Επιστροφή στο Forum : Powerline Communications DEI
Powerline Communications
What is powerline communications?
Powerine communications (referred to in the industry as PowerLine Communications, or PLC) is a rapidly evolving market that utilizes electricity power lines for the high-speed transmission of data and voice services.
How does powerline communications function?
PLC works by transmitting high frequency data signals through the same power cable network used for carrying electricity power to household users. Such signal cannot pass through a transformer. This requires devices ("outdoor devices") that combine the voice and data signals with the low-voltage supply current in the local transformer stations to bridge the last mile. In the house, "indoor devices" (adapters) are used in order to filter out the voice and data signals and to feed them to the various applications (e.g. PC/Internet, telephone, etc.).
Is powerline communications a new technology?
The technology has roots going back to the 1940s. It has been used by power utilities for simple telemetering and control of electrical equipment in their networks. What is new is the integration of activities outside the building with those inside the building at a much higher bandwidth, 2.5 mbps or higher – this means voice and data transmission via the mains supply voltage network right through to every power socket in the building, as well as in the reverse direction at high speed.
What are PLC advantages?
Availability of an extensive communications infrastructure in place, thus eliminating the need for building of redundant facilities. Only the substation server equipment and customer conditioning/service units need to be installed in order to establish a digital powerline network.
Powerlines carry signals for long distances without requiring regeneration. Their near light speed propagation makes them very powerful for fast delivery of video and audio data. There is no topology limitation for powerlines.
High transmission rate, right now 3 mbps in uploading and downloading. Sumitomo Electric Industries, Ltd. developed high speed PLC modems, whose data transmission rate is 45 mbps, several times higher than ADSL. The data transmission rate is expected up to 200 mbps in the future by improving the PLC chip.
Permanent on-line connection with the potential for lower charges.
No need for complicated wiring and additional installations. Move your computers and appliances where you want.
Secure data-encryption.
Lower investment costs compared to those envisaged for other broadband data access systems.
Electric companies could offer a broader bundle of services then telecom providers.
What are PLC weaknesses?
Powerline solutions, like phoneline solutions, are unintentional radiators. Emissions can potentially cause interference with radio, television, community antenna television, telephone and DSL services.
Data signal disruption due to noise interference and signal loss over longer distances.
Problems with bypassing transformers.
From a market perspective, powerline networking technology faces potentially serious competition from wireless local area network (WLAN) solutions.
Providers would still need to come up with with a “last mile” solution for hooking up individual subscribers to the neighborhood transformer. That connection could be through cable or phone lines, or wireless.
Powerline's maximum access speed is shared with all users connected to the same local network station. The more people that are simultaneously on the Internet, the lower the speed obtained.
Powerline Communications
What is powerline communications?
Powerine communications (referred to in the industry as PowerLine Communications, or PLC) is a rapidly evolving market that utilizes electricity power lines for the high-speed transmission of data and voice services.
How does powerline communications function?
PLC works by transmitting high frequency data signals through the same power cable network used for carrying electricity power to household users. Such signal cannot pass through a transformer. This requires devices ("outdoor devices") that combine the voice and data signals with the low-voltage supply current in the local transformer stations to bridge the last mile. In the house, "indoor devices" (adapters) are used in order to filter out the voice and data signals and to feed them to the various applications (e.g. PC/Internet, telephone, etc.).
Is powerline communications a new technology?
The technology has roots going back to the 1940s. It has been used by power utilities for simple telemetering and control of electrical equipment in their networks. What is new is the integration of activities outside the building with those inside the building at a much higher bandwidth, 2.5 mbps or higher – this means voice and data transmission via the mains supply voltage network right through to every power socket in the building, as well as in the reverse direction at high speed.
What are PLC advantages?
Availability of an extensive communications infrastructure in place, thus eliminating the need for building of redundant facilities. Only the substation server equipment and customer conditioning/service units need to be installed in order to establish a digital powerline network.
Powerlines carry signals for long distances without requiring regeneration. Their near light speed propagation makes them very powerful for fast delivery of video and audio data. There is no topology limitation for powerlines.
High transmission rate, right now 3 mbps in uploading and downloading. Sumitomo Electric Industries, Ltd. developed high speed PLC modems, whose data transmission rate is 45 mbps, several times higher than ADSL. The data transmission rate is expected up to 200 mbps in the future by improving the PLC chip.
Permanent on-line connection with the potential for lower charges.
No need for complicated wiring and additional installations. Move your computers and appliances where you want.
Secure data-encryption.
Lower investment costs compared to those envisaged for other broadband data access systems.
Electric companies could offer a broader bundle of services then telecom providers.
What are PLC weaknesses?
