1 / 22

All-Optical Header Processing in Optical Packet-Switched Networks

All-Optical Header Processing in Optical Packet-Switched Networks. Hoa Le Minh, Fary Z Ghassemlooy and Wai Pang Ng Optical Communications Research Group Northumbria Communications Research Lab Northumbria University U.K. July, 2005. Contents. Overview of processing in optical networks

derick
Download Presentation

All-Optical Header Processing in Optical Packet-Switched Networks

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. All-Optical Header Processingin Optical Packet-Switched Networks Hoa Le Minh, Fary Z Ghassemlooy and Wai Pang Ng Optical Communications Research Group Northumbria Communications Research Lab Northumbria University U.K. July, 2005

  2. Contents • Overview of processing in optical networks • New Node Architecture • Proposed processing scheme • Results • Summary

  3. [bit/s] 1P 100T 10T 1T 100G 10G 1G 100M Total Data Voice 1995 2000 2005 2010 Optical Communications Traffic demand forecast (NEC–2001) Capacity increase : 2~4 times a year Bit cost decrease : 1/2 time a year • 1st generation optical networks: packet routing and switching are mainly carried out using high-speed electronic devices. • However, as the transmission rate continues to increase, electronically processing data potentially becomes a bottleneck at an intermediate node along the network. • Solution: All-Optical processing

  4. Future Optical Networks Source: NEC-2001

  5. PL H Edge Router Edge Router Edge Router Edge Router Edge Router Edge Router All-Optical Packet-Switched Networks(Core network) Core Network Optical transparent !

  6. P1 P2 P3 O/E Processing E/O PL H H A_99 … Routing table for a network with 128 nodes All-Optical Packet-Switched Networks 23 5 10 2 3 8 9 45 13 6 • All electronic node: • O/E & E/O conversions  limit processing speed • All-Optical node: • A large routing table – opt. memory issue • Complexity

  7. Electronic Processing Vs. Optical Processing

  8. All-Optical Processing -Proposed Approach Offers • Novel routing table in pulse-position modulation format • Small and fixed number of routing table entries regardless of the number of nodes in network. • High scalability • Using simple optical configuration (SMZI). • Ultrahigh speed and high capability • Header address matching is done readily with reduced size routing table.

  9. PL PL PL H H H Clk Clk Clk Proposed Header Processing Unit Port 1 All-Optical Switch Data packet Port 2 … Delay fiber Port M Optical Header Processor H Header Extraction PPM Conversion Control port 2 Control port M Control port 1 C[M] PPRT Control Synchronization Pattern of port 1 … Optical AND gate 1 Clk Clock Extraction Pattern of port 2 Optical AND gate 2 Matching pulse (Synchronized) … … Pattern of port M Optical AND gate M

  10. 1 0 1 1 0 … Data Packet Format Payload Header Sync Others Address Controls Parity … N bits (N optical pulses) • Data packet: • Optical pulses in RZ-format, • Speed a few hundreds Gbit/s • - Each bit slot spreads from dozens to a few picoseconds

  11. a3a2a1a0 LSB Tb 0 1 1 0 1 0 0 1 RZ Data Tsym Tsym Ts PPM 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Tb – bit duration, Ts – slot duration Pulse Position Modulation Format In PPM M-bit address symbol is converted into 2M-slot symbol

  12. 20Ts 21Ts 22Ts 23Ts x(t) y(t) SW1 SW2 SW3 SW4 a1 a2 a3 a0 Header Ext. Unit PPM Generation Optical Circuit N-bit address-codeword: A = [ai {0,1}], i = 0, …, N PP-format address: y(t) = x(t + ai2iTs)

  13. ith … … … … 0 1 2 3 4 2N-1 … … 0 1 2 3 4 2N-1 0 1 2 3 4 2N-1 PPM Based Routing Table M = 3 2N entries Processing gain: 2N- entry RT  M- entry PPM routing table M is fixed  number of entries is fixed at each node

  14. PPM Based Routing Table – contd. • Is initialized with the clock synchronization . M entries are filled by: • Single optical pulse + Array of 2N optical delay lines; Or, • M pattern generators + M optical modulators.

  15. SOA B A.B SOA1 B A A A.B SOA2 Ultrafast Optical AND Gate Implementation: - Using optical interferometer configuration Symmetric Mach-Zehnder Interferometer (SMZI) Terahertz Optical Asymmetric Demultiplexer (TOAD)

  16. All-Optical Switch C[1] 1 M 1 SMZI-1 C[2] 2 SMZI-2 … C[M] M SMZI-M Using an array of SMZI with controls provided from the processing unit

  17. Simulation Parameters ParametersValue Data bitrate 50Gbits/s Data packet length 53 bytes (424 bits) Data packet guard time 3 ns Header length 4 bits Data power (per pulse) 2mW Data pulse width (FWHM) 1 ps PPM slot Ts 5 ps Wavelength 1554 nm

  18. Simulation Results Incoming packet Extracted clocks

  19. Switched Outputs Node 1 Node 2 Node 3

  20. Summary • A novel node architecture encooprating all optical processing with much reduced routing table entries based om PPM was proposed and simulated using VPI simulation package. • It is possible to significantly increase the number of nodes in network as well as enlarge the size or routing table at each node without introducing large processing delay.

  21. Acknowledgements • One of the authors Hoa Le Minh is sponsored by the Northumbria University for his PhD study.

  22. Thank you!

More Related