1. Secured Operating Regions of Slotted ALOHA in the Presence of Interfering Signals from Other Networks and DoS Attacking Signals Jahangir H. Sarker and Hussein T. Mouftah School of Information Technology and Engineering (SITE), University of Ottawa, Ottawa, Ontario, Canada K1N 6N5 E-mail: jsarker@site.uottawa.cajsarker@site.uottawa.ca J. H. Sarker / SITE.uOttawa.ca/~jsarker

2. WiSense Seminar November 3, 2011 Outline of the Presentation Potential applications of Slotted ALOHA. GSM-the most successful cellular system. Slotted ALOHA and GSM system. Radio Frequency Identification (RFID)-next most widely used technology. Slotted ALOHA and RFID system. Applications of RFID technology. Slotted ALOHA in the presence of interfering signals from other networks and the DoS attacking signals. Security problem of Slotted ALOHA system in the presence of interfering signals from other networks and the DoS attacking signals. Security improvement using multiple channels and capture. Security improvement by limiting the number of retransmission trials. Security improvement using new packet rejection. Conclusions 2 J. H. Sarker / SITE.uOttawa.ca/~jsarker

3. Potential Applications of Slotted ALOHA The random access channels (RACH) of Global System for Mobile (GSM) communications The random packet access channels (RPACH) General Packet Radio Services (GPRS) Wideband Code Division Multiple Access (WCDMA) system cdma2000 IEEE 802.16 IEEE 802.11 3 J. H. Sarker / SITE.uOttawa.ca/~jsarker WiSense Seminar November 3, 2011

4. GSM-the Most Successful Cellular System 1/(2) 4 http://www.dailywireless.org/2009/08/21/4-billion-gsm-users-sept-2009/ J. H. Sarker / SITE.uOttawa.ca/~jsarker WiSense Seminar November 3, 2011

5. GSM-the Most Successful Cellular System 2/(2) 5 http://www.dailywireless.org/2009/08/21/4-billion-gsm-users-sept-2009/ J. H. Sarker / SITE.uOttawa.ca/~jsarker WiSense Seminar November 3, 2011

6. Slotted ALOHA and GSM System 1/(7) 6 Mainly 3 elements – MS – BS – MSC J. H. Sarker / SITE.uOttawa.ca/~jsarker WiSense Seminar November 3, 2011

7. Slotted ALOHA and GSM System 2/(2) 7 J. H. Sarker / SITE.uOttawa.ca/~jsarker WiSense Seminar November 3, 2011

8. Slotted ALOHA and GSM System 3/(7) 8 890-915 MHz for uplink 935-960 MHz for Downlink 200 kHz carrier spacing This gives 124 possible carriers in UL and DL. Fu(n)=890.2+0.2(n-1) MHz 1<=n<=124 Fu(n) =Fu(n)+45 MHz J. H. Sarker / SITE.uOttawa.ca/~jsarker WiSense Seminar November 3, 2011

9. Slotted ALOHA and GSM System 4/(7) 9 J. H. Sarker / SITE.uOttawa.ca/~jsarker WiSense Seminar November 3, 2011

10. Slotted ALOHA and GSM System 5/(7) 10 J. H. Sarker / SITE.uOttawa.ca/~jsarker WiSense Seminar November 3, 2011

11. Slotted ALOHA and GSM System 6/(7) 11 J. H. Sarker / SITE.uOttawa.ca/~jsarker WiSense Seminar November 3, 2011

12. Slotted ALOHA and GSM System 7/(7) 12 There are five different structures of the RACH [24, 25] with approximately 400,000 and n*780,000 RACH slots per hour (n= 1, 2, 3, 4). It is interesting to know the exact choice of these five different possibilities. According to specifications, a maximum of r retransmissions is allowed for each mobile call during the access period. The parameter r can be set to four different possible values 1, 2, 4 or 7 J. H. Sarker / SITE.uOttawa.ca/~jsarker WiSense Seminar November 3, 2011

