Presentation on theme: "Cable Broadband EOC (Ethernet On Cable) By Introduction."— Presentation transcript:
Cable Broadband EOC (Ethernet On Cable) By Introduction
Evolution of CATV o CATV is originally used for uni- directional TV signal o CATV is upgraded to allow bi- directional comm. We need a communication device that provides return path. By C a b l e B r o a d b a n d
By C a b l e B r o a d b a n d o 1st generation : not based on widely accepted on standards. o 2nd generation : based on standards : DOCSIS(USA) and DVB/DAVIC (Europe) o 3rd generation : wireless modems, or some more symmetrical cable modems: Generation of cable modem to cover
By C a b l e B r o a d b a n d 1.An optical connection between the distribution center at the H/E and the ONU 2.A coaxial connection between the ONU and the subscriber. HFC network consists of The HFC network provides high speed data service through optical and coaxial cables using a CMTS(Cable Modem Termination System) installed at the Head End, and the CM(Cable Modem) installed at the end user.
By C a b l e B r o a d b a n d The HFC network has a upstream frequency of 5MHz ~ 42MHz, and 54MHz ~ 750MHz for downstream. The upstream frequency is used for CATV signals and data services. The frequency range can be expanded up to 2GHz, and about 80% of service providers has expanded to 750~870MHz, and about 70% can use the range of up to 750MHz. Frequency Use in HFC Network
By C a b l e B r o a d b a n d Configuration (In the Network) CMTS H/E ONU CM Max ~100 km (3-30 Mbit/s) CMTS : Cable Modem Termination System CM: Cable Modem CM can only talk to CMTS, while CMTS can talk(broadcast) to any(all) Solution 1
By C a b l e B r o a d b a n d CMTS in the head-endCable Modem in the house Modulator Demodulator + Modulator Demodulator + upstream downstream - encoding : QPSK/16-QAM - total BW :5-42  Mhz - single slot BW : 0.2– 6.4MHz - single slot data rate : 10, 30 in ver1.x, ver2.0 Mbps - encoding : 64- QAM/256-QAM - total BW : 42 - 860 Mhz - single slot BW : 6MHz - single slot data rate : 30–40 Mbps
By C a b l e B r o a d b a n d Configuration (In the Network) Switch H/E Master CDM Max ~2 km (100 Mbit/s) ONU : Optical Network Unit (Master) CDM: Cable Data Modem Solution 2 (LS HFC) ONU Switch is an optical switch CDM: Cable Data modem is different with Cable Modem The cable modem works with STB partially.
By C a b l e B r o a d b a n d Master in ONU Cable Data Modem in the house Modulator Demodulator + Modulator Demodulator + upstream downstream encoding : OFDM/256-QAM - total BW :2-34  Mhz - No limit for uploading for UCC, VoIP
By C a b l e B r o a d b a n d Modulation CDM are based on OFDM (Orthogonal Frequency Division Multiplexing) modulation. This is already used in xDSL, WLAN, and PLC to name a few. This type of modulation enables the HFC network to increase its strength against interference noise and time delay on a coaxial network Some strong points of OFDM is as the following. It is efficient in multi-path fading channels with large time spreads The data rate per subscriber is adaptable (according to the SNR detected at this subcarrier) Interferences (and impulsive noise) only affect some carriers while the remaining carriers ensure reliable communication
By C a b l e B r o a d b a n d Coaxial network: Attenuation is less than 50 dB for better performance Link Budget
By C a b l e B r o a d b a n d LS HFC Equipment L2 Switch Outdoor Master Indoor Master CPE Modem Indoor Diplexer Indoor Spliter Diplexer Outdoor Diplexer
By C a b l e B r o a d b a n d Example Network 1 Ethernet On Cable Outdoor
By C a b l e B r o a d b a n d Ethernet On Cable Indoor Example Network 2