doc.: IEEE /0782r0 Submission July 2010 Daewon Lee, LG ElectronicsSlide 1 STA MU-MIMO Group Management Signaling Design Date: Authors:

doc.: IEEE /0782r0 Submission July 2010 Daewon Lee, LG ElectronicsSlide 2 Abstract We discuss on methods of MU-MIMO Group ID management and MAC signaling. We also give some options of MAC signaling design and compare properties of each option.

doc.: IEEE /0782r0 Submission Group ID extension [3] (1/4) Extend the Group ID concept in order to support larger number of STAs Extend PHY Group ID with (logical) MAC Grouping July 2010 Daewon Lee, LG ElectronicsSlide 3

doc.: IEEE /0782r0 Submission Group ID extension [3] (2/4) Gives the AP possibility to allocate and manage more combinations of STAs STA-A, STA-B, etc can correspond to MAC Address, Associated ID, or some other unique identifier If AP only operates the system with 1 MAC extended Group ID for a given PHY Group ID, then the operation should be equivalent to Group ID proposal in 11-10/0073r3 July 2010 Daewon Lee, LG ElectronicsSlide 4 STA A STA B STA C STA D STA A STA E STA F STA G STA H STA B STA F STA G... Group ID = xxx MAC Extended Group ID = aaaMAC Extended Group ID = bbbMAC Extended Group ID = ccc Multiple extended Group can be defined as long as relative position for a given STAs is not changed under PHY group ID = x

doc.: IEEE /0782r0 Submission Group ID extension (3/4) Example operation #1 (essentially Group ID based approach [2]) July 2010 Daewon Lee, LG ElectronicsSlide 5

doc.: IEEE /0782r0 Submission Group ID extension (4/4) Example operation #2 (essentially SS Paging ID based approach [1]) July 2010 Daewon Lee, LG ElectronicsSlide 6

doc.: IEEE /0782r0 Submission MAC Signal Field Design (1/4) Assuming multiple grouping of STAs for a given single Group ID, multiple methods of MAC signaling is possible MAC signaling methods can be classified depending on the size of the target entity –Option 1 : Signaling addressing entire (multiple ‘extended’ groups) grouping of STAs for a given Group ID –Option 2 : Signaling addressing a single ‘extended’ group of STAs for a given Group ID –Option 3 : Signaling addressing a single STA July 2010 Daewon Lee, LG ElectronicsSlide 7

doc.: IEEE /0782r0 Submission MAC Signal Field Design (2/4) Option 1 : Signaling addressing entire (multiple ‘extended’ groups) grouping of STAs for a given Group ID –Assuming Max 4 STAs per MU-MIMO transmission –Some restrictions of multiple STA signaling for different ‘extended’ group needed (possibly mandated in specification) –Total “1+6*N” bytes of information per signaling July 2010 Daewon Lee, LG ElectronicsSlide 8

doc.: IEEE /0782r0 Submission MAC Signal Field Design (3/4) Option 2 : Signaling addressing a single ‘extended’ group of STAs for a given Group ID –Assuming Max 4 STAs per MU-MIMO transmission –Total “6~7” bytes of information per ‘extended’ group signaling –Mechanism to allow multiple Group ID assignments may be needed e.g. if STA#a (pre) assigned with Group ID #1, receives MAC signaling with Group ID #1 without itself as NOT part of Group ID #1 still needs to retain pre-assignment of Group ID #1 July 2010 Daewon Lee, LG ElectronicsSlide 9

doc.: IEEE /0782r0 Submission MAC Signal Field Design (4/4) Option 3 : Signaling addressing a single STA –Flexibility of modifying/changing grouping of a single STA –No restriction of STA grouping necessary in specification (although probably needed in implementation) –3 Bytes per STAs July 2010 Daewon Lee, LG ElectronicsSlide 10

