1. 21-14-0053-00-MuGM IEEE 802.21 MEDIA INDEPENDENT HANDOVER DCN: 21-14-0061-01-MuGM Title: Proposal to amend the group manipulation command Date Submitted: Mar, 19, 2014 Presented at IEEE 802.21 session #61 in Beijing Authors or Source(s): Yoshikazu Hanatani, Toru Kambayashi, (Toshiba) Abstract: 1

2. 21-14-0053-00-MuGM IEEE 802.21 presentation release statements This document has been prepared to assist the IEEE 802.21 Working Group. 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. The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.21. The contributor is familiar with IEEE patent policy, as outlined in Section 6.3 of the IEEE-SA Standards Board Operations Manual and in Understanding Patent Issues During IEEE Standards Development http://standards.ieee.org/board/pat/guide.html> Section 6.3 of the IEEE-SA Standards Board Operations Manualhttp://standards.ieee.org/guides/opman/sect6.html#6.3 http://standards.ieee.org/board/pat/guide.html IEEE 802.21 presentation release statements This document has been prepared to assist the IEEE 802.21 Working Group. 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. The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.21. The contributor is familiar with IEEE patent policy, as stated in Section 6 of the IEEE-SA Standards Board bylaws and in Understanding Patent Issues During IEEE Standards Development http://standards.ieee.org/board/pat/faq.pdf> Section 6 of the IEEE-SA Standards Board bylawshttp://standards.ieee.org/guides/bylaws/sect6-7.html#6 http://standards.ieee.org/board/pat/faq.pdf 2

3. In a GKB for a group manipulation command targeting a group X, the complete subtree part can be used to indicate the members of the group X. If the group X does not require a group key, only the complete subtree part exists in the GKB, with an encrypted key data part being omitted. A GKB provides an efficient way to create a group without a group key. The scheme allows an alternative way to create a group without a group key. Instead of indicating the members of the group X, the complete subtree part can indicate the members of the complementary set of the group X, i.e. U – X where U is the whole set. This scheme enables reduction of the size of a group manipulation command. Create GKBs, say G and G’, which cover X and (U – X) resp. Compare the sizes of G and G’. If G is not larger than G’, use G which indicates the members of X to construct the group manipulation command. Otherwise, use G’ which indicates the members of (U – X).

4. In order for a recipient to distinguish the two cases, a group manipulation command accompanies a flag named Complement Flag. If the flag is 0, the complete subtree part indicates the members of X. Otherwise, if the Complement Flag is 1, the complete subtree part indicates the members of the complement of X. Suppose that a recipient receives a group manipulation command targeting a group, say X. Also suppose that the Complement Flag of the command is 0. Then, the recipient checks if it is indicated by the complete subtree part. If it is, it joins in X. Otherwise, it leaves X. When a recipient receives a group manipulation command targeting X the Complement Flag of which is 1, the recipient checks if it is indicated by the complete subtree part. If it is, it leaves X. Otherwise, it joins in X. The Complement Flag thus reverses behavior of a recipient. See Table 1 for description of the behaviors.

5. Table 1 Complement Flag = 0R is indicated by CSR is not indicated by CS R is in XR does nothingR leaves X R is not in XR joins in XR does nothing Complement Flag = 1 R is in XR leaves XR does nothing R is not in XR does nothingR joins in X It is assumed that a recipient R receives a group manipulation command having the complete subtree part CS.

6. Flow Diagram: Generate Complete Subtree 21-14-0053-00-MuGM 6 Input : Group Management Tree, MIHF IDs of the group members Complement Complement = 1 Generate Complete subtree of the MIHF IDs Generate Complete subtree of the complement set of the MIHF IDs Output: Complement, CompleteSubtree fragments, SubgroupRange Yes

7. Flow Diagram: Process Complete Subtree TLV 21-14-0053-00-MuGM7 Input : Group Management Tree, Leaf ID, Complement, CompleteSubtree Complement = 0 Is Leaf ID covered by Complete subtree? Go to Step [join] or [stay] Go to Step [Leave] Yes

8. Examples of the condition Result of comparing data sizes of two complete subtrees CompleteSubtree of group member CompleteSubtree of non-group member Choose smaller one. The number of new group member 21-14-0053-00-MuGM8 The number of new group members < The number of all members managed by the group management tree 2

9. Change requests (rev1) Define a data type of Complement in Table F.24 and Type Values for TLV encoding in Table L.2 Add Complement field to following primitives 7.4.31.3 MIH_MN_Group_Mnipulate.response 7.4.32.1 MIH_Net_Group_Manipulate.request Add Complement field to following messages 8.6.1.22 MIH_MN_Group_Manipulate response 8.6.1.23 MIH_Net_Group_Manipulate request 8.6.1.24 MIH_Net_Group_Manipulate indication Add an explanation text after the pseudo codes (CreateCompleteSubree, CreateCompleteSubtree flagments) in the case of Complement = 1. Add flow diagram in p.4 and explanation texts to 9.4.3.1.1. Add explanation texts to 9.4.3.1.2. Add flow diagram in p.5 and explanation texts to 9.4.3.2. 21-14-0053-00-MuGM9