Abstract: Physical layer structures and related access schemes for unsynchronized communication networks are provided. Access channel information, preferably including a common synchronization code associated with all transceiver stations in a communication network and a cell-specific synchronization code uniquely associated with one of the transceiver stations, is modulated onto at least one set of time-continuous signal components of a communication signal. In order to access the communication network, communication terminals search for the access channel information in one or more sets of time-continuous signal components and synchronization parameters are then determined based on a location of the access channel information in the sets of time-continuous signal components. Some embodiments of the invention provide for joint frame synchronization and coarse timing synchronization.

Abstract: According to the invention there is provided a method of controlling an optical communication system comprising an optical transmitter, an optical receiver and an optical fiber interconnecting the optical transmitter and the optical receiver, the method comprising determining the performance of the optical communication system and controlling at least one setting parameter of the optical transmitter according to the measured performance.

Abstract: Provided is an optical apparatus and method wherein power transfer coefficients arising from SRS are measured at a designated co-location point and the power of dithers, which are impressed on the channels of a multiplexed optical signal propagating through the optical apparatus, is measured at each co-location point. Within the optical apparatus distances between co-location points are short and the power transfer coefficients are effectively constant. Consequently, the power of each channel of the multiplexed optical signal at the co-location points is obtained from the power of the dithers at a respective one of the co-location points and the power transfer coefficients measured at the designated co-location point. In some embodiments, information on the channel power at the co-location points is used to provide instructions for compensating for fluctuations in channel power and/or channel count at an input and/or channel count within the optical apparatus.

Abstract: In a coherent optical receiver, an incoming optical signal is combined with a local oscillator (LO) optical signal and the combined optical signals are detected by an optical detector and receiver arrangement. The receiver produces first and second loop control signals having respectively relatively slow and fast response speeds dependent upon frequency and phase variations between the incoming signal and the LO signal. An electrical source produces an electrical signal having a GHz frequency controlled by the second control signal. An optical source produces an optical signal with a first component having a first frequency controlled by the first control signal, and a second component having a frequency offset from the first frequency by a second frequency dependent upon the frequency of the electrical signal. The LO signal is derived from the second optical component via an optical filter and amplifier.

Abstract: According to an aspect of the present invention one or more radio units of a wireless device are used to measure or detect clues about the radio propagation environment and type of space that surrounds a wireless device. From the measurements, the wireless device may determine the type of location that it is located within, whether that is simply a determination between inside and outside or a more complex determination of the type of building or space that the wireless device is located within. In either case, this determination can be used to automatically change/adjust the radio system operation parameters the wireless device operates in accordance with. With the type of location determined, a wireless device may then automatically select the appropriate radio system operation parameters for the type of location that it is in and the corresponding regulations that apply.

Abstract: Methods and systems for re-routing a connection through an explicitly routed network. The methods involve initially re-routing the connection to a reduced constraint connection through the network; establishing a fully constrained path through the network; subsequently re-routing the connection to the fully constrained connection through the network.

Abstract: A method and an apparatus for implementing carrier suppressed data format on conventional OTDM modules is provided. Adaptive phase shifting of optical signals traversing one of the tributaries of an OTDM module is performed with feedback loop control. A tapped portion of the input carrier signal is phase modulated at a frequency fc, and is combined with a tapped portion of the output from the OTDM. A phase shifter controller fed with this combined signal photodetects and band-pass filters the signal around fc to extract the amplitude of the AC component of the envelope of the combined signal, which depends upon the phase difference between successive pulses of the OTDM output. This signal is used to control a phase shifter coupled along one of the tributaries of the OTDM to adjust the phase difference of the signals of the two tributaries so that carrier suppression results.

Abstract: A semiconductor laser adapted for telecommunications applications. The optical mode delivered by the laser has a high power output beam and a narrow far field, thus, enabling efficient coupling of the laser into small numerical aperture optical fibers. The laser is made up of a semiconductor heterostructure and one or more optical trap layers.

Abstract: Methods, systems and apparatus are provided which prevent frame mis-ordering in an explicitly routed network when switching from a first path to a second path. In a first embodiment, last frame and first frame markers are transmitted, and a receiver buffers all frames received between receipt of the last frame marker and the first frame marker. In a second embodiment, a last frame marker is sent to which an acknowledgement must be received before transmitting on the second path. In a third embodiment, only a first frame marker is sent. The receiver, upon receipt, signals a network card for the first path to stop forwarding frames, also buffers frames for some period. In a fourth embodiment, the merge point node forwards frames over different paths with unique markings so the outgoing card can distinguish them.

Abstract: Methods and systems for re-routing a connection through an explicitly routed network. The methods involve initially re-routing the connection to a reduced constraint connection through the network; establishing a fully constrained path through the network; subsequently re-routing the connection to the fully constrained connection through the network.

