dependent backoff)
CFP slot
pre-assigned slots based on hashing of PD ID
assign slots through peer association
CCA with fixed backoff

16. Fully Distributed Interference Avoidance (II)
interference avoidance among multiple peer groups
access control as a participant
participates on single peer group
implicit control : follow the access scheme according to the type of slot
participates on multiple peer groups
explicit control : defer to access, schedule peer communications among peer groups
access control as an initiator
select start time of the PAC service phase
may defer to start
reschedule PAC service phase
opportunistic transmission
based on designed statistical access

17. Start Interference Avoidance
initiator or participant
initiator
participant
interfere sync slot, groupcast slot, relay slot of other peer network?
serve to single peer network? N Y N N
interfere sync slot, groupcast slot, CFP slot, relay slot of other peer network? Y
reschedule
(or adjust length of slots)
perform CCA
according to access slot Y
discard possible ? N
not occupied?
select start time of service phase Y
remove transmit request
delay transmission Y Y
use slot
complete
complete
complete
complete

18. Groupcast group in a peer network addressing form a group
collaboration by sharing information
provide missing part of service specific information
form a group with implicit invite and explicit grouping
addressing
unicast in a peer network
network ID + group ID + local device ID
broadcast in a peer network
network ID + broadcast group ID + broadcast device ID
groupcast in a peer network
network ID + group ID + broadcast device ID
broadcast in proximity
set broadcast frame type
form a group
any guest can invite a device in a peer network by advertising needed service capability with group ID
in implicit grouping, a PD responses to the group data request by sending group data response
in explicit grouping, a PD responses to the group request and can send group data frame after receiving ACK
PAC
device6
peer service group 1
peer service group 2
group 1
peer service group 3

19. Multi-hop Operation to extend peer group coverage
peer group relay capable PD finds an isolated PD by receiving the device advertisement frame
peer group relay capable PD starts to retransmit sync and to relay frames onward on RELAY MAC slots assigned to the relay PD
isolated PD can send frames on RELAY MAC slots with CCA
relay PD receives onward frame and relay the frame on selected slots base upon the frame type
this procedure is for one-hop relay
GROUP
IDLE
CFP
RELAY
CAP
PD in tier 0
GROUP
IDLE
CFP
RELAY
CAP
PD in tier 1

20. Relative Positioning relation matrix based positioning
PD 1a
PD 1b
PD 0
tier 1
tier 2
tier 3
PD 1b2a
PD 1c
relation matrix based positioning
angular distance to a neighbor PD
for PDs in a fixed peer group
to search a nearest PD to support
establish PD map
two hop neighbor’s relation matrix
neighbor local device identifier
RSSI
distribute in a device advertisement frame
neighbor relation list field
relative positioning conjecture

21. QoS multiple class of data primitives
specify data rate, transmission QoS, unicasting/groupcast/broadcast
PD-DATA
data rate
service class : real-time, reliable, best effort
address : unicasting, groupcast, broadcast
PD-DATA-GROUP
PAC service profile ID
implicit grouping and data request
explicit grouping before data request

22. Appendix : Performance Evaluation
Simulation setup
general simulation parameters ( )
large scale fading : 2.4GHz
reference time duration for data : 256 us for 16B
discovery phase
discovery ID length : 4 bytes
data phase
full buffer
add a performance metric, power consumption

23. PHY Parameters modulation : BPSK, ½ coding symbol rate : 1MHz
Bandwidth : 2MHz
data rate : 500Kbps
TX power : 20dBm
Rx sensitivity : -82dBm
channel loss : large sclae fading, p as 50% and Lurban as 6.8dB

24. Discover : one-to-one peer group
operation
initiator sends Discover request frame (12 bytes, air time: 0.192ms)
frame control(2B)+group ID(2B)+Src addr (2B)+authenticator(2B)
IE control(1B)+offset(1B)
FEC(2B)
participant responses with Advertise request frame (30bytes, air time: 0.480ms)
frame header (10B) + IE (18B) + FEC (2B)
superframe structure
sync inter : 101ms, sync slot (1ms)
initiator : Discover Phase Superframe :
sync-group-idle-group-idle-group-sync-idle-group-idle-group-idle /2 sync interval
group slot : 20ms
idle slot : 20ms
participant : Advertise Phase Superframe : same as Discover Phase

25. CDF of Discovery Latency50
100
150
200
250
300
350
x 100us

26. Multiple Peer Group Simulation
Simulation setup
multiple peer group scenario
identical service peer groups
multiple services peer groups
moving PDs peer group
additional performance metrics
overhead to achieve avoidance of interference
delay variance

27. Summary MAC primitives & command frames
MAC frame formats & MPDU structure
Fully distributed resource scheduling at MAC sublayer
Fully distributed interference avoidance
Multi-hop relaying based peer group extension
Relative positioning
Primitives for multiple grades of PAC service