68th IETF, Prague Czech Republic

Issues with L2 abstractions and how they affect QOS-based handovers

Nada Golmie

Advanced Networking Technologies DivisionNational Institute of Standards and Technologies

Gaithersburg, MD 20899USA

http://www.antd.nist.gov/seamlessandsecure.shtml

268th IETF, Prague Czech Republic

Media Independent Handover Architecture

What are the performance implications for the MIH transport protocol over layer 3? What are the protocol interactions and performance implications between the MIH layer being specified and layer 3 mobility protocols such MIPv6, HMIP and FMIP?

Mobile Node Access Point

Set triggerTrigger Set

trigger Trigger

User Preferences

QOS

Measurementsor

L2 trigger

Queryor

configure

TriggerSet

trigger

ApplicationHandover DecisionEngine (QDE)

IEEE 802.21

L22L21L2

Queryor

configure

Measurementsor

L2 trigger

Implementation specific

IEEE 802.21

Layer 3 Layer 3

Layer 3 transport

68th IETF, Prague Czech Republic

QOS-based handovers building blocks

1. Application QOS requirements

2. Measurements characterizing the network performance conditions: Consider instantaneous network conditions end-to-end Derive abstraction of link specific parameters

3. A QOS-based Decision Engine (QDE): Considers application QOS requirements and network performance

measurements Performs appropriate actions when triggers are received

4. Signalling and information exchange Exchange information between various network entities and the QDE,

including technology and protocol types, network measurements Set and relay link triggers For example the Media Independent Handover (MIH) function (IEEE

802.21) at layer 2.5

468th IETF, Prague Czech Republic

Media Independent Handover Architecture

Why L2 abstractions?Link specific parameters are not the same across different media types

and implementations and therefore they cannot be used at higher layers without a complete description of the media and the implementation.

Main issues with L2 abstractions: Mapping function between link specific measurements and L2

abstractions: Provides information to higher layers about the status of the link Configures and sets link specific thresholds

No one-to-one mapping between link specific measurements and L2 abstractions

The need to characterize the network conditions end-to-end Cached measurements from past observations and previous connections Default estimates Measurements can be obtained via the MIH using the Information service

or other network nodes.

68th IETF, Prague Czech Republic

Issues with the Media Independent Handover Architecture

668th IETF, Prague Czech Republic

MIH Transport Protocol Design in Mipshop

• Define the delivery of information for MIH event, command and information services through a “layer 3 or above” protocol• Availability of information anywhere in the network• Use of MIH services even in the absence of MIH L2

support • Re-use of existing L3 discovery and signaling

mechanisms• Has received several proposals including DHCP, GIST,

UDP and has formed protocol design team.