Cigré Colloquium SC D2 / India 2013 Paper D SMART, UTILITY-GRADE WI-FI MESH FOR DISTRIBUTION GRIDS

Transcription

1 P. Schwyter, Ph.Schneider - ABB Switzerland Ltd. Cigré Colloquium SC D2 / India 2013 Paper D SMART, UTILITY-GRADE WI-FI FOR DISTRIBUTION GRIDS October 21, 2013 Slide 1

2 D2-01_04 Authors & Topics covered Authors Mr. Philipp Schneider Head Smart Grid Communication Solutions Mr. Paul Schwyter Product Manager Data Networking Topics Drivers & enablers for Wi-Fi Mesh solutions Physical aspects of wireless communication and latest technical achievements to create utility grade Wi-Fi networks Managing large Wi-Fi deployments hand in hand with the fiberoptic back-haul Case study Q & A October 21, 2013 Slide 2

3 Wi-Fi development over years IEEE *. Early versions of IEEE date back to 1985 Wi-Fi Alliance founded to improve interoperability 11Mbps in 2-.4GHz band (802.11b) g for up 54Mbps & WPA security i with improved security (WPA2 & amendments) n MIMO technology allows up to 600Mbps; 2006/2009* use 5GHz band & more Networking capabilities Manufacturer floated devices before standard was released ac as latest IEEE driven definition for Gbps throughput Increasing performance based on complex modulations and multi-stream technologies requiring powerful signal-processing resources * Useful link: close to release October 21, 2013 Slide 3

4 Networking for utilities Broadband enables smarter grid applications Distribution Automation & Control Automated Metering Renewables Integration Field Data Applications Demand Response Outage Management Power Quality & Planning

5 Invest in communication to generate the core-revenues Minimize ACT ACT* = Aggregated Commercial and Technical losses Incorrect Meter readings / manipulations Energy Tapping Poor administration & missing visibility : "One in every three units of power generated in India is lost,".. "This would translate into revenue losses of Rs 40,000 crore ( approx. 6.6 billion USD!) per year for the power companies." He is talking about the innocuous sounding statistic called the ATC, which stands at an average of 35%. * Sometimes also called ATC instead. October 21, 2013 Slide 5

6 For the smart cities A wireless network is a key smart city enabler Police Electric, Gas and Water Utilities Fire Public Access EMS Intelligent Transportation Systems (ITS) Video Surveillance Mobile Municipal Workforce

7 Private vs. public networks Considerations Networks that support mission-critical applications, require stringent performance or run multiple applications should use private networks Utilities that want control should deploy private networks Utilities looking to quickly fix a point problem may use public, those deploying a long-term grid modernization solution should use private Utilities with diverse service territories will need private with a corresponding backbone Cyber Security aspects need special attention and are much better controllable in a private networks Using a private network opens new business opportunities

8 Commercial temptations Various business models In addition to operational services a utility may provide: Free public Wi-Fi services Indirect customer binding to local utility Position / local content based advertising Attractiveness of region / city Hybrid / partially free Wi-Fi services Public Wi-Fi as additional revenue stream Finance operational infrastructure from additional services Bundle Electricity (& possibly water/gas) with communication

9 Shannon s law in a nutshell an how reality may be... C =B * log 2 (1+S/N) with: C = maximum number of bits that can be transmitted per second B = the channel bandwidth (Hz) S = the power of the Signal received by the receiver ( in W) N = the power of the Noise present at the receiver, a function of B ( in W) October 21, 2013 Slide 9

10 Shannon s law in a nutshell Basic conclusions Shannon s law is given and there are no ways overcoming these physical limits Shannon s law represents the best case ; real performance can be impacted e.g. by : Reflections, fading, other RF sources Ways to improve performance between two devices Shorten distance between devices Increase output-power however possibly conflicting with neighbouring hops October 21, 2013 Slide 10

11 Ways to improve Higher connectivity, coverage, throughput & availability Mesh technology Sophisticated, predictive routing algorithms Self-organizing & self-healing Minimizes engineering efforts Maximises flexibility Optimizes network usage Multipoint backhauling Adaptive power algorithms Minimizes interferences Airtime optimization October 21, 2013 Slide 11

12 Self-organizing The routers automatically discover one another, intelligently choosing optimal paths back to the wired connection. Wired backhaul Optimal routing paths Backup links

13 Optimal path selection Optimal path is determined by end-to-end quality, not hops. Wired backhaul Optimal routing paths Backup links

14 Auto-discovery Newly added routers participate in auto-discovery, Wired backhaul Optimal routing paths Backup links

15 Optimal path recalculation Newly added routers participate in auto-discovery, recalculating the optimal paths to the wired connection. Wired backhaul Optimal routing paths Backup links

16 Adding backhaul adds capacity Capacity can be dynamically upgraded by adding backhaul connections as needed. Wired backhaul Optimal routing paths Backup links

17 Automatic reclustering Network automatically reclusters to take advantage of additional backhaul. Wired backhaul Optimal routing paths Backup links

