Date Submitted: September 17, 2001 doc.: IEEE 802.15-<01/304r2> September, 2001 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: IEEE802.15.3: A proposal to add geographical coverage based criteria to PNC selection. Date Submitted: September 17, 2001 Source: Shig Sugaya, Kaz Takamura, Masa Akahane Company: Sony Corporation Address: 2-17-1 Higashi-Gotanda Oval Court 13F Shinagawa-ku, Tokyo Japan 141-0022 Voice: +81.3.6409.3238, FAX: +81.3.6409.3203 E-Mail: sugaya@wcs.sony.co.jp, takamura@wcs.sony.co.jp, akahane@wcs.sony.co.jp Re: [ P802.15.3/D0.6, P802.15-01/259r0] Abstract: This proposal presents modified comparison order of fields and PNC selection frame body that provide an accessible DEV count for geographical coverage based PNC selection. Purpose: To provide an improvement to the current version of the 802.15.3 MAC Notice:This document has been prepared to assist the IEEE P802.15. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor acknowledges and accepts that these viewgraphs becomes the property of IEEE and may be made publicly available by P802.15. S.Sugaya, K.Takamura, M.Akahane, Sony Corporation Masa Akahane, Sony Corporation

Assumptions on PNC Selection <September, 2001> doc.: IEEE 802.15-<01/304r2> September, 2001 Assumptions on PNC Selection Exist two kind of PNC-Capable DEVs A DEV which wants to be a PNC A DEV which does NOT want to be a PNC PNC is selected among DEVs which want to be a PNC DEVs which do NOT want to be, or CANNOT be a PNC shall associate a Piconet by acquiring the Beacon “PNC-Capable” DEVs should NOT participate in PNC selection process if they are set “Abstain to be a PNC” S.Sugaya, K.Takamura, M.Akahane, Sony Corporation Masa Akahane, Sony Corporation

Case: Only 1 DEV wants to be PNC <September, 2001> doc.: IEEE 802.15-<01/304r2> September, 2001 Case: Only 1 DEV wants to be PNC There may only be 1 DEV to be set as PNC Most cases all the DEVs to establish a Piconet are controlled by a single user Turn on a DEV which should be the PNC and wait for 1 second then turn on the other DEVs S.Sugaya, K.Takamura, M.Akahane, Sony Corporation Masa Akahane, Sony Corporation

Case: More than 2 DEVs want to be a PNC <September, 2001> doc.: IEEE 802.15-<01/304r2> September, 2001 Case: More than 2 DEVs want to be a PNC There may exist multiple DEVs want to be a PNC In such a case multiple users want to establish an ad-hoc Piconet PNC selection process is started if all the applicable DEVs which want to be a PNC turn their power on within 1 second (It might be a rare case such as a recovery from power failure) If DEVs which want to be a PNC missed the association time window (“the” 1 second), they should associate the established Piconet as a “Loser” If it is NOT accepted, Need PNC Handover by setting “Des-mode” ON to the DEV If there are more than 2 DEVs set “Des-mode” ON, then PNC selection process is started S.Sugaya, K.Takamura, M.Akahane, Sony Corporation Masa Akahane, Sony Corporation

Geographical Coverage Based PNC Selection Procedure September, 2001 Geographical Coverage Based PNC Selection Procedure Current PNC Selection PNC PNC Good PNC Selection Bad PNC Selection Alternate PNC DEV Non-Alternate PNC DEV S.Sugaya, K.Takamura, M.Akahane, Sony Corporation

Basic Mechanism Adopt Inquiry transaction <September, 2001> doc.: IEEE 802.15-<01/304r2> September, 2001 Basic Mechanism Adopt Inquiry transaction All DEVs (PNC Capable or Incapable) respond to the Geographical Inquiry Request (GI-Req) Alternate PNCs count the number of nearby DEVs and compile their IDs, then broadcast the ID list of detected DEVs ID : 48bit IEEE802 address of a DEV DEVs that received this list broadcast a Geographical Inquiry Response (GI-Res) only when their own ID is not on the list S.Sugaya, K.Takamura, M.Akahane, Sony Corporation Masa Akahane, Sony Corporation

Geographical Inquiry Process (GIP) <September, 2001> doc.: IEEE 802.15-<01/304r2> September, 2001 Geographical Inquiry Process (GIP) Only Alternate PNCs broadcast GI-Req After the expiration of Timeout, update the DEV List and re-broadcast GIP is terminated if no response is received within the 2nd or later Response Timeout Non Alternate PNCs return only GI-Res Non Alternate PNCs check whether its own ID is on the DEV ID List when they receive GI-Req Broadcast GI-Res if its own DEV ID is NOT on the list No response is returned if its own DEV ID is on the list S.Sugaya, K.Takamura, M.Akahane, Sony Corporation Masa Akahane, Sony Corporation

