1. doc.: IEEE 15-13-0440-00-0dep Submission March 2013 Jussi Haapola (CWC) Slide 1 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: Dependability Techniques at Communications Layers Date Submitted: July 17, 2013 Source: Jussi Haapola (Centre for Wireless Communications / University of Oulu) Contact: Jussi Haapola (Centre for Wireless Communications / University of Oulu) Voice: +358 40 8363 018, E-Mail: jussi.haapola@ee.oulu.fi Re: Dependable Interest Group Working Document Abstract: Dependable Interest Group Techniques for Dependability Purpose: Dependable Interest Group Notice:This document has been prepared to assist the IEEE P802.15. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release:The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15.

2. doc.: IEEE 15-13-0440-00-0dep Submission March 2013 Jussi Haapola (CWC) IEEE 802.15 IG DEP Dependable Interest Group Dependability Techniques at Communications Layers Geneva, SUI Wednesday AM1, July 17, 2013 Slide 2

3. doc.: IEEE 15-13-0440-00-0dep Submission March 2013 Jussi Haapola (CWC) Definition of Dependability in IG DEP: “For us, “Dependability in network” means to guarantee the lowest performance high enough to provide a sense of highly reliable, safe, secure, fault tolerant, robust services in any predictable and even unpredictable and worse environments.” In order to tackle this we need to define Dependability in Communications Layers. Addressed layers: Application, Transport, Network, Data Link, Physical, and Management layer on the side with hooks to other layers. Introduction Slide 3

4. doc.: IEEE 15-13-0440-00-0dep Submission March 2013 Jussi Haapola (CWC) Slide 4 Application Quote from Hawaii session: “Collect trending retransmissions and other info to prevent failures.” Methods to enable/ensure Dependability Outlier detection Statistics collection and analysis for estimation, prediction and projection. External data processing (cloud services) Retransmissions Security algorithms Reprogramming

5. doc.: IEEE 15-13-0440-00-0dep Submission March 2013 Jussi Haapola (CWC) Slide 5 Transport Methods to enable/ensure Dependability Out of sequence delivery Early drop Congestion avoidance Tailored transport protocols Selective retransmissions Security Adaptive parameter adjustment

6. doc.: IEEE 15-13-0440-00-0dep Submission March 2013 Jussi Haapola (CWC) Slide 6 Network Methods to enable/ensure Dependability Multiple redundant routes Redundancy in broadcast packets Route management Out of sequence delivery Secure routes Adaptive parameter adjustment

7. doc.: IEEE 15-13-0440-00-0dep Submission March 2013 Jussi Haapola (CWC) Slide 7 Data Link Quote from Hawaii session: “MAC layer error may be able to correct by adaptation to guarantee delay specification (e.g. to switch to fragmentation, change to lower coding rate, change back-off window, change number of retransmission attempts, cooperate with other MACs to create virtual MIMO, use L2R), rather than incur delay by going to Apps layer.” Methods to enable/ensure Dependability Adaptive parameter adjustment Cooperation Fragmentation Collaborative relaying / mesh relaying Channel access structure adaptation Secure access control (association, key exchange)

8. doc.: IEEE 15-13-0440-00-0dep Submission March 2013 Jussi Haapola (CWC) Slide 8 Physical Quote from Hawaii session: “MIMO and multipath are friends of dependability with PHY layer redundant links.” Quote from Hawaii session: “PHY layer can be adaptable to environment, by switching frequency particularly, if you are in a null.” Quote from Hawaii session: “PHY layer error may be able to correct by adaptation (switch to a better antenna) to guarantee delay specification rather than incur delay by going to Apps layer.” Methods to enable/ensure Dependability MIMO Frequency shifting Error correction techniques Antenna switching / steering / beamforming, etc. Power control Adaptive coding Spreading Sequences Multiple transceivers PHY layer security (spatio-temporal correlations, “natural” unique security keys, etc.)

9. doc.: IEEE 15-13-0440-00-0dep Submission March 2013 Jussi Haapola (CWC) Slide 9 Management Plane Methods to enable/ensure Dependability Making protocol parameters transparent across layers for joint optimisation / control Cross-layer protocols Application dependent protocol selection throughout stack