1. Com & Net Call admission control (JABA-SD = MBA-SD) May 14, 2002 김 영 덕

2. 2 ydkim Call admission controlISDL Outline  Introduction  CAC Review  JABA-SD, MBA-SD  Formulation of the burst admission control Measurement Sub-Layer Scheduling Sub-layer  Optimal Solution  Implementation issue  Result  Considerations  Reference

3. 3 ydkim Call admission controlISDL Review  Call admission control  Preventive congestion control.  Typical Condition of decision to accept New connection dose not affect the QoS of current connection Can provide the QoS requested by the new connection?  CAC schemes Non – Statistical allocation (peak bandwidth allocation) Statistical allocation  Basic components of Admission control

4. 4 ydkim Call admission controlISDL Introduction  Contribution  Formulate the burst admission as an integer programming problem.  Optimal burst scheduling algorithm for multiple burst requests  Illustration of the importance of interaction between adaptive physical layer and the burst algorithm.  CDMA  Spreading limit : Increase BW -> Wideband  Law of large number -> Burst admission contorl

5. 5 ydkim Call admission controlISDL Channel model(P layer)  Fading Channel model  Fast fading (Rayleigh fading)  Slow fading (log-normal fading)

6. 6 ydkim Call admission controlISDL Adaptive coding & Modulation  Adaptive coding  Using CSI(Channel State Information)  Variable coding Scheme depending on channel condition Ex)  Spreading stage  Spreading by PN sequence T b : bit duration T s : Symbol duration T c : Chip duration W : system BW : Instantaneous bit rate g : spreading gain Overall Processing gain : Instantaneous Symbol Energy to interference ratio :

7. 7 ydkim Call admission controlISDL Adaptive coding & Modulation(Cont’d)  Relative average bit rate of SCH  Required Tx power ratio

8. 8 ydkim Call admission controlISDL Formulation  Measurement Sub-Layer  Forward Link Measurement Admissible region Factor of measurement  Current cell loading Pk  Current forward link loading  Reverse Link Measurement Soft- Handoff Cells Neighbor cells not in soft -handoff  Admissible region(reverse link)  Factor of measurement Reverse link inteference Reverse pilot strength measurement from soft hand off cells Forward link pilot strength measurement reported from mobile user

9. 9 ydkim Call admission controlISDL Formulation(Cont’d)  Scheduling Sub – layer  Objective function System resource utilization Overall system delay Delay penalty function

10. 10 ydkim Call admission controlISDL Optimal solution  Optimization problem  Contnstraint  Recursive form  Problem solve step  Step1 : Resource space partitioning  Step2 : Quantization  Step3 : Partial Resource allocation  Step4 : Termination

11. 11 ydkim Call admission controlISDL Step I  Resource Space Partitioning Resource space Define Set Non overlaping sub space Completet pattition :

12. 12 ydkim Call admission controlISDL Step2/3  Quantization Quantize non-empty partitions to evaluation of. Define Quantization partition  Partial Resource Allocation

13. 13 ydkim Call admission controlISDL Step 4  Termination  Resulting optimal allocation

14. 14 ydkim Call admission controlISDL Sub-optimal Solution  Resource Index  Priority Function Higher priority : Occupy Small system resource & long wait time Iteration start : p=1 where Try to allocate m resource to one of the competing requests accoding ti their priorities. Highest priroity : Iteration Stop :

15. 15 ydkim Call admission controlISDL Simulation result  Base line I : First come First serve  Base line II : JABA (Physical layer & Burst admission layer are isolate)  Number of channels available on the forward link with Varying distances from the base-station  Forward link coverage area as a function of number of channels.

16. 16 ydkim Call admission controlISDL Simulation result(Cont’d)  Average admission probabilities on the reverse link.  Outage probabilities for voice users.

17. 17 ydkim Call admission controlISDL Consideration  Challenging Problem  Additional dimension first investigate the effects of the inter-dependence among new and backlog requests the variations in channel conditions (which may render pre-determined scheduling decisions obsolete or irrelevant)  Avenue Research to incorporate fairness considerations in making admission control and scheduling decisions considering incorporating fairness factor