Broadcast of DEV ID List September, 2001 Broadcast of DEV ID List Alternate PNC DEV Non Alternate PNC DEV GI-Req (1st) Receive Timeout GI-Res GI-Req (2nd) Receive Timeout with Received DEV ID List GIP is terminated when there is no response received within Receive Timeout At least two times of GI-Req shall be transmitted Alternate PNC determines Accessible DEVs by exchanging more than one GI-Res Other DEVs return at least one GI-Res Advantage: Broadcasting DEV ID List reduces the number of response traffics S.Sugaya, K.Takamura, M.Akahane, Sony Corporation

Add on Current PNC Selection <September, 2001> doc.: IEEE 802.15-<01/304r2> September, 2001 Add on Current PNC Selection First Alternate PNC Broadcasts Alternate PNC Announcement Other Alternate PNC Broadcast Alternate PNC Announcement (ex.0) Comparison Order 1: Designated mode in capability field Comparison Order 2 : SEC bit in capability field Comparison Order 3 : Battery / AC power Comparison Order 4 : PS bit (ex.1) Geographical Inquiry Process (ex.2) Comparison Order 5 : MAX GTS slots Comparison Order 6 : Repeater memory Comparison Order 7 : Transmit Power Level Comparison Order 8 : MAX PHY rate Comparison Order 9 : DEV ID (ex.3) A Winner of among Alternate PNCs Broadcasts PNC Announcement First Beacon Transmission Add GIP on the current PNC Selection No need if a PNC has uniquely been determined in higher comparison If PNC has not uniquely been determined, enter GIP S.Sugaya, K.Takamura, M.Akahane, Sony Corporation Masa Akahane, Sony Corporation

Alternate PNC Announcement September, 2001 No PNC Selection (ex.0) No PNC selection process occurs Time DEV #1 DEV #2 PNC-Announcement Alternate PNC Announcement DEV #3 Alternate PNC Beacon DEV #4 DEV #5 CS Timeout S.Sugaya, K.Takamura, M.Akahane, Sony Corporation

September, 2001 No GIP (ex.1) In case high order PNC selection process uniquely determine a PNC Time DEV #1 Pullout Alternate PNC Announcement DEV #2 Alternate PNC PNC-Announcement Alternate PNC Announcement DEV #3 Alternate PNC Pullout Beacon Alternate PNC Announcement DEV #4 Alternate PNC DEV #5 Comparison Order 1-4 Comparison “Won by #4” Order 1-4 “Won by #3” Back-off Back-off CS Timeout S.Sugaya, K.Takamura, M.Akahane, Sony Corporation

APA: Alternate PNC Announcement September, 2001 GIP (ex.2) In case there are DEVs that one of the Alternate PNCs is out of reach GI-Res Time DEV #1 GI-Res DEV #2 PNC- Announcement APA GI-Req.-1 GI-Req.-2 APA DEV #3 #2,#4,#5 #1,#2,#4,#5 GI-Req.-1 GI-Req.-2 APA Alternate PNC Pullout Beacon #3 #3,#2,#5 DEV #4 Alternate PNC GI-Res DEV #5 Comparison Order 1-4 Receive-Timeout #1 #2 #3 #4 #5 “Tie Break” Receive-Timeout Back-off Receive-Timeout Receive-Timeout CS Timeout GIP APA: Alternate PNC Announcement Accessible DEV Check “Won by #3” S.Sugaya, K.Takamura, M.Akahane, Sony Corporation

September, 2001 GIP (ex.3) In case all DEVs are within the accessible range from Alternate PNCs GI-Res Time DEV #1 GI-Res DEV #2 PNC- Announcement APA GI-Req.-1 GI-Req.-2 APA DEV #3 #1,#2,#4,#5 #1,#2,#4,#5 Alternate PNC GI-Req.-1 GI-Req.-2 APA Pullout Beacon #3 #3,#1,#2,#5 DEV #4 Alternate PNC GI-Rep DEV #5 Comparison Order 1-4 Receive-Timeout #1 #2 #3 #4 #5 Receive-Timeout “Tie Break” CS Timeout Back-off Receive-Timeout Receive-Timeout Comparison Order 5-9 GIP “Won by #3” Accessible DEV Check “Tie Break” S.Sugaya, K.Takamura, M.Akahane, Sony Corporation