Powerline solutions, like phoneline solutions, are unintentional radiators. Emissions can potentially cause interference with radio, television, community antenna television, telephone and DSL services.
Data signal disruption due to noise interference and signal loss over longer distances.
Problems with bypassing transformers.
From a market perspective, powerline networking technology faces potentially serious competition from wireless local area network (WLAN) solutions.
Providers would still need to come up with with a “last mile” solution for hooking up individual subscribers to the neighborhood transformer. That connection could be through cable or phone lines, or wireless.
Powerline's maximum access speed is shared with all users connected to the same local network station. The more people that are simultaneously on the Internet, the lower the speed obtained.
Lipon gia na ksekatharosoume kapia pragmata. H texnologia twn powerline einai poli makria apo thn emporikh ekmetaleush. Akoma ta pio vasika pragmata opws ena modem h ti modulation type tha xrhsimopoihtei den exoun apofasisitei. Pio pithano pantws modulation einai to MFSK ( M-ary Frequency Shift Keying). Telos pantwn, gia na mhn eiserxomai se texnika zitimata....h DEI den exei kamia sxesh na kanei me powerlines! H DEI steinei diktia optikwn inwn auth th stigmh gia thlepikoinoniakh xrhsh. Oi powerlines -otan vgoun sthn agora- tha vroun xrhsh se diktia kleistwn xwrwn. Diladi, tha einai dinaton na steisoume ena LAN sto spiti mas, xwris na tripisoume tous toixous gia na perasoume kalwdia h na xilothoume gia ena wireless LAN. Tha mporoume aplws na valoume ena eidiko termatiko sthn priza tou spitiou, to opio tha sindeetai mesw enws edikou interface me to pc kai etsi na steisoume ena LAN. Alla ola auta einai mallon poli makria akoma (toulaxiston 7-8 xronia).....
Μέσω οπτικών ινών θα είναι ακόμα καλύτερα!!! :D Άλλα δεν λέγανε όλοι ότι θα χρησιμοποιήσει τα καλώδια ρεύματος;
Kita,
Den tin xalai na perasi kainourgia kalodia esto kai optikon inon, Why?
Why exi olokliro to diktio etimo apo 8emata kolonon, to mono pou exi einai na perasi kalodia. Gia auto mpori na ependisi perisotera se kalodia.
Geia kai xronia polla!
Akoma ta pio vasika pragmata opws ena modem h ti modulation type tha xrhsimopoihtei den exoun apofasisitei. Pio pithano pantws modulation einai to MFSK ( M-ary Frequency Shift Keying). Telos pantwn, gia na mhn eiserxomai se texnika zitimata....
Na mpoume! Na mpoume se texnikes leptomereies, giati pisteyw edw mesa einai polloi (opws egw) pou 8a endiaferomastan na ma8ename kati parapanw giaythn thn texnologia!
An mporeseis kapoia stigmh na moirasteis liges apo tis gnoseis sou 8a eimastan ypoxreoi! :)
Giannhs.
File Giannh,
katarxas den thelo na eknevrizesai.... :D afou thes leptomeries tha tis exeis:
Lipon, h idea na xrhsimopoithoun oi grammes tou revmatos gia tilepikoinonies opioasdipote morfhs den einai kai poli kainouria. Apenantias, h idea auth einai palia. Wstoso mexri simera , h epiteuxh ikanpoihtikou simatos (SNR megalitero apo 10 dB) htan mia diskolh ipothesh. Kai auto ginotan logo tou exeritika megalou thorivou pou prokalouse to idio to ilektriko revma! Ta teleutaia 5 xronia omos xarh se ipsilhs apodotikothtas kodikes(Turbo Codes) kati tetio epiteuthike. H kodikopoish tou simatos se genikes grammes (h allios to coding opws einai gnoston), stoxevei sthn oso to pio dinaton error-free metadosh enos simatos. Auto epigxanetai me th metadosh kapiwn extra bit (gnosta ws parity check bits) me ta opoia o apodikopoihths (h decoder) mporei na apofasisei an to sigekrimeno bit h simbolo (an milame gia M-ary Modulation) htan ontos to original bit h simbolo pou metadothike. Etsi den exoume mono entopismo tou lathous (error detection) alla kai diorthosi tou (error correction).
