Abstract:
Frequency-division multiplexing and demultiplexing systems and methods for use with M transmit and N receive antennas, M equaling at least two. In one embodiment, a frequency-division multiplexing system includes: (1) a differential modulator that generates MnullM unitary space-frequency signals from incoming message bits and (2) a time-frequency transformer, coupled to the differential modulator, that transforms the MnullM space-frequency signals into space-time transmit signals for the M transmit antennas.
Abstract:
A method and apparatus is proposed for use in a communication system in which an optical communications path including a plurality of optical spans, each of the optical spans contributing nonlinear distortions to an optical signal passing there-through includes, providing a dispersion pre-compensation to the optical signal in the optical communications path, such that the limiting nonlinear effect that produces signal distortions for long-haul transmission is suppressed, prior to transmission through a plurality of optical spans, and providing a dispersion post-compensation to the optical signal in the optical communications path after transmission through the plurality of optical spans.
Abstract:
A method for optical layer management of an optical channel in an optical network includes inserting specific data patterns into a frame of an optical signal in the optical channel such that when a framing header is extracted from the optical signal, the specific data patterns are readily identifiable, the specific data patterns being indicative of respective line statuses of the optical channel. Additionally, a method for optical layer management of an optical channel in an optical network includes extracting a frame header from an optical signal in the optical channel and analyzing the optical signal for the presence of previously inserted specific data patterns, the specific data patterns being indicative of respective line statuses of the optical channel.
Abstract:
A method (100) is provided for operating a media gateway (40) in a telecommunications system (A). The gateway (40) provides bearer paths for communication traffic between network segments (20, 30) via contexts (C1 . . . Cn). Each context includes a collection of terminations (T1 . . . Tn) that link the gateway (40) to the network segments and a topology that defines the bearer paths between the terminations within the context. The method includes: receiving a new topology for one of the contexts within the gateway, the received topology defining a desired pattern of bearer paths between the terminations included in the context; comparing the received topology to a current topology for the context, the current topology defining a currently existing pattern of bearer paths between the terminations included in the context; based upon the foregoing comparison, determining which terminations within the context are to be disconnected from one another; disconnecting terminations within the context from one another in accordance with the foregoing determination; comparing the received topology to the current topology for the context; based on the foregoing comparison, determining which terminations within the context are to be connected to one another; and, connecting terminations within the context to one another in accordance with the foregoing determination. Suitably, the gateway employs one or more dedicated terminations belonging to designated contexts within the gateway as multicast channels (84, 86). The multicast channels are linked to a tone source (80) that generates one or more call tones (e.g., ring tone, hold tone, etc.). Accordingly, when selected terminations in the gateway are to receive the respective call tones, they are moved to the appropriate designated context and connected to the dedicated termination.
Abstract:
The mobile telephone answer delay system enables a subscriber to momentarily delay receipt of an incoming call. The mobile telephone answer delay system places an incoming call on hold and provides the calling party with a prerecorded announcement in response to the mobile telephone subscriber inputting a first predetermined code in response to an incoming call indication. The recorded announcement indicates to the calling party that the subscriber is available to take the call but is momentarily unable to answer the call and will pick up shortly. The recorded announcement is repeated at predetermined intervals until the subscriber picks up the incoming call by inputting a second predetermined code.
Abstract:
Techniques and systems for monitoring of optical signals are described. Each of a plurality of optical signals is supplied to an optical port. A port signal is generated based on each of the optical signals and each of the port signals is subjected to a time delay to create a time delayed signal, with a different time delay being present in each of the time delayed signals. The time delayed signals are multiplexed to create a multiplexed signal comprising a plurality of multiplexed signal components, each component corresponding to one of the time delayed signals and exhibiting a time delay characterizing the corresponding time delayed signal. A desired one or ones of the multiplexed signal components are selected by analysis or display by specifying a time delay present in the time delayed signal represented by the desired component, and selecting a signal component exhibiting the specified time delay.
Abstract:
Techniques and systems for allocating bandwidth in a communication channel to devices using the communication channel are described. A communication system includes a central device and one or more remote devices. The central device may transmit information to and receive information from each of the remote devices and each of the remote devices may transmit information to and receive information from the base station. The central device receives information relating to the quality of the communication channel experienced by remote device and adjusts the bandwidth allocated to each remote device based on the communication channel quality experienced by that device. The total frequency range encompassed by the communication channel may also increase or decrease as the average quality of the communication channel for all remote devices increases or decreases. Increasing the frequency range available to a device while maintaining the channel quality allows a directly proportional increase in the communication rate with the device.
Abstract:
A wavelength selection and, optionally, amplification device that finds utility as an optical filter or laser and is realized using two waveguide grating routers with different free spectral range values.
Abstract:
A portable wireless network gateway aggregates bandwidth demand of different devices operating under different communications protocols. Network connectivity is provided by encapsulating data from the different devices to make the data appear to be data native to a single network. For example, the single network is a cellular wireless network. The different communications protocols include but are not limited to IEEE 802.11, IEEE 802.3, USB, cellular wireless protocols, Bluetooth, RS-232, and IEEE 11.1R.
Abstract:
An apparatus for optical coupling having a first array of individual waveguides optically communicating with a free space region at a first junction and each waveguide having a tapered region proximate the junction where a gap spacing between tapered regions of adjacent individual waveguides is substantially constant is proposed. The gap spacing is a minimum amount of space between adjacent individual waveguides. The first array of individual waveguides also has a horn region immediately proximate the tapered region and opposite the first junction with an increasing width whose maximum establishes the gap spacing.