M YSORE 2013 Preferential Subject 1: Role of ICT in Power System COMMUNICATION ALTERNATIVES FOR SMART GRIDS: THE INTEGRATED APPROACH Jaume Darné and Claudio Rizoli Spain D2 –

M YSORE 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.

M YSORE 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

M YSORE 2013 Interoperability Smart Grid Communications: QoS Stovepipes or QoS Interoperability. Bakken, Schantz and Tucker

M YSORE 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.

M YSORE 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

M YSORE 2013 WiFi Radio Spectra

M YSORE GHz WiFi, Real Spectrum

M YSORE 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 group of standards. Wimax based on the IEEE standards Bluetooth initially IEEE and now BSIG Zig-Bee defined by IEEE

M YSORE 2013 Network Topology

M YSORE 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

M YSORE 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

M YSORE 2013 WiFi, Delay Probability

M YSORE 2013 Routing Capacity Blocking probability Normalized Traffic (E/N)

M YSORE 2013 The IEEE n 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

M YSORE 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

M YSORE 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”

M YSORE 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

M YSORE 2013 Network Node

M YSORE 2013 Network Node Application

M YSORE 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

M YSORE 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

M YSORE 2013