Throughput test results
All of the draft 802.11n products exhibited impressive throughput and range performance. At close range, the results were comparable for the home and office environments—at almost 140 Mbps. This level of throughput is clearly competitive with 100Base-T and a major improvement over the legacy 802.11 a,b,g technology (Figure 1).
Throughput vs. distance in the office environment (Figure 8) was higher than in the home (Figure 9). This may be because the sparse office furniture was creating fewer obstructions than the furniture and fixtures in the home.
The Atheros-based devices exhibited the longest range and were providing throughput above 30 Mbps even at 180 ft of operating range and through 7 walls. This level of throughput is more than adequate for an HDTV video stream and represents a true breakthrough in the new generation MIMO WLAN technology.
In the home setting, the close range performance was similar to the office environment—approaching 140 Mbps. However, due to a higher number of obstructions such as furniture, bathroom and kitchen fixtures, the throughput of all products dropped off more significantly as a function of distance.
Nevertheless, the best-performing products still held up the impressive throughput of around 40 Mbps even at 80 ft and through 4 walls—a significant range for the home and with bandwidth to spare for multiple video streams.
The measurement data is organized to show all the office graphs together and all the home graphs together (Figures 8-9). To help compare the competitive performance of the tested products, the plots are also grouped by MIMO configuration: 3x3, 2x3 and 2x2 (Figures 10-13).
Click here for Figure 8
Figure 8: Throughput vs. range performance in the office environment—nearly 140 Mbps at close range and 80 Mbps at 100 ft with DIR 655 generally in the lead.
Click here for Figure 9
Figure 9: Throughput vs. range in the home environment dropped off faster than in the office due to more obstructions such as furniture and household fixtures. Even so, D-Link and Belkin equipment exhibited smother roll-off with D-Link throughput of almost 40Mbps at 100 ft.
Click here for Figure 10
Figure 10: Throughput vs. range for 3x3 MIMO devices in the office environment.
Click here for Figure 11
Figure 11: Throughput vs. range for 3x3 MIMO devices in the home environment.
Click here for Figure 12
Figure 12: Throughput vs. range for 2x3 MIMO devices in the office environment.
Click here for Figure 13
Figure 13: Throughput vs. range for 2x3 MIMO devices in the home environment.
Click here for Figure 14
Figure 14: Throughput vs. range for 2x2 MIMO devices in the office environment.
Click here for Figure 15
Figure 15: Throughput vs. range for 2x2 MIMO devices in the home environment.
The measured data reveals that D-Link DIR-655 AP/router is the top performer in its 3x3 class and across the board. The DIR-655 exhibits throughput of nearly 140 Mbps at short range, holds above 60 Mbps at 100 feet and still maintains close to 40 Mbps at 180 feet in the office environment (Figure 10). In the home (Figure 11) DIR-655 will let you to watch high quality HDTV even at 150 ft since it maintains about 20 Mbps of throughput at that distance.
Linksys WRT-350 performs best in the 2x3 class. Its throughput peaks just below 120 Mbps in the office and gradually drops to 20 Mbps at around 170 ft (Figure 12). In the home, Linksys dropped below 20 Mbps at around 60 feet, so HDTV would be limited to this range.
D-Link DIR-625 tops the 2x2 category in the home and in the office. Its acceptable HDTV range would be about 180 feet in both settings.
Click here for Figure 16
Figure 16: Short range average throughput organized into NxM groups. The points were obtained by averaging short range measurements in the home and office settings.
Click here for Figure 17
Figure 17: Gigabit Ethernet AP/routers' performance in the office environment.
Click here for Figure 18
Figure 18: Gigabit Ethernet AP/routers' performance in the home environment.
Three of the AP/routers in the test featured Gigabit Ethernet ports: D-Link DIR-655, Linksys WRT350N (Figures 17-18). Among this group D-Link DIR-655 came in first.
Part 3 of this three-part article is available athttp://www.wirelessnetdesignline.com/howto/201800198.
A PDF version of this report is available atwww.octoscope.com), a Boston area consulting company.
