1 Infokommunikcis rendszerek Lesson 2. elads Vezetkes tviteli kzegek Wire-line transmission Takcs Gyrgy Infocom 2. ea. szep. 14. Melyik tviteli kzeg jobb? Infocom 2. ea. szep. 14.2 What is cheaper? Cooling the servers in Europe ir in US? Travel bits even to the Arctic or Antarctic and operate servers (like Google, Facebook, Twitter, Amazon, Apple, Microsoft) in naturally cold areas? Infocom 2. ea. szep. 14.3 4 Behind every Google search, Facebook update, or Twitter tweet lies a gigantic computing infrastructure, at the heart of which sit massive server farms that collectively account for some 230 million tons of carbon dioxide emissions annually -- more than emitted by the entire country of Argentina. Air-conditioning can consume as much as half the total power that digital giants like Google, Facebook, Twitter, Amazon, Apple, Microsoft, and IBM need to run their huge server facilities, and these are growing rapidly. One solution is to move to a place thats already cold. Naturally cold air and, better yet, cold water, can result in significant energy savings. Locations for server farms are being explored across the far north, from Alaska to Iceland. Google is operating a site in the Finnish town of Hamina. Facebook is building a server farm in Lule, Sweden, just south of the Arctic Circle. Lefdal, which offers an abundance of clean, renewable energy from nearby hydroelectric dams and wind farms, as well as a unique cooling system that will pump icy cold water from about 650 feet below sea level, is expecting its first tenant to be IBM Norway. 5 Fnyvezet szlak rz tartalkkal Rz rprak GSM Rdis kapcsolat Infocom 2. ea. szep. 14. ITK hlzat 6 Vezetkes tviteli kzegek Sodrott rpras rzkbelek Koaxilis kbelek Fnyvezet kbelek Infocom 2. ea. szep. 14. infokom. rendsz. 2. elads szept. 13. komea_2_ A tovbbi infrastruktra tartalk helye Infocom 2. ea. szep. 14. 8 Kzeg jellemzk tviteli tulajdonsgok (csillapts, ksleltets, reflexi, diszperzi, thalls, zajok, zavar hatsok) Fektetsi, ktsi krdsek Illesztsek, szerelvnyek, vgzdtetsek Hibk, hibahely-behatrols Infocom 2. ea. szep. 14. 9 Wireline transmission media Symmetrical twisted pair copper cable Coaxial cable Optical fibre cable Constuction issues, connecting, error detection, error localosation. Infocom 2. ea. szep. 14. 10 Media and cable characteristics Transmission parameters (attenuation, delay, reflection, crosstalk, noises, interferences) Laying, connecting technologies Faults, fault localization Matching, accessories, termination Infocom 2. ea. szep. 14. 11 Symmetric or asymmetric? Related to the ground To protect from interferences The basic equations and characteristics of wires are very similar Infocom 2. ea. szep. 14. 12 Electromagnetic field around the symmetric wire Infocom 2. ea. szep. 14. 13Infocom 2. ea. szep. 14. 14Infocom 2. ea. szep. 14. infokom. rendsz. 2. elads szept. 13. komea_2_ Jellsek u(x,t)feszltsg, a tvolsg s id fggvnye voltage as the function of time and distance i(x,t) ram, a tvolsg s id fggvnye current as the function of time and distance (gamma)komplex csillaptsi egytthat Attenuation coefficient R,G,C,Legysgnyi hossz kbelszakasz ellenllsa, tvezetse, kapacitsa, induktivitsa resistance, conductivity, capacity, inductivity of the unit length cable Z a kbel komplex bemen impedancija The complex input impedance of the cable. Zo A kbel hullmimpedancija The characteristic impedanceof the cable Infocom 2. ea. szep. 14. 16 Equivalent circuit for a (dx) fragment of a wire Infocom 2. ea. szep. 14. 17 The basic equations for wires Infocom 2. ea. szep. 14. 18 The solution of basic equations Infocom 2. ea. szep. 14. 19 Consequence No.1 waveform of voltage as a function of distance along the wire Infocom 2. ea. szep. 14. 20Infocom 2. ea. szep. 14. 21 Consequence No.2 waveform of voltage as a function of time Infocom 2. ea. szep. 14. 22 Transmission properties of wires: attenuation, phase shift, characteristic impedance Infocom 2. ea. szep. 14. 23 Phenomenon at the end of terminated wire Reflection coefficient Infocom 2. ea. szep. 14. infokom. rendsz. 2. elads szept. 13. komea_2_ Phenomenon at the end of terminated wire example No1. : matched termination Infocom 2. ea. szep. 14. 25 Phenomenon at the end of terminated wire example No2. : shortcut at the end Infocom 2. ea. szep. 14. 26 Phenomenon at the end of terminated wire example No3. : open end Infocom 2. ea. szep. 14. 27 Phenomenon at the end of terminated wire example No4. : ohmic termination Infocom 2. ea. szep. 14. 28Infocom 2. ea. szep. 14. 29 Far end crosstalk and near end crosstalk Infocom 2. ea. szep. 14. 30Infocom 2. ea. szep. 14. 31 Characteristics of an UTP cabeling passing the CAT6 specifications Infocom 2. ea. szep. 14. 32 Propagation delay parameters The propagation speed is about 70% of light speed Infocom 2. ea. szep. 14. 33 The reflected signal response at the cable input after sending a nerrow pulse. The far end is terminated by open end! Infocom 2. ea. szep. 14. 34 Attenuation as a function of frequency Infocom 2. ea. szep. 14. 35 Near end crosstalk as a function of frequency Infocom 2. ea. szep. 14. 36 Characteristics of an UTP cabeling failing the CAT6 specifications What is the problem with this cable? Infocom 2. ea. szep. 14. 