xx Layer2.5functionality Layer 2.5 Functionality Peretz Feder Ajay Rajkumar Lucent Technologies May 13, 2004

xx Layer2.5functionality Objectives 1.To crystallize the concept and boundary of layer To describe the scope of the triggers with relation to Layers 3 and Define interfaces to mobility management at layer 3 4.Identify the decision entity and its relation to the executive entity

xx Layer2.5functionality IETF based Layer 3 Mobility mechanism is Mobile IP Handover capable Layer 3 mobility is not optimized for real time applications Objective is to improve or assist layer 3 handover performance Do we have the mandate to change it in ? Lets explore layer 3-

xx Layer2.5functionality Layer 2.5 Boundary Definition Mobile NodeNetwork

xx Layer2.5functionality Mobility Model Multi radio interface at the MT Network may not control (or own) all the interfaces available to the MT Propose to include a layer 2.5 entity at the MT that selects one of the available interfaces. However, the selection mechanism is vendor specific!! Network has peer-to-peer relation with the state machine entity Network assisted through handover recommendation Network assisted through SLA directory update Upon decision, L2.5 invokes the layer 3 (IP) handover mechanism providing it a single access choice

xx Layer2.5functionality Layer 2.5 Selection Entity Selects a preferred access and let layer 3 execute without delay How? Process all the triggers and apply a vendor specific algorithm Triggers include locally measured attributes, loading conditions, available QoS, normalized signal quality Hints include cost of link, roaming agreements, network provided neighboring list

xx Layer2.5functionality Example: Preference Rules Translated into Decision Matrix Air- interface 3G High 3G Medium 3G Low 3G Unavailable High Med Low 3G NA 3G Work offline or sleep medium_threshold is preferred over 3G high_threshold low_threshold is preferred over 3G medium_threshold

xx Layer2.5functionality Example: Preference Rules Translated into Decision Matrix Interface NA High Med Low NA Work offline or sleep is preferred over any_threshold

xx Layer2.5functionality Recommendation Dont attempt to fix layer 3 deficiencies Develop layer 2+ entity that assists layer 3 mobility Dont waste time defining the selection algorithm Make layer 3 execute the handover decision Define the interface to L3. Bidirectional SAP or Ethertype_21? –3G cant talk the Ethertype language –MIB is too slow