|
Access Technology |
Data Rates (typical) |
Installation Costs (typical) |
Monthly Costs (typical) |
Availability |
Accessibility Considerations |
Policy Issues |
|
Dial-up modem |
14.4, 28.8, & 56.6 kbps |
$50-100 modem |
$20/month for telephone line; free to $20/month for ISP |
Widespread availability in U.S. |
Requires separate phone line or uses existing phone line |
Use of free ISPs raises user privacy concerns |
|
ISDN |
128 kbps |
$100-150 |
Residential: $50-60/month Business: $90-100; may be metered |
Still the only moderate speed option available in some areas of U.S. |
Won’t be necessary once DSL is ubiquitous |
A federal court ruling in TN (1993) found that ISDN service must be delivered across the state at the same cost |
|
Cable modem |
Asymmetric service: Uplink: 128 kbps Downlink: to 2 Mbps or higher; typical is 500 kbps |
~$150 |
~$50/month |
Increasingly available in urban/suburban areas in U.S. A few years ahead on deployment compared to DSL |
Runs over cable television plant (coax in the home) Many plants are still one-way; require phone line for upstream Shared network architecture; cable co. can tout 30 Mbps but typically a segment won’t see more than 10 Mbps or less and this is shared by up to 500 homes Still issues with EMI on a shared network and security issues with a shared, always on network |
Bundling of ISP service with network access raises competition questions Quasi-public organizations competing with private companies in some rural areas in U.S. |
|
DSL modem |
ADSL: 256 kbps (upstream) and up to 1.5 Mbps (downstream) |
$150 setup & $150 modem |
Residential: $50/month Business: vary based on committed throughput but begins at $90/month |
Multiple types of DSL service available Problem: Extremely distance sensitive; current maximums for ADSL service is 18,000 feet |
Uses existing phone line (i.e., telephone calls can be done concurrently with Internet surfing) Key benefit: a dedicated connection back to the DSL multiplexer |
"Digital divide" between access in urban/suburban vs. rural areas in U.S. of increasing policy concern Free DSL service available only to heavily populated DSL centers (rural and suburban areas must pay for service) If no competition, then little incentive for private companies to upgrade facilities |
|
Leased line |
1.544+ Mbps |
$200-300 setup |
$400-2,000 month |
Readily available but financially reasonable only to a business, school, or other large organization |
Direct, always on connection |
Traditional money maker for telcos (so may slow deployment of other access technologies, i.e., DSL) |
|
Satellite |
Downstream: 400 Kpbs with phoneline upstream (Direct PC) Downstream capabilities expanding to 30-45 Mbps |
$150 setup |
$20-50/month (based on usage) |
Ubiquitous availability |
Promising technology to deliver all services |
May help bridge urban/rural broadband divide |
|
Wireless |
128 kbps — 10 Mbps (depending on deployment, equipment, etc.) |
$1,500 per node and $150 user (unlicensed) $2,000 for services such as LMDS per user |
No recurring costs (equipment is owned) |
Well-suited for rural areas with little infrastructure |
Requires line of sight (LOS) Capabilities being developed that allow for 54+ Mbps and "near line of sight" (for unlicensed service) |
Disaggregation of spectrum (for licensed service) Right of way issues Speculation on spectral rights (a public good) |
Contacts:
Jeff Evans
Senior Research Engineer
Georgia Tech Research Institute
(404) 894-8245