Abstract: An E-plane filter comprises a housing having a waveguide filter channel and a septum defining a plurality of couplers spaced apart along the length of the filter channel, thereby forming a resonator cavity between each adjacent coupler. The portion of the filter channel which accommodates the couplers and each resonator cavity is curved or otherwise changes direction in a plane transverse to the channel walls.

Abstract: Apparatus and method to reassemble fragments of data packets are provided which minimized unaligned memory accesses. The second and subsequent fragments have an end of fragment (EOF) portion of the payload moved to before a start of fragment (SOF) portion such that only one unaligned memory access per fragment is required.

Abstract: HARQ methods and systems and systems are provided which adaptively switch between two modes such as an NCP (non-complete puncture) mode, and a SAW (stop and wait) mode. Advantageously, this is done to avoid buffer overflow associated with ongoing NCP, and the delay associated with SAW. The switch between the modes can be performed on the basis of any number of criteria. These may include buffer size, consecutive negative acknowledgements in respect of either of the modes, length of time in one or the other mode, to name a few examples.

Abstract: Increasing the gain-coupling of a DFB directly modulated semiconductor laser permits the output response to be overdamped without lowering the relaxation oscillation frequency of the output. The overdamping permits the laser to operate at modulation frequencies which approach the relaxation oscillation frequency with satisfactory error performance. The performance improvement is sufficient to permit operation of the laser in an uncooled environment.

Abstract: An optical network comprises nodes coupled via optical fibers and forming one or more loops each comprising a plurality of the nodes. Amplified spontaneous emission (ASE) loops in the network are avoided by providing, for each loop, optical seam filters, which may include add/drop multiplexer functions, for different spectral bands of an optical spectrum of the network in different ones of the nodes of the loop. Each optical seam filter optically interrupts the loop for optical wavelengths within the respective spectral band, so that each loop is optically interrupted for all spectral bands of the optical spectrum.

Abstract: A method of garment fitting, selection and creation is provided. The invention provides for the scanning of an individual to provide a photo-realistic virtual 3-D image of the individual in a physically simulated 3-D garment and provides for the use of measurements of the individual to intelligently recommend garments, produce patterns for custom made garments, provide alteration suggestions to fit a garment to the particular individual. The measurements and the photo-realistic 3-D information is stored so that an individual does not need to re-input information or undergo multiple scans, and can shop from home using the previously obtained information profile. Measurements and suggestions can be used by the individual or automatically sent to a manufacturer, dressmaker or tailor for the creation or alteration of a garment to achieve a correct fit for the individual.

Abstract: Channels in an optical WDM network are each identified by at least two dither tones with which the channel is modulated, the dither tones alternating with a predetermined periodicity so that at any instant each channel is modulated by only one dither tone. The dither tones are continuously generated at precise frequencies. Channel detection by detecting the dither tones, for channels having optical powers over a wide dynamic range, makes use of an FFT process which can detect dither tones for high power channels in a single operation. Coherent averaging of FFT results over time is used to detect dither tones for low power channels over multiple FFT operations.

Abstract: Provided is a managed network service delivery system and method. The managed network service delivery system includes an IOC (Internetworking Operating Center) and a SCA (SAM (Security Activity Manager) Collector Agent) at at least one of a plurality of customer sites of a customer. The customer sites are connected to the IOC through a VPN (Virtual Private Network) or directly from a respective one of the SCAs to the IOC. The SCAs collect log and statistical information from equipment at a respective one of the customer sites and provide summary information to the IOC. The SCAs also perform queries regarding status of equipment and report to the IOC. The customer accesses reports from a web server at the IOC or through a PSTN (Public Switched Telephone Network) connection at the SCAs. A redundant connection, through the PSTN, between a SCA and the IOC provides a robust system for management, monitoring and security of the customer sites.

Abstract: A communications network has data and dedicated control network communication links between nodes. The control network is automatically and reliably created by each node determining each of its neighbor nodes to which it has a direct data link, each node having at least two neighbor nodes, and establishing a control network link for communicating control network traffic directly with each of these neighbor nodes. Each control network link can, if a dedicated control network link is not available, use bandwidth of a data link between the respective nodes, a link selection protocol being based on shared risk link groups and available bandwidth.

Abstract: A novel circuit topology which provides for the digital automatic gain control of a VCO is disclosed. The topology of the VCO is based on the negative transconductance oscillator due to its intrinsically simple biasing scheme. A system parameter sensitive to the performance level of the VCO is firstly measured. A digital control signal is then generated in response to the measured system parameter. The biasing current provided by the tail circuit of the VCO is adjusted based on the value of the digital control signal. In this way, the biasing current of the VCO may be adjusted to an optimal value for all frequencies of operation. The automatic control aspects of the present invention is useful in monolithic implementations since it automatically compensates for variations in load resistance, process parameters and component tolerances without requiring expensive manual adjustments at the board level.