1. Centralized Clustering Resolution to CID 127
Month Year
doc.: IEEE yy/xxxxr0
March 2014
Centralized Clustering Resolution to CID 127
Date:
Presenter:
Dejian Li
John Doe, Some Company

2. March 2014
Author List
Dejian Li

3. Fujitsu Research & Development Center /CWPAN
Author List
March 2014
Name
Company
FAN Xiaojing
Fujitsu Research & Development Center /CWPAN
WANG Hao
wangh.cn.fujitsu.com
TIAN Jun
tianjun.cn.fujitsu.com
Dejian Li

4. March 2014
Abstract
This is a submission for comment resolution on D0.01 for comment #127. This submission provides a centralized CDMG PCP/AP clustering mechanism for 11aj to improve spatial sharing and increase sleep chances for the PCP during SP. The centralized CDMG PCP/AP clustering mechanism keeps backward compatibility with DMG devices.
Dejian Li

5. Centralized PCP/AP Clustering in 11ad
Month Year
doc.: IEEE yy/xxxxr0
March 2014
Centralized PCP/AP Clustering in 11ad
Centralized PCP/AP clustering is where there can be multiple S-APs in the BSA of any one S-AP, and all S-APs are coordinated via a single centralized coordination service set (CCSS).
A CCSS comprises a centralized coordination service root (CCSR) and a set of one or more synchronization APs (S-APs).
The CCSR is the entity that provides coordination services for the CCSS to minimize interference, such as provides to each S-AP the Cluster Time Offset availability information from nearby co-channel S-APs (see Annex Y).
Dejian Li
John Doe, Some Company

6. Centralized PCP/AP Clustering in 11ad
March 2014
Centralized PCP/AP Clustering in 11ad
Cluster formation (see )
In order to become a member PCP/AP after receiving a DMG Beacon of an S-AP, a PCP/AP can monitor the channel for DMG Beacon frames during each Beacon SP.
If an empty Beacon SP is discovered, the PCP/AP can join the cluster.
Cluster maintenance
In the case when a member PCP/AP has not received DMG Beacon frames from its S-AP for a duration exceeding 4×aMinBTIPeriod (16) beacon intervals, the PCP/AP shall either
Stop the current BSS then become an S-AP within the CCSS as described in ; or
Monitor the channel for DMG Beacon frames for an interval of length at least aMinChannelTime.
Dejian Li

7. Problems of Cluster Formation
March 2014
Problems of Cluster Formation
The centralized PCP/AP clustering in 11ad is designed for the co-channel PCPs/APs, thus can not be used directly by 11aj.
The firstly discovered co-channel PCP/AP cluster may not be appropriate to join due to locations.
The signal quality of the S-AP may be poor;
The PCP/AP identifies that it can not receive the CDMG Beacons of many member PCPs/APs.
Dejian Li

8. Centralized Cluster formation for 11aj
March 2014
Centralized Cluster formation for 11aj
The channels that are frequency overlapped should be grouped into one set, such that the CCSR can configure and coordinate a 1.08GHz S-AP and a 2.16GHz S-AP like they are operating on the same channel.
The available channel set for centralized CDMG PCP/AP cluster is {3, 7, 8}, since channel 2 is in the excluded channel list in 11ad.
Available channels for CDMG ECPAC
Extend the coordination functions of CCSR to cover the channel set
In order to mitigate interference between the 1.08GHz and 2.16GHz clusters, the CDMG CCSR shall configure and coordinate all the S-APs operating in the same channel set and provide all the cluster information to the 1.08 GHz S-AP and 2.16GHz S-AP.
Dejian Li

9. Centralized cluster formation for 11aj
March 2014
Centralized cluster formation for 11aj
A CDMG PCP/AP should join a cluster with better signal quality of the S-AP or the member PCPs/APs.
Because all the S-APs in the channel set are coordinated by the CCSR, joining any cluster in the channel set does not decrease coexistence
The signal quality may be SNR of S-AP or the following ratio
The determination of which cluster is the most appropriate one is beyond the scope of 11aj.
The S-AP provides cluster synchronization and control information of all the S-APs in the channel set to the PCP/AP that is joining the cluster, to support the PCP/AP to detect S-APs on other channel.
Dejian Li