Parola auta, akoma kai me th xrhsh tou kaliterou encoding, oi powelines den mporoun na ilopoihthoun gia enan aplo logo : den exei akoma kataskevastei ena plires sistima modem (modulator-demodulator h allios diamorfoths kai apodiarmofoths). Otan imouna prin ena mhna sto panepistimio mou (Agglia) mas egine mia epidixh apo enan professor pou didaskei sto panepistimio tou Kent, o opios mas etrexe merika modela pou eixe sxediasei (sth Simulink - mia glossa exomoioshs) kai mas ekane xekatharo pos to sima sth powerline einai exeraitika evaisthito ean to sima pou theloume na metadosoume metavalaitai diarkws se platos (amplitude) kai se fash (phase). Epomenws tropoi diamorfwshs tou shmatos ta opoia me apla logia na "periexoun" thn pliroforia sto platos tou pou diarkws allazei (se auth thn periptwsh h diamorfwsh onomazetai ASK-Amplitude Shift Keying), h tropoi diamorfoshs pou me to idio skeptiko na periexei thn plhrforia sth fash tou shmatos pou kai auth diarkws metavaletai (PSK-Phase Shift Keying), einai aporipteoi. Kai o idios o professor pou mas ekane th dialexh kathws kai o head tou department mou (to opoio diathetei idiko powerline laboratory edw kai 6 xronia pou xrhmatodoteitai apo th BT kai th DERA -to Vretaniko Ipourgeio Aminas-) mas eipan pws to kalitero sisthma diamorfwshs pou armozei stis powerlines einai to FSK kai sigekrimena to MFSK. Tha exigiso aplws ti simenei FSK (tha to exete hdh katalavei), se auth th periptwsh h parametros tou simatos pou allazei kai pou emperiexei thn plhroforia einai h sixnothta tou simatos). Etsi kai ta dio megeth sta opoia h powerline san grammh metadoshs einai evaisthth (to platos kai h fash) paramenoun stathera. Gia nas exigiso twra pws leitourgei to MFSK tha mpu parei 1 wra - aplws fantasteite pws anti na stelnoume tis plirofories se diadikh morfh tis stelnoume se M-ary morfh...(anti gia 0 kai 1 , stelnoume px 0001 kai 1000). To MFSK einai to protimhteo sisthma giati parexei poli kali sxesh BER vs SNR (me apla logia , to sima exei ta ligotero dinata lathos bit me oso to dinaton mikrotero logo isxhs tous simatos pros thn isxh tou thorivou), kai einai aplo se ilopoihsh (den apaitei poliploka kiklomata oute sto transmitter alla oute kai sto receiver).
Auta, elpizo na min sas kourasa....gia oti allo theletai just ask!
Kostas, Mhxanikos Thlepikoinwniwn.
Empire Pistebo Mas Kalipse apo oles Tis pleures.
Ποιος ήρθε; :D ¨
Όχι φίλε Samis83, δε μας κούρασες και είναι πολύ κατατοπιστικά σχετικά με τη νέα τεχνολογία αυτά που μας είπες, αν και οι γνώσεις μου δε μου επιτρέπουν να τα κατανοήσω όλα "πολύ απλά" όπως έλεγες και εσύ... :D
Φίλε samis83 καθόλου δεν μας κούρασες, μια και σε όλους εδώ μέσα, μας αρέσει η τεχνολογία σε όποιο βαθμό και αν την κατανοούμε. Τουλάχιστο το κεντρικό νόημα (τη μη άμεση εμπορική εκμετάλευση) όλοι το κατανόησαν και σε ευχαριστούμε.
Για το θέμα της τεχνολογίας που θα χρησιμοποιήσει η ΔΕΗ πάντως δεν έχω δει κάτι επίσημο (μια και δεν υφίσταται κάποιο site). Ξέρω και εγώ για το δίκτυο οπτικών ινών που στήνει, αλλά δεν ξέρω τίποτα για την τεχνολογία που θα χρησιμοποιήσει προς τον τελικό καταναλωτή. Αν ξέρει κάτι κάποιος ας το αναφέρει, αλλά παρακαλώ εμπεριστατομένα (όχι άκουσα, μου είπαν κλπ.) με κάποια μορφή παραπομπής. :arrow:
Ξέρω και εγώ για το δίκτυο οπτικών ινών που στήνει, αλλά δεν ξέρω τίποτα για την τεχνολογία που θα χρησιμοποιήσει προς τον τελικό καταναλωτή. Αν ξέρει κάτι κάποιος ας το αναφέρει, αλλά παρακαλώ εμπεριστατομένα (όχι άκουσα, μου είπαν κλπ.) με κάποια μορφή παραπομπής. :arrow:
Den yparxei tipota epishmo, alla den xreiazetai na eisai mentioum, gia na katalabeis ti den tha xrhsimopoihsei. Sigoura DEN tha xrhsimopoihsei to diktyo dianomh hlektrismou, giati h texnologia den xrhsimopoieitai pouthena sto kosmo mazika.
