mysore 2013
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Mysore 2013. D2 – 01 - 16. Preferential Subject 1: Role of ICT in Power System COMMUNICATION ALTERNATIVES FOR SMART GRIDS : THE INTEGRATED APPROACH Jaume Darné and Claudio Rizoli Spain. Mysore 2013. Energy Network Challenges. High data rates High scalability. QoS support - PowerPoint PPT PresentationTRANSCRIPT
MYSORE 2013
Preferential Subject 1: Role of ICT in Power System
COMMUNICATION ALTERNATIVES FOR SMART GRIDS: THE INTEGRATED
APPROACHJaume Darné and Claudio Rizoli
Spain
D2 – 01 - 16
MYSORE 2013Energy Network Challenges
• High data rates• High scalability. • QoS support • Cost-effective. • Interoperability of equipment from different vendors• Service integration flexibility. • Efficient frequency reuse in Radio Links• Seamless mobility• Cyber security.
• Flexibility.
MYSORE 2013Quality of Service
Not a general parameter. Specific for every Service
Basic Requirements concerns to Latency and Reliability
Requirements are balanced by Cost
Wired media can offer guaranteed QoS
Packet radios at ISM bands cannot offers a sustainable
QoS
Packet radios at private bands may offer QoS
Mesh topologies increases the possibilities of QoS
MYSORE 2013Interoperability
Smart Grid Communications: QoS Stovepipes or QoS Interoperability. Bakken, Schantz and Tucker
MYSORE 2013Efficient Resources Reuse
• In Smart Grid, Telecom is a resource not an objective• Smart Grid requires massive Telecom deployment. • TCO must be considered• There is no universal Telecom technology. • FO, Cooper Cable or Radio should be carefully implemented• Every application may require specific technology. • Efficient frequency reuse in Radio Links• RF channels should be planned considering interferences• Radio ISM bands may be blocked because external
interferences.
• Mesh topologies increase the connectivity opportunities.
MYSORE 2013Flexibility for Long Life
• Smart Grid requires huge investments with planned ROI
• Network behavior must be open to new Technologies
• Network must use suitable technology oriented to the
application
• Substitution of a network technology cannot affects to the
others
• Interoperability is a desired feature
• Services must be Technology independent
• Technological Components can be changed with minimal
network disturbances
MYSORE 2013WiFi Radio Spectra
MYSORE 20132.4 GHz WiFi, Real Spectrum
MYSORE 2013Systems at 2.4 GHz
• 2.4 GHZ belongs to the Industrial, Scientific and Medical bands which are free of use only with some restrictions in transmitted power.
• Other popular ISM band are located around 5 GHz.• Comercial Systems operating at 2.4 GHz are:
• WiFi is defined in the IEEE 802.3 group of standards.
• Wimax based on the IEEE 802.16 standards• Bluetooth initially IEEE 802.15.1 and now BSIG• Zig-Bee defined by IEEE.802.15.4
MYSORE 2013Network Topology
MYSORE 2013Radio Preferred Topologies
Bus topology cannot be used. Radio space is a shared media
Star. The most widely used in commercial Wi-Fi applications
Tree. Commonly used in low density areas
Line. Basically is a Point to Point architecture with 2 transmitters
Mesh. Requires flow control complexity
Ring. Technically possible but not widely used
MYSORE 2013Packet Radio
• Radio Transmitters may be full duplex or half duplex• Full Duplex Radio Data Transmitters normally are used
in PtP links• Packet Radios are Half Duplex Radio Data
Transmitters • PR alternatively switch on/off the Tx and Rx parts • Tx and Rx uses the same RF channel alternatively• CSMA-CA protocol is used to minimize the collisions • Some systems are able to jump the channel 1600 T/s
MYSORE 2013WiFi, Delay Probability
MYSORE 2013Routing Capacity
1
2
3
10
4
Bloc
king
pro
babi
lity
Normalized Traffic (E/N)
MYSORE 2013The IEEE 802.11n Standard
• Last and widely used WiFi standard• Covers both bands 2.4 GHz and 5 GHz• May use double bandwidth channels (40 MHz)• Collaborative system with multiple radios and
antennas• Implements MIMO and Beam Forming techniques• Suitable for Mesh topologies• Efficient configuration in dense areas may be
complex
MYSORE 2013New Improvements
New trends are focused to increase the effective bandwidth and QoS• Channel aggregation• Multiband aggregation• New ISM bands in use for packet radio• Use of Routing Protocols improve the QoS
New Proprietary protocol solutions promises unprecedent efficiency and QoS in homogenous network.
Hardware with low energy consumption eases its placement in unattended places
MYSORE 2013Radio Wave Propagation
• Wave propagation is a frequency dependent issue• Losses increases proportionally to the frequency• Loss, Diffraction (Scattering) and Reflection must to
be main parameters to consider• For long ranges the local effects are averaged by the
distance• Smart Grids are always “Short Range”• In GHz wavelength range, walls are “reflectors” and
streets are “waveguides”
MYSORE 2013Propagation Models
• Path losses are not an easy matter to calculate.• Different models are proposed covering different
cases• Statistical models are suitable for system simulations• Empirical models are site specific but more reliable• Smart Grid practically limits the distances to a few
Km• Free Space, Friis, Weissberger and Two Ray models
should be discarded• HATA models and its variants gives optimistic results
in WiFi bands because his validity ends at 1.5 GHz• COST models family seems to be more appropriate
MYSORE 2013Network Node
MYSORE 2013Network Node Application
MYSORE 2013Question 1.35
Authors highlighted the importance of implementing Point to Point links rather than multidirectional diffusion ones. Does it beneficial in terms of cost?
• Point to point link is a consequence to use of directional antennas
• Directional antennas maximises the desired signal while the unwanted interferences are attenuated
• In the counterpart setting the node requires to point the antennas
• In terms of cost, PtP links are more expensive and is necessary to balance with the technical benefits
MYSORE 2013Question 1.36
Do you consider using Point to Point links across the entire network to share media with other services?
• Point to point link is an expensive solution which should be reserved for mission critical links and / or in highly interfered areas.
• In a mesh network, a certain node may use different type of antennas depending of the nature of the link
• Mesh networks based on standards takes advantage of the use of specific resources suitable for determinate situations
MYSORE 2013