Performance Analysis of Control Hold, Suspended, and Dormant State for Packet Data Services December 8, 1998 D. N. Knisely Lucent Technologies 1100 E. Warrenville Rd. Naperville, IL (630) (630) (fax) COPYRIGHT STATEMENT © Copyright Lucent Technologies, Bell Labs, 1998; Permission is granted to Telecommunications Industry Association (TIA) participants to copy any portion of this document for the legitimate purposes of the TIA. Copying this document for monetary gain or other non-TIA purposes is prohibited. NOTICE This contribution has been formulated to assist the TIA TR-45.5 Subcommittee. The document is submitted to the Subcommittee as a basis for discussion and is not binding on Lucent Technologies. The contents may be subject to change in form and numerical value after further study. Lucent Technologies specifically reserves the right to add to or amend the quantitative statements made herein. TR /98.12.____.____ TR /98.12.____.____

December 8, Goal: How can the Physical Layer Best Support the MAC for Packet Data Services? Provide a Quantitative Method to Determine the Relative Merits of the cdma2000 Phase 1 MAC States for Realistic Packet Data Scenarios Define the Appropriate Characteristics of a Typical Packet Data Service Session Establish a Model for cdma2000 Phase 1 MAC/Physical Layer Packet Data Operation: –Active -> Control Hold -> Active –Active -> Suspended -> Active –Active -> Dormant -> Active Analyze the Model for Representative Cases

December 8, Overview Packet Data Model Attributes Classification of “Gaps” in Packet Data Model of Air Interface for CH, Suspended, and Dormant States Analysis of CH, Suspended, and Dormant States for Various Gap Sizes Conclusions Recommendations

December 8, Packet Data Traffic Model

December 8, Packet Model - Parameters

Packet Model - Comparison of CHS, Suspended, and Dormant

Packet Model - With Control Messages

December 8, Assumptions Generally Assumes Highly Optimized Implementations –Nearly Ideal Over the Air Scenarios –Small Backhaul Delays –No Intervals for IWF Latency, A-interface Latency, etc. –Greatly Improved Common Channel Access Methods (for Suspended and Dormant) Control Hold State == Control Hold Normal Substate Suspended State == Suspended Slotted Substate Assume No Mobile Station Mobility; Re-connect Never Requires Page Only Direct Transitions to Target States Modeled –I.e., Active -> (CH/Suspended/Dormant) -> Active –Results for Multi-hop Transitions are Considerably Worse Mobile Terminated Transitions Modeled –Most Important Gaps are in Forward Traffic –Initial Gap when MS Initiates a Transaction (t1) Not Considered Most Optimistic Assumptions for Control Hold State –Distributed Control; Minimal Infrastructure Delays –“Quick” Channel Assignments and State Transition Signaling are 5 ms –Assume Active State == Continuous Transmission at 9.6 Kbps; for Higher Rate Bursts, Relative Differences between CH, Suspended, and Dormant are Much Smaller Reduced Power Control Effectiveness and Re-stabilization of PC Not Considered for CHS DTX Operation Tactive = 0 Pin-hold = ~-11 dB P1/8-rate = ~-7 dB

December 8, Model Parameter Values Comparison of CHS, Suspended, and Dormant for Intra-Transaction (t3) Gaps

December 8, Model Parameter Values Comparison of CHS, Suspended, and Dormant for Inter-Transaction (t4) Gaps

December 8, Model Parameter Values Comparison of CHS, Suspended, and Dormant for Inter-Session (t5) Gaps

December 8, Anatomy of Trtt(-dcch) Small Gap Performance Very Sensitive to Trtt- dcch

December 8, Observations Optimizing Small Gaps (<400 ms) is Very Difficult and Probably Not Worth the Required Complexity –Gains are Small Even Under Optimal Assumptions –Cost is Significant (False Transitions, Additional Resource Allocation and Signaling Overhead, etc.) MAC/RLP Provides an Efficient Mechanism to Trigger Movement Out of Active (“Q-bit”) –However, Triggers for Subsequent Transitions (e.g., Control Hold to Suspended) are More Complex and Less Effective (e.g., Timeouts) Differences between Control Hold vs. Suspended/Dormant are Surprisingly Small (Even for Very Small Gaps) –e.g., Added Latency for 200 ms Gaps  Control Hold: 50%  Suspended: 60%  Dormant: 90% –Overall Transmit Power Difference Negligible  Suspended: <.1dB  Dormant: <.2 dB For Gaps >> 200 ms, Suspended or Dormant Incurs Less Interference than Control Hold with Small Increase in Latency

December 8, Observations (Cont’d) Control Hold and Suspended are Alternatives, Not Complementary for Small Gaps –Multi-step Transitions (e.g., Active -> CHS -> Suspended) Make Delay Even Worse with Negligible Benefit Differences between Suspended and Dormant are Small for Packet Data Scenarios, Assuming: –Make Common Improvements to Both States (i.e., Quick Reconnect; Improved Common Channel Operation) –Only Difference is RLP Reset (<= 1 RTT) –RLP Reset May be Required in Many Cases Anyway Control Hold Slotted Substate Seems Not to be a Good Fit for Packet Data Scenarios –If Slot Interval is Big Enough for Real Savings, then Suspended or Dormant would be Better Alternatives cdma2000 Standard Differs from the Concepts in the RTT –MAC Matches the RTT Closely –Physical Layer Support for MAC States/Substates Does Not Match RTT Descriptions –May Need to Resync… Some Simplification May be Possible

December 8, Conclusions (Cont’d)

December 8, Conclusions (Cont’d)

December 8, Recommendations Discuss, Refine, and Adopt Model for Analysis of Physical Layer Modes of Operation that Support of Packet Data MAC States Utilize the Model to Analyze Physical Layer Alternative Proposals for Control Hold and Suspended States/Substates –Control Hold Normal vs. Gated vs. Slotted –Suspended Normal vs. Slotted –Suspended vs. Dormant