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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
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Mysore 2013 D2 – 01 - 16 PreferentialSubject 1: Role of ICT in Power System COMMUNICATION ALTERNATIVES FOR SMART GRIDS: THE INTEGRATEDAPPROACH Jaume Darné and Claudio Rizoli Spain
Mysore 2013 Energy 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 2013 Quality 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 2013 Interoperability Smart GridCommunications: QoSStovepipesorQoSInteroperability. Bakken, Schantz and Tucker
Mysore 2013 Efficient 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 2013 Flexibility 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 2013 WiFi Radio Spectra
Mysore 2013 2.4 GHz WiFi, Real Spectrum
Mysore 2013 Systems 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 2013 Network Topology
Mysore 2013 Radio 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 2013 Packet 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 2013 WiFi, Delay Probability
Mysore 2013 Routing Capacity Blocking probability 1 2 3 4 10 Normalized Traffic (E/N)
Mysore 2013 The 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 2013 New 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 2013 Radio 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 2013 Propagation 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 2013 Network Node
Mysore 2013 Network Node Application
Mysore 2013 Question 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 2013 Question 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