doc.: IEEE s Submission January 2011 Dee Denteneer, PhilipsSlide 1 MCCAOP Advertisement discussion Date: Authors:

doc.: IEEE s Submission January 2011 Dee Denteneer, PhilipsSlide 2 Abstract This presentation provides a perspective on the MCCA comments received during the recirculation and specifically zooms in on the MCCAOP advertisement mechanism as in the Draft 8.0 and provides a tentative route towards a solution.

doc.: IEEE s Submission Overview MCCA comments: 40 –More or less editorial: 23 (will do my best) –Advertisements: 17 (this presentation) Concerning the Advertisements –Terminology –Completeness When are advertisement elements part of the ‘same’ advertisement –Teardown of reservations –‘Partial ‘ advertisements January 2011 Dee Denteneer, PhilipsSlide 3

doc.: IEEE s Submission Current structure January 2011 Dee Denteneer, PhilipsSlide 4

doc.: IEEE s Submission Suggested modification Add an Advertisements Set Sequence Number –As per 814r1 –Groups together a number of Advertisement elements Add an MCCAOP Advertisements Overview element –Contains a Advertisements Set Sequence Number –Contains a bitmap, indicating which Advertisement elements are available in the current Advertisment Set January 2011 Dee Denteneer, PhilipsSlide 5

doc.: IEEE s Submission Proposed data structure, changes to current January 2011 Dee Denteneer, PhilipsSlide 6 B7B8 B15 B16B17B18B19B20B21 MCCA Access Fraction MCCA Access Fraction Limit Accept Reservations Advertisement Set Sequence Number TX-RX Report Present Broadcast Report Present Interfering Report Present Last Advertisement Advertisement Identifier Bits: *MCCA Information field

doc.: IEEE s Submission Proposed structure, Advertisements Overview element January 2011 Dee Denteneer, PhilipsSlide 7 Element IDLengthAdvertiseme nts Set Sequence Number Accept Reservations MAFMAF limit Active Advertisements Bitmap Octets: Figure s29—MCCAOP Advertisements Overview element Advertisements Element 1 Active Advertisements Element 2 Active …….Advertisements Element 16 Active Bits123:1516 Figure s29—Active Advertisements Bitmap field The Advertisements Elements n Active indicates which of the advertised Advertisement elements with the same set sequence number are part of the current Advertisement Set

doc.: IEEE s Submission Functionality The set of tracked MCCAOP reservations is distributed over Advertisement elements Each Advertisement element has a 4 bit identifier and contains reports that contain the reservations The advertisement set sequence number groups the Advertisements elements The overview element is regularly transmitted and acts as a key to validate completeness Given a Advertisement Set Sequence Number, limited changes are allowed to the Advertisement Set –An element can be retrieved, indicated in the Overview element –An element can be added, indicated in the Overview element –However, an element cannot be changed –Once a bit for an advertisement element has been set to 1 and afterwards set to 0, it may never been set to 1 again with the same Advertisement Set Sequence Number January 2011 Dee Denteneer, PhilipsSlide 8

doc.: IEEE s Submission Functionality A complete overhaul of the distribution of reservations over the Advertisements elements is possible by increasing the Advertisement Set Sequence Number. This invalidates all Advertisement elements with an older Sequence number However, given an advertisement element with the right sequence number, and that is still indicated in the bitmap as active, a mesh STA knows this Advertisement element is still ok Enhanced Advertisements Request possible –Request the Overview –Request a specific set of elements –Request the delta given your own bitmap January 2011 Dee Denteneer, PhilipsSlide 9

doc.: IEEE s Submission Reflection We now discuss how this scheme meets the objections raised in the comments January 2011 Dee Denteneer, PhilipsSlide 10

doc.: IEEE s Submission Terminology (cf /814r1) advertisement set: Set of all Reservations to be advertised equals All tracked reservation Distributed over multiple Advertisement elements –Use advertisement set sequence number to group these –Index each Advertisement Element An advertisement equals the transmission of all (complete), active Advertisement elements and the advertisement overview element Advertisement frames may carry zero or more Advertisement elements and one or zero overview element January 2011 Dee Denteneer, PhilipsSlide 11

doc.: IEEE s Submission Completeness The Advertisement Overview element is a key to the current Advertisement Set of a mesh STA A mesh STA can easily check the completeness of its picture of the Advertisement Set of a neighbor by using the Advertisements Overview element A mesh STA can simply request a delta to complete its picture of the Advertisement Set of a neighbor January 2011 Dee Denteneer, PhilipsSlide 12

doc.: IEEE s Submission Teardown A mesh STA can easily teardown the reservations in a Advertisement element by setting the corresponding bit in the bitmap to zero To teardown individual reservations you could delete one Advertisement element and advertise a new Advertisement element Note: Once an advertised reservation needs to be advertised, there are two choices: –Increase Sequence number, retransmit everything –If a “bit” in the bitmap has not been used before, the element that contains the changed reservation can be placed in a new “bit” and the old bit is invalidated (aka set to 0). January 2011 Dee Denteneer, PhilipsSlide 13

doc.: IEEE s Submission Partial Advertisements Advertisements are by nature partial, so this notion can be deleted New reservations can simply be advertised by transmitting a new Advertisement element and setting the corresponding bit to 1 in the Advertisements Overview element January 2011 Dee Denteneer, PhilipsSlide 14

doc.: IEEE s Submission Possible further changes Is it clever to include several “reports” in one Advertisement element, or rather: have the elements typed (i.e. this gives an extra hierarchical level in the data structure) Even further, do we need elements to group reservations, or do we rather wotk with the individual reservations January 2011 Dee Denteneer, PhilipsSlide 15

doc.: IEEE s Submission Advertisement element, possible simplifcation January 2011 Dee Denteneer, PhilipsSlide 16 Element IDLengthAdvertisement Element Information Reservation 1……..Reservation n Octets: Figure s29—MCCAOP Advertisements element Set Sequence number Number of reservations Advertisement typeAdvertisement Element Index Bits1:89:1617:1819:24 Figure s29—Advertisements Element Information Note: dispense of the “Report level”, give a type to the Advertisement element Allows for 64 Advertisement elements and needs a larger bitmap in the overview element Note: could also index and type the reservations themselves

doc.: IEEE s Submission January 2011 Dee Denteneer, PhilipsSlide 17 References 11-10/814r1 „MCCAOP Advertisements“ –contains normative text implementing these ideas IEEE s D8.0