Deniz Gurkan

All-optical half adder using an SOA and a PPLN waveguide for signal processing in optical networks.

We demonstrate an all-optical half adder for bit-wise addition of two serial data streams that simultaneously generates Sum and Carry outputs. The module performs the required XOR and AND operations using only two nonlinear optical elements. Difference Frequency Generation in a periodically poled lithium niobate waveguide serves as the AND gate and cross-gain modulation in a semiconductor optical amplifier is employed to generate the XOR output. Error free operation for RZ data is reported.

All-optical address recognition for optically-assisted routing in next-generation optical networks

Optical fiber communication technology enabled high-speed, long-distance capacity in todays networks. The packet switching functions such as address recognition and routing are performed in the electrical domain after optical-to-electrical conversion. As more real-time applications come online, demand for bandwidth increases, and electronic processing may potentially become a bottleneck at the intermediate nodes along the network. We introduce some optical address recognition schemes for optically-assisted routing that may decrease the processing delay at these nodes.

All-optical decrementing of a packet's time-to-live (TTL) field and subsequent dropping of a zero-TTL packet

We demonstrate an optical time-to-live (TTL) decrementing module for optical packet-switched networks. Our module acts on a standard NRZ-modulated binary TTL field within a 10 Gb/s packet and decrements it by one if the TTL is nonzero. If the TTL of the incoming packet is zero, the module signals an optical switch to drop the packet. Our technique is independent of the TTL length, does not require the use of ultrashort RZ optical pulses, requires no guard time between the end of the TTL field and the packet data, and has only a 2.4 dB power penalty at 10/sup -9/ bit-error rate.

Tunable all-optical time-slot-interchange and wavelength conversion using difference-frequency-generation and optical buffers

In this letter, we demonstrate a module that simultaneously performs optical time-slot interchange and wavelength conversion of the bits in a 2.5-Gb/s data stream to achieve a reconfigurable time/wavelength switch. Our switch uses difference-requency-generation (DFG) for wavelength conversion and fiber Bragg gratings as wavelength-dependent optical time buffers. This tunable technique employs high-extinction-ratio and low-additive-noise DFG.

All-optical wavelength and time 2-D code converter for dynamically-reconfigurable O-CDMA networks using a PPLN waveguide

We demonstrate all-optical wavelength and time code conversion for O-CDMA networks at 2.5-Gbit/s with 10-Gchip/s. Difference-frequency generation provides wavelength-shifting and fiber-Bragg gratings introduce cyclic time-shifts to the incoming code, generating a new time/wavelength code with less than 0.7-dB power penalty.

Monitoring of the heartbeat sounds using an optical fiber Bragg grating sensor

Heartbeat is intuitively examined via a stethoscope that amplifies the sound. Diagnosis may be broadened by extracting more information: strength, frequency components, and sound pressure. This paper is on the demonstration of an optical fiber Bragg grating sensor to monitor the heartbeat using sound pressure and possibly extending to application of ballistocardiography (BCG: the heartbeat-associated movements imparted by recoil and impact). To our knowledge, cardiac examination with BCG and sound sensing using FBG technology has not been explored. In this setup, heartbeat sounds are translated into an electrical signal using a strain-sensitive reflective FBG sensor that provides differential changes in the reflection spectrum. For a proof-of-concept demonstration, FBG sensor is glued to the vibrating membrane of a subwoofer of a speaker set. Using recordings of various heartbeat sounds, spectral changes are recorded at a 250-Hz sampling rate. The results show increased sensitivity to: strength of the heartbeat, frequency and temporal content of the oscillatory wave pattern

Simultaneous label swapping and wavelength conversion of multiple independent WDM channels in an all-optical MPLS network using PPLN waveguides as wavelength converters

This paper presents the demonstration of all-optical simultaneous label swapping and wavelength conversion of multiple independent wavelength-division multiplexed (WDM) channels using periodically poled lithium niobate (PPLN) waveguides as wavelength converters. Label swapping is one of the required functions in the physical layer for efficient data flow control in the proposed multiprotocol label switching (MPLS) networks. The technique operates directly on the optical signal without optoelectronic (O/E) conversion; therefore, it is bit-rate, label length, and protocol/format independent. Experimental results are presented for the label swapping of distinct 8-b-long labels in a system with 2 WDM data channels at 10 Gb/s. There is a guard time of 400 ps between the payload and the label. The power penalty introduced by the method is less than 3 dB. This method can potentially accommodate 10 WDM channels simultaneously over the PPLN waveguides /spl sim/40 nm /spl lambda/-shifting bandwidth.

Variable-bit-rate header recognition for reconfigurable networks using tunable fiber-Bragg-gratings as optical correlators

We demonstrate variable-bit-rate recognition of the header information in a data packet. Our technique is reconfigurable for different header sequences and uses optical correlators as look-up tables. We use this optical technique to recognize the header and switch a series of incoming data packets at 155 Mb/s, 622 Mb/s, and 2.5 Gb/s to one of two outputs in a reconfigurable network. Penalty-fee routing with a 1.6 ns guard time is achieved.

OpenFlow Configuration Protocol: Implementation for the of Management Plane

Separation of data and control plane offers benefits of having programmability of the forwarding tables according to the needs of the applications. The need for efficient and effective management of network resources is crucial in providing effective control plane functionality to the applications. OpenFlow standardization efforts at Open Networking Foundation resulted in an OpenFlow Configuration specification to address the management of resources in OpenFlow-enabled switches. We report the implementation of the OF-Config 1.1 standard [revision - 25th June 2012] as softconf.d to retrieve and update the controller IP of an OpenvSwitch.

Cooperative Communication Based on IDMA

Cooperative communication schemes can provide diversity gain. However, when the network model is compose of multiple source-destination pairs with multiple common relays, interference problems arise. In this paper, we propose a cooperative transmission scheme based on Interleave-division multiple-access (IDMA) with decode-and-forward (DF) and amplify-and-forward (AF) protocols so that destinations can cancel the interference and achieve diversity gain. The simulations show diversity gains of at least 8dB when cooperative communication has been implemented with IDMA over DF and AF protocols. We also provide an insight to how power allocation between sources and relays would affect the performance. It reveals that relay nodes can be adaptive to select DF or AF protocol based on the constraints of power allocation and the locations of relays.