To diktyo ths DEH/Wind tha einai mallon enas syndyasmos xDSL, optikon inon, umts kai mobile (gprs), opos einai kai ths Wind sthn Italia.
http://www.wind.it/eng/media/interscambio.php
Den yparxei tipota epishmo, alla den xreiazetai na eisai mentioum, gia na katalabeis ti den tha xrhsimopoihsei. Sigoura DEN tha xrhsimopoihsei to diktyo dianomh hlektrismou, giati h texnologia den xrhsimopoieitai pouthena sto kosmo mazika.
To diktyo ths DEH/Wind tha einai mallon enas syndyasmos xDSL, optikon inon, umts kai mobile (gprs), opos einai kai ths Wind sthn Italia.
http://www.wind.it/eng/media/interscambio.php
Μάλλον κάτι τέτοιο βλέπω και εγώ, αλλά δεν αποκλείω και τα απλά δισύρματα, μια και έχει δικούς της χώρους (για τους μετρητές) σε κάθε πολυκατοικία. Όσο για το umts και mobile που γράφεις, το θεωρώ λίγο δύσκολο μια και θα πρέπει οπωσδήποτε να υπάρχει συνεργασία με εταιρεία κινητής. (ξέρεις τίποτα σχετικό; )
Μάλλον κάτι τέτοιο βλέπω και εγώ, αλλά δεν αποκλείω και τα απλά δισύρματα, μια και έχει δικούς της χώρους (για τους μετρητές) σε κάθε πολυκατοικία. Όσο για το umts και mobile που γράφεις, το θεωρώ λίγο δύσκολο μια και θα πρέπει οπωσδήποτε να υπάρχει συνεργασία με εταιρεία κινητής. (ξέρεις τίποτα σχετικό; )
Gia asyrmath stather prosvash, nomizo kykloforoun polles anaksiopoihtes adeies. Gia mobile den ksero tipota sxetiko. Alla den nomizo oti mia etaireia thlepikoinonion pou thelei na ginei h deuterh megalyterh tou xorou, na agnohsei ton "xrysoforo" tomea the ellhnikhs agoras. Tora pos tha mpei den to ksero, afou den nomizo oti yparxei problepsh na dothei 5h adeia pros to paron. Alla nomizo Stet kai Quest den einai toso isxyres, oste na arnithoun mia kalh protash synergasias.
Eidika h Quest (h Stet den ksero)...8a mporouse na xrhsimopoieisei oti na nai gia na ginei 3h :)
Na doume an to thread katapelths ths tellas "eimaste mia ap ta idia parte ta @@ mas me mydia" alh8evei
Gia asyrmath stather prosvash, nomizo kykloforoun polles anaksiopoihtes adeies. Gia mobile den ksero tipota sxetiko. Alla den nomizo oti mia etaireia thlepikoinonion pou thelei na ginei h deuterh megalyterh tou xorou, na agnohsei ton "xrysoforo" tomea the ellhnikhs agoras. Tora pos tha mpei den to ksero, afou den nomizo oti yparxei problepsh na dothei 5h adeia pros to paron. Alla nomizo Stet kai Quest den einai toso isxyres, oste na arnithoun mia kalh protash synergasias.
Ασύρματη σταθερή άδεια η ΔΕΗ έχει ήδη. Εγώ ανέφερα ειδικά για UMTS για το οποίο υπάρχουν μόνο τρεις άδειες (οι τρεις εταιρείες κινητήής έχουν από μια). Τώρα, η μεν Stet πήρε την άδεια ασύρματης σταθερής των 25 GHz της Europrom οπότε μπορεί να δώσει υπηρεσίες σταθερής σε μεγάλους πελάτες. Άλλωστε δεν την ενδιαφέρουν ιδιαίτερα οι μικροί πελάτες. Απλά θέλει στους μεγάλους πελάτες να συμπληρώσει την παροχή κινητών υπηρεσιών με σταθερή και internet.
H Quest από την άλλη είναι διαφορετική περίπτωση. Παρά το γεγονός ότι έχει και αυτή άδεια παροχής υπηρεσιών σταθερής και κινητής, επειδή έχει προς το παρόν μικρό κομμάτι αγοράς και είναι δύσκολο (ή μάλλον ακριβό) να αποσπάσει μεγαλύτερο, δεν αποκλείεται αν βρεθεί κάποια μεγάλη τηλ/κή εταιρεία που να ενδιαφέρεται, να ενδώσει σε μια πρόταση εξαγοράς. Έτσι λοιπόν αν η ΔΕΗ θελήσει να συμπληρώσει τις υπηρεσίες της με κινητή δεν αποκλείεται κάποιος "γάμος". Βέβαια αυτά είναι σενάρια, αλλά ποτέ δεν ξέρεις.
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