1. AST San Jose Lab: IEEE 802.11s Mesh Network US
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2. Useful URLs www.ieee802.org/11 www.802wirelessworld.com
IEEE WLAN main site with schedules, standards, announcements, contacts, etc.
Documents older than
Need address and a password to join
Attendance, membership status, etc.
Documents newer than
me to get on the ‘ieee-stds-11’ reflector.
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3. 802.11s –PAR
To develop an IEEE Extended Service Set (ESS) Mesh with an IEEE Wireless Distribution System (WDS) using the IEEE MAC/PHY layers that supports both broadcast/multicast and unicast delivery over self-configuring multi-hop topologies.
To extend the IEEE MAC. No physical layer is included.
To provide a protocol for auto-configuring paths between APs over self-configuring multi-hop topologies in a WDS to support both broadcast/multicast and unicast traffic in an ESS Mesh using the four-address frame format or an extension.
A target configuration is up to 32 devices participating as AP forwarders in the ESS Mesh.
To utilize IEEE i security mechanisms, or an extension thereof, for the purpose of securing an ESS Mesh.
802.11s Project Authorization Request (PAR) = Doc # r2
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4. 802.11s – Example of Mesh Network
Internet
Internet
Mesh
Portal
Mesh
Point
Mesh
Portal
Mesh
Point
Mesh Network
Mesh
Point
Mesh AP
Mesh AP
STA
STA
STA
STA
STA
BSS
BSS
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5. 802.11s –Functional Requirements and Scope (2)
Mesh Topology Learning, Routing and Forwarding
Mesh Security
Mesh Measurement
Mesh Discovery and Association
Mesh Medium Access Coordination
Compatibility to Service
Interworking
Mesh Configuration and Management
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6. 802.11s –Functional Requirements and Scope(1)
High-level view on the system functions interactions
Service
Integration
Mesh RF Resource Ctrl & Management
Mesh Security
Mesh Routing
&
Forwarding
Mesh Medium Access
Coordination
Flow Control
Auto Discovery &
Topology Learning
Mesh Interworking
Mesh
Measurement
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7. 802.11s—Functional Requirements and Scope (3)
Mesh Topology Learning, Routing and Forwarding :
QOS Routing
On-demand routing/proactive routing.
Topology-based protocol/distance-vector based protocol.
Uniform protocol/non-uniform protocol.
Architecture to support alternative routing protocols
Mesh routing in the presence of low-power mesh points
Mesh routing with Multiple radio devices
Broadcast/multicast/unicast data delivery support
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8. 802.11s—Functional Requirements and Scope (4)
Mesh Security :
Secure association of Mesh Point
Secure data message/management message/routing message
Centralized/distributed authentication and key management
Extension of i for mesh
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9. 802.11s—Functional Requirements and Scope (5)
Mesh Measurement :
Specification of radio-aware metrics for use by mesh network
Mesh link/path quality measurements
Measurement to support channel selection
Measurement to aid STAs in making roaming decision
Mesh Discovery and Association :
Protocols to allow Mesh Points to discover Mesh Networks
Protocols to allow Mesh Points to associate with a Mesh Network
Protocols to allow Mesh Points to associate with other Mesh Points within a Mesh Network
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10. 802.11s—Functional Requirements and Scope (6)
Mesh Medium Access Coordination :
Mitigate performance degradation caused by hidden nodes/exposed nodes
Support of admission control
Support of congestion control
Improve spatial reuse
Management of multiple classes of traffic
Coordinating channel access across multiple nodes to avoid performance degradation
Mesh link communication coordination
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11. 802.11s—Functional Requirements and Scope (7)
Compatibility to Services :
Mesh Point DS Services integration
Mesh compatibility with STA mobility/roaming
Techniques to meet r system requirement
Interworking :
Interface with high level protocol
Interface with other IEEE 802 LANs
Mesh Configuration and Management :
Support for managed network management model
Support for unmanaged network management model
Self-configuration support
Information exchange about Capability information of Mesh Points
Mesh network channel selection
Support for time synchronization
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12. 802.11s –Usage Models (Potential Markets) 1
Residential.
Indoor environment.
Mesh point number: 8.
Easy Installation.
Coexistence with other Mesh networks/BSSs.
Office.
Mesh point number: 32.
Higher device density and bandwidth requirements as compared with campus networks.
Support unmanaged mode and central managed mode.
Campus/Community/Public Access Network.
Seamless connectivity over large geographic areas.
Mesh point number:
Provide alternatives to traditional internet access methods.
Centralized management.
Scalability, automatic reconfiguration and reliability.
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13. 802.11s –Usage Models (Potential Markets) 2
Public Safety
Semi-permanent infrastructure and Mobile mesh points coexist.
Mesh point number: 32.
Mostly outdoors.
Node mobility.
Dynamic variations in radio propagations.
Strong requirements of network self-configuration and self-management.
Military.
Sensitive to energy conservation.
STAs need to become mesh AP temporarily.
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14. 802.11s – Key Documents 11-04/54r2 “PAR for IEEE 802.11 ESS Mash”
11-04/56r1 “Five Criteria for IEEE ESS Mesh”
11-04/1174r13 “Functional Requirements and Scope”
11-04/1175r10 “Comparison Categories and Informative Checklists”
11-04/662r16 “Usage Models”
11-04/1477r4 “Terms and Definitions for s”
11-04/1430r12 “Call For Proposal”
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15. 802.11s – Major Deadlines
Those wishing to submit a proposal must send the TGS Chair a notice of intent to submit at the end of the Friday before the March 2005 Meeting.
