1. Gigabit Ethernet An Affordable Solution
Group Members
James Denaro
Gaurav Asthana

2. Evolution of Gigabit Ethernet
Ethernet standard first developed in 1970’s by Xerox PARC.
IEEE 802 committee standardizes the ethernet.
IEEE 802.3z task force finalizes the gigabit ethernet protocol in June 1998.

3. Gigabit Ethernet Protocol Architecture
To go from 100mbps to 1000mbps, changes are made to the physical layer and data link layers only.
Merging of Ethernet and ANSI X3T11 FiberChannel technologies provides the solution.
High speed of fiber channel and backward compatibility due to the IEEE protocol is achieved.

4. Ethernet Protocol Stack

5. Gigabit Ethernet Interface Carrier
Gigabit Ports: short-wave (SX), long-wave (LX), long-haul (LH), and copper physical interfaces (CX).
Supported Media: short-wave laser, long-wave laser, and short copper.
Fiber-optic cable comes in three types: multimode (62.5 um), multimode (50 um), and single mode.

6. 802.3z and 802.3ab Distance Chart

7. The Standard
IEEE Std Edition sets parameters for systems using CSMA/CD access method.
Describes how the transmission and reception of data must occur.
Section details the transmitter optical waveform (transmit eye)

8. Transmitter Eye mask

9. Receiver Vertical eye-closure penalty [dB] = 10 log A0/AN
Horizontal eye-closure jitter >= 65ps

10. Test Parameters
Bit Error Rate (BER) is the ratio of bits that have errors relative to the total number of bits received in a transmission.
Jitter is due to clock edges and position of data bits sent by the transmitter. IEEE specifies their requirements in the eye diagram.

11. Receiver and Post-Amplifier
Optical receiver, a PIN diode or an Avalanche Photo Detector (APD) converts optical input to a small electrical current.
The current is converted to an electrical voltage by a TIA.
Post amp amplifies the incoming Trans-Impedance Amplifier (TIA) voltage signals to standard I/O levels.
Improves signal integrity of the system.

12. Typical transceiver setup

13. Testing using the TDS 8000B scope and CSA

14. Project Goals
Reduction of cost, by exploring cheaper parts, technologies and designs.
New design is compatibile with the existing Ethernet protocols.
Minimization of the Bit Error Rate and Jitter.