18 Self-healing If a backhaul link fails, Wired backhaul Optimal routing paths Backup links

19 Reconfigure around backhaul failure If a backhaul link fails, the network automatically re-optimizes in real-time. Wired backhaul Optimal routing paths Backup links

20 Self-healing Similarly, if interference causes a path to fail, Wired backhaul Optimal routing paths Backup links

21 Reconfigure around interference Similarly, if interference causes a path to fail, the network re-configures to route around the obstruction. Wired backhaul Optimal routing paths Backup links

22 Optimizes across path, channels and bands Mesh software can leverages multiple paths, channels and bands to create robust, high performance networks Mesh links dynamically choose 5 GHz or 2.4 GHz band Channel within band automatically chosen on a per link basis 2.4 GHz Link 5.X GHz Link Wired backhaul Optimal routing paths Backup links

23 Importance of airtime Airtime is fundamental, must be monitored and controlled Radio Wi-Fi is a shared medium; only one device can transmit at a time Wi-Fi devices connect to network at various data rates Low rate connections require more airtime than high rate connections Low rate users penalize high rate users Low quality user links consume an inordinate amount of airtime as it takes longer to send a bit of data at a lower rate Traditional traffic rate-limits either at the node or on the back-end don t help This phenomenon results in Network congestion 54 Mbps transmission 1 Mbps transmission Unfair distribution of bandwidth between users (i.e. bandwidth hogging) time 54 Mbps & 1Mbps Clients

24 Effective use of airtime Extends capacity and provides determinism Airtime utilization is continuously monitored When congestion is detected Neighboring routers are alerted Client traffic pre-emptively adjusted Airtime allocations are applied equally to all clients in the affected area Airtime allocation enables usable network capacity that surpasses traditional Wi-Fi network capacity Provides more consistent network access for users and fair sharing of resources How ACC is unique Monitors airtime, not merely traffic levels Clients given airtime, not throughput limits Client limits activated only during high congestion Network Capacity light Airtime Congestion Control Extends Wi-Fi Network Capacity Ideal Airtime Congestion Control Wi-Fi Network Load congested

25 Optimizing channel capacity Maximizes network capacity and reliability Dynamic real-time coordination of power and rate per packet across the local RF domain Per packet, per-link power and rate control Dynamic and adaptable within milliseconds Simplifies network operation Reduces need for detailed network planning and optimization Eliminates need to statically set rate and power parameters per node Increases capacity and reliability by facilitating reuse of the spectrum

26 Dynamic Power Control Lower power and higher data rates for short, unobstructed links enable concurrent transmission, increasing overall capacity Wired backhaul Optimal routing paths Alternate back-up routes

27 Dynamic Power Control Higher power and lower data rates for long or obstructed links maximizes transmission success, increasing reliability Wired backhaul Optimal routing paths Alternate back-up routes

28 Dynamic power, rate, and link control If a different path will support higher overall throughput because of higher data rates and greater spatial reuse, another path is selected to maximize end-to-end throughput and capacity. Wired backhaul Optimal routing paths Alternate back-up routes

29 Why interference isn t an issue 500 Devices in Urban Area (2.4 GHz ) 0% have noise level > 80 dbm 500 Devices in Urban Area (2.4 GHz ) 99.5% had a throughput >2 Mbps Adaptive mesh architecture exploits diversity in the spatial and spectral domains Spectrum management techniques for interference resiliency Outdoor-optimized radio hardware Cognitive radio algorithms ABB Group

30 Importance of Network Management Overall NMS for efficient operation Typical utility networks are usually built based on complementing technologies for the various network layers Characteristics of technologies and hierarchies have to be reflected in NMS An overall NMS allows fast and efficient interaction when needed

31 Case study: United States Silicon Valley Power Customer need Private wireless communications network to enable AMI, distribution automation, mobile workforce and public Internet access Lower operational costs and greater bandwidth than offered by cellular networks Our response Wireless broadband mesh network connected to SVP s fiber network Customer benefits Smart metering with Elster EnergyAxis for 51,000 electric customers Real-time outage detection Customer energy usage information Public Internet access Future solar energy, smart appliance and electric vehicle integration Future mobile municipal workforce automation, replacing cellular cards

32 Case study Guam Guam Power Authority Customer need Communications network to support comprehensive smart grid rollout with multiple applications Our response Island-wide communications network using a combination of fiber and wireless mesh Customer benefits Enabled complete set of smart grid applications Outage management critical application due to typhoons that periodically hit the island Distribution automation Energy conservation Advanced metering infrastructure Mobile workforce management

33 Summary Wi-Fi Mesh is a well established technology complying to application requirements such as Bandwidth / throughput / latency Security & High availability The Wi-Fi Mesh equipment should be based on wireless standards of IEEE enhanced with performance boosting algorithms to make the best out of wireless Ruggedized for use by utilities (climatic, EMC ) Wi-Fi Mesh is usually used in conjunction with other more back-haul oriented technologies (e.g. fibre optic backbone); an overall NMS makes operation efficient and minimizes OPEX A Wi-Fi Mesh can be implemented with minimized CAPEX October 21, 2013 Slide 34

34 Wi-Fi potential thank you for your attention! October 21, 2013 Slide 35