Directed Multicast Service (DMS) Month Year Month Year doc.: IEEE 802.11-yy/xxxxr0 doc.: IEEE 802.11-yy/xxxxr0 September 2008 Directed Multicast Service (DMS) Authors: Date: 2008-9-9 Slide 1 Emily Qi (Intel Corp) et al Page 1 Emily Qi John Doe, Some Company

Directed Multicast: Motivation Month Year Month Year doc.: IEEE 802.11-yy/xxxxr0 doc.: IEEE 802.11-yy/xxxxr0 September 2008 Directed Multicast: Motivation Enable aggressive and flexible client power saving Sleeping STA doesn’t need to wake up at every DTIM or FBMS interval to receive multicast frames Sleeping STA only need to wake up to check AID TIM bit at a desirable interval (e.g. listen interval) Other benefits: Protect directed multicast by using the client’s negotiated Pairwise cipher with the AP Today, multicast is protected by the lowest common (or open) authentication Enable reliable service Unicast is more reliable than multicast Slide 2 Emily Qi (Intel Corp) et al Page 2 Emily Qi John Doe, Some Company

Directed Multicast Service (DMS) Overview Month Year Month Year doc.: IEEE 802.11-yy/xxxxr0 doc.: IEEE 802.11-yy/xxxxr0 September 2008 Directed Multicast Service (DMS) Overview STA advertises Directed Multicast Service (DMS) Capability Non-AP STA sends a request to specify traffic classes (i.e multicast address) for the directed multicast traffic delivery AP may accept or reject the traffic class specified by the non-AP STA If the service is accepted by the AP, AP shall transmit the requested group addressed (multicast) traffic as the individual addressed (unicast) traffic to the requesting STA in an A-MSDU frame format, and AP may still transmit the group addressed traffic for other STAs within the multicast group in the BSS as normal. The requesting STA shall discard group addressed frame that matches a multicast address entry of the list. Other STAs will process group addressed traffic as normal. See doc 08/0050r3 Slide 3 Emily Qi (Intel Corp) et al Page 3 Emily Qi John Doe, Some Company

DMS Request and Response frames Month Year doc.: IEEE 802.11-yy/xxxxr0 September 2008 DMS Request and Response frames DMS Request frame: Category Action Dialog Token Request Type (“Add” or “Remove”) DMS Descriptor List Octets: 1 variable DMSID Length TCLAS Elements (optional) TCLAS Processing Element (optional) Octets: 1 variable 3 DMS Descriptor DMS Response frame: Category Action Dialog Token DMS Status List Octets: 1 DMS Status DMSID DMS Status Octets: 1 Emily Qi (Intel Corp) et al Slide 4 Emily Qi

A-MSDU is used for Directed Multicast June 2007Month Year Month Year doc.: IEEE 802.11-yy/xxxxr0 doc.: IEEE 802.11-yy/xxxxr0 September 2008 A-MSDU is used for Directed Multicast Original destination address (DA) is transmitted in A-MSDU subframe header (the DA field) The DA and SA fields of the A-MSDU subframe header contain the values passed in the MA-UNITDATA.request and MA-UNITDATA.indication primitives. (e.g. DA=multicast address) RA (Address 1) in the MAC header is set to the requesting non-AP STA address Support of A-MSDU processing is mandatory according to the IEEE 802.11n specification. Emily Qi (Intel Corp) et al Zhen Xie, Atheros, et al.John Doe, Some Company Page 5 Zhen Xie, Atheros, et al.John Doe, Some Company Emily Qi

Question 1: Directed Multicast is not scalable Month Year Month Year doc.: IEEE 802.11-yy/xxxxr0 doc.: IEEE 802.11-yy/xxxxr0 September 2008 Question 1: Directed Multicast is not scalable Not scalable DMS provides power saving and same level of reliability as unicast for traffic classes, at the cost of bandwidth Solutions Limit the service for less than x associated STAs Enable this feature in the environment with less than x associated STAs, for example, home environment Allow AP to disable/reject this service when the limit is reached Again this is an optional feature. Slide 6 Emily Qi (Intel Corp) et al Page 6 Emily Qi John Doe, Some Company

Month Year doc.: IEEE 802.11-yy/xxxxr0 September 2008 Question 2: TGv vs. TGaa The issue was raised that Directed Multicast proposal may overlap with TGaa Scope: “Improved link reliability and low jitter characteristics for multicast/broadcast audio/video streams.” DMS should be considered in TGv: DMS adds to existing multicast enhancements in TGv, naturally fits in TGv; DMS addresses TGv objective [Req 2120] Including DMS in TGv can benefit low bandwidth applications sooner Including DMS in TGv should also benefit TGaa Straw Poll taken in the May TGv/TGaa joint meeting: Directed multicast proposal (08-0049)should be considered in: TGv:25; TGaa:8; abstain: 8 Emily Qi (Intel Corp) et al Emily Qi

Other Questions? September 2008 Month Year doc.: IEEE 802.11-yy/xxxxr0 Slide 8 Emily Qi (Intel Corp) et al Emily Qi

Existing Multicast Enhancements in TGv Month Year Month Year doc.: IEEE 802.11-yy/xxxxr0 doc.: IEEE 802.11-yy/xxxxr0 September 2008 Existing Multicast Enhancements in TGv FBMS – Flexible Broadcast/Multicast Service Enables flexible delivery interval for broadcast/multicast as STA’s request (at multiples of the DTIM intervals) Enables group addressed frames to be transmitted at higher data rates, reducing the amount of basic rate traffic sent over the radio link. Multicast Diagnostics Reporting STA provides the AP an indication of the number of dropped group addressed frames in order to enable reliable service DMS adds to existing multicast enhancements in TGv, naturally fits in TGv Slide 9 Emily Qi (Intel Corp) et al Page 9 Emily Qi John Doe, Some Company

DMS and 802.11aa targets different applications space Month Year doc.: IEEE 802.11-yy/xxxxr0 September 2008 802.11aa Requirements Reliable Multicast is a complex problem, and different applications may require different solutions. DMS provides same level of reliability as unicast for all traffic classes, at the cost of bandwidth Directed multicast can be used while streaming a multicast Standard Definition (SD) stream to 2 or 3 STAs, it does not scale well for High Definition (HD) video streaming. 802.11aa targets B/M robustness (reliability is a part of robustness) for HD video streaming (high bandwidth) applications .11n is sufficient for Standard Definition video streaming DMS targets low bandwidth applications, which is not the target of 802.11aa DMS and 802.11aa targets different applications space Emily Qi (Intel Corp) et al Emily Qi

DMS should be considered in TGv Month Year doc.: IEEE 802.11-yy/xxxxr0 September 2008 DMS should be considered in TGv DMS addresses TGv objective [Req 2120], complements TGv FBMS FBMS provides power saving for TGv devices. However, the legacy device (non-TGv device) within the BSS will experience unexpected B/M delivery delay. DMS provides power saving for TGv devices without introducing latency on the legacy (non-TGv) device. However, its usage is limited to a small number of associated STAs due to bandwidth requirements. Including DMS in TGv can benefit low bandwidth applications sooner TGv is in the process of initial ballots, expected sponsor ballot in Jan-09 TGaa is at the stage of calling for proposals, expected sponsor ballot Nov-10 Including DMS in TGv should also benefit TGaa All features (e.g. DMS) specified in the existing draft standard and draft amendments (e.g. TGv) can be utilized by later amendments (e.g. TGaa) Emily Qi (Intel Corp) et al Emily Qi