OBSS Preamble Detection May 2015 OBSS Preamble Detection Evaluation Date: 2015-05-11 Authors: Name Affiliations Address Phone Email Suhwook Kim LG Electronics 19, Yangjea-daero 11gil, Seocho-gu, Seoul 137-130, Korea +82-2-6912-6589 suhwook.kim@lge.com Wookbong Lee wookbong.lee@lge.com Hyeyoung Choi hy0117.choi@lge.com Jeongki Kim jeongki.kim@lge.com Kiseon Ryu kiseon.ryu@lge.com HanGyu Cho hg.cho@lge.com Suhwook Kim, LG Electronics

May 2015 Abstract This submission provides evaluation of OBSS preamble detection using PHY/MAC integrated simulator We use preamble decoding procedure which is agreed within integrated simulator member We consider frame type (Data/ACK) and link direction (DL/UL) to analyze OBSS preamble detection probability Suhwook Kim, LG Electronics

Submissions on Preamble Detection May 2015 Submissions on Preamble Detection 14-1420r1[1], 15-367r0[2] Evaluate OBSS preamble detection using MAC simulator OBSS preamble error probability is above 80% Suhwook Kim, LG Electronics

Preamble Error Model May 2015 Signal Detect: At the start of preamble, Preamble Error Detect Preamble PPDU Signal Detect: At the start of preamble, If the signal strength is above -82 dBm, receiver can start to detect the PPDU. [1] The receiver should be in IDLE status to detect the preamble. If the receiver is sending/receiving a frame or processing in inter-frame (SIFS), it cannot detect any preamble even though the signal strength is above -82 dBm Preamble Error Detect: At the end of preamble, In 1420r1, if minimum SINR ≤ 0 dB in preamble duration, then the preamble has errors. Otherwise, the preamble is correct. [1] But in this submission, we use SINR-PER curve which is addressed from Box 0 calibration with channel model defined in SS document (980r10) Preamble is modeled as 24 bits/symbol (BPSK 1/2) [3] Preamble of Data frame: L-Part (5 symbols) + VHT-Part (5 symbols) Preamble of Control frame: L-Part (5 symbols) Suhwook Kim, LG Electronics

May 2015 Preamble Error Model The receiver will be locked by the first-arrived packet, and later-arrived packets are considered as interference [3] If preamble passes, the receiver continues to receive the rest part of the packet [3] If successfully decoding of a MAC frame, defer for NAV; Otherwise, set CCA to busy for the entire PPDU If preamble fails, the receiver terminates current reception [3] The entire PPDU fails The receiver is unlocked again and then CCA-ED threshold is used to determine if the medium is busy In this submission, CCA-ED=-62 dBm Suhwook Kim, LG Electronics

Simulation Setup [2] May 2015 Simulator Type MAC simulator (in 367r0) PHY/MAC Integrated simulator Tx Power (AP/STA) 20/15dBm Antenna Gain (AP/STA) 0/-2 dBi Traffic Model UL only full buffer (in 367r0) DL only, UL only, mixed DL&UL full buffer BSS Bandwidth 80MHz Noise Figure Noise Floor -101dBm per 20MHz Rate Control Algorithm single MCS chosen per link to maximize goodput (in 367r0) Open Loop Link Adaption [4] MSDU size (bytes) 1476 TXOP size 4 ms Max Retx 10 Simulation Time (sec) PER Curve AWGN(in 367r0) addressed from Box 0 calibration Suhwook Kim, LG Electronics

Simulation Setup: modified Scenario 1 [2] May 2015 Simulation Setup: modified Scenario 1 [2] Same as 15-367r0[2] 3 channels Chosen to maximize distance between two apartments one 1 channel. 5 STAs per AP 1 antenna per AP & STA Suhwook Kim, LG Electronics

Throughput May 2015 5% 50% 90% Mean DL only 0.67 Mbps 10.15 Mbps UL only 3.24 Mbps 7.69 Mbps 27.33 Mbps 11.80 Mbps DL (in DL&UL) 1.08 Mbps 2.59 Mbps 4.65 Mbps 2.82 Mbps UL (in DL&UL) 2.36 Mbps 5.74 Mbps 14.13 Mbps 7.65 Mbps Suhwook Kim, LG Electronics

May 2015 Preamble detection Nt: number of total OBSS preambles which has signal strength above -82 dBm Nd: number of detected OBSS preambles signal strength is over -82 dBm & arrived at IDLE status Ns: number of success decoded OBSS preambles Suhwook Kim, LG Electronics

OBSS Preamble detection May 2015 OBSS Preamble detection Nd / Nt Ns / Nd Ns / Nt DL only DL Data 90.51% 46.17% 41.79% UL ACK 92.50% 71.73% 66.35% UL only UL Data 63.07% 63.08% 39.78% DL ACK 65.35% 99.14% 64.79% DL & UL 61.09% 27.11% 16.56% 63.42% 51.83% 32.87% 57.93% 50.40% 29.20% 63.28% 99.21% 62.78% Suhwook Kim, LG Electronics

