1. doc.: IEEE 802.11-13/0720r1 SubmissionSlide 1 Date: 2013-07-16 Presenter: Spatial Sharing Mechanism in 802.11aj (60GHz) July 2013 Francois Chin

2. doc.: IEEE 802.11-13/0720r1 SubmissionSlide 2 Author List July 2013 Francois Chin

3. doc.: IEEE 802.11-13/0720r1 Submission Background: 802.11ad Beamforming TXSS Beamforming training in 802.11ad : there are two phases for the beamforming training described in IEEE 802.11ad specification [1]: Sector level sweep (SLS) and Beam Refinement Protocol (BRP). SLS consists of TX sector sweep (TXSS) and RX sector sweep (RXSS) Slide 3 PCP/AP  For the initial connection between two devices (Station (STA) and PBSS Control Point/Access Point (PCP/AP)), STA will receive with a quasi-omni- directional antenna while PCP sends a sequence of frames covering different TX sectors or vice versa. STA Figure 1. An example of TXSS Source: IEEE 802.11ad July 2013 Francois Chin

4. doc.: IEEE 802.11-13/0720r1 Submission Background: 802.11ad Beamforming RXSS Slide 4 Source: IEEE 802.11ad A device with a simple antenna may not have enough TX gain to reach a distant receiver that is using an omni-directional receiving antenna RX Sector Sweep may be employed by the device with the higher performance antenna system Allows a simple antenna device, like a handset, to connect at greater range Simple Antenna Device RX Sector Sweep is used to initiate beamforming on this link After the beamforming training, STAs know their best sector ID for transmission /reception Figure 2. An example of RXSS July 2013 Francois Chin

5. doc.: IEEE 802.11-13/0720r1 Submission Assume that beamforming training has been done: STAs know their best Sector ID for transmission The existing spatial sharing mechanism in [1]: Spatial sharing can only be done in Service Period (SP), not Contention Based Access Period (CBAP) Both existing SP and candidate SP need to perform measurement before usage The mechanism is not very efficient. From PCP/AP’s perspective, it is a blind selection process. Background: 802.11ad Spatial Sharing Mechanism Slide 5 Figure 3. Example of spatial sharing assessment July 2013 Francois Chin

6. doc.: IEEE 802.11-13/0720r1 SubmissionSlide 6 Proposed Method: A method to recommend an existing SP for spatial sharing with the new pair of devices with directional transmission –Existing SP has one or more pairs of devices with directional transmission, all spatial sharing Assumption: PCP/AP is updated with the beamforming training results between any two STAs, in terms of best selected sector IDs. Proposed Spatial Sharing Selection Method July 2013 Francois Chin

7. doc.: IEEE 802.11-13/0720r1 Submission Assumption: Each STA has 12 sectors with 30 degree transmission angel. The beamforming training results are shown in Table 1 and 2 PCP/AP has scheduled SP 1 and SP 2 for pair (A, B) and (C, D), respectively. Purpose: To recommend an initial SP for the candidate SP with pair (E, F) from the existing SP set {SP 1, SP 2 } for spatial sharing. Source device aDestination device bS(a, b) AB1 AE4 AF2 BA7 BE7 BF9 EA12 EB2 EF3 FA7 FB10 FE7 Table 1: Beamforming training results among {A, B, E, F} Table 2: Beamforming training results among {C, D, E, F} Source device aDestination device bS(a, b) CD10 CE8 CF12 DC4 DE5 DF3 EC4 ED1 EF3 FC6 FD9 FE7 Slide 7 Example – Spatial Sharing in 802.11ad Figure 4. An example of Spatial Sharing July 2013 Francois Chin

8. doc.: IEEE 802.11-13/0720r1 Submission First, PCP/AP uses Table 1 to check whether SP 1 is available for the candidate SP with pair (E, F). From Table 1, A and B choose Sector 1 and 7 (blue areas) to communicate with each other. E and F intend to use Sector 3 and 7, respectively. Neither E nor F would be affected by A, because the beamforming results show that the Sector 4 and 2 would be the best sector for A to transmit to E and F, respectively, which are different with Sector 1. The sector number difference between two best sectors S(A, B) and S(A, E), denoted by δ A → B, E, is calculated as 3; Similarly, δ A→B, F = 1. Thus, A’s transmission has no interference to E and F. However, if B is transmitting to A with Sector 7, E would be affected by B because the same Sector 7 is selected for B to transmit to A and E. In this case, δ B→A, E = 0. Therefore, the existing SP 1 does Not satisfy with the condition of spatial sharing with the candidate SP with pair (E, F). δ indicates the sector number difference between two best sectors S(a, b) and S(a, c) chosen by one source device a to two different destination devices b and c. Slide 8 Procedure of Initial Recommendation (1/2) Figure 4. An example of Spatial Sharing July 2013 Francois Chin

