Technical standards such as FSAN can’t overcome all the hurdles that may impede the fiberization of homes. BellSouth has the advantage of serving a region that is undergoing rapid economic and population growth. That means lots of new housing developments, each one a relatively easy opportunity for fiberization because the ground is already dug up for laying all sorts of power and telecommunications infrastructure. That’s not the situation in most of the United States, where installing fiber means new construction. Not to mention the headaches in Europe. BellSouth’s Spears says a Telecom Italia colleague was amazed by a photo of a landscape stripped bare by a developer. Spears recalls the Italian told him, “When we go into Rome and start digging in the street, we may run into some artifact, and they put a fence around it and halt construction until archaeologists do their work.”
The market for fiber to the home is young, and analysts shy away from forecasting its growth. “It’s hard to make projections based on services that don’t exist yet,” says Jeff Kagan, an industry analyst in Marietta, Ga. In the short term, the biggest question mark is how U.S. consumers and cable operators will respond to digital high-definition television, which will gobble up bandwidth like nothing we have seen so far. In the long term, continued growth of the Internet will push digital demand upward. The static images common on many Web pages load slowly at 56,000 bits/second, driving demand for DSL and cable modems in the megabits/second range. As increasing numbers of Web-site designers yield to the temptation to display moving images, even these lightning-like hookups may begin to feel sluggish.
Extrapolating the 20-fold growth in bandwidth of the 1990s-modems jumped from 2,400 to 56,000 bits/second-leads to a projection that by 2020, 100 megabits/second will be routine. And that may be conservative. Adel Saleh, chief network architect at Corvus in Columbia, Md., says that 100 megabits/second could come to homes as soon as 2005. Saleh predicts that by 2010, wavelength multiplexed systems will provide bandwidth on the order of 1,000 megabits/second. With that kind of capacity, the biggest problem will be figuring out how to tap into our inner Gernsback.
Battle of the Last Mile
Technology How it works Capacity (Mbit/s) Advantage Limitations Fiber to the home Fiber carries data to homes. Could also carry broadcast video, either in same signal or at other wavelengths. Several hundred, up to 1,000 Highest speed Cost of construction Digital subscriber line (DSL) Transmits digital data on phone lines at frequencies higher than those used for voice. Frequencies are separated at the home. Individual homes get dedicated lines. Downstream: 6-8
Upstream: up to 1.5 Can use existing phone lines No service for homes more than 5.5 km from phone switching node Top speeds possible only on short lines Not available for all phone customers Cable modem Data travels to home on TV (coaxial) cable in a frequency band used for one video channel. Upstream transmission is at a lower frequency or on phone wires. Downstream: typically ~1
Upstream: typically 0.1-0.5 Uses existing coaxial cable Individual data rate drops with number of users Poor security Not available on all cable systems Wireless (terrestrial) Local antenna broadcasts microwaves, picked up by home antenna. Broadcasts video signals, and can transmit data. Comparable to DSL No cable installation Multipath interference from buildings Trees, terrain and rain can block signals Interference possible from other cells Signals travel limited distance (like cell phone) Wireless (satellite) Satellite broadcasts data signals; individual receivers pick off their signal. Might be added to direct broadcast satellite service, or to mobile low-earth-orbit service such as Teledesic. To be defined No cable, no local broadcast antennas Better suited to broadcasting because of large satellite coverage area Limited data rates likely