1. 21-07-0141-01-0000 IEEE 802.21 MEDIA INDEPENDENT HANDOVER DCN:21-07-0141-01-0000 Title: Data Type Encoding Date Submitted: May 12, 2007 Presented at IEEE 802.21 session #20 in Montreal Authors or Source(s): Yoshihiro Ohba, Subir Das, Yuu-Heng Alice Cheng, Miriam Tauil, Kenichi Taniuchi Abstract: This document describes problem with data type encoding in 802.21.

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3. 21-07-0141-01-0000 Issues Value encoding rules for some TLVs are defined in IE definition (while others are defined in TLV definition), e.g., Link Identifier TLV value is defined in Table 9 of Section 6.4.6.1.1 Location TLV value is defined in 6.4.6.3.2 Link parameter value list refers to “generic link parameters” and the parameters are defined in Section 6.4.6.2.6 There are a lot of duplicate value assignment in primitive definition and TLV definition, e.g., SuppportedMIHCommandList bitmap is defined in Sections 7.4.1.2.2, 7.4.1.3.1, 7.4.1.4.2 and 8.5.2 LinkAction is defined in Sections 7.3.15.12 and 8.5.27. …

4. 21-07-0141-01-0000 A Possible Approach Define data types and their encoding rule in a common place A general idea is to move Table 22 to a normative Annex with adding encoding rule. Define IEs, TLVs and primitives using the data types Advantage: Duplicate format definition can be avoided The specification can be more readable (detailed type definitions are not in the main sections)

5. 21-07-0141-01-0000 Data Type Categorization Basic Data Types: Data types that are not derived from any other data types Those are for general purpose. Derived Data Types: Data types that are derived from other data types Data Types for general purpose Data Types for addresses Data Types for link Identification and manipulation Data Types for QoS Data Types for location Data Types for IP configuration Data Types used by Information Elements …

6. 21-07-0141-01-0000 Basic Data Types Type NameDefinitionRangeBinary Encoding Rule LIST(DATATYPE)A list of values of type DATATYPE. N/ASee Annex M.1.1. SEQUENCE(DATATYPE1,DATATYPE 2[,…]) A data type that consists of two or mote data types. N/ADATATYPE1,DATATYPE2,[,…] are encoded in the order of appearance. Each data type is encoded using the encoding rule for the data type. CHOICE( DATATYPE1,DATATYPE2[,…]) A data type that consists only one of data types DATATYPE1,DATATYPE2[, …]). N/AA one-octet Selector field, followed by a variable length Value field. The Selector value determines the data type. If Selector==i, (i+1)-th data type in the list of data types DATATYPE1,DATATYPE2,[,…] is selected. The Value field is encoded using the encoding the rule for the selected data type. NULLA data type with an empty data. N/ANo octet is encoded for this data type. This data type is used for to define an optional data type. BITMAP(size)A bitmap of the specified size in number of bits. Each bit has a value of ‘0’ or ‘1’. Each bit of a BITMAP(N) value [N=8*i, i=1, 2, …] is encoded as an N/8-octet value in order of significance. INTEGER(size)An integer of the specified size in number of octets. Each octet has a value of 0x00 to 0xff. Each octet of an INTEGER(N) value [N=1,2,..] is encoded in network-byte order into an N-octet field. CHAR(size)An array of 8-bit characters with the specified number of octets. N/AEach character is encoded in order of appearance where each bit of each character is encoded in order of significance. INFORMATION_ELEMENTA binary encoded structure that is defined in Section 6.4.6. N/ASee Section 6.4.6.

7. 21-07-0141-01-0000 Example Derived Types : General Purpose Type NameDerived FromDefinitionValid Range ENUMERATEDINTEGER(1)A type to represent an enumerated attribute. 0 - 255 BOOLEANENUMERATEDA type to represent a Boolean attribute. 0 : False, 1 : True OCTET_STRINGLIST(CHAR(1))A type to represent an array of octets. N/A PERCENTAGEINTEGER(1)A type to represent a percentage. 0 - 100 STATUSENUMERATEDA type to represent a status of a primitive execution. 0 Success 1 Unspecified Failure 2 Rejected 3 Authorization Failure 4 Network Error

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9. Example Derived Types : Link Identification Type NameDerived FromDefinitionValid Range LINK_IDSEQUENCE( LINK_TYPE MAC_ADDRESS) A type to represent the identifier of a link that is not associated with any PoA. The MAC_ADDRESS contains a MAC address of MN. This may be used for the link currently being used by MN or the link that was used before handover. N/A LINK_TUPLE_ IDSEQUENCE( LINK_ID, CHOICE( MAC_ADDRESS, NULL)) A type to represent the identifier of a link that may be associated with a PoA. The optional MAC_ADDRESS contains a MAC address of PoA. N/A LINK_POA_LISTSEQUENCE( LINK_ID, LIST(MAC_ADDRESS) ) A type to represent a list of PoAs for a particular link. The LIST(MAC_ADDRESS) is sorted from most preferred first to least preferred last. N/A

10. 21-07-0141-01-0000 IE Definition Example NoName of Information ElementDescriptionData Type Name General Information Elements 1.1TYPE_IE_NETWORK_TYPE[Same as D05]NETWORK_TYPE 1.2TYPE_IE_OPERATOR_IDENTIFIER[Same as D05]OPERATOR_ID 1.3TYPE_IE_SERVICE_PROVIDER_IDENTIFIE R [Same as D05]SERVICE_PROVIDER_ID Access Network Specific Information Elements 2.1TYPE_IE_ACCESS_NETWORK_I DENTIFIER [Same as D05]ACCESS_NETWORK_ID 2.2TYPE_IE_NETWORK_SYSTEM_ID[Same as D05]NETWORK_SYSTEM_ID 2.3TYPE_IE_ROAMING_PARTNERS[Same as D05]ROAMING_PARTNERS 2.4TYPE_IE_COST[Same as D05]COST 2.5TYPE_IE_NETWORK_SECURITY[Same as D05]NETWORK_SECURITY 2.6TYPE_IE_NETWORK_QOS[Same as D05]NETWORK_QOS 2.7TYPE_IE_NETWORK_DATA_RATE[Same as D05]DATA_RATE 2.8TYPE_IE_NETWORK_IP_CONFIG_METHO DS [Same as D05]IP_CONFIG_METHODS 2.9………

11. 21-07-0141-01-0000 TLV Definition Example TLV Type NameTLV Type Value TLV Value Data TypeDefined Annex SOURCE MIHF ID0MIHF_IDM.2.8 DESINTATION MIHF ID1MIHF_IDM.2.8 SESSION ID2SESSION_IDM.2.9 STATUS3ENUMERATEDM.2.1 MIH EVENT LIST4MIH_EVENT_LISTM.2.11 ………… Please refer to 21-07-0158-00-0000-TLVTypeValues.ppt for why not using per-message TLV value assignment.

12. 21-07-0141-01-0000 Discussion There may be three options to take: Option 1: Ignore this proposal Option 2: Adopt this proposal Option 3: Think about use of ASN.1