10. March 2014
A centralized cluster enabled PCP/AP that intends to join a cluster with a CDMG S-AP shall successfully perform the following steps in order:
The CDMG PCP/AP shall monitor the channel for CDMG Beacon frames during each Beacon SP over an interval of length at least aMinChannelTime and measure the signal quality of CDMG Beacon frames.
 The second non-PCP/non-AP STA shall attempt to associate with the S-AP and thereby receive an Announce frame from the S-AP. The contents of the Announce frame are passed to the PCP/AP. All the centralized cluster information of the S-APs operating on the channels in the same channel set shall be included in the Announce frame. The cluster information of the S-APs can be conveyed in Extended Cluster Report elements.
The CDMG PCP/AP determines whether to join the current cluster based on the signal quality of the current S-AP or the member PCPs/APs. If the CDMG PCP/AP elects to join the current cluster, proceed to step (d); otherwise, The CDMG PCP/AP shall monitor the channels for CDMG Beacon frames during each Beacon SP of all centralized clusters over an interval of length at least aMinChannelTime using the cluster information. The CDMG PCP/AP shall determine an intended cluster based on the signal quality of the CDMG Beacon frames of each cluster. The second non-PCP/non-AP STA shall disassociate with the current S-AP and associate with the S-AP of the intended cluster, receive the Announce frame from the S-AP and pass the contents of the Announce frame to the PCP/AP.
Upon receiving an Announce frame that includes the ECPAC Policy element, the PCP/AP shall select a Cluster Time Offset index from the intersection of 1) the Cluster Time Offset indices of the empty Beacon SPs with 2) the indices indicated by the Available Cluster Offset Bitmap field in the ECPAC Policy element. If the intersection is empty, the PCP/AP shall select a Cluster Time Offset index of an empty Beacon SP. The selected Cluster Time Offset index is passed to the second non-PCP/non-AP STA.
The second non-PCP/non-AP STA shall respond to the Announce frame with an Information Response frame that includes the Cluster Time Offset element containing the Cluster Time Offset Index set to the selected index.
The PCP/AP shall operate its BSS at the selected Cluster Time Offset on the channel of the S-AP and include the PCP/AP clustering control field in transmitted CDMG Beacon frames.
Dejian Li

11. Cluster Maintenance Problem of cluster maintenance March 2014
It is hard to find a 2.16GHz DMG S-AP that newly joins the CCSS for a 1.08GHz cluster. Thus, the cluster merging can not be implemented for the 1.08GHz cluster, leading to compatibility problem.
Dejian Li

12. Cluster Maintenance March 2014
Month Year
doc.: IEEE yy/xxxxr0
March 2014
Cluster Maintenance
The CCSR should report the cluster information of the newly joined 2.16GHz S-AP to the 1.08GHz S-APs, to facilitate the detection of the new S-AP.
The cluster information of the new 2.16GHz S-AP includes the cluster ID, cluster synchronization and control information, channel number.
The 1.08GHz S-AP should report the cluster information of the new 2.16GHz S-AP to its cluster members, using Extended Cluster Report element [2].
The 1.08GHz S-AP/member PCP/AP attempts to monitor the 2.16GHz channel during each Beacon SP of the new 2.16GHz S-AP and determines whether to join the new cluster.
PCPs/APs in a centralized cluster should transmit the Cluster Switch Announcement element prior to switching cluster.
The Cluster Switch Announcement element can be used to update Available Cluster Offset Bitmap for the S-AP or reduce the time of cluster maintenance for 1.08GHz member PCPs/APs.
Dejian Li
John Doe, Some Company

13. March 2014
Summary
This submission provides centralized CDMG PCP/AP clustering solution for comment #127 on the comment resolution for D0.01.
Modifications to ad centralized cluster formation:
CCSR configures and coordinates the S-APs operating in the same channel set to mitigate interference.
PCP/AP that is joining a cluster may select a cluster with better signal quality to join, using the cluster information provided by the S-AP.
Modifications to ad centralized cluster maintenance:
If a new 2.16GHz S-AP joins the CCSS, the 1.08GHz S-AP reports the new S-AP cluster information that is provided by CCSR to its cluster member PCPs/APs using Extended Cluster Report elements.
PCPs/APs in a centralized cluster should transmit the Cluster Switch Announcement element prior to switching cluster.
Dejian Li

14. March 2014
Reference
In the IEEE P802.11ad 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.
11-13/ Decentralized-clustering-mechanism-for aj-60ghz-nt
Dejian Li