Technology

Speed

Physical Medium

Application

GSM mobile telephone service

9.6 to 14.4 Kbps

RF in space (wireless)

Mobile telephone for business and personal use

High-Speed Circuit-Switched Data service (HSCSD)

Up to 56 Kbps

RF in space (wireless)

Mobile telephone for business and personal use

Regular telephone service (POTS)

Up to 56 Kbps

twisted pair

Home and small business access

Dedicated 56Kbps on frame relay

56 Kbps

Various

Business e-mail with fairly large file attachments

DS0

64 Kbps

All

The base signal on a channel in the set of Digital Signal levels

General Packet Radio System (GPRS)

56 to 114 Kbps

RF in space (wireless)

Mobile telephone for business and personal use

ISDN

BRI: 64 Kbps to 128 Kbps
PRI: 23 (T-1) or 30 (E1) assignable 64-Kbps channels plus control channel; up to 1.544 Mbps (T-1) or 2.048 (E1)

BRI: Twisted-pair
PRI: T-1 or E1 line

BRI: Faster home and small business access
PRI: Medium and large enterprise access

IDSL

128 Kbps

Twisted-pair

Faster home and small business access

AppleTalk

230.4 Kbps

Twisted pair

Local area network for Apple devices; several networks can be bridged; non-Apple devices can also be connected

Enhanced Data GSM Environment (EDGE)

384 Kbps

RF in space (wireless)

Mobile telephone for business and personal use

satellite

400 Kbps (DirecPC and others)

RF in space (wireless)

Faster home and small enterprise access

frame relay

56 Kbps to 1.544 Mbps

Twisted-pair or coaxial cable

Large company backbone for LANs to ISP
ISP to Internet infrastructure

DS1/T-1

1.544 Mbps

Twisted-pair, coaxial cable, or optical fiber

Large company to ISP
ISP to Internet infrastructure

Universal Mobile Telecommunications Service (UMTS)

Up to 2 Mbps

RF in space (wireless)

Mobile telephone for business and personal use (available in 2002 or later)

E-carrier

2.048 Mbps

Twisted-pair, coaxial cable, or optical fiber

32-channel European equivalent of T-1

T-1C (DS1C)

3.152 Mbps

Twisted-pair, coaxial cable, or optical fiber

Large company to ISP
ISP to Internet infrastructure

IBM token ring/802.5

4 Mbps (also 16 Mbps)

Twisted-pair, coaxial cable, or optical fiber

Second most commonly-used local area network after Ethernet

DS2/T-2

6.312 Mbps

Twisted-pair, coaxial cable, or optical fiber

Large company to ISP
ISP to Internet infrastructure

Digital Subscriber Line (DSL)

512 Kbps to 8 Mbps

Twisted-pair (used as a digital, broadband medium)

Home, small business, and enterprise access using existing copper lines

E-2

8.448 Mbps

Twisted-pair, coaxial cable, or optical fiber

Carries four multiplexed E-1 signals

cable modem

512 Kbps to 52 Mbps
(see "Key and explanation" below)

Coaxial cable (usually uses Ethernet); in some systems, telephone used for upstream requests

Home, business, school access

Ethernet

10 Mbps

10BASE-T (twisted-pair); 10BASE-2 or -5 (coaxial cable); 10BASE-F (optical fiber)

Most popular business local area network (LAN)

IBM token ring/802.5

16 Mbps (also 4 Mbps)

Twisted-pair, coaxial cable, or optical fiber

Second most commonly-used local area network after Ethernet

E-3

34.368 Mbps

Twisted-pair or optical fiber

Carries 16 E-l signals

DS3/T-3

44.736 Mbps

Coaxial cable

ISP to Internet infrastructure
Smaller links within Internet infrastructure

OC-1

51.84 Mbps

Optical fiber

ISP to Internet infrastructure
Smaller links within Internet infrastructure

High-Speed Serial Interface (HSSI)

Up to 53 Mbps

HSSI cable

Between router hardware and WAN lines
Short-range (50 feet) interconnection between slower LAN devices and faster WAN lines

Fast Ethernet

100 Mbps

100BASE-T (twisted pair); 100BASE-T (twisted pair); 100BASE-T (optical fiber)

Workstations with 10 Mbps Ethernet cards can plug into a Fast Ethernet LAN

Fiber Distributed-Data Interface (FDDI)

100 Mbps

Optical fiber

Large, wide-range LAN usually in a large company or a larger ISP

T-3D (DS3D)

135 Mbps

Optical fiber

ISP to Internet infrastructure
Smaller links within Internet infrastructure

E-4

139.264 Mbps

Optical fiber

Carries 4 E3 channels
Up to 1,920 simultaneous voice conversations

OC-3/SDH

155.52 Mbps

Optical fiber

Large company backbone
Internet backbone

E-5

565.148 Mbps

Optical fiber

Carries 4 E4 channels
Up to 7,680 simultaneous voice conversations

OC-12/STM-4

622.08 Mbps

Optical fiber

Internet backbone

Gigabit Ethernet

1 Gbps

Optical fiber (and "copper" up to 100 meters)

Workstations/networks with 10/100 Mbps Ethernet plug into Gigabit Ethernet switches

OC-24

1.244 Gbps

Optical fiber

Internet backbone

SciNet

2.325 Gbps (15 OC-3 lines)

Optical fiber

Part of the vBNS backbone

OC-48/STM-16

2.488 Gbps

Optical fiber

Internet backbone

OC-192/STM-64

10 Gbps

Optical fiber

Backbone

OC-256

13.271 Gbps

Optical fiber

Backbone

Key and Explanation

We use the U.S. English "Kbps" as the abbreviation for "thousands of bits per second." In international English outside the U.S., the equivalent usage is "kbits s^-1" or "kbits/s".

Engineers use data rate rather than speed, but speed (as in "Why isn't my Web page getting here faster?") seems more meaningful for the less technically inclined. Many of us tend to think that the number of bits getting somewhere over a period of time is their speed of travel.

Relative to data transmission, a related term, bandwidth or "capacity," means how wide the pipe is and how quickly the bits can be sent down the channels in the pipe. (The analogy of multiple lanes on a superhighway with cars containing speed governors may help. One reason why digital traffic flows faster than voice traffic on the same copper line is because digital has managed to convert a one-lane or narrowband highway into a many-lane or broadband highway.)

These "speeds" are aggregate speeds. That is, the data on the multiple signal channels within the carrier is usually allocated by channel for different uses or among different users.

Key: "T" = T-carrier system in U.S., Canada, and Japan...."DS"= digital signal (that travels on the T-carrier or E-carrier)..."E" = Equivalent of "T" that uses all 8 bits per channel; used in countries other than U.S. Canada, and Japan...."OC" = optical carrier (Synchronous Optical Network)...."STM" = Synchronous Transport Modules (see Synchronous Digital Hierarchy)

Only the most common technologies are shown. "Physical medium" is stated generally and doesn't specify the classes or numbers of pairs of twisted pair or whether optical fiber is single-mode or multimode. The effective distance of a technology is not shown. There are published standards for many of these technologies. Some of these are indicated on pages linked to from the table.

Cable modem note:The upper limit of 52 Mbps on a cable is to an ISP , not currently to an individual PC. Most of today's PCs are limited to an internal design that can accomodate no more than 10 Mbps (although the PCI bus itself carries data at a faster speed). The 52 Mbps cable channel is subdivided among individual users. Obviously, the faster the channel, the fewer channels an ISP will require and the lower the cost to support an individual user.