Proposal for ESS Mesh Date: 2005-03-16 Authors: doc.: IEEE 802.11-05/0165r0 March 2005 March 2005 Proposal for ESS Mesh Date: 2005-03-16 Authors: Notice: This document has been prepared to assist IEEE 802.11. 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 grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.11. Patent Policy and Procedures: The contributor is familiar with the IEEE 802 Patent Policy and Procedures <http:// ieee802.org/guides/bylaws/sb-bylaws.pdf>, including the statement "IEEE standards may include the known use of patent(s), including patent applications, provided the IEEE receives assurance from the patent holder or applicant with respect to patents essential for compliance with both mandatory and optional portions of the standard." Early disclosure to the Working Group of patent information that might be relevant to the standard is essential to reduce the possibility for delays in the development process and increase the likelihood that the draft publication will be approved for publication. Please notify the Chair <stuart.kerry@philips.com> as early as possible, in written or electronic form, if patented technology (or technology under patent application) might be incorporated into a draft standard being developed within the IEEE 802.11 Working Group. If you have questions, contact the IEEE Patent Committee Administrator at <patcom@ieee.org>. SongYean Cho, Samsung Electronics. Steven Conner, Intel Corp.

Contents What is ESS Mesh? ESS Mesh Architecture doc.: IEEE 802.11-05/0165r0 March 2005 March 2005 Contents What is ESS Mesh? ESS Mesh Architecture ESS Mesh Functional Components Possible Directions for ESS Mesh SongYean Cho, Samsung Electronics. Steven Conner, Intel Corp.

What is ESS Mesh? Extended Service Set (ESS) What does ESS provide? doc.: IEEE 802.11-05/0165r0 March 2005 March 2005 What is ESS Mesh? Extended Service Set (ESS) A set of one or more Basic Service Sets (BSSs) interconnected by Distribution System (DS) What does ESS provide? ESS enables the MAC to transport MSDUs between stations that are not in direct communication with each other over a single instance of the wireless medium through Distributed System Service (DSS) SongYean Cho, Samsung Electronics. Steven Conner, Intel Corp.

doc.: IEEE 802.11-05/0165r0 March 2005 March 2005 Distributed System Transport of MSDUs (unicast, broadcast, multicast) transparently to upper layers : between stations in the same BSS - IntraBSS between the access points (APs) in ESS - InterBSS between portals and BSSs in ESS STA1 STA 2 STA 3 STA 4 MSDU STA 5 MSDU Logical Link Layer 802.11 MAC /PHY AP AP 802.11 MAC /PHY Portal DSS DSS ESS BSS 1 BSS 2 DS 802.x LAN SongYean Cho, Samsung Electronics. Steven Conner, Intel Corp.

Distributed System Services doc.: IEEE 802.11-05/0165r0 March 2005 March 2005 Distributed System Services Service Description Association The service to establish access point/station (AP/STA) mapping and to enable STA to invocate the distribution system services (DSSs) Authentication The service to establish the identity of one station as a member of the set of stations authorized to be associated with another station Deauthentication The services to void an existing authentication relationship Disassociation The service to remove an existing association relationship Reassociation The service to enable an established association relationship Distribution The service to deliver MSDUs in DS Integration The service to deliver MSDUs between DS and existing, non-IEEE 802.11 LAN via Portal 1 2 3 4 5 6 7 SongYean Cho, Samsung Electronics. Steven Conner, Intel Corp.

Distributed System Services (cont’d) doc.: IEEE 802.11-05/0165r0 March 2005 March 2005 Distributed System Services (cont’d) STA1 STA 2 STA 3 STA 4 STA 5 Logical Link Layer Mesh AP Mesh AP Mesh Portal 1 1 DSS 1 1 1 ( Wired  Wireless ) Parts to be changed DSS 2 2 2 2 2 ESS 3 3 3 3 3 DS 4 4 4 4 4 5 5 6 6 5 5 5 6 7 BSS 1 BSS 2 802.x LAN 802.11 MAC /PHY 802.11 MAC /PHY SongYean Cho, Samsung Electronics. Steven Conner, Intel Corp.

ESS Mesh LAN Architecture doc.: IEEE 802.11-05/0165r0 March 2005 March 2005 ESS Mesh LAN Architecture Router Extended Service Set Bridge Mesh Portal + Mesh AP Mesh Point 802.11 AP STA 802.11 MESH Mesh Point Mesh Link BSS Mesh AP STA BSS Mesh AP STA BSS Mesh AP SongYean Cho, Samsung Electronics. Steven Conner, Intel Corp.

Interoperability Mesh Points doc.: IEEE 802.11-05/0165r0 March 2005 Mesh Portal + Mesh AP + Mesh AP + Interoperability 802.X BSSs Connected by Wireless DS Mesh Points SongYean Cho, Samsung Electronics. Steven Conner, Intel Corp.

802.11s Mesh Functional Elements doc.: IEEE 802.11-05/0165r0 March 2005 March 2005 802.11s Mesh Functional Elements Mesh Internetworking Mesh Config. and Mgmt. Compatibility to 802.11 Services Mesh Topology Learning, Routing, and Forwarding Mesh Discovery and Association Mesh Security Mesh Medium Access Coordination Mesh Measurement SongYean Cho, Samsung Electronics. Steven Conner, Intel Corp.

