Ralf Jennen, ComNets, RWTH Aachen University Media Independent Handover in Heterogeneous Networks Ralf Jennen Department of Communication Networks RWTH Aachen University, Faculty 6, Germany FFV Workshop, th FFV Workshop

2Ralf Jennen, ComNets, RWTH Aachen UniversityOutline Scenario: Heterogeneous Networks Media Independent Handover (MIH) –IEEE (Draft Standard) –MIH Services Event Command Information –Modelling of the MIH Protocol Acknowledgement Service Conclusion IEEE= Institute of Electrical and Electronics Engineers MIH= Media Independent Handover

3Ralf Jennen, ComNets, RWTH Aachen University Scenario: Heterogeneous Networks LAN= Local Area Network MAN= Metropolitan Area Network WAN= Wide Area Network LAN Home MAN Operator 1 WAN Operator 1 WAN Operator 2

4Ralf Jennen, ComNets, RWTH Aachen University Focus of IEEE Mobile terminals are surrounded by a multitude of –Devices –Networks –Different communication technologies –Business actors Problems to solve: –Handover between two link layer technologies has a break-before- make characteristic –IP connectivity may be lost completely => packet loss, high delays, and service disruption –Handover is not “seamless” for the application “The standard specifies IEEE 802 media access- independent mechanisms that optimize handovers between heterogeneous IEEE 802 systems and between IEEE 802 systems and cellular systems.” IEEE has the goal to facilitate handovers and to maximize handover efficiency IP= Internet Protocol

5Ralf Jennen, ComNets, RWTH Aachen University Efficiency of Handovers Control Plane –Shorten/unify discovery, selection, and attachment phases –Support of make before break handovers –Minimize number of unnecessary handovers / handover signaling User Plane –Minimize impact of handovers on active services –MIH knows the following parameters Packet Quality of Service (QoS) parameters –Minimum Packet Transfer Delay –Average Packet Transfer Delay –Maximum Packet Transfer Delay –Jitter –Packet Loss Rate –Packet Error Rate Link QoS parameters –Link Throughput –Link Packet Error Rate –Supported Classes of Service Class of Service (CoS) parameters –Class Minimum Packet Transfer Delay –Class Average Packet Transfer Delay –Class Maximum Packet Transfer Delay –Class Packet Delay Jitter –Class Packet Loss Rate –Mappings to technology specific parameters Cos= Class of Service QoS= Quality of Service

6Ralf Jennen, ComNets, RWTH Aachen University MIH Function & Service Access Points MIH Function MIH User Media-specific SAPs (802.3, , , 3GPP, 3GPP2, etc.) Transport Service Provider MIH_LINK_SAP MIH_SAP MIH_NET_SAP MIH= Media Independent Handover NET= Network SAP= Service Access Point

7Ralf Jennen, ComNets, RWTH Aachen University MIH General Reference Model MIH_NET_SAP MIH Function MIH Event Service MIH Command Service MIH Information Service MIH_LINK_SAP MIH_SAP LLC_SAP MIH User Layer 3 or higher Mobility Management Protocol, eg.: - Mobile IP for mobile node controlled mobility - Proxy Mobile IP for network controlled mobility Link Layer Remote MIH Function MIH_NET_SAP L3 L2 L2= Data Link Layer L3= Network Layer LLC= Logical Link Control SAP= Service Access Point

8Ralf Jennen, ComNets, RWTH Aachen University Event Service Link events are translated to media independent MIH events Subscription based Triggers may originate from local link events or in a remote system Several types of events –MAC and PHY state change events –Link parameter events –Predictive events –Link handover events –Link transmission events MAC= Medium Access Control Sublayer PHY= Physical Layer

9Ralf Jennen, ComNets, RWTH Aachen University Command Service Translates MIH commands to link commands Commands are used for –Handover signaling and execution –Control of the behavior of a link –Configuration of event creation –Information retrieval Command may have its sink in a –Local node –Peer node Place of command execution may be within the peer’s –MIH user –MIH entity –Link layer MIH Function MIH User Lower Layers MIH Function MIH User Lower Layers MIH Event MIH Command Link Event Link Command Remote MIH Event MIH Command Link Event Link Command Local System Remote System EventsCommands MIH Indication

