Network-assisted resource management for wireless data networks Xiaoxin Qiu Kapli Chawla Justin C.-I. Chuang Nelson Sollenberger July, 2001 IEEE Journal on Select Areas in Communications

2 Prolog Next generation Wireless system will provide packet data based service with low cost and high spectrum efficiency So, the efficient radio resource management is important ！

3 Outline Introduction Earlier Resource Management Network-Assisted Resource Management NA-LI-DPA and NA-DPA with Max Throughput Simulation Results and Analysis System model Compare with RPA Conclusion

Network-assisted resource management for wireless data networks Introduction

5 Intro. (1/5) FCA (Fixed Channel Assignment) A area is partitioned into a number of cells A number of channels are assign to each cells Can ’ t adapt to traffic conditions and user distribution

6 Intro. (2/5) DCA (Dynamic Channel Assignment) The main idea is to evaluate the cost of using each candidate channel, and select the Min. cost channel Most DCA algorithms are designed efficient for voice Reference from IEEE Personal Communication, June 1996

7 Intro. (3/5) DPA (Dynamic Packet Assignment) Algorithm 1.MS looks to the STRONGEST BS. 2.BS broadcasts destination MS IDs and numbers of packets to be delivered 3.MS scans all DOWNLINK pilots and sends list of acceptable channels to BS 4.BS assigns channels to all packets and broadcasts MS IDs, assigned channels 5.BS delivers packets on the assigned channels and sends pilots.

8 Intro. (4/5)

9 Intro. (5/5) Reference from:IEEE J. Select. Area Commum. Aug 1998

Network-assisted resource management for wireless data networks Network-Assisted Resource Management

11 Network-Assisted Least- interference-based DPA (1/2) Idea ： For BS to calculate the SINR Need ： channel occupancy and path loss How to calculate SINR ： P:power G ii 和 G ji :path loss Q jk :channel occupancy n i :noise

12 Network-Assisted Least- interference-based DPA (2/2) A channel with a MAX SINR is assigned to the user Transmission mode depend on link quality Optional Enhancement with Mode-0 NA-LI-DPA+ In interference-limited wireless data network

13 Network-Assisted DPA with MAX throughput (1/3) Idea ： Optimize the overall links Need ： channel occupancy and path loss(2) Throughput: T: system throughput A: current resource assignment

14 Network-Assisted DPA with MAX throughput (2/3) Algorithm: 1. 計算現在的 T(A) and A : (resource assignment) 2. 計算 user i 的 Ai （ k ） at channel k Ai =( c i, m i, P) T （調整 m i 後） 3. 計算 T(A ⊕ Ai(k)) 以求出最好的 throughput A i OPT = arg (max Ai （ k ） (T(A ⊕ Ai(k))) 最後的選擇： T(A ⊕ A i OPT )

15 Network-Assisted DPA with MAX throughput (3/3) 判斷式： Reassign an existing user: Ex: To different channel Starting assignment =

Network-assisted resource management for wireless data networks Simulation Results and Analysis

17 System Model Traffic ： best-effort data （ downlink ） PHY layer: EGPRS-like frame structure Modulation B-O-QAM (Binary-offset QAM) Q-O-QAM (Quaternary-offset QAM) Link layer:RLC/MAC sub layer （ EGPRS ）

18 Transmission Mode

19 Performance Result (1/4) Average user throughput (1/2)

20 Performance Result (2/4) Average user throughput (2/2)

21 Performance Result (3/4) Aggregate throughput per site

22 Performance Result (4/4) Average number of users per site

Network-assisted resource management for wireless data networks Conclusion

24 Conclusion (1/2) FCA 、 DCA 、和 DPA 的介紹 NA-LI-DPA 和 NA-DPA with MAX throughput Idea: 利用 Inter-base signal 來將 resource allocation 的負擔從 air interface or terminal 轉移到 Backbone 和 BS Terminal just calculate path loss SINR 和 channel occupancy 交給 BS

25 Conclusion (2/2) Just for single service （ downlink data ） Advantage: 提升 throughput 和減低 terminal 的負擔 Question: Power control ? Bandwidth for inter-base signal Integrate voice and data ? Does it suitable for another system?