11s will allocate some time for the voluntary preliminary presentation of proposals at the March and May Meetings.
All the proposals will be submitted and presented at the July 2005 meeting of
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16. 802.11s – ST Partial Proposal Admission Control Congestion Control
Neighbor-list LC-EDCA
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17. 802.11s –Admission Control(1)
Admission control is used for real-time traffic.
Admission control is done at the destination Mesh Point (MP).
A request message is used to get the available bandwidth of the selected path, and the requested bandwidth.
The destination decides if the request is admitted.
The forwarding information is established when the response message is sent back to the source MP.
The available bandwidth equals the difference between the total bandwidth allocated to the real-time traffic and the bandwidth used by the real-time traffic.
The bandwidth used by the real-time traffic at any node is measured based on the real-time packets the node detected.
To Internet
To Internet
Mesh
Portal
Mesh
Portal
Mesh
Point
Mesh
Point
Req
Mesh
Point
Req
Mesh AP
Rps
Rps
Mesh AP
STA
STA
STA
STA
STA
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18. 802.11s –Admission Control(2)
The reasons for re-admission control.
Node mobility
False admission.
The congested MP randomly selects some admitted traffic and notifies the source MP to request admission again.
To Internet
Mesh
Portal1
MAP2’s request is granted!
To Internet
Mesh
Portal2
Mesh
Point2
The available bw of MP1: 5Mbps
The available bws of other MPs: 10Mbps
The bw requested by MAP1:3Mbps
The bw requested by MAP2: 4Mbps
Rep(6)
Req(4)
Rep(8)
Mesh
Point3
Req(1)
Mesh
Point1
Req(2)
Rep(7)
Req(3)
Mesh
AP1
Mesh
AP2
Rep(5)
STA
STA
STA
STA
STA
MAP1’s request is granted!
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19. 802.11s—Congestion Control (1)
Actual Scheduling Result when load=700kb/s
e2e throughput
674k
449k
355k
235k
Congested nodes
238k
347k
450k
697k
Rx: k k k k 235k
Tx: k k k k k
Wasted TX
Ideal Scheduling, when the network is overloaded
430k
430k
430k
430k
430k
430k
430k
430k
e2e
throughput
Rx: k k k 860k 860k
Tx: k k k 860k 430k
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20. 802.11s—Congestion Control (2)
.11e Access Category-based congestion control
Each MP detects network congestion according to:
Delay.
Queue size.
Packet loss rate.
When congestion occurs, random early congestion notification information is sent to the source MP.
Source MP polices the packet transmission rate.
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21. 802.11s –Neighbor-list LC-EDCA(1)
Two mesh point priorities are used to lower the collision probability
Highest priority (transmit the first frame after a shorter IFS idle medium time)
Low priority (the standard EDCA medium access method is used)
A neighbor list is maintained in each STA
Each Mesh point allocates one weight to each of its neighbors
The TXOP owner (the highest or low priority mesh point) selects the next highest priority mesh point. This adds robustness and quick recovery in a scenario where packets are lost.
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22. 802.11s –Neighbor-list LC-EDCA(2)
The highest priority MPs
Services more than one Access Category
Gets the medium access right after the medium is idle for LCIFS
Switches to the low priority state when the LCTXOP ends
The last frame of its LCTXOP carries NHPM information
The low priority MPs
Use EDCA medium access method to access the medium
The last frame of a TXOP carries NHPM information
MP: Mesh Point
NHPM: Next Highest Priority MP
LCTXOP: LC-EDCA TXOP
LCIFS: LC-EDCA IFS
MP1
MP2
MP3
Nbr 1
(3,1)
(1,1)
(2,1)
Nbr 2
NHPM: 3
NHPM: 2
LCTXOP
LCTXOP
LCTXOP
MP_1
NHPM: 1
NHPM: 3
NHPM: 1
TXOP
LCTXOP
LCTXOP
MP_2
NHPM: 2
NHPM: 1
LCTXOP
LCTXOP
MP_3
LCIFS
LCIFS
LCIFS
LCIFS
LCIFS
LCIFS
LCIFS
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23. 802.11s –Neighbor-list LC-EDCA(3)
Neighbor-List LC-EDCA simulation results(1/2)
Scenario 1, Scenario 4 & Scenario 6 of 11n
PHY rate has been set to Mbps, and we simulated with a real channel as defined in slide 10.
Results have been obtained using both Continuation TXOP and MSDU aggregation (MPDU max size = 8K). Any Block Acknowledgement procedure has been disabled.
Results for low priority stations and TXOP-only simulations: TXOP[AC:0] = 1504; TXOP[AC:1] = 1504; TXOP[AC:2] = 6016; TXOP[AC:3] = For high priority LC-EDCA stations, TXOP = 6016.
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24. 802.11s –Neighbor-list LC-EDCA(4)
Neighbor-List LC-EDCA simulation results (1/2)
Scenario 1, Scenario 4 & Scenario 6 of 11n
PHY rate has been set to Mbps, and we simulated with a real channel as defined in slide 10.
Results have been obtained using both Continuation TXOP and MSDU aggregation (MPDU max size = 8K). Any Block Acknowledgement procedure has been disabled
Results for low priority stations and TXOP-only simulation: TXOP[AC:0] = 3008; TXOP[AC:1] = 3008; TXOP[AC:2] = 3008; TXOP[AC:3] = For high priority LC-EDCA stations, TXOP = 3008.
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25. Grazie, Merci, and Thank You for your attention!
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