LAN MAC 1,a) 1 2016 6 27, 2016 12 1 IoT LAN LAN AP MAC 1 Null Function Data Frame NFDF NFDF LAN NFDF LAN LAN MAC Null Function Data Frame Effectiveness of MAC Layer Information in Communication Quality Estimation of Wireless LANs Takafumi Shintani 1,a) Kaori Maeda 1 Received: June 27, 2016, Accepted: December 1, 2016 Abstract: In IoT (Internet of Things), various devices upload various information and wireless access networks is necessary for many devices without restriction of location to access to the Internet. Also, wireless access network speed is being rapidly accelerated by increasing of streaming services of mobile terminals. Though wireless access networks are used in many scenes, quality of wireless networks fluctuates intensely compared to wired core networks and its fluctuation gives a significant impact on quality of end-to-end communication. In this paper, we focus on wireless LANs as a wireless access network and propose an index to estimate communication quality of wireless LANs. We use a retransmission rate of Null Function Data Frame (NFDF) which is one of the Media Access Control (MAC) information as an estimation indication. First, we investigate whether retransmission rates of NFDF is effective for congestion detection of wireless LANs by some experiments. Next, we show a correlation between NFDF transmission frequency and estimation accuracy of communication quality. Finally, we describe effective scope of our proposal to estimate communication quality of wireless LANs. Keywords: wireless access network, communication quality, wireless LAN, Media Access Control, Null Function Data Frame 1. IoT 1 Graduate School of Information Sciences, Hiroshima City University, Hiroshima 731 3194, Japan a) shintani@v6.netsci.info.hiroshima-cu.ac.jp [1] LTE LAN LAN c 2017 Information Processing Society of Japan 664
LAN [2], [3], [4] LAN LAN AP MAC 1 Null Function Data Frame NFDF [5] LAN NFDF NFDF LAN [6], [7] NFDF NFDF NFDF 2 3 LAN 4 NFDF 5 6 7 2. 2.1 LAN [8] LAN ICMP RTT ICMP LAN LAN Received Signal Strength IndicatorRSSI RSSI 2.2 MAC LAN IEEE802.11 QoS Quality of Service IEEE802.11e [9] CSMA/CA QoS MAC QoS [4] IEEE802.11 [10] LAN RSSI TCP LAN LAN IP RSSI LAN RTS/CTS RSSI 2.3 Null Function Data Frame NFDF power save mode [11] AP MAC [6], [7] NFDF [6] RSSI NFDF RSSI NFDF [7] LAN UDP TCP NFDF NFDF LAN [12] NFDF NFDF NFDF NFDF NIC Network Interface Card c 2017 Information Processing Society of Japan 665
3. NFDF 3.1 NFDF NFDF LAN NFDF RSSI UDP NFDF LAN 3.2 1 NFDF NFDF RSSI 30 45 dbm RSSI NFDF NFDF IEEE802.11g NFDF AP LAN AP NFDF AP iperf UDP 0 5 10 13 15 Mbps 60,000 10 13 15 Mbps 3 17 37% NFDF Atheros AR928X Type NFDF Flag Retry 1 MAC 10 NFDF NFDF (1) = 100 (1) NFDF NFDF NFDF 5 ASUS Eee Slate LYNX 3D Nexus7 Nexus10 ipad NFDF [6] [7] NFDF 0.4 [sec/frame] RSSI NFDF RSSI 30 45 dbm 46 55 dbm 56 70 dbm 3 5 0 5 10 13 15 Mbps NFDF 2 8 40 AP SSID 6 3.3 1 10 NFDF ASUS Eee Slate Windows Fedora20 1 1 2 3 5 NFDF 2,064 ASUS Eee Slate 329,865 ipad 2 3 1 4 5 NFDF RSSI 10 Table 1 1 RSSI NFDF Average of the number of transmitted NFDFs by the difference of RSSI. Fig. 1 1 Measurement environment. c 2017 Information Processing Society of Japan 666
