1. MAC Protocol to Support Dynamic Bandwidth for 802.11aj (60GHz)
Sept 2012
doc.: IEEE /xxxxr0
July 2013
MAC Protocol to Support Dynamic Bandwidth for aj (60GHz)
Date:
Presenter:
Xiaoming Peng
Xiaoming Peng / I2R

2. Author List
July 2013
Xiaoming Peng

3. July 2013
Abstract
This document is to propose a channelization for China 60GHz frequency band for aj (60GHz)
This document is to propose a MAC protocol amendment to support dynamic bandwidth for aj (60GHz)
The proposed MAC protocol supports the backward compatibility with ad legacy device
This contribution has been discussed in CWPAN group
Xiaoming Peng

4. Highlight of The Main Changes
July 2013
Highlight of The Main Changes
Add Slide 13-14
To support network setup and operation in small band (e.g. Channel 5 or Channel 6) only.
Add Slide 15-18
To support interoperability with 11ad legacy devices.
Add Slide 22-23
To add two more study cases to support Mixed Mode with 11ad legacy devices.
Xiaoming Peng

5. Background: China 60GHz Spectrum
July 2013
The released 60GHz spectrum in China only has 5GHz bandwidth, corresponding to channel 2 & 3 used in IEEE ad.
USA, Canada, Korea
Europe
China
Japan
Australia
Unlicensed 60 GHz spectrum bands.
Xiaoming Peng

6. Proposed Channelization for 60GHz bands for 802.11aj (1/2)
July 2013
Proposed Channelization for 60GHz bands for aj (1/2)
Advantage of the proposed channelization for 60GHz bands in China
China only has 5GHz bandwidth available in 59-64GHz  only has two logical channels if only use 2.16 GHz BW
Further divide 2.16GHz band used in ad channelization into two 1.08GHz sub-bands, then it become 6 logical channels: 2 bands with 2.16GHz bandwidth (Channel 2 & 3), 4 bands with 1.08GHz bandwidth (Channel 5, 6, 7, 8)；
Channelization for 60GHz bands in China
Xiaoming Peng

7. Proposed Channelization for 60GHz bands for 802.11aj (2/2)
July 2013
Proposed Channelization for 60GHz bands for aj (2/2)
Support dynamic bandwidth  Capable of supporting wider applications for lower power, e.g. Smart Phone, Tablet etc.
The impact to implementation in RF, Analog baseband is very minimal. It only needs to add to support four more new center frequency in PLL design, a new filter to support 1.08GHz in analog baseband etc；
The support of dynamic bandwidth in the channelization for China 60GHz bands provides the basis of keeping the interoperability with ad device；
Channelization for 60GHz bands in China
Xiaoming Peng

8. MAC Protocol: Support Dynamic Bandwidth
Sept 2012
doc.: IEEE /xxxxr0
MAC Protocol: Support Dynamic Bandwidth
July 2013
Proposed MAC Protocol amendment for aj: support dynamic bandwidth and keep interoperability with ad
When operating in 2.16GHz channel（Channel 2,3)，it is capable of keeping interoperability with ad device；
When operating in 1.08GHz（Channel 5,6,7,8），it sends common beacon over 2.16GHz channel. The common beacon can use ad beacon as baseline so that ad device can also recognize the common beacon;
This allows aj device to keep the interoperability with ad device while exploring the benefits in channels with 1.08GHz bandwidth.
Revised 60GHz Channelization
Common Beacon
(e.g., ad DMG Beacon frames)
Proposed frame structure for IEEE aj
Xiaoming Peng
Xiaoming Peng / I2R

9. Proposed MAC Protocols (1)
Sept 2012
doc.: IEEE /xxxxr0
July 2013
Proposed MAC Protocols (1)
Support that PCP/AP 1 operates in Channel 2 with 3 devices (STA 1, STA 2 and STA 3)
STA (to become PCP/AP 2) wants to share Channel 2
STA (to become PCP/AP 2) may join PCP/AP 1’s network and send a Channel Split Request frame for the split of Channel 2.
Order
Information 1
Category 2
DMG Action 3
Dialog Token 4
Channel Switch Announcement element
Channel Split Request frame Action field format
Xiaoming Peng
Xiaoming Peng / I2R