Possible Directions for ESS Mesh doc.: IEEE 802.11-05/0165r0 March 2005 March 2005 Possible Directions for ESS Mesh Enhanced MAC Multi-channel support Discovery and Association for ESS Mesh Support passive and active discovery mechanism Routing and Forwarding Layer 2 Routing Efficient Route Building among Mesh Point, Mesh AP and Mesh Portal Minimized cost to route STAs through Mesh AP and Mesh Portal Flexible path selection for Usage Model Enhanced Security SongYean Cho, Samsung Electronics. Steven Conner, Intel Corp.

Multi-Channel Support doc.: IEEE 802.11-05/0165r0 March 2005 March 2005 Multi-Channel Support Why Multi-Channels? To exploit orthogonal multiple channels - 3 channels in 802.11b - 12 channels in 802.11a To improve throughput - Allow simultaneous transmission How to Use Multi-Channels? By extending 802.11 DCF to accommodate multi-channel support By enabling mesh points to listen to others through different channels By tuning trade off between - Reducing interference - Maximizing channel utilization Y X Q Z defer Y X Q Z Single channel Multiple channels SongYean Cho, Samsung Electronics. Steven Conner, Intel Corp.

Routing Considerations doc.: IEEE 802.11-05/0165r0 March 2005 March 2005 Routing Considerations Reactive Update routing info only when it is needed Pros: Low control overhead for routing with spares and little traffic  but unbounded Cons: High route acquisition latency Frequent control msg flooding with high mobility and variable traffic pattern and peers Weak : Distributed & short lived traffic Strong : Mobility & network size Proactive Periodically update routing info among Mesh Point, Mesh AP, Mesh Portal Pros: Global topology Low latency Easy QoS support Cons: Large routing table High control overhead for routing  but bounded cost Weak : Mobility, network size Strong : Distributed traffic pattern ESS Mesh  Low mobility & moderate network size & distributed traffic patterns Proactive is beneficial SongYean Cho, Samsung Electronics. Steven Conner, Intel Corp.

Proactive Routing for ESS Mesh doc.: IEEE 802.11-05/0165r0 March 2005 March 2005 Proactive Routing for ESS Mesh Main Actions to Select Routes among Mesh Points, Mesh APs, Mesh Portals Sensing neighbor Mesh Point (or Mesh AP) Advertising topology information periodically Minimized info enough to select routing path Minimized forwarding enough to reach all nodes Computing routes based on the known topology Main Advantages Shorter topology information message Less forwarding of topology information message Tolerant to loss of topology information message Stable as link state routing SongYean Cho, Samsung Electronics. Steven Conner, Intel Corp.

Types of Communications in ESS doc.: IEEE 802.11-05/0165r0 March 2005 March 2005 Types of Communications in ESS 1 Mesh AP A Supported Communication Peers Through Mesh Points and Mesh APs - Mesh Point vs. Mesh Point - Mesh Point vs. STA with a Mesh AP - STA vs. STAs with a Mesh AP Through Mesh Portals - Mesh Point vs. STA with an 802.11 AP - STA in a Mesh AP vs. STA with a 802.11 AP Mesh Point A 3 STA 2 802.11 MAC/PHY BSS 2 Wireless Distribution System Mesh Point B STA 1 802.11 MAC/PHY Mesh Point C Mesh Portal bridge Mesh AP B Bound the Cost to Support All Types of Communication in ESS Mesh Size of forwarding table in ESS Mesh Time to process the data frame STA 6 802.X MAC/PHY 802.11 Portal BSS 5 4 STA 3 802.11 MAC/PHY 802.11 AP 4 STA 4 802.11 MAC/PHY 802.11 MAC/PHY BSS STA 5 6 STA 6 802.11 MAC/PHY SongYean Cho, Samsung Electronics. Steven Conner, Intel Corp.

Flexible Path Selection doc.: IEEE 802.11-05/0165r0 March 2005 March 2005 Flexible Path Selection Path Selection based on Quality Defining the parameters for link quality measurement Distributing measured values within ESS Mesh Computing path quality based on measured values Path Selection based on DCS Distributing information on channel usage Negotiating channels to be used Selecting channels to be used Adaptable to Usage Scenarios SongYean Cho, Samsung Electronics. Steven Conner, Intel Corp.

Enhanced Security Built on 802.11i security Enhanced Security March 2005 Enhanced Security Built on 802.11i security Utilizing existing mechanism for STA to AP security Existing mechanism only address STA to AP security Enhancement needed to address security between mesh points Enhanced Security Network topology and routing information protection Security between mesh points (e.g. APs) via authentication, key management, and protection of control message and data SongYean Cho, Samsung Electronics.

Summary ESS Mesh is about : Possible Directions for ESS Mesh doc.: IEEE 802.11-05/0165r0 March 2005 March 2005 Summary ESS Mesh is about : Connecting BSSs (Mesh AP + STA) Including Mesh Points Including STAs in 802.X through Mesh Portals Possible Directions for ESS Mesh Multi-channel support Proactive Routing for Mesh Flexible Path Selection Enhanced Security SongYean Cho, Samsung Electronics. Steven Conner, Intel Corp.