13. How Slotted ALOHA Works 1/(2)? 13 J. H. Sarker / SITE.uOttawa.ca/~jsarker WiSense Seminar November 3, 2011

14. How Slotted ALOHA Works 2/(2)? 14 J. H. Sarker / SITE.uOttawa.ca/~jsarker WiSense Seminar November 3, 2011

15. How Mobile RFID Works 1/(4)? 15 J. H. Sarker / SITE.uOttawa.ca/~jsarker WiSense Seminar November 3, 2011

16. How Mobile RFID Works 2/(4)? 16 J. H. Sarker / SITE.uOttawa.ca/~jsarker WiSense Seminar November 3, 2011

17. How Mobile RFID Works 3/(4)? 17 J. H. Sarker / SITE.uOttawa.ca/~jsarker WiSense Seminar November 3, 2011

18. How Mobile RFID Works 4/(4)? 18 J. H. Sarker / SITE.uOttawa.ca/~jsarker WiSense Seminar November 3, 2011

19. Future Store Checkout with RFID tagged items 19 J. H. Sarker / SITE.uOttawa.ca/~jsarker Video Show http://www.youtube.com/watch?v=zBz3aoikLpU WiSense Seminar November 3, 2011

20. RFID Technology in Construction 1/(3) 20 J. H. Sarker / SITE.uOttawa.ca/~jsarker RFID chips are tied to the rebar at a predetermined location before concrete is poured. The encapsulated RFID tag is placed in the area shown by the red circle. RFID chips are read with a handheld scanner. WiSense Seminar November 3, 2011

21. RFID Technology in Construction 2/(3) 21 J. H. Sarker / SITE.uOttawa.ca/~jsarker Tunnel segments stored in the Woodstock plant all contain RFID chips that can be scanned through the concrete. The application of RFID for tracking construction materials can provide an accurate and efficient means for reducing time and resources being spent collecting and managing data. In a recent example, the NRC in collaboration with Armtec, has developed a system for tracking precast tunnel liner segments manufactured in Armtec’s Woodstock, Ontario plant. The commercially available encapsulated RFID tags which, during the fabrication process, are embedded in the liner segments. WiSense Seminar November 3, 2011

22. RFID Technology in Construction 3/(3) 22 J. H. Sarker / SITE.uOttawa.ca/~jsarker As the segments move through the plant, their status (i.e., fabrication, quality, storage and shipping) and associated data are updated by the field crew using mobile computers. Armtec is using the system in its Woodstock plant to track the fabrication and inventory data for 58,000 tunnel liner segments being supplied for the York- Spadina subway extension project in Toronto, for two 6.5 km tunnels. The system helps reduce time and resources spent locating concrete units in the storage yard and managing production and quality control data. Another key benefit of the system is that it generates the product handover documentation in electronic format that many asset owners are now requesting. For example, the product handover documentation is currently used by Toronto Transit Commission (TTC) construction contractors working at the subway site to validate the materials received. Source: http://www.nrc-cnrc.gc.ca/eng/ci/v16n2/9http://www.nrc-cnrc.gc.ca/eng/ci/v16n2/9 RFID-based life cycle tracking of precast concrete units WiSense Seminar November 3, 2011

23. RFID Technology and Printed Electronics 1/(3) 23 J. H. Sarker / SITE.uOttawa.ca/~jsarker Electronic devices can be printed on commercial off-set machines. (Source: pmTUC) Reel-to-reel flexographic printing of electronic devices. (Source: Acreo) Dimatix Materials Printer (DMP) DMP-2800 Series Printer FUJIFILM RFID can be used widely in almost all items Printed electronics opened that door WiSense Seminar November 3, 2011

24. RFID Technology and Printed Electronics 2/(3) 24 J. H. Sarker / SITE.uOttawa.ca/~jsarker Printed RFID tags (Source: PolyIC) Printed RFID tag.(Source: PolyIC) WiSense Seminar November 3, 2011

25. RFID Technology and Printed Electronics 3/(3) 25 J. H. Sarker / SITE.uOttawa.ca/~jsarker RFID can be used widely in almost all items Price per tag is an important issue WiSense Seminar November 3, 2011

26. Success of Printed Electronics 26 J. H. Sarker / SITE.uOttawa.ca/~jsarker Intelligent Packaging Application WiSense Seminar November 3, 2011

27. Biomedical Applications of RFID 27 J. H. Sarker / SITE.uOttawa.ca/~jsarker Wearable RFID-Enabled Sensor Nodes for Biomedical Applications Source: Wearable RFID-Enabled Sensor Nodes for Biomedical Applications, Li Yang, Rushi Vyas, Amin Rida, Jonathan Pan, and Manos M. Tentzeris, IEEE 2008 WiSense Seminar November 3, 2011