10. Proposed MAC Protocols (2)
Sept 2012
doc.: IEEE /xxxxr0
July 2013
Proposed MAC Protocols (2)
If PCP/AP 1 agrees to split Channel 2
PCP/AP 1 replies a Channel Split Response frame to the STA (to become PCP/AP 2).
PCP/AP 1 informs other STAs through a Channel Switch Announcement element contained in DMG Beacon/Announce frames .
PCP/AP 1 proceeds to split Channel 2
Order
Information 1
Category 2
DMG Action 3
Dialog Token 4
Channel Splitting field 5
Beacon Interval field (optional) 6
Channel Switch Announcement element (optional) 7
Extended Schedule element (optional)
Channel Split Response frame Action field format
Proposed Frame Structure to support Dynamic Bandwidth for aj
Xiaoming Peng
Xiaoming Peng / I2R

11. Proposed MAC Protocols (3)
Sept 2012
doc.: IEEE /xxxxr0
July 2013
Proposed MAC Protocols (3)
After the split of Channel 2 into Channel 5 and Channel 6,
PCP/AP 1 sends out common DMG beacons in Channel 2 during NP1 to announce its operation and shows its channel bandwidth status (using the reserved B45-46 to indicate Channel Bandwidth info) contained in Beacon Interval Control field).
Following which PCP/AP 2 (The STA become PCP/AP 2) sends out common DMG beacon in Channel 2 during NP2 to announce its operation and shows its channel bandwidth status .
PCP/AP 1 and PCP/AP 2 each creates a quiet period (QP) in their respective networks.
PCP/AP 2 synchronizes with PCP/AP 1 by receiving the time stamps in PCP/AP 1’s common DMG beacons in its BTI.
Non-AP/non-PCP STAs continue their packet transmissions in small band network in Channel 5 after tuning in and receiving the DMG Beacon frames sent out by PCP/AP 1 in its BTI, coupled with the necessary procedures like beamforming, associations and new schedules for service periods (SPs) and contention-based periods (CBAPs).
Non-AP/non-PCP devices STAs that want to join the network in Channel 6 have to tune in and receive DMG Beacon frames sent by PCP/AP 2 in its BTI, coupled with the necessary procedures.
Xiaoming Peng
Xiaoming Peng / I2R

12. Proposed MAC Protocols (4)
July 2013
Proposed MAC Protocols (4)
Constant monitoring of Channel 2 common DMG beacons sent out by PCP/APs 1 and 2 in NP1 and NP2, respectively.
Assume Channel 6 ceases its network operation.
Absence is noted by PCP/AP 1 when it detects no common DMG beacon frames sent during NP1.
PCP/AP 1 shall wait for a aMaxExpireDuration duration before making the decision that Channel 6 network has ceased operation.
Case 1: After which, the PCP/AP 1 can proceed to expand its bandwidth from Channel 5 to Channel 2 (see the following figure), or
Case 2: After which, the PCP/AP1 can proceed to remain its operation in Channel 5.
Xiaoming Peng

13. Proposed MAC Protocols (5)
July 2013
Proposed MAC Protocols (5)
Suppose that PCP/AP 1 starts up or operates in the small band, e.g., Channel 5. To mitigate interference, PCP/AP 1 must periodically send notification signals during notification periods (NPs) on Channel 2.
Each NP contains at least a beacon header interval (BHI) which may include beacon transmission interval (BTI), association beamforming training (A-BFT) and / or announcement transmission interval (ATI) as shown in the following figure.
Xiaoming Peng

14. Proposed MAC Protocols (6)
July 2013
Proposed MAC Protocols (6)
Later, a new PCP/AP 2 intends to start its network in the adjacent Channel 6.
First, PCP/AP 2 scans the channel to know whether Channel 6 is empty or not.
If Channel 6 is available, PCP/AP 2 will send a Channel Request frame to PCP/AP 1 for NP allocation. 
PCP/AP 1 may reject the PCP/AP 2 request if another network has been successfully established in Channel 6. Otherwise, PCP/AP 1 should accept PCP/AP 2 request through a Chanel Response frame.
PCP/AP 1 shall allocate a pseudo-static SP for the NP of PCP/AP 2 (i.e., BHI 2) on Channel 2 through an Extended Schedule element.
Xiaoming Peng

15. Backward Compatibility of IEEE 802.11aj
July 2013
Backward Compatibility of IEEE aj
[3] has described “Backward Compatibility Feature for aj”
Legacy Mode
Case 1: An IEEE ad device scans to find an available large band and starts its network as normal ad device.
Case 2: An IEEE ad device scans to find an IEEE802.11ad or IEEE aj network operating in the large band and joins as a non-PCP/non-AP STA.
Mixed Mode
Support the backward compatibility for IEEE ad devices when IEEE aj networks are operating in small bands.
Xiaoming Peng