9. doc.: IEEE 802.11-13/0720r1 Submission Second, PCP/AP uses Table 2 to check whether SP 2 is available for the candidate SP with pair (E, F). Thus, we have δ C→D, E = 2 δ C→D, F = 2 δ D→C, E = 1 δ D→C, F = 1 δ E→F, C = 1 δ E→F, D = 2 δ F→E, C = 1 δ F→E, D = 2 Since the minimum value of the above δ’s is larger than 0, the existing SP 2 can be recommended as an initial SP for the candidate SP with pair (E, F). Slide 9 Procedure of Initial Recommendation (2/2) Finally, PCP/AP responds to E-F pair with the best initial recommendation of SP 2. Figure 4. An example of Spatial Sharing July 2013 Francois Chin

10. doc.: IEEE 802.11-13/0720r1 Submission The Condition for Spatial Sharing Spatial sharing condition: As long as any source STA involved in an existing SP does not employ the same transmit sector with the one that it employs to communicate with any other STA involved in a candidate SP, and vice versa, the PCP/AP may schedule this existing SP and the candidate SP time- overlapping with each other for spatial sharing. Furthermore, if a pair of existing SP and candidate SP satisfies the above condition, the larger the sector number difference δ, between any two of transmit sectors employed by a source STA to communicate with its destination STA and with any other STA involved in the other SP, the better chance to implement spatial sharing and interference mitigation among them. Therefore, the parameter δ is considered as the criteria of the selection for the best initial slot that can be scheduled slot or contention based slot. Slide 10 July 2013 Francois Chin

11. doc.: IEEE 802.11-13/0720r1 Submission The Flow Chart of Proposed Method Slide 11 Start End Y N Y N PCP/AP checks the next existing SP e for a candidate SP c with transmission pair (i, j) and set δ* e = 0; For each scheduled transmission pair (x, y) in this SP e Does any of the following cases occur between the intended transmission pair (i,j) and (x, y) ? S(x, i) == S(x, y) || S(x, j) == S(x, y) || S(y, i) == S (y, x) || S(y, j) == S(y, x) || S(i, x) == S(i, j) || S(i, y) == S(i, j) || S(j, x) == S(j, i) || S(j, y) == S(j, i) Calculate the values of δ If δ < δ* e δ* e = δ; Finish the traverse of the existing SP set {SP e }? Add SP e into initial recommendation set {SP e } with δ* e Finish the traverse of the scheduled transmission set {x, y} e in this SP e ? Y Search the best initial recommendation from {SP K } with the selection criteria of the largest δ* e N Figure 5. Flow chart of the proposed method for IEEE 802.11aj network July 2013 Francois Chin

12. doc.: IEEE 802.11-13/0720r1 Submission Benefits of Proposed Spatial Sharing Selection Method Accurate allocation of spatial sharing among pair of devices; Avoids unnecessary operation of measuring and report feedback among those pair of devices that may cause interference with each other if they transmit concurrently; Fast allocation of spatial sharing among pair of devices; Power saving of the resource allocation for the spatial sharing as it can significantly reduce the number of pair of devices that can be used for measuring and report feedback Slide 12 July 2013 Francois Chin

13. doc.: IEEE 802.11-13/0720r1 Submission Modifications to 802.11ad PCP/AP will be informed and updated of the results of the beamforming training among non-PCP/non-AP STAs. At the last step of beamforming phase, non-PCP/non-AP initiator (responder) shall notify PCP/AP through a SSW-Report frame which contains an SSW Report field indicating Source AID, Destination AID, Sector Select, DMG Antenna Select, SNR Report, etc.  The Source AID field identifies the transmitter that is the intended initiator (responder) of beamforming.  The Source AID field identifies the receiver that is the intended responder (initiator) of beamforming. Slide 13 Figure 6. SSW-Report frame format and Initiator (Responder) Link Report field July 2013 Francois Chin

14. doc.: IEEE 802.11-13/0720r1 Submission Conclusions Proposed a method to recommend an existing SP for spatial sharing with the new pair of devices with directional transmission –based on the priori information of beamforming training results among devices –Existing SP has one or more pairs of devices with directional transmission, all spatial sharing Proposed SSW-report frame format for non-PCP/non-AP STAs to report the results of the beamforming training, in terms of best sector IDs, to PCP/AP Slide 14 July 2013 Francois Chin

15. doc.: IEEE 802.11-13/0720r1 Submission Reference [1] IEEE P802.11ad TM -2012 Standard “Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications – Amendment 3: Enhancements for Very High Throughput in the 60 GHz band,” December 2012. Slide 15 July 2013 Francois Chin

16. doc.: IEEE 802.11-13/0720r1 SubmissionSlide 16 Thank YOU July 2013 Francois Chin