10Ralf Jennen, ComNets, RWTH Aachen University Information Service Data about neighboring networks in the geographical area of a mobile node Access network specific information –Operator –Roaming agreements –Costs –Security mechanisms –QoS Information for a dedicated point of access –Location –Data rate –Addressing –Type –Extensible with access network specific, service specific, or vendor specific information QoS= Quality of Service

11Ralf Jennen, ComNets, RWTH Aachen University Point of Service, Point of Attachment Mobile node have always an MIHF entity Network nodes that implement the MIHF are either called –MIH PoS if they exchange MIH messages with a mobile node –MIH non-PoS if they exchange messages only with other MIH network nodes Network node with a layer 2 connection to the mobile node is called PoA PoA of the current link is called serving PoA In case of handover –Candidate PoA –Target PoA Node that does not offer layer 2 connections to mobile nodes is a non-PoA PoA= Point of Attachment PoS= Point of Service

12Ralf Jennen, ComNets, RWTH Aachen University Mobile Node Access Network a PoA Access Network b PoA Core Network Operator 1 PoS Core Network Operator 2 PoS Core Network Operator 3 PoS Internet Visited Network Home Subscriber Network Information Database Correspondent Node RP1/RP2/RP3 RP1/RP3/ RP4/RP5 RP1/RP3/ RP4/RP5 RP3/ RP4/ RP5 RP4/ RP5 PoA= Point of Attachment PoS= Point of Service RP= Reference Point Example of an MIH Network Serving PoA Candidate/Target PoA

13Ralf Jennen, ComNets, RWTH Aachen University Services (contd.) Service management allows –Capability discovery of an MIHF entity –Registration of MIH users at the MIHF –Subscribtion to MIH events –Setup the communication between MIHF entities Flow control –Limit rate of MIH messages –Rate-limiting of forwarded messages is out of scope –Token Bucket mechanism (RFC4443) MIH protocol acknowledgement service –Reliable data transport: message loss rate < 0.01 –Acknowledged mode with retransmission timeout (RTO) calculation (RFC2988) RFC= Request for Comments RTO= Retransmission Timeout

14Ralf Jennen, ComNets, RWTH Aachen University Acknowledgement Service: Signal Flow Graph S R G a (z)P a Delay investigation with an ARQ Model of System a: A= Successful Transmission ARQ= Automatic Repeat Request B= Retransmission State G(z)= Delay Generation Function P= Channel Transition Matrix R= Receive State RTO= Retransmission Timeout S= Send State z = Delay Operator S1S1 RA1A1 B P 1b P 0b G c (z) G b (z)P b Block Error Rate (BLER) of system i given by P 1i. Changing P 1i if the BLER of the underlying channel increases. => The Hidden Markov Model (HMM) is exchanged. A B z RTO P 1a P 0a G a (z)P a S0S0 R0R0 A0A0 P 0a ARQ Model with 2 Retransmissions and handover from System a to System b: G a (z)P a B0B0 z RTO P 1a R1R1 P 0a G a (z)P a B1B1 z RTO P 1a R2R2 P 0a z RTO P 1a F0F0 G a (z)P a GoodBad p 00 p 11 p 10 p 01 ε 0 =1ε 0 =0 P0P0 P1P1 Trigger Probability increases from retransmission to retransmission. Network is a Time Varying System.

