Competing Methodologies and Future Trend in Residential High-Speed Internet Access Hung Nguyen, Ph.D. The Aerospace Corporation 15049 Conference Center Dr. Chantilly, VA 20151
A simple solution to the labor shortage: Build broadband to the home Michael Vizard Editor-In-Chief Infoworld 7/24/2000 8/4/2000 HHN/VTIC 2000 2
The Current Cost of Internet Access Second phone line $25/month+installation with dial-up ISP $20/month. Total cost is ~$45/month at <56 kbps. Cable modem ~$40/month plus modem ($150) and installation ($100) at 27 Mbps shared with 8 or more neighbors. ADSL varies $50-$200/month plus modem or router/bridge ($200) and installation (usually waived) for 144 Kbps to 1Mbps. 8/4/2000 HHN/VTIC 2000 3
Current Internet Access Methods Internet or WAN Other service networks (e.g. telephony, CATV, wireless, satellite Access network termination and interworking Analog (POTS/modem) access network xdsl access network Cable access networks Wireless access network Wireless Cable network Direct satellite network 8/4/2000 HHN/VTIC 2000 4
Summary of xdsl Technology ACRONYM NAME DATA RATE LINE CODE MODE NUMBER OF TWISTED PAIRS DSL Digital subscriber line 160 Kb/s 2B1Q Duplex One HDSL High-data-rate DSL 1.544 Mb/s 2.048 Mb/s 2B1Q Duplex Duplex Two Three SDSL Single-line DSL 1.544 Mb/s 2.048 Mb/s CAP DMT Duplex Duplex One One ADSL Asymmetric DSL 1.5 to 6.144 Mb/s CAP Downstream One 16 to 640 Kb/s DMT Upstream RADSL Rate-adaptive DSL Adaptive to ADSL rates CAP Upstream and One DMT downstream VDSL Very-high-data-rate DSL 13 to 52 Mb/s CAP Downstream One (A)DSL Lite (or UADSL) Asymmetrical DSL Lite Universal ADSL 1.5 to 2.3 Mb/s 1.5 Mb/s 512 Kb/s DMT CAP DMT Upstream Downstream Upstream One 8/4/2000 HHN/VTIC 2000 5
xdsl Spectrum 8/4/2000 HHN/VTIC 2000 6
xdsl - Some Important Abbreviations & Facts LEC: Local Exchange Carrier: LBOCs Were the only provider of DSL service Now called Incumbent LEC (ILEC) CLEC: Competitive LEC. Most rapid growth industry DSLAM: DSL Access Multiplexers OEM: also fast growth due to market demand CO and CPE equipment: Cisco, Nortel, etc DSL chip maker: Alcatel, ADI, NEC... 8/4/2000 HHN/VTIC 2000 7
Some xdsl Providers Local Bell Operating Companies Major ISPs Earthlink.net FirstWorld Communications Dsl.net, Speakeasy.net, Megapath.net, etc Freebies: freedsl.com... Information sites http://whatis.com/dsl.htm http://www.dslreports.com/ 8/4/2000 HHN/VTIC 2000 8
2B1Q Line Code: 4-level PAM BITS QUATERNARY VOLTAGE SYMBOL LEVEL 00-3 -2.5 01-1 -0.833 10 +3 +2.5 11 +1 +0.833 8/4/2000 HHN/VTIC 2000 9
CAP - Carrierless Amplitude and Phase CAP is closely ralated to QAM (Quadrature Amplitude Modulation) The I&Q (inphase and quadrature) in QAM generated by sine & cosine mixer and combined in analog domain The I&Q in CAP generated digitally, combined and then digital-to-analog converted => precise matching between I and Q. 8/4/2000 HHN/VTIC 2000 10
DMT - Discrete Multi-Tone DMT employs many sub-carriers (up to 256) & transmit in parallel. All sub-carriers are orthogonal to each other. Use of FFT and IFFT Each sub-carrier can have amplitude and/or phase modulation for that sub-band. Similar to OFDM (orthogonal frequency division multiplexing) in wireless communication. 8/4/2000 HHN/VTIC 2000 11