37 Propagation delay parameters The propagation speed is about 70% of light speed Infocom 2. ea. szep. 14. 38 The reflected signal response at the cable input after sending a nerrow pulse. The far end is terminated by open end! There are reflections from a mid position but only in pairs 36-78! Infocom 2. ea. szep. 14. 39 The attenuation is OK! Infocom 2. ea. szep. 14. 40 Near end crosstalk failed at pairs 36-78! Infocom 2. ea. szep. 14. 41 The problem is in the cable a wire split at 22,9 m ! Infocom 2. ea. szep. 14. 42Infocom 2. ea. szep. 14. 43 Structure of a coaxial cable Infocom 2. ea. szep. 14. 44Infocom 2. ea. szep. 14. 45Infocom 2. ea. szep. 14. 46Infocom 2. ea. szep. 14. Twinax, is a type of cable similar to coaxial cable, but with two inner conductors instead of one. Due to cost efficiency it is becoming common in modern (2013) very-short-range high-speed differential signaling applications. Infocom 2. ea. szep 48Infocom 2. ea. szep. 14. 49 Principle of optical fibre Fibre diameter 125m !!!! Infocom 2. ea. szep. 14. 50 Typical core and cladding diameters -Sizes are in microns Infocom 2. ea. szep. 14. 51 Transport of light in an optical fibre n refractive index Infocom 2. ea. szep. 14. 52 Types of mode propagation in fiber optic cable Infocom 2. ea. szep. 14. 53Infocom 2. ea. szep 54 Attenuation dB/km Wavelength hullmhossz Infocom 2. ea. szep. 14. 55Infocom 2. ea. szep. 14. 56 Chromatic dispersion Infocom 2. ea. szep. 14. 57 Principle of Wavelenght division multiplexing (example with three wavelength) Infocom 2. ea. szep. 14. 58Infocom 2. ea. szep. 14. 59Infocom 2. ea. szep. 14. 60 Schematic setup of a simple erbium-doped fiber amplifier. Two laser diodes (LDs) provide the pump power for the erbium-doped fiber Infocom 2. ea. szep. 14. 61Infocom 2. ea. szep. 14. 62Infocom 2. ea. szep. 14. 63Infocom 2. ea. szep. 14. 64Infocom 2. ea. szep. 14. 65Infocom 2. ea. szep. 14. 66 Infocom 2. ea. szep optical ground wire (OPGW) used in the construction of electric power transmission combines the functions of grounding and communications. OPGW What is cheaper? Cooling the servers in Europe ir in US? Travel bits even to the Arctic or Antarctic and operate servers (like Google, Facebook, Twitter, Amazon, Apple, Microsoft) in naturally cold areas? Infocom 2. ea. szep Infocom 2. ea. szep Behind every Google search, Facebook update, or Twitter tweet lies a gigantic computing infrastructure, at the heart of which sit massive server farms that collectively account for some 230 million tons of carbon dioxide emissions annually -- more than emitted by the entire country of Argentina. Air-conditioning can consume as much as half the total power that digital giants like Google, Facebook, Twitter, Amazon, Apple, Microsoft, and IBM need to run their huge server facilities, and these are growing rapidly. One solution is to move to a place thats already cold. Naturally cold air and, better yet, cold water, can result in significant energy savings. Locations for server farms are being explored across the far north, from Alaska to Iceland. Google is operating a site in the Finnish town of Hamina. Facebook is building a server farm in Lule, Sweden, just south of the Arctic Circle. Lefdal, which offers an abundance of clean, renewable energy from nearby hydroelectric dams and wind farms, as well as a unique cooling system that will pump icy cold water from about 650 feet below sea level, is expecting its first tenant to be IBM Norway. 70Infocom 2. ea. szep. 14. infokom. rendsz. 2. elads szept. 13. komea_2_ Copper or Fibre? Infocom 2. ea. szep. 14. 72 CAT 7 UTP CAT 7 SFTP CAT 7 SSTP Infocom 2. ea. szep. 14. 73 Where to put 10 GB twisted pair cables? Infocom 2. ea. szep. 14. 74 100 Gbit/s Ethernet 802.3ba is the designation given to the higher speed Ethernet task force which completed its work to modify the standard to support speeds higher than 10 Gbit/s in The speeds chosen by 802.3ba were 40 and 100 Gbit/s to support both end-point and link aggregation needs. The decision to include both speeds came from pressure to support the 40 Gbit/s rate for local server applications and the 100 Gbit/s rate for internet backbones. Infocom 2. ea. szep Infocom 2. ea. szep Class F cable Class F cable is a cable standard for Ethernet and other interconnect technologies that can be made to be backward compatible with Class D and Class E. Class F features even more strict specifications for crosstalk and system noise than Class E. To achieve this, shielding has been added for individual wire pairs and the cable as a whole. Besides the foil shield, the twisting of the pairs and number of turns per inch increases RF shielding and protects from crosstalk. Class F is recognized for all the country organizations members of ISO. Infocom 2. ea. szep Class F cable The Class F cable standard has been created to allow 10 Gigabit Ethernet over 100 m of copper cabling (also, 10 Gbit/s Ethernet now is typically run on Cat 6a). The cable contains four twisted copper wire pairs, just like the earlier standards. Class F can be terminated either with 8P8C compatible GG45 electrical connectors which incorporate the 8P8C standard or with TERA connectors. When combined with GG45 or TERA connectors, Class F cable is rated for transmission frequencies of up to 600 MHz. Infocom 2. ea. szep