May 2003 doc IEEE 802 11 03376 r

May 2003 doc. : IEEE 802. 11 -03/376 r 0 Throughput Enhancement via Frame Aggregation Sunghyun Choi*, Youngsoo Kim*+, Hyosun Hwang+, and Kyunghoon Jang+ *Seoul +Samsung Submission National University (SNU) and Advance Institute of Technology (SAIT) 1 S. Choi, SNU and Youngsoo Kim, Samsung/SNU

May 2003 doc. : IEEE 802. 11 -03/376 r 0 Contents • Introduction • Throughput performance analysis by packet size • Frame aggregation • Result – Throughput analysis – Performance evaluation by real platform • Conclusion Submission 2 S. Choi, SNU and Youngsoo Kim, Samsung/SNU

May 2003 doc. : IEEE 802. 11 -03/376 r 0 Introduction • Objective – To achieve high throughput/efficient schemes to improve the current 802. 11 MAC/PHY • Background – 802. 11 MAC/PHY has fixed overheads irrespective of packet size – The small-size packet can cause more throughput degradation – To reduce the overheads is the one of main concerns to enhance current 802. 11 WLAN Submission 3 S. Choi, SNU and Youngsoo Kim, Samsung/SNU

May 2003 doc. : IEEE 802. 11 -03/376 r 0 Frame Size Affects Throughput • 802. 11 MAC/PHY have big fixed overheads – MAC header, IFSs, ACK, and Backoff – PLCP preamble & header Submission 4 S. Choi, SNU and Youngsoo Kim, Samsung/SNU

May 2003 doc. : IEEE 802. 11 -03/376 r 0 Throughput Performance Analysis • Assumptions – There is a single transmitter and a single receiver – The 802. 11 DCF is used – All the datagrams have a fixed size – The transmitter has infinite number of datagrams – Throughput is determined at the LLC SAP between LLC and IP Submission 5 S. Choi, SNU and Youngsoo Kim, Samsung/SNU

May 2003 doc. : IEEE 802. 11 -03/376 r 0 Theoretical Throughput for 54 Mbps Preferred Operation Range However, … Submission 6 S. Choi, SNU and Youngsoo Kim, Samsung/SNU

May 2003 doc. : IEEE 802. 11 -03/376 r 0 Internet Packet Size Distribution • Reference: by Agere in Hot Chips ’ 01 • There are too many small packets !!! Submission 7 S. Choi, SNU and Youngsoo Kim, Samsung/SNU

May 2003 doc. : IEEE 802. 11 -03/376 r 0 Frame Aggregation • Aggregation of multiple frames in order to reduce the fixed overheads relatively! • Aggregation was once part of 802. 11 e in 802. 11 e/D 1. 0 – It defined a new management frame for this aggregation mechanism – Multiple MSDUs are aggregated into a single management frame Submission 8 S. Choi, SNU and Youngsoo Kim, Samsung/SNU

May 2003 doc. : IEEE 802. 11 -03/376 r 0 Frame Aggregation Made Easy! • Our proposal is defining the frame aggregation above the MAP SAP !!! • We don’t need a new frame type for this purpose – A normal MPDU can be used as the aggregated frame arrives at the MAC SAP as an MSDU • This can be added into any existing MAC implementation with minor SW modification !!! Submission 9 S. Choi, SNU and Youngsoo Kim, Samsung/SNU

May 2003 Original doc. : IEEE 802. 11 -03/376 r 0 Frame Formats (Example) With aggregation Submission 10 S. Choi, SNU and Youngsoo Kim, Samsung/SNU

May 2003 doc. : IEEE 802. 11 -03/376 r 0 Modified 802. 11 Reference Model • Adding a proxy sublayer called Aggregation Sublayer Submission 11 S. Choi, SNU and Youngsoo Kim, Samsung/SNU

May 2003 doc. : IEEE 802. 11 -03/376 r 0 Theoretical Throughput w/ Aggregation Submission 12 S. Choi, SNU and Youngsoo Kim, Samsung/SNU

May 2003 doc. : IEEE 802. 11 -03/376 r 0 Performance Measurement • Implement frame aggregation in real platform • Linux & Intersil-based platform Traffic source 1 AP STA Traffic source 2 Traffic source 3 Submission 13 S. Choi, SNU and Youngsoo Kim, Samsung/SNU

May 2003 doc. : IEEE 802. 11 -03/376 r 0 Measurement Results Submission 14 S. Choi, SNU and Youngsoo Kim, Samsung/SNU

May 2003 doc. : IEEE 802. 11 -03/376 r 0 Conclusion • Shown via analysis that frame aggregation is a good way to improve 802. 11 MAC efficiency • Measurements from real implementation also show the performance enhancement • Frame aggregation can be done above the MAC SAP very easily • Frame aggregation can be considered an enhanced mechanism Submission 15 S. Choi, SNU and Youngsoo Kim, Samsung/SNU

May 2003 doc. : IEEE 802. 11 -03/376 r 0 Any Comments or Questions ? Submission 16 S. Choi, SNU and Youngsoo Kim, Samsung/SNU