1. Aug 2012 1 LTE-cdma2K 1x/eHRPD Idle Reselection Solutions

2. Aug 2012 2  Background  Requirement from China Telecom at Nanjing meeting, refer to [C22- 20120206-020 CT-Requirement for loading balance between eHRPD and E-UTRAN]. Load balancing between eHRPD and E-UTRAN 2

3. Aug 2012 3  A new attribute UEClass is proposed.  UEClass is created from subscription data or operator/vendor-based policy.  UEClass is sent to UE by AN via UEClass attribute during eHRPD session negotiation  eAN obtains each UE’s UEClass in following ways  Through Inter-User Priority parameter from 3GPP2 AAA  Or from other parameters sent from 3GPP MME  When network detects its loading problem:  eNB broadcasts inter-RAT reselection rules using UEClass bitmap to the UEs through overhead signaling Proposal 3

4. Aug 2012 4  If UEClass bitmap is provided by eAN, AT will perform the followings:  If AT finds its assigned UEClass is directed to stay in eHRPD by eAN, then the AT puts eHRPD ServingPrioirty as highest and overrides LTE priority and follows existing reselection procedure  If AT finds its assigned UEClass is directed go to LTE by eAN, then the AT ignores eHRPD ServingPriority and follows existing reselection procedure  Otherwise, if UEClass bitmap is not provided, then AT follows existing reselection procedure with the parameters defined in OtherRATNeighborList message Proposal (cont’) 4

5. Aug 2012 5  Assume the total UEClass number is 8, bits 13~6 are part 1 (YELLOW): UEClass reselection indicator  Bit 13=0 means eAN directs ATs of UEClass8 stay in eHRPD  Bit 13=1 means eAN directs ATs of UEClass8 go to EUTRAN  Bits 12~6 follow the same way for UEClass7~1  Bits 5~1 are part 2 (BLUE): Random reselection indicators.  Together with part1 bits, part 2 bits are used to further specify which types of IMSIs are selected (associated bits set to ‘1’) for the UEClass randomization.  UEs without assigned UEClass or assigned UEClass but corresponding random reselection indicators w/ ‘0’ will follow existing reselection procedure UEClass Bitmap Format UEClass 8 indicator Bit 1Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 Bit 13 … UEClass1 indicator Random Reselection indicator for UATI%10=0,1 Random Reselection indicator for UATI%10=2,3 Random Reselection indicator for UATI%10=4,5 Random Reselection indicator for UATI%10=6,7 Random Reselection indicator for UATI%10=8,9

6. Aug 2012 6  Example 1: All UEs in UEClass 8 go to EUTRAN, UEs in UEClass 1 stay in eHRPD, w/o randomization  Example 2: UEs in UEClass 8 will go to EUTRAN with randomization, UEs in UEClass 1 will stay in eHRPD with randomization. UEs with UATI%10=0,1,2,3,6,7 are selected; UEs with UATI%10=4,5,8,9 will follow existing reselection procedure UEClass Format Examples MSB LSB UEClass8 1 UEClass8 1 Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 Bit 13 … … UEClass1 0 UEClass1 0 1 1 1 1 1 1 1 1 1 1 UEClass8 1 UEClass8 1 Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 Bit 13 …. UEClass1 0 UEClass1 0 1 0,1 1 0,1 1 2,3 1 2,3 0 4,5 0 4,5 1 6,7 1 6,7 0 8,9 0 8,9

7. Aug 2012 7 Inter-RAT reselection when UEClass Bitmap is provided (Call Flow) AT1AT2 eHRPD Session Negotiation with AT1(UEClass=k) Broadcast InterRATLoad infor ( UEClassBitmap exists, UE Classk=0, UEClassm=1) E-UTRAN eHRPD Session Negotiation with AT2 (UEClass=m) eHRPD AT2 is in eHRPD idle state AT1 is in eHRPD idle state AT2 goes to E-UTRAN AT1 stays in eHRPD

8. Aug 2012 8 Inter-RAT reselection when UEClass Bitmap is not provided (Call Flow) AT1AT2 eHRPD session Negotiation b/w eAN and AT1(UEClass=k) Broadcast InterRATLoad infor ( No UEClass Bitmap ) E-UTRAN eHRPD Session Negotiation b/w eAN and AT2 (UEClass=m) eHRPD AT2 is in eHRPD idle state AT1 is in eHRPD idle state AT1 and AT2 follow existing reselection procedure and may stay in eHRPD AT1 and AT2 follow existing reselection procedure and may switch to E-UTRAN

9. Aug 2012 9  Load balancing between LTE and eHRPD can be achieved through the approach defined in this proposal.  The negotiation for UEClass between AT and AN provides a flexible way to deliver AT’s Inter-RAT load class.  UEClass can be obtained either from Inter-user Priority from AAA, or from MME  UEClass bitmap can be provided to activate the usage of UEClass when necessary  Provides flexible control from the network,  Keeps backward compatible with the existing reselection procedures. Summary

10. Aug 2012 10 Thanks