Network-assisted resource management for wireless data networks

1. 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 spectrumefficiency • 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

4. 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

10. 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 Gii和Gji:path loss Qjk:channel occupancy ni: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 =( ci, mi, P)T（調整mi後） • 3.計算T(A⊕Ai(k))以求出最好的throughput AiOPT = arg (max Ai（k）(T(A⊕Ai(k))) 最後的選擇： T(A⊕AiOPT)

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

16. 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

23. 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?