Proposed ERTS & ECTS Mechanisms Month 2000 doc.: IEEE 802.11-00/xxx March 2001 Proposed ERTS & ECTS Mechanisms Author: Matthew Sherman AT&T Labs - Research 180 Park Avenue Florham Park, NJ 07932 973-236-6791 mjsherman@att.com Date: March 12, 2001 Matthew Sherman, AT&T Labs - Research John Doe, His Company

Problem addressed 802.11e is developing mechanisms to support QoS Month 2000 doc.: IEEE 802.11-00/xxx March 2001 Problem addressed 802.11e is developing mechanisms to support QoS Many situations when the ability to cause groups of STA to cease transmissions would be useful Accommodate TBTT for Beacon transmission Accommodate protocol enhancements / coexistence HCF / Token passing schemes, Bluetooth, HIPERLAN, etc Hidden terminals Overlapped BSS mitigation Would like technique applied to also work with Legacy STA (LSTA) Would like ability to differentiate between Legacy and groups of 802.11e STA (ESTA) Matthew Sherman, AT&T Labs - Research John Doe, His Company

Approach to Problem Develop method to Set NAV in a STA group Month 2000 doc.: IEEE 802.11-00/xxx March 2001 Approach to Problem Develop method to Set NAV in a STA group Develop method to Reset NAV in a STA group Deferred to later 802.11 meeting Use existing frame formats as much as possible Enhances compatibility with LSTA Matthew Sherman, AT&T Labs - Research John Doe, His Company

Approach to Problem (Cont.) Month 2000 doc.: IEEE 802.11-00/xxx March 2001 Approach to Problem (Cont.) Play with usage / interpretation of RTS & CTS Later CF-End as well Have ESTA use Addresses for qualifiers and signaling Apply Duration field based on contents of Addresses Based signaling / qualifiers on Address types Unicast Multicast Broadcast Chose mappings that are consistent with current usage of address fields in standard Matthew Sherman, AT&T Labs - Research John Doe, His Company

Suggested ECTS Mechanisms Month 2000 doc.: IEEE 802.11-00/xxx March 2001 Suggested ECTS Mechanisms Enhance CTS (ECTS) usage to allow setting Duration/ID field to any valid Duration value Broadens context for Duration field use Enhance CTS usage to allow any valid address in RA field LSTA will always set NAV for duration indicated Rules for Compliant ESTA will vary (See Chart) Non-compliant ESTA act as LSTA Allow use of PIFS with this message for preferential media access (EAP / EPC only) Matthew Sherman, AT&T Labs - Research John Doe, His Company

Map of New Capabilities (CTS) Month 2000 doc.: IEEE 802.11-00/xxx March 2001 Map of New Capabilities (CTS) Message RA Effect (LSTA always set NAV) CTS Unicast Set NAV Unicast (Self) Multicast Set NAV if in Group Broadcast Set NAV if legacy Matthew Sherman, AT&T Labs - Research John Doe, His Company

Suggested ERTS Mechanism Month 2000 doc.: IEEE 802.11-00/xxx March 2001 Suggested ERTS Mechanism Enhance RTS (ERTS) usage to allow setting Duration/ID field to any valid Duration Broadens context for Duration field use Enhance RTS usage to allow group addresses in TA field LSTA will always set NAV for duration indicated Compliant ESTA do not set NAV if not in group Non-compliant ESTA act as LSTA ESTA forward CTS if addressed in RA Allow use of PIFS with this message for preferential media access (EAP / EPC only) Matthew Sherman, AT&T Labs - Research John Doe, His Company

Map of New Capabilities (RTS) Month 2000 doc.: IEEE 802.11-00/xxx March 2001 Map of New Capabilities (RTS) Message TA RA Effect on ESTA (LSTA always set NAV) RTS unicast1 Reserved unicast2 Set NAV, Respond CTS, Obey NAV for CTS multicast1 broadcast Set NAV if Group, send CTS to Group, ignore NAV for CTS multicast2 multcast1 Broadcast Matthew Sherman, AT&T Labs - Research John Doe, His Company

