ECE 4006 Senior Design Project Talal Mohamed Jafaar Ibrahima Bela Sow Mohammad Faisal Zaman Bringing Gigabit Ethernet to the Masses Supervisor: Dr. Martin Brooke

Introduction and Background

Ethernet History ► DIX Ethernet (1970s) ► Fast Ethernet (1995) ► Gigabit Ethernet (1998)

Gigabit Ethernet Technology ► “Fiber Channel” ► Multi-mode transmission ► Fiber and copper based networks

Gigabit Ethernet Physical Layers

Gigabit Specifications

Purpose ► Construct a test-bed to perform experiments and determine methods to implement Gigabit Ethernet at an affordable cost for the general consumer by moving the fiber-optic transceiver of an Ethernet card to an experimental board that will be located outside of the computer.

Experimental Board ► HFBR 53D5 fiber optic transceiver ► Differential I/O

First Step ► Testing the fiber-optic transceivers ► What parts do we have ► What parts do we need to order

Challenges ► Soldering and unsoldering ► Proper line termination ► Grounding ► Board Quality ► Getting parts on time

So Far ► Tested modules ► Unsoldered old modules ► Found parts to order

Complete Circuit Diagram of Intel Gigabit Ethernet card

Circuit assembled on experimental board Connected using SMA Connectors and RG-316 Co-ax Cable to the Ethernet Board

General Comments ► ► Signal scheme uses NRZ (Non return-to-zero Signaling) ► ► For a 1-Gb data supply we would expect a fundamental frequency of 500 MHz.

Circuit Components ► Resistors  Basic Function is to match the impedance of the 50 Ohm Coax lines and for AC- coupling ► Differential Mode  Reduces noise in the signal

De-coupling Capacitors ► High impedance caused by inductance of power supply lines and high frequencies ► protects against current spikes due to fast switching

Testing and Results

Test Setup for the Experimental Board Test Setup for the Experimental Board Experiments were conducted under the supervision of Dr. Brooke in MiRC

Interpretation of the Eye Pattern

Eye Pattern Observations ► PN-7 Encoding with 10ft. Cable (Top) ► PN-7 Encoding with 100ft. Cable (Bottom) ► Two different lengths of Optical Cable were utilized to test effects of attenuation

Bit Error Rate ► The bit error rate (BER) is the percentage of bits that have errors relative to the total number of bits received in a transmission

Inferences RESULTS OBTAINED ► Eye Pattern Results ► BER Results ► Results show that the experimental board can perform data transfer at Gigabit Ethernet speed with acceptable performance.

Primary Issues with Integration In the process of integrating the experimental board and the Gigabit Ethernet Card several issues were faced: ► Redundant Components on Ethernet Board had to be removed using pliers ► Signal Detect Pin Connection ► Ground Pin Connection

Redundant Components ► The box identifies the redundant components on the Gigabit Ethernet Board. They need to be removed because they already occur in the experimental board, and will cause impedance mismatch among other problem.

Actual Board View ► Red circles indicate removed components ► Pin 1 is Ground Pin ► Pin 4 is Signal Detect

Test Setup for the Final System 1)Experimental board attached to the Experimental Ethernet card. 2) RG-316 Co-axial Cables, which connect the transmitter and receiver ‘s SMA connectors to their respective pins on Gigabit Ethernet Card. 3)Experimental Gigabit Ethernet Card 4)50ft. Roll of Optical Fiber. 5)5 Volts power supplies powering the receiver and the transmitter. 6)Oscilloscope used to verify the presence of the Signal Detect signal. 7)The two computer screens used to test the transfer of data between the two computers.

Initial Test Results and Concerns ► Intel ProSet Diagnostic Software was used to perform basic diagnostic tests. CONCERNS: ► More advanced test were performed. While transmission of data packets was successful, receiving packets failed.

Identification of the Problem ► Tests were conducted to isolate the location of the problem. Attention was focused on the distances between the connections and the meshes of each signal. Before After n Discontinuity must be less than 10% of the signal wavelength. In our case minimum acceptable discontinuity was 1 cm. (Detailed Explanation present in report)

Final Test Results ► Upon resolution the problem, the advanced diagnostic tests were repeated, and the data packet transfer test was followed by successful transmission of useful files between the computers.

Success ► Project is successful ► Thus, future groups can modify the transceiver and other components without dealing with the Ethernet card ► Hopefully it will soon be possible to have fiber connections in homes all over the globe.