Cable Broadband

1. Cable Broadband EOC (Ethernet On Cable) Introduction By

2. 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

3. Generation of cable modem to cover 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: By C a b l e B r o a d b a n d

4. HFC network consists of • An optical connection between the distribution center at the H/E and the ONU • A coaxial connection between the ONU and the subscriber. 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

5. Frequency Use in HFC Network 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 750~870MHz로, and about 70% can use the range of up to 750MHz. By C a b l e B r o a d b a n d

6. Configuration (In the Network) Solution 1 Max ~100 km (3-30 Mbit/s) CM CM CM CMTS ONU H/E CM CM CM • CMTS : Cable Modem Termination System • CM: Cable Modem ※ CM can only talk to CMTS, while CMTS can talk(broadcast) to any(all) By C a b l e B r o a d b a n d

7. CMTS in the head-end Cable Modem in the house upstream Modulator Modulator + + Demodulator downstream Demodulator - encoding : 64-QAM/256-QAM - total BW : 42 [65]-860 Mhz - single slot BW : 6[8]MHz - single slot data rate : 30–40 Mbps - encoding : QPSK/16-QAM - total BW :5-42 [65] Mhz - single slot BW : 0.2–6.4MHz - single slot data rate : 10, 30 in ver1.x, ver2.0 Mbps By C a b l e B r o a d b a n d

8. Configuration (In the Network) Solution 2 (LS HFC) Max ~2 km (100 Mbit/s) CDM CDM CDM Switch Master ONU H/E CDM CDM CDM • ONU : Optical Network Unit (Master) • CDM: Cable Data Modem Switch is an optical switch CDM: Cable Data modem is different with Cable Modem partially. The cable modem works with STB By C a b l e B r o a d b a n d

9. Cable Data Modem in the house Master in ONU Modulator Modulator upstream + + downstream Demodulator Demodulator encoding : OFDM/256-QAM - total BW :2-34 [32] Mhz - No limit for uploading for UCC, VoIP By C a b l e B r o a d b a n d

10. 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

11. Link Budget Coaxial network: Attenuation is less than 50 dB for better performance By C a b l e B r o a d b a n d

12. LS HFC Equipment Indoor Diplexer Indoor Master Outdoor Master L2 Switch Indoor Spliter Diplexer CPE Modem Outdoor Diplexer By C a b l e B r o a d b a n d

13. Example Network 1 Ethernet On Cable Outdoor By C a b l e B r o a d b a n d

14. Example Network 2 Ethernet On Cable Indoor By C a b l e B r o a d b a n d

15. THANK YOU By C a b l e B r o a d b a n d