15Ralf Jennen, ComNets, RWTH Aachen University Acknowledgement Service: Analysis SRA B z z z SRA B z z z S1S1 RA1A1 B P 1b P 0b G c (z) G b (z)P b S0S0 R0R0 A0A0 P 0a G a (z)P a B0B0 z RTO P 1a R1R1 P 0a G a (z)P a B1B1 z RTO P 1a R2R2 P 0a z RTO P 1a F0F0 G a (z)P a cdf= Cumulative Distribution Functionpdf= Probability Density Function delay p p p p

16Ralf Jennen, ComNets, RWTH Aachen UniversityConclusion IEEE Overview –MIH Services –MIH Deployment Signal Flow Graph Model of MIH Protocol Acknowledgement Service –Allows calculation of an appropriate number of retransmissions –Allows to include MIH triggers –Allows investigation of sensitivity to triggers and Retransmission Timeout –Outlook: Include aspects of Time Varying Systems

17Ralf Jennen, ComNets, RWTH Aachen University Thank you for your attention ! Ralf Jennen Kopernikusstr. 5, Room 110

18Ralf Jennen, ComNets, RWTH Aachen University Backup Slides I haven't lost my mind -- it's backed up on tape … somewhere.

19Ralf Jennen, ComNets, RWTH Aachen University Scenario: Heterogeneous Home Networks Multi- Mode Mobile Node 1 Access Point Core Network Operator 1 Home Network Gateway Home Subscriber Network Information Database Correspondent Node Internet Information Database Node 3 Access Point Multi-Mode Mobile Node 2 Access Point Node 4 Nomadic Node 5 Bridge

20Ralf Jennen, ComNets, RWTH Aachen University Services & Mobility Management The general model is specialized for the specific technologies IEEE 802.3, IEEE , IEEE , 3GPP, and 3GPP2 MIHF offers three services: –MIH Event Service –MIH Command Service –MIH Information Service The MIH is implemented by a mobility management protocol, e.g. –Mobile IP (RFC3775) for mobile node controlled mobility –Proxy Mobile IP (PMIP) for network controlled mobility –The MIH standard does not rely on a specific mobility management protocol MIHF= Media Independent Handover Function

21Ralf Jennen, ComNets, RWTH Aachen University Example of IEEE in OMEGA Mobile Node 1 Network 1 PoA & PoS Network 2 PoA & PoS Core Network PoS Network 3 PoA & PoS Operator Core Network PoS Home Network Home Subscriber Network Information Database Correspondent Node wired or wireless Internet Information Database Mobile Node 2 Mobile Node 2 is a Mobile Node for Network 3 and a PoA for Mobile Node 1 Direct communication between Mobile Node 1 and 2 is possible PoA= Point of Attachment PoS= Point of Service

22Ralf Jennen, ComNets, RWTH Aachen University MIH Events & Commands MIH= Media Independent Handover MIH Function MIH User Lower Layers MIH Function MIH User Lower Layers MIH Event MIH Command Link Event Link Command Remote MIH Event MIH Command Link Event Link Command Local SystemRemote System Events Commands MIH Indication Remote MIH commands can be executed within the remote MIH function, remote lower layers, or remote MIH users. MIH uses the four types of primitives: request, indication, response, and confirm Message exchange between the MIH function in the local and remote system via the MIH protocol

23Ralf Jennen, ComNets, RWTH Aachen University MIH protocol header (8 octets) Source MIHF identifier TLV Destination MIHF identifier TLV MIHF service specific TLVs MIH protocol frame MIH protocol payload VER (4) Ack Req (1) Ack Res (1) UIR (1) M (1) FN (7) Rsvd1 (1) MIH Message ID (16) Rsvd2 (4) Transaction ID (12) Variable Payload Length (16) SID (4) Opcode (2) AID (10) MSB LSB MIH Protocol Frame & Header M= More Fragment Opcode= Operation Code Req= Request Res= Response Rsvd= Reserved Ack= Acknowledgement AID= Action Identifier FN= Fragment Number MSB= Most Significant Bit LSB= Least Significant Bit SID= Service Identifier UIR= Unauthenticated Information Request VER= Version

24Ralf Jennen, ComNets, RWTH Aachen University MN= Mobile Node PoA= Point of Attachment PoS= Point of Service RP= Reference Point MIH PoS MIH Non-PoS MIH MIH PoS Candidate PoA Serving PoA Non-PoA Network Entity Non-PoA Network Entity MN RP1 RP2 RP3 RP4RP5 RP4 RP5 MIH Reference Points