16. July 2013
Mixed Mode (1/3)
Case 1: Suppose that only PCP/AP 1 operates in Channel 5 while Channel 6 is empty.
If an ad legacy device requests to join, aj PCP/AP 1 may change its channel to Channel 2 first, and then operate like ad PCP/AP and accept ad legacy device as non-PCP/AP STA
PCP/AP 1 may also decide to operate in Channel 5 and allocate SPs or CBAPs to ad legacy device in Channel 2 through DMG Beacon or Announce frames as show in the following figure.
To distinguish different channel bandwidths, we use the reserved Bit 5 of the Allocation Type field to indicate allocation type, which supports the backward compatibility to IEEE ad devices.
Bit 4
Bit 5
Bit 6
Meaning
SP allocation in large band 1
SP allocation in the small band
CBAP allocation in large band
CBAP allocation in small band
All other combinations
Reserved
Xiaoming Peng

17. July 2013
Mixed Mode (2/3)
Case 2 : Both Channel 5 and 6 are occupied by PCP/AP 1 and PCP/AP2, respectively.
Suppose that 11ad legacy STA A intends to join in PCP/AP 1’s network.
PCP/AP 1’s allocations for STA A must abide by TWO conditions:
No overlaps with the existing allocations either in large band or in small bands.
PCP/AP 2 shall avoid to schedule the allocations time-overlapping with that of STA A.
The mixed mode works as below:
First, PCP/AP 1 shall hear the latest DMG Beacon or Announce frames or directly request PCP/AP 2 to reply with Extended Schedule elements .
Second, PCP/AP 1 schedules the allocations for STA A and may notify the result to PCP/AP 2 through an Allocation Request frame.
Third, PCP/AP 2 may reply with an Allocation Grant frame to grant this schedule or not.
Lastly, PCP/AP 1 sends the schedule result to STA A (and PCP/AP 2) through Extended Scheduling element transmitted in DMG Beacon or Announce frame.
Xiaoming Peng

18. July 2013
Mixed Mode (3/3)
Case 3: Suppose that only PCP/AP 1 operates in Channel 5 and has scheduled the allocations for ad legacy devices within Channel 2.
In this case, another PCP/AP 2 that intends to start up will know that Channel 6 is empty.
PCP/AP 2 follows the same procedures in Slide 14 to establish its BSS in Channel 6.
Since PCP/AP 2 has received the Extended Schedule element through the Beacon/Announce frames transmitted by PCP/AP 1, it will avoid to schedule its SPs or CBAPs that would overlap with the allocations for ad legacy devices in the following medium time.
Xiaoming Peng

19. Case Study A: Support Dynamic Bandwidth
July 2013
Case Study A: Support Dynamic Bandwidth
Case A: Two PCP/APs operate in two adjacent small bands within the same large band.
Xiaoming Peng

20. Case Study B: Support Dynamic Bandwidth
July 2013
Case Study B: Support Dynamic Bandwidth
Case B: Only one PCP/AP operates in a small band when the adjacent small band is unoccupied.
Xiaoming Peng

21. Case Study C: Support Dynamic Bandwidth
July 2013
Case Study C: Support Dynamic Bandwidth
Case C: Only one PCP/AP operates in a large band when the large band is available.
This is similar to ad
Xiaoming Peng

22. Case Study D: Mixed Mode
July 2013
Case Study D: Mixed Mode
Case D: Only one PCP/AP operates in a small band when the adjacent small band is unoccupied.
In this case, IEEE ad devices join as non-PCP/non-AP STAs.
Xiaoming Peng

23. Case Study E: Mixed Mode
July 2013
Case Study E: Mixed Mode
Case E: Two PCP/APs operate in two adjacent small bands within the same large band.
In this case, IEEE ad legacy devices join one of BSSs as non-PCP/non-AP STAs.
Xiaoming Peng

24. July 2013
Conclusion
This presentation proposed a channelization for China 60GHz frequency band for aj (60GHz)
This presentation proposed a MAC protocol amendment to support dynamic bandwidth for aj (60GHz)
The proposed MAC protocol supports the backward compatibility with ad legacy devices
Xiaoming Peng

25. July 2013
Reference
[1] r0 - Physical Channel Consideration for Chinese 60GHz band [2] r0 - Proposal of Channelization for aj [3] r1 - Backward Compatibility Feature for aj [4] r9 - IEEE aj PAR [5] r7 - IEEE aj 5C
Xiaoming Peng

26. July 2013
Thank YOU
Xiaoming Peng