January 2013 doc.: IEEE 802.11-13/0153r0 July 2017 Measurements of temporal occupancy and a comparison of indoor performance of OFDM vs CCK/DSSS Authors: Date: 2016-07-11 Jim Lansford (Qualcomm/CU-Boulder) Clint Chaplin, Chair (Samsung)

Abstract As a class project, students made measurements of: January 2013 doc.: IEEE 802.11-13/0153r0 July 2017 Abstract As a class project, students made measurements of: 1) Channel occupancy of WLAN traffic in different environments to assess how much time is spent in each of the data rates and overall protocol efficiency, and 2) Comparison of indoor performance of OFDM vs CCK/DSSS Jim Lansford (Qualcomm/CU-Boulder) Clint Chaplin, Chair (Samsung)

1) Channel occupancy - Problem Statement July 2017 1) Channel occupancy - Problem Statement Use packet capture and analysis tools to analyze the temporal occupancy, packet type distribution, and data rate distribution of deployed 802.11 systems in the following environments: High density, unmanaged public retail networks Managed university network (campus-wide ESS) Residential unmanaged networks Jim Lansford (Qualcomm/CU-Boulder)

July 2017 Methodology Most students used Microsoft Network Monitor to capture packets Has a “monitor mode” to capture packets by scanning across channels (unassociated) Some students used OmniPeek if they had access Save as a .cap file so Wireshark can analyze Students used Excel to create charts Some wrote custom scripts to analyze packets Summarize results in reports Most students only examined 2.4GHz networks, so that is all that will be summarized here Jim Lansford (Qualcomm/CU-Boulder)

July 2017 Data Capture #1 Microsoft Network Monitor (free) can be used to capture packets in any channel in unassociated mode - OmniPeek has the same capability, but isn’t free Jim Lansford (Qualcomm/CU-Boulder)

Data capture #2 Wireshark used to sort and classify packet traffic July 2017 Data capture #2 Wireshark used to sort and classify packet traffic Jim Lansford (Qualcomm/CU-Boulder)

Locations for Measurements July 2017 Locations for Measurements Pearl Street Mall (dense retail shops) Unmanaged networks University of Colorado Campus Managed network – ESS Residential environment Dorm, apartment, house Pearl Street Mall Engineering - University of Colorado at Boulder Jim Lansford (Qualcomm/CU-Boulder)

Results #1: Pearl Street (1/2) July 2017 Results #1: Pearl Street (1/2) Number of Packets Collected: ~12,000 Collection Date & Time: 04/24/2017 @ 2:40pm Collection Length: 00:02:39 Over 75% of packets transmitted at data rate of 1&2Mbps and almost 69% of time at 1Mbps Jim Lansford (Qualcomm/CU-Boulder)

Results #1: Pearl Street (2/2) July 2017 Results #1: Pearl Street (2/2) Jim Lansford (Qualcomm/CU-Boulder)

Results #2: CU-Boulder (1/2) July 2017 Results #2: CU-Boulder (1/2) Number of Packets Collected: ~12,000 Collection Date & Time: 04/17/2017 @ 4:00pm Collection Length: 00:02:57 Over 70% of the packets used data rate of 1&2Mbps with over 53% of time at 1Mbps. Jim Lansford (Qualcomm/CU-Boulder)

Results #2: CU-Boulder (2/2) July 2017 Results #2: CU-Boulder (2/2) Jim Lansford (Qualcomm/CU-Boulder)

Results #3: Residential (1/2) July 2017 Results #3: Residential (1/2) Number of Packets Collected: ~11,000 Collection Date & Time: 04/23/2017 @ 12:10am Collection Length: 00:02:12 Although over 29% of packets used data rate of 1Mbps, the time spent at this data rate was ~15%. Over 25% of packets used data rate of 54Mbps (59% of the time) and ~28% of packets used a rate of 24Mbps (3.1% of the time). Jim Lansford (Qualcomm/CU-Boulder)

Results #3: Residential (2/2) July 2017 Results #3: Residential (2/2) Jim Lansford (Qualcomm/CU-Boulder)

Additional results – Pearl Street July 2017 Additional results – Pearl Street Occupancy: 2.06/2.3 minutes Jim Lansford (Qualcomm/CU-Boulder)

Additional results – Campus July 2017 Additional results – Campus Occupancy: 0.66/0/92 minutes Jim Lansford (Qualcomm/CU-Boulder)

Additional results – Residence July 2017 Additional results – Residence Occupancy: 0.7/2.45 minutes Jim Lansford (Qualcomm/CU-Boulder)

2) Indoor OFDM vs DSSS/CCK - Problem Statement July 2017 2) Indoor OFDM vs DSSS/CCK - Problem Statement Use packet capture and analysis tools to compare the performance of OFDM preambles vs DSSS/CCK preambles: Assess PER or throughput vs distance Compare indoor and outdoor if possible Ensure that captured packets are only coming from the target AP, which has been configured to run iPerf with the desired preamble type Jim Lansford (Qualcomm/CU-Boulder)

Indoor measurements – Discovery Learning Center @ CU-Boulder July 2017 Indoor measurements – Discovery Learning Center @ CU-Boulder Cisco Aironet 2700 Dual Band Access Point and Iperf 3 AP manually configured to send only 1Mbps for DSSS tests AP manually configured for OFDM-only preambles and 7Mbps payload for OFDM tests Jim Lansford (Qualcomm/CU-Boulder)

Indoor measurements – raw data - #1 July 2017 Indoor measurements – raw data - #1 Jim Lansford (Qualcomm/CU-Boulder)

Indoor measurements – graph - #1 July 2017 Indoor measurements – graph - #1 Jim Lansford (Qualcomm/CU-Boulder)

Indoor measurements – raw data - #2 July 2017 Indoor measurements – raw data - #2 DSSS 6Mbps OFDM S.No Range (in meters) Bytes sent by client (in KBytes) Bytes received by receiver(in KBytes) Packet Error Rate 1) 3 384 312 0.1875 2) 6 300 0.21875 3) 9 309 0.1953 4) 14 283 0.2630 5) 18 255 0.33593 6) 23 252 0.34375 7) 28 232 0.3960 S.No Range (in meters) Bytes sent by Client(in MBytes) Bytes Received by Server (in MBytes) Packet Error Rae 1) 3 1.88 1.87 0.005 2) 6 1.75 3) 9 2.00 4) 14 5) 18 1.71 0.02 6) 23 1.62 1.54 0.05 7) 28 1.44 0.11 Interference? Jim Lansford (Qualcomm/CU-Boulder)

Indoor measurements – graph - #2 July 2017 Indoor measurements – graph - #2 DSSS 6Mbps OFDM 0.11 0.396 Jim Lansford (Qualcomm/CU-Boulder)

Summary (2.4GHz) 1Mbps traffic predominates July 2017 Summary (2.4GHz) 1Mbps traffic predominates Beacons Probe request/response - In congested environment, many more probe responses than probe requests RTS/CTS Over 75% of packets were 1Mbps management frames in congested environments OFDM preambles performed better than DSSS indoors Always delivered better throughput at the same range Difficult to assess failed preambles, but throughput results were consistent All papers are available Jim Lansford (Qualcomm/CU-Boulder)