doc.: IEEE /0782r0 Submission Examples of Signaling Methods (1/2) Assuming AP needs to signal 2 groups (GroupID) with 8 extended groups each, with 4 STAs in each extended group. Also assume there is only 8 STA –Option 1 : 2 x ( 1 byte + 8 x 6 byte ) = 98 bytes –Option 3 : 2 x 8 x 3 byte = 48 byte July 2010 Daewon Lee, LG ElectronicsSlide 11

doc.: IEEE /0782r0 Submission Examples of Signaling Methods (2/2) Assuming AP needs to signal 4 groups (GroupID) with 6 extended groups each, with 4 STAs in each extended group. Also assume there is only 16 STA –Option 1 : 4 x ( 1 byte + 6 x 6 byte ) = 148 bytes –Option 3 : 2x16x3 byte = 96 bytes (may depend on exact grouping) July 2010 Daewon Lee, LG ElectronicsSlide 12

doc.: IEEE /0782r0 Submission Observations from examples If AP needs to signal large amounts of exclusive STA groups (i.e. groups of STA which do not have same STAs in each group) –Option 1 may save signaling overhead If AP needs to signal (extended) groups of STAs with overlapping STAs in each (extended) groups –Option 3 may save signaling overhead July 2010 Daewon Lee, LG ElectronicsSlide 13

doc.: IEEE /0782r0 Submission Signaling Flexibility Aspect Unicast and Broadcast of control elements –in general broadcast information is costly in terms of system throughput since lowest MCS needs to be used –in general it is inefficient to replicate information in unicast –if information element is self-contained so that information for different STAs does not necessary be multiplexed together then it would be possible for a given information element be transmitted in either unicast or broadcast In general having the possibility of modifying STA grouping per STA in unicast or broadcast been beneficial in terms of flexibility July 2010 Daewon Lee, LG ElectronicsSlide 14

doc.: IEEE /0782r0 Submission MAC Signal Field Design Observations General Observation –Single Group ID assignment MAC signaling field seems beneficial –Option 1 requires entire grouping assignment to be signaled when logical grouping of a single STA is needed (potential overhead) –Option 2 requires additional mechanisms or STA behaviors defined in order to efficiently support ‘extended’ groups –Option 3 seems to be most robust in terms of STA group assignment flexibility and overhead If the specification is to only support 1 method of Group ID assignment, then strongly propose option 3 to be the single candidate –Else the specification should at least support option 3 to be robust, additional signaling mechanisms could be considered further July 2010 Daewon Lee, LG ElectronicsSlide 15

doc.: IEEE /0782r0 Submission Summary MU-MIMO support will be the major differentiation between 11ac and 11n. MU-MIMO should be designed to support wide range of scenarios allowing optimization of MU-MIMO performance in different target usage scenarios It will be important to study further relations between grouping and sounding procedures needed for MU-MIMO transmissions Allowing AP to manage large pool of potential MU-MIMO capable STAs is needed Allow preemptive grouping of STA at the AP allows effective grouping management protocol and enhances overall MU-MIMO performance Propose to strongly consider Group ID extension methods in order to support efficient MU-MIMO operations Propose to support Group ID assignment signaling method ‘option 3’ in Framework document July 2010 Daewon Lee, LG ElectronicsSlide 16

doc.: IEEE /0782r0 Submission Strawpoll Do you support adopting Group ID management MAC signaling field as described in Slide 10 of r0 and editing the spec framework document, , accordingly? –Note this does not preclude the possibility of supporting additional Group ID management MAC signaling fields later in the specification.) –Yes –No –Abstain July 2010 Daewon Lee, LG ElectronicsSlide 17

doc.: IEEE /0782r0 Submission Reference [1] Lee D.W., et. al., “MU-MIMO STA scheduling strategy and Related PHY signaling,” IEEE /0362r02 [2] Kim J., et. al., “GroupID Concept for Downlink MU-MIMO Transmission,” IEEE /0073r02. [3] Lee D.W., et. al., “STA Group Management for MU-MIMO,” IEEE /581r00. July 2010 Daewon Lee, LG ElectronicsSlide 18