Wireless data communication in Control Systems

Transcription

1 Rules, standards and challenges for class Ståle Sneen

2 Index DNV / class systematics Rules, standards Challenges and future work 2

3 DNV / class systematics 3

4 More than 140 years of managing risk Det Norske Veritas (DNV) was established in 1864 in Norway The main scope of work was to identify, assess and manage risk initially for maritime insurance companies 4

5 DNV s main services 5

6 Highly skilled people across the world 300 offices 100 countries 9,000 employees, of which >80% have a university degree 6

7 Integrity at the core Independent foundation Self-owned with no shareholders Stakeholders are represented in our governing bodies and committees We use profits to continuously develop our people and our research and innovation 7

8 Any vessel in international trade must in practice be classed. (to get insurance, charter, access to port etc.) 8

9 Class systematics In general equivalent systematics for maritime and offshore 9

10 Class systematics 10

11 Rules, standards 11

12 Interference with existing systems / infrastructure 12

13 Rules: Wireless Networks Up to : only permitted in systems not required by main class From : permitted also for systems required by main class 13

14 Examples of current wireless applications today Azipod condition monitoring Crane remote operation Alarm indication PDA remote indication of alarm status etc. Sensors for harsh environment temperature, pressure, vibration, distance; inside engines etc. 14

15 DNV Rules / IACS Unified Requirements E22 DNV Rules Pt.4 Ch.9: Control systems The Rules for wireless cover four main topics - ISM frequency bands - Encryption - Integrity of transmission - Interference IACS UR E22: On board use and application of programmable electronic systems The Rules refer to IACS Unified Requirements E22 regarding system application Both DNV Rules and E22 and define three system categories - The system categories are not identical, but comparable - DNV Rules always apply for DNV classed ships 15

16 DNV Rules / IACS Unified Requirements E22 Non-important c&m system / E22 System category I - DNV definition: - Non-important control and monitoring systems are systems supporting functions for which the Society has no requirements according to relevant definitions in the Rules - Examples: - Maintenance support systems - Information and diagnostic systems - And other systems not covered by the rules of the Society - Additional requirements for wireless: - None. Same requirements as for wired systems apply: - EMC emission requirements - The wireless equipment/system must not influence other equipment/systems 16

17 DNV Rules / IACS Unified Requirements E22 Important (or secondary essential) c&m systems / E22 System category II - DNV definition: - An important control and monitoring system is a system supporting services which need not necessarily be in continuous operation for maintaining the vessel's manoeuvrability, but which are necessary for maintaining the vessels main functions as defined in the Rules. Additional class notations may extend the term important services. Such extensions, if any, can be found in the relevant rule chapters. - Examples: - Thrusters not part of steering or propulsion - Fire detection and alarm system - Water ingress detection and alarm system - Additional requirements for wireless: - Alternative means of control (to be brought in action within reasonable time) - Wireless data communication protocols incorporating - Message integrity - Configuration and device authentication - Message encryption - Security management - Compliance with radio frequency and power level requirements of ITU and flag state - Spread spectrum communication in compliance with IEEE 802 series is recommended 17

18 DNV Rules / IACS Unified Requirements E22 Essential c&m systems / E22 System category III - DNV definition - An essential control and monitoring system is a system which needs to be in continuous operation for maintaining the vessel's propulsion and steering. Additional class notations may extend the term essential services. Such extensions, if any, can be found in the relevant rule chapters. - Examples: - Machinery protection systems / equipment - Electronic fuel injection systems - Control system for propulsion and steering - Additional requirements for wireless: - Engineering analysis according to relevant international standard is required 18

19 Challenges and future work 19

20 Challenges Wireless data communication must co-exist with the existing EMC environment on the ship - Wireless equipment shall not fail due to electromagnetic radiation from other equipment - Wireless equipment shall not cause other equipment to fail due to radiated emission - Problems in case several wireless networks are installed within a relatively small area The ISM band permits frequencies up to 5.8 GHz - Immunity to radiated electromagnetic field tested up to 2 GHz - Radiated emission tested up to 2 GHz 20

21 Challenges Compliance with requirements to radio frequency and power / level requirements of International Telecommunications Union Compliance with requirements to radio frequency and power / level requirements of individual Flag-states Port-state and local regulations - May concern use of radio-frequency transmission - Could prohibit operation of wireless communication - Could vary from country to country or port to port - Could lead to a requirement for the wireless equipment to be switched off 21

22 Challenges Interference issues cause stricter requirements to testing Type testing and Testing onboard of installed systems to verify co-existing without interference Testing to verify that the wireless communication equipment does not fail because of electromagnetic interference 22

23 Challenges Access to network - Corrupt or alter data - Access confidential or critical data content Commercial off-the-shelf technology - Remote access by satellite links - Malicious or inadvertent access may cause failures in ship systems External attacks - DoS attacks - Jamming - Consequences for essential systems or safety systems - Consequences for the industry 23

24 Challenges Message encryption - Configuration - Device authentication - Flexibility - Contrasting needs Message speed and integrity - Time to reach recipient - Safe operation of equipment - Fault prevention, fault detection, fault diagnosis, fault correction - Transition to fail-safe state upon detection of a failure - Predictability of states 24

25 Handheld wireless transmitters and EMC related challenges Maritime VHF handset ( ) MHz GSM cellular phone (900, 1800, 1900) MHz VHF radios are mandatory. Strict EMC radiated emission requirements for all maritime electronic (non-radio) equipment in this frequency range. Upper EMC test requirement range extended from 1 GHz to 2 GHz in 2001 PDA, laptop (WLAN, Bluetooth) - WLAN (2.4, 5.8) GHz - Bluetooth (2.4 GHz) Class have no current EMC test requirements for f > 2 GHz 25

26 Future work / development Class have no current EMC test requirements for radiated emission and radiated immunity > 2 GHz IACS work group to be established Upper frequency range extended to 6 GHz? Adopt current EU/CE requirements or add special requirements for class? Other requirements? Power level restrictions? - Optimistic note from IEC regarding RF electromagnetic immunity - The primary threat above 800 MHz is from radio telephone systems and other intentional RF emitting devices with power levels similar to that of radio telephones. Other systems operating in this frequency range, e.g. radio LANs operating at 2,4 GHz or higher frequencies, are generally very low power (typically lower than 100 mw), so they are much less likely to present significant problems. New type approval programme in progress - TAP will summarize the requirements Statutory requirements in continuous development - IMO will continue to develop SOLAS Ch.4 (radio communications) and SOLAS Ch.5 (safety of navigation) wrt. use of WLAN and other wireless communication technology > 2 GHz 26

27 Questions? 27

28 Safeguarding life, property and the environment 28