OBSS Preamble detection per BSS May 2015 OBSS Preamble detection per BSS Suhwook Kim, LG Electronics

RSSI of detected OBSS preambles May 2015 RSSI of detected OBSS preambles Data Frame Preamble sent by STA Preamble sent by AP Suhwook Kim, LG Electronics

RSSI of detected OBSS preambles May 2015 RSSI of detected OBSS preambles ACK Frame Preamble sent by STA Preamble sent by AP Suhwook Kim, LG Electronics

Effective SINR of detected OBSS preambles May 2015 Effective SINR of detected OBSS preambles Data Frame – Success Maximum SINR of BPSK ½ in MMIB = 9.1 dB Preamble sent by AP Preamble sent by STA Suhwook Kim, LG Electronics

Effective SINR of detected OBSS preambles May 2015 Effective SINR of detected OBSS preambles Data Frame – Failed Preamble sent by AP Preamble sent by STA Suhwook Kim, LG Electronics

Effective SINR of detected OBSS preambles May 2015 Effective SINR of detected OBSS preambles ACK Frame – Success Maximum SINR of BPSK ½ in MMIB = 9.1 dB Preamble sent by STA Preamble sent by AP Suhwook Kim, LG Electronics

Effective SINR of detected OBSS preambles May 2015 Effective SINR of detected OBSS preambles ACK Frame – Failed Preamble sent by AP Preamble sent by STA Suhwook Kim, LG Electronics

Simulation Setup: Scenario 3 May 2015 Simulation Setup: Scenario 3 1 channel 19 APs operate in one same channel 30 STAs per AP 1 antenna per AP & STA ICD = 30 meter 2 1 3 4 5 6 16 15 9 10 7 14 11 12 17 8 18 13 Suhwook Kim, LG Electronics

Throughput May 2015 5% 50% 90% Mean DL only 0.0 Mbps 0.50 Mbps UL only 0.75 Mbps 2.32 Mbps 1.02 Mbps DL (in DL&UL) 0.32 Mbps 0.08 Mbps UL (in DL&UL) 0.73 Mbps 2.20 Mbps 0.98 Mbps Suhwook Kim, LG Electronics

OBSS Preamble detection May 2015 OBSS Preamble detection Nd / Nt Ns / Nd Ns / Nt DL only DL Data 93.22% 31.49% 29.35% UL ACK 97.53% 52.41% 51.11% UL only UL Data 73.24% 35.53% 26.02% DL ACK 84.28% 99.05% 83.48% DL & UL 78.84% 15.31% 12.07% 83.62% 17.85% 14.92% 72.65% 34.47% 25.04% 84.23% 99.01% 83.39% Suhwook Kim, LG Electronics

OBSS Preamble detection per BSS May 2015 OBSS Preamble detection per BSS Suhwook Kim, LG Electronics

RSSI of detected OBSS preambles May 2015 RSSI of detected OBSS preambles Data Frame Preamble sent by STA Preamble sent by AP Suhwook Kim, LG Electronics

RSSI of detected OBSS preambles May 2015 RSSI of detected OBSS preambles ACK Frame Preamble sent by STA Preamble sent by AP Suhwook Kim, LG Electronics

Effective SINR of detected OBSS preambles May 2015 Effective SINR of detected OBSS preambles Data Frame – Success Maximum SINR of BPSK ½ in MMIB = 9.1 dB Preamble sent by AP Preamble sent by STA Suhwook Kim, LG Electronics

Effective SINR of detected OBSS preambles May 2015 Effective SINR of detected OBSS preambles Data Frame – Failed Preamble sent by STA Preamble sent by AP Suhwook Kim, LG Electronics

Effective SINR of detected OBSS preambles May 2015 Effective SINR of detected OBSS preambles ACK Frame – Success Maximum SINR of BPSK ½ in MMIB = 9.1 dB Preamble sent by STA Preamble sent by AP Suhwook Kim, LG Electronics

Effective SINR of detected OBSS preambles May 2015 Effective SINR of detected OBSS preambles ACK Frame – Failed Preamble sent by AP Preamble sent by STA Suhwook Kim, LG Electronics

May 2015 Conclusion In this submission, we evaluate OBSS preamble detection using PHY/MAC integrated simulator We ran the simulations in modified residential scenario and indoor small BSS scenario We observed following trends Preamble error prob. of Data frame is HIGHER than ACK frame Preamble error prob. of DL Data frame is HIGHER than UL Data frame On the other hand, preamble error prob. of DL ACK frame is LOWER than UL ACK frame Preamble error prob. is generally higher in mixed DL&UL traffic model Preamble of DL ACK is almost decoded successfully (~99%) Suhwook Kim, LG Electronics

May 2015 Reference [1] 11-14/1420r1 The Impact of Preamble Error on MAC System Performance [2] 11-15/0367r0 OBSS Preamble Detection [3] 11-14/1523r5 Offline Discussion Minutes of SLS Calibration [4] 11-14/620r0 link adaptation for PHY SLS calibration Suhwook Kim, LG Electronics