ECE 4006 Senior Design Project

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ECE 4006Senior Design Project
Bringing Gigabit Ethernet to the Masses

• Talal Mohamed Jafaar
• Ibrahima Bela Sow
• Mohammad Faisal Zaman

Supervisor Dr. Martin Brooke
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Introduction and Background
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Ethernet History

• DIX Ethernet (1970s)
• Fast Ethernet (1995)
• Gigabit Ethernet (1998)

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Gigabit Ethernet Technology

• Fiber Channel
• Multi-mode transmission
• Fiber and copper based networks

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Gigabit Ethernet Physical Layers
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Gigabit Specifications
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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.

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Experimental Board

• HFBR 53D5 fiber optic transceiver
• Differential I/O

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First Step

• Testing the fiber-optic transceivers
• What parts do we have
• What parts do we need to order

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Challenges

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

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So Far

• Tested modules
• Unsoldered old modules
• Found parts to order

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Complete Circuit Diagram of Intel Gigabit
Ethernet card
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Circuit assembled on experimental board
Connected using SMA Connectors and RG-316 Co-ax
Cable to the Ethernet Board
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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.

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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

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De-coupling Capacitors

• High impedance caused by inductance of power
  supply lines and high frequencies
• protects against current spikes due to fast
  switching

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Testing and Results
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Test Setup for the Experimental Board

• Experiments were conducted under the supervision
  of Dr. Brooke in MiRC

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Interpretation of the Eye Pattern
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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

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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

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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.

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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

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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.

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Actual Board View

• Red circles indicate removed components
• Pin 1 is Ground Pin
• Pin 4 is Signal Detect

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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.

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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.

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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
• Discontinuity must be less than 10 of the signal
  wavelength. In our case minimum acceptable
  discontinuity was 1 cm. (Detailed Explanation
  present in report)

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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.

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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.