25Ralf Jennen, ComNets, RWTH Aachen University Flow Control (based on RFC 4443: ICMPv6) Limit rate of MIH messages Rate-limiting of forwarded messages is out of scope Token Bucket mechanism –Limiting the average rate of transmission to N, where N can be either packets/second or a fraction of the attached bandwidth of a link –Allowing up to B error messages to be transmitted in a burst, as long as the long-term average is not exceeded –The rate-limiting parameters should be configurable –In the case of a token-bucket implementation, the best defaults depend on where the implementation is expected to be deployed ICMPv6= Internet Control Message Protocol for the Internet Protocol version 6

26Ralf Jennen, ComNets, RWTH Aachen University Messsage Sequence Charts for Handover between WiMAX and two candidate WLAN access networks

UP Entity MIH_Get_Information.request Information Query MIH User MIHF MAC WiMAX MAC WLAN PoA WiMAX PoS WiMAX MIH User PMIPv6 Client MIIS Server PoA WLAN PoS WLAN MIH User PMIPv6 Client PoA Cn PoS Cn MIH User UP Entity MIH_Get_Information.Request MIH_Get_Information.Response MIH_Get_Information.confirm MIH_Net_HO_Candidate_Query.request MIH_Net_HO_Candidate_Query.Request MIH_Net_HO_Candidate_Query.indication MIH_Net_HO_Candidate_Query.response MIH_Net_HO_Candidate_Query.Response MIH_Net_HO_Candidate_Query.confirm MIH_N2N_HO_Resource.request MIH_N2N_HO_Resource.Request MIH_N2N_HO_Resource.indication MIH_N2N_HO_Resource.Request MIH_N2N_HO_Resource.responseMIH_N2N_HO_Resource.Response MIH_N2N_HO_Resource.confirmMIH_N2N_HO_Resource.indication MIH_N2N_HO_Resource.responseMIH_N2N_HO_Resource.Response MIH_N2N_HO_Resource.confirm Resource Availability Check Traffic flow b/w MN and Serving Network MIH_N2N_HO_Commit.request MIH_N2N_HO_Commit.RequestMIH_N2N_HO_Commit.indication MIH_N2N_HO_Commit.ResponseMIH_N2N_HO_Commit.response MIH_N2N_HO_Commit.confirm MIH_Net_HO_Commit.requestMIH_Net_HO_Commit.Request MIH_Net_HO_Commit.indication Response Preparation Pre-Registration Mobile Node Serving Network (MAG1, WiMAX) Other Network Candidate Network 1 (MAG2, WLAN) Candidate Network n (MAGn, WLAN) LMA/ AAA Traffic flow b/w MAG1 and LMA

UP Entity Link Up Indication MIH User MIHF MAC WiMAX MAC WLAN PoA WiMAX PoS WiMAX MIH User PMIPv6 Client MIIS Server PoA WLAN PoS WLAN MIH User PMIPv6 Client PoA Cn PoS Cn MIH User UP Entity Higher Layer (PMIPv6) Handover Execution Mobile Node Serving Network (MAG1, WiMAX) Other Network Candidate Network 1 (MAG2, WLAN) Candidate Network n (MAGn, WLAN) LMA/ AAA Higher Layer (PMIPv6) Handover Execution Proxy Binding Update (Lifetime=0) Proxy Binding Acknowledgement Buffering Establish new L2 connection Using Link_Action.request MIH_Net_HO_Commit.response MIH_Net_HO_Commit.Response MIH_Net_HO_Commit.confirm Link_Up.indication MIH_Link_Up.indication Detect MS’s Attachment Proxy Binding Update Proxy Binding Acknowledgement (Router Solicitation) Configure WLAN Interface Traffic flow b/w MN and Candidate Network 1 Traffic flow b/w MAG2 and LMA Router Advertisement Resource Release MIH_N2N_HO_Complete.request MIH_N2N_HO_Complete.Request MIH_N2N_HO_Complete.indication MIH_N2N_HO_Complete.response MIH_N2N_HO_Complete.Response MIH_N2N_HO_Complete.confirm