What Enhancements Accomplish Month 2000 doc.: IEEE 802.11-00/xxx March 2001 What Enhancements Accomplish If no LSTA Can set NAV independently in any group of ESTA Some ability to control remote groups via RTS/CTS relay Since can have “Group” of one, can set for single ESTA as well If LSTA are present Must treat as special case Always part of addressed group Matthew Sherman, AT&T Labs - Research John Doe, His Company

Comments on Mechanisms Month 2000 doc.: IEEE 802.11-00/xxx March 2001 Comments on Mechanisms No new frame formats required Fully backward-compatible Additional RTS mappings possible Open to other mappings Open to partial acceptance of mappings Implementation of mechanisms are optional Indicating support of mapping mandatory in ESTA Duration field in other frame types could also be used to reserve channel RTS/CTS seemed most appropriate Matthew Sherman, AT&T Labs - Research John Doe, His Company

Comments specific to Overlapped BSS Month 2000 doc.: IEEE 802.11-00/xxx March 2001 Comments specific to Overlapped BSS Goal of new mappings is to allow suppression of groups of terminals in overlap Technique assumes ability exists to assign terminals to groups Currently those techniques are considered beyond 802.11 Techniques are identified in 802.1 Best if applied with ability to solicit interference info from STA Which other STA are heard at what power level Mechanisms being developed using Generic Action Frame Existing proposed elements may need to be enhanced Matthew Sherman, AT&T Labs - Research John Doe, His Company

Example Applications of March 2001 Example Applications of New Mechanisms Matthew Sherman, AT&T Labs - Research

Example ECTS Usage Reduction of TBTT Overrun* Month 2000 doc.: IEEE 802.11-00/xxx March 2001 Example ECTS Usage Reduction of TBTT Overrun* ECTS B Prior TX PIFS TBTT NAV Set by Legacy STA Legacy Tx Suppressed ETx1 RA=Broadcast ETx2 ETxN * Assumes ESTA knows not to overrun TBTT ETxX are transmissions by ESTA Matthew Sherman, AT&T Labs - Research John Doe, His Company

Example ECTS Usage Sharing with Unknown Protocol Month 2000 doc.: IEEE 802.11-00/xxx March 2001 Example ECTS Usage Sharing with Unknown Protocol ECTS Prior Tx PIFS NAV Set by all STA Unsolicited Tx Suppressed Unknown or Foreign Protocol RA=Senders Address Duration Expires (NAV Resets) Matthew Sherman, AT&T Labs - Research John Doe, His Company

Example Usage - BSS Overlap* Month 2000 doc.: IEEE 802.11-00/xxx March 2001 Example Usage - BSS Overlap* Legend: Group 12 - ESTA in BSS1 that interfere with BSS2 Group 21 - ESTA in BS21 that interfere with BSS1 Tx12 - Transmissions from any BSS 1 STA Tx21 - Transmissions from any BSS 2 STA Tx1 - Transmission from BSS 1 STA not in overlap Tx2 - Transmission from BSS 2 STA not in overlap BSS2 BSS1 ECTS Tx2 RA=Group 21 BSS2 Group 21 Suppressed Tx to/from ESTA in overlap Tx12 RA=Group 12 Tx21 Tx1 BSS1 Group 12 Suppressed * Multicast addresses for groups 1 and 2 need not be assigned (Never necessary to suppress groups 1 or 2) Matthew Sherman, AT&T Labs - Research John Doe, His Company

Example Usage Hidden STA Suppression* Month 2000 doc.: IEEE 802.11-00/xxx March 2001 Example Usage Hidden STA Suppression* ECTS RA=Group A ERTS TA=Group A RA=RSTA Hidden Node Suppressed Hidden STA suppressed Continued Suppression * Assumes Hidden ESTA is only STA in group to begin with (Group A) Matthew Sherman, AT&T Labs - Research John Doe, His Company