<September, 2001> doc.: IEEE 802.15-<01/304r2> September, 2001 GI-Req Command (new) Octets:2 2 6 6 x N Command Type Length DEV ID Receive Timeout Number of Received DEVs Received DEV ID List Octets:6 ･･･ 6 Received DEV ID #1 Received DEV ID #N Figure tbd：GI-Request Command Set different Receive Timeout for each DEV to avoid potential collisions Add received DEV ID List in GI-Req every time Cf) Maximum length (N=255) will be 1,544[Octets] S.Sugaya, K.Takamura, M.Akahane, Sony Corporation Masa Akahane, Sony Corporation

Figure tbd：GI-Res Command <September, 2001> doc.: IEEE 802.15-<01/304r2> September, 2001 GI-Res Command (new) Octets:2 2 6 Command Type Length DEV ID Figure tbd：GI-Res Command GI-Res frame simply consists of Command Type, Length and DEV ID The probability of collisions decreases with random access method if the length of the frame is short S.Sugaya, K.Takamura, M.Akahane, Sony Corporation Masa Akahane, Sony Corporation

Potential Extension by GIP September, 2001 Potential Extension by GIP GIP is extensible to the Daughter DEVs Inquiry Hidden or out-of-reach DEVs will be accommodated in a Daughter Piconet by making Daughter PNC Non PNC DEV Parent DEV Alternate PNC DEV Parent PNC Alternate PNC DEV Non PNC DEV Daughter PNC Parent DEV Non PNC DEV Parent Piconet Daughter DEV Daughter Piconet GIP Daughter Piconet Creation S.Sugaya, K.Takamura, M.Akahane, Sony Corporation

Potential Collisions in GIP <September, 2001> doc.: IEEE 802.15-<01/304r2> September, 2001 Potential Collisions in GIP Collisions of GI-Req (Case 1) Set different Timeouts for each DEV Retransmission can decrease the probability of collisions GIP is terminated if no response is received Collisions of GI-Res (Case 2) Detect collisions by checking whether its own DEV ID is on retransmitted GI-Req Broadcast GI-Res if its own DEV ID is NOT on the list GIP is terminated if its own DEV ID is on the list S.Sugaya, K.Takamura, M.Akahane, Sony Corporation Masa Akahane, Sony Corporation

(Case 1) GI-Req Collision <September, 2001> doc.: IEEE 802.15-<01/304r2> September, 2001 (Case 1) GI-Req Collision GI-Res Time DEV #1 APA GI-Req-1st GI-Req-2nd Pullout #3,#1,#4 #3,#1,#4 DEV #2 GI-Req-1st GI-Req-2nd GI-Req-3rd APA Pullout Alternate PNC #2 #2,#1,#4,#5 DEV #3 Collision GI-Req-2nd GI-Req-3rd APA Alternate PNC PNC-Announcement #2 #2,#1,#3,#5 DEV #4 Alternate PNC GI-Res DEV #5 Receive-Timeout Receive-Timeout Receive-Timeout Receive-Timeout Back-off Receive-Timeout Receive-Timeout Receive-Timeout CS Timeout Receive-Timeout Even though the 1st GI-Req collides, a deadlock can be avoided at the 2nd GI-Req if the different Timeouts have been set S.Sugaya, K.Takamura, M.Akahane, Sony Corporation Masa Akahane, Sony Corporation

(Case 2) GI-Res Collision September, 2001 (Case 2) GI-Res Collision GI-Res Time DEV #1 GI-Res GI-Res DEV #2 APA GI-Req-1st GI-Req-2nd APA PNC-Announcement Collision #4,#1 #4,#1,#5,#2 DEV #3 Alternate PNC GI-Req-1st GI-Req-2nd GI-Req-3rd Pullout #3 #3 #3,#5,#2 DEV #4 Alternate PNC GI-Res GI-Res DEV #5 Receive-Timeout Back-off Receive-Timeout CS Timeout Receive-Timeout Receive-Timeout Back-off In the case of GI-Res collision, responses are retransmitted since their DEV IDs are NOT on the next GI-Req S.Sugaya, K.Takamura, M.Akahane, Sony Corporation

Conclusion Provision Geographical Inquiry Process (GIP) is specified September, 2001 Conclusion Provision There may exist DEVs which do NOT participate in the PNC selection process Geographical Inquiry Process (GIP) is specified All the DEVs reply responses to the inquiry in order to report their existence Reconfirmation is done by exchanging Accessible DEV List Response with Accessible DEV List efficiently reduces data exchange Better Alternate-PNCs in terms of geographical coverage are selected S.Sugaya, K.Takamura, M.Akahane, Sony Corporation