情報処理学会論文誌 Vol.58 No.3 664 671 (Mar. 2017) 図 3 RSSI が小さいエリアでの NFDF 再送率の変化 Fig. 3 Transition of retransmission rates of NFDFs in the area 図 2 RSSI が大きいエリアでの NFDF 再送率の変化 of small RSSI. Fig. 2 Transition of retransmission rates of NFDFs in the area of large RSSI. c 2017 Information Processing Society of Japan 667
2 NFDF Table 2 Averages and variances of retransmission rate of NFDFs. NFDF 2 NFDF 1 ASUS Eee Slate 5 ipad NFDF 3.3.1 NFDF NFDF 2(a) NFDF 2(b) (c) NFDF NFDF 2(c) ipad NFDF NFDF 3 RSSI NFDF (b) (c) (a) NFDF 2 NFDF 3.3.2 RSSI NFDF 2 3 RSSI NFDF NFDF 2(a) 3(a) RSSI 3(a) NFDF 2 NFDF RSSI NFDF 2 (b) (c) 3 (b) (c) NFDF RSSI NFDF NFDF RSSI 4. NFDF 3.3 NFDF LAN 1 NFDF NFDF 10 Mbps 0 5 Mbps NFDF NFDF RSSI NFDF NFDF RSSI NFDF NFDF LAN NFDF NFDF NFDF NFDF LAN NFDF NFDF LAN 5. NFDF 5.1 4 NFDF 3 NFDF 5.2 3 10 Mbps 10 Mbps NFDF θ 3 θ 10 Mbps 0 5 Mbps NFDF θ θ 10 Mbps 13 15 Mbps c 2017 Information Processing Society of Japan 668
Table 3 3 θ Threshold (θ) of congestion occurence of each target terminal. 4 Table 4 Rates of wrong estimate. NFDF NFDF 1 2 3(b) 4(a) NFDF 5.3.2 RSSI 4 1 2 (a) (b) NFDF RSSI NFDF 3(a) 1 ASUS Eee Slate RSSI 13.5 NFDF RSSI NFDF NFDF 3 5 RSSI θ θ (a) 5 Mbps θ (b) 13 Mbps θ 2 NFDF RSSI 5.3 4 (a) (b) 5.2 (a) (b) NFDF 1 5.3.1 NFDF 4(a) NFDF 3 5 3 5.4 5.3 NFDF NFDF NFDF NFDF NFDF LAN NFDF NFDF 3 ipad ios:9.3.2 iphone6 ios:9.3.1 NFDF 6. NFDF LAN 6.1 NFDF LAN NFDF AP NFDF AP NFDF c 2017 Information Processing Society of Japan 669
Fig. 4 4 Configuration example of an estimation system. LAN AP MAC NFDF NFDF NFDF LAN 1 AP NFDF RTS/CTS [10] 6.2 NFDF NFDF AP NFDF AP 4 AP NFDF NFDF AP NFDF MAC 4 AP AP NFDF 4 NFDF 1 NFDF 10 NFDF AP 10 LAN AP AP LAN NFDF 7. MAC 1 NFDF LAN NFDF RSSI NFDF NFDF LAN NFDF NFDF 6 [1] (2016), http://www.soumu.go.jp/ main content/000402062.pdf, 2016-05-20. [2] Vol.51, No.3/4, pp.67 74 (2005). [3] Balachandran, A., Voelker, G.M., Bahl, P. and Rangan, P.V.: Characterizing User Behavior and Network Performance in a Public Wireless LAN, Proc. 2002 ACM SIGMETRICS International Conference on Measurement and Modeling of Computer Systems, pp.195 205 (2002). [4] IEEE 802.11 MAC 2008-MBL-046 (Sep. 2008). [5] IEEE Computer Society LAN MAN Standards Committee, Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications (1999). c 2017 Information Processing Society of Japan 670
[6] LAN MAC MoMuC2009-31 pp.27 32 (Sep. 2009). [7] WLAN MoMuC2009-73 pp.13 18 (Mar. 2009). [8] LAN p.153 (Mar. 2007). [9] IEEE Std 802.11e-2005, Part11: Wireless LAN and Physical Layer (PHY) Specifications Amendment 8: Mediam Access Control (MAC) Quality of Service Enhancements, IEEE (2005). [10] WLAN 2005 BS-3-6 pp.32 33 (Mar. 2005). [11] He, Y., Yuan, R., Ma, X. and Li, J.: The IEEE 802.11 Power Saving Mechanism: AN Experimental Study, Proc. WCNC2008 2008 IEEE Wireless Comms. and Networking Conf., pp.1362 1367 (Apr. 2008). [12] Shintani, T., Maeda, K. and Kondo, T.: An Investigation of Effectiveness of an Estimation Method of Wireless Network Conditions using MAC Layer Informations, IEICE Technical Report, IA2015-59 (Nov. 2015). 2015 LAN 1982 c 2017 Information Processing Society of Japan 671