28. Biosensor and Indicator & RFID 28 J. H. Sarker / SITE.uOttawa.ca/~jsarker Inkjet printed oxygen indicator Source: VTT 2008 Printed enzymatic power supply with integrated capacitor Active RFID tag is better WiSense Seminar November 3, 2011

29. Organic RFID 29 J. H. Sarker / SITE.uOttawa.ca/~jsarker Source: Design and manufacturing of organic RFID circuits Coping with intrinsic parameter variations in organic devices by circuit design, Jan Genoe, Kris Myny, Soeren Steudel, and Paul Heremans, IEEE 2010 WiSense Seminar November 3, 2011

30. Multi-channel Slotted ALOHA System in the Presence of Interference from other Net. & Attacking Signals 30 J. H. Sarker / SITE.uOttawa.ca/~jsarker Application of Slotted ALOHA with retransmission cut-off is huge Interference from other Net. DoS attacking signals WiSense Seminar November 3, 2011

31. Security Improvements of Slotted ALOHA System 31 J. H. Sarker / SITE.uOttawa.ca/~jsarker Four ways of improving the security 1 & 2. Security improvement using multiple channels and capture. 3. Security improvement by limiting the number of retransmission trials 4. Security improvement using new packet rejection WiSense Seminar November 3, 2011

32. Security Problem under DoS Attacking Signal & Interference from Other Networks 32 J. H. Sarker / SITE.uOttawa.ca/~jsarker Interference from other Net. DoS attacking signals WiSense Seminar November 3, 2011

33. Security Improvement Using Capture 33 J. H. Sarker / SITE.uOttawa.ca/~jsarker Improvement with capture 1Improvement with capture 2 WiSense Seminar November 3, 2011

34. Security Improvement using Multiple Channels 34 1-channel system 5-channel system J. H. Sarker / SITE.uOttawa.ca/~jsarker Improvement with multi-channel WiSense Seminar November 3, 2011

35. Security Improvement using Multiple Channels 35 J. H. Sarker / SITE.uOttawa.ca/~jsarker WiSense Seminar November 3, 2011

36. Security Improvement using Multiple Channels & Capture 36 J. H. Sarker / SITE.uOttawa.ca/~jsarker WiSense Seminar November 3, 2011

37. Security Improvement by Limiting the Number of Retransmission Trials 37 J. H. Sarker / SITE.uOttawa.ca/~jsarker WiSense Seminar November 3, 2011

38. Security Improvement using New Packet Rejection 38 J. H. Sarker / SITE.uOttawa.ca/~jsarker The y-axis should be multiplied by Source: Secured Operating Regions of Slotted ALOHA in the Presence of Interfering Signals from Other Networks and DoS Attacking Signals, Journal of Advanced Research – Elsevier, 2011, Vol. 2, Issue 3, July 2011,Journal of Advanced Research – ElsevierVol. 2, Issue 3 pp. 207-218. Available at http://www.sciencedirect.com/science/article/pii/S2090123211000488 WiSense Seminar November 3, 2011

39. Conclusions 39 The potential application of Slotted ALOHA based technologies are presented The security improvement of Slotted ALOHA in the presence of interference from other networks and DoS attacking signals is studied The current security protected measures such as encryption makes the packets unreadable by unauthorized users. The authentication technique is used to protect the system from illegal users and authorization separates the legal users. In a Slotted ALOHA based network, the interference from other networks and DoS attacking noise packets may collide with message packets and reduces the secured transmission. We have used four different techniques to improve the security of Slotted ALOHA. Security improvement using multiple channels – The use of multiple channels in the Slotted ALOHA protocol reduces the packet collisions Security improvement using capture effect – Capture effect reduces the packet collisions – 3 types of captures are considered Security improvement by limiting the number of retransmission trials. – The retransmissions cut-off technique can limit the aggregate packet flow – It is possible that the 3rd technique retransmissions cut-off technique is not enough to control the flow of message packets. Because of that the 4th technique called new packet rejection probability is introduced. – The system is secured or stable with almost any high value of new packet generation rate. J. H. Sarker / SITE.uOttawa.ca/~jsarker WiSense Seminar November 3, 2011

40. Thank you 40 Thanks a lot for your kind attention J. H. Sarker / SITE.uOttawa.ca/~jsarker WiSense Seminar November 3, 2011

41. Questions? 41 J. H. Sarker / SITE.uOttawa.ca/~jsarker WiSense Seminar November 3, 2011