ADSL Network Access Architecture Internet backbone Service-specific interfaces PC ATM network Private leased-line network Other networks (e.g., FR) Access Node* PSTN ATU-C ATU-C ATU-C Passive Split Copper Loop Network interface Passive Split ATU-R * Can be co-located with CO switch or remote within distribution palnt To phones Premise LAN Premise cable wiring Set-top 8/4/2000 HHN/VTIC 2000 12
Key MCNS DOCSIS Technical Specifications DOWNSTREAM UPSTREAM ACCESS CONTROL MANAGEMENT SUBSCRIBER INTERFACE NETWORK INTERFACES 64 and 256 QAM with variable interleaving QPSK and 16 QAM 6 MHz carrier 200 KHz to 3.2 MHz carrier 27 or 36 Mbps data rate Reed Solomon FEC DES Encryption 320 Kbps - 10 Mbps data rate Reed Solomon FEC DES Encryption MCNS SNMP 10Base-T Packetbased, contention and reservation slots, QoS hooks MIB definitions provided USB and IEEE 1394 planned 10Base-T 100Base-T ATM FDDI 8/4/2000 HHN/VTIC 2000 13
Broadcom Cable Modem Block Diagram 8/4/2000 HHN/VTIC 2000 14
Data Over Cable Architecture PSTN Internet or WAN Cable head-end with PoP router Internet Router Head-end switch (e.g., LAN) Local servers RF-modulated video signals CMTS CMTS RF combiner Upstream Splitter & filters Tx ------ - Rx Fiber O/E node O/E node Cable distribution system Coax PC Cable mode m LAN Customer premise equipment Managementand OSS, security and access control TCP/IP traffic CMTS: cable modem termination system O/E: optical to electrical conversion 8/4/2000 HHN/VTIC 2000 15
Multi-point Distribution System Local (LMDS) & Multi-channel (MMDS) Analog video distribution from base station to households. Line-of-sight operation. MMDS: 2.5-2.7 GHz, 33 analog channels of 6 MHz within 50 km radius. Upstream may be via phone line. LMDS: at 28 GHz to promise 1,300 MHz bandwidth with bi-directional & interactive data services. 8/4/2000 HHN/VTIC 2000 16
Wireless Local Loop (WLL) Multi-point Distribution System 8/4/2000 HHN/VTIC 2000 17
An MMDS Experimental System Internet 3xT1 Base station antenna (shared tower) Downstream at 2.6 GHz and 27 Mbps Upstream at 2.1 GHz and 3x650 Kbps Rooftop antenna Transceiver Simple user site Video AT&T intranet FDDI Ring Alcatel point-to-point radio Cisco 4500 Router Alcatel Cisco 4500 Router RF system Cable head-end Cable modem Rooftop antenna Transceiver User Computer 100BaseT switch Application servers PSTN PBX VoIP gateway Application servers Base station Cable modem 10 BaseT Ethernet Bridge User Computer WAN access point VoIP client Telephones 8/4/2000 HHN/VTIC 2000 Telephone functional 18 Fully user site
Current LMDS Providers Spectrum auctions completed March 1998. Field trials and service roll-out Some LMDS vendors: Alcatel (was Newbridge) Harris (was WavTrace) Some service providers: LMDS Communications Inc. Competed field trial (New Castle, PA) for small & medium business. Home Telephone Inc., Charleston, SC 8/4/2000 HHN/VTIC 2000 19
Internet Access Using Satellite Gateway Public network ISP Internet ISP 8/4/2000 HHN/VTIC 2000 20
Space-Borne Internet Access Providers 8/4/2000 HHN/VTIC 2000 21
Global Access in Telecommunications 8/4/2000 HHN/VTIC 2000 22
Conclusions xdsl & cable modem are 2 leading contenders. Fewer cable modem providers, more visible in big cities, backed up by large corporations. More xsdl providers, smaller & less wellknown, recently public with negative profit. Satellite Internet access could dominate but will have to clear the initial insertion & cost LMDS is rolling out and could be extremely competitive due to the wireless technology 8/4/2000 HHN/VTIC 2000 23