Abstract: Techniques for routing communication sessions are described. According to various embodiments, a set of routing paths are available for routing a communication session across a network. For instance, the routing paths represent Label Switched Paths (LSPs) across a Multi-Protocol Label Switching (MPLS) network. According to various embodiments, attributes of a communication session are leveraged to identify a routing path for routing the communication session. According to various embodiments, performance degradation in a communication session across a particular routing path is detected such that a replacement routing path is selected.

Abstract: Techniques for spread spectrum wireless over non-contiguous channels are described. In at least some embodiments, a set of channels is selected for wireless communication, with at least some of the channels being non-contiguous (e.g., non-adjacent) from one another. A spreading sequence is selected, such as based on attributes of a selected set of channels. Communication data that is to be transmitted over the set of channels is combined with the spreading sequence to generate a spread spectrum signal. The spread spectrum signal is then divided into multiple sub-signals for transmission over the set of channels.

Abstract: Techniques for propagating communication awareness over a cellular network are described. According to various implementations, communication awareness of a communication session is propagated to an infrastructure component of a cellular network, such as a base station controller. Communication awareness of a communication session, for instance, can be employed to control various operational parameters of a cellular device that participates in a communication session.

Abstract: Techniques for subscription for communication attributes are described. According to various embodiments, communication attributes include various descriptive information and state information for entities and data flows across a communication system. According to various embodiments, entities involved in a communication system can subscribe to receive various communication attributes including extended attributes not explicitly identified as being available from a particular entity. According to one or more embodiments, various actions can be performed based on communication attributes, such as to optimize communication performance across a communication system.

Abstract: The principles of the present invention provide for using directional antennas to adaptively communicate in a wireless mesh network. A number of infrastructure components are included in a wireless mesh network environment. Each infrastructure component includes an omni-directional antenna and one or more directional antennas (e.g., electronically steered phased array antennas) that can be used to communicate with other infrastructure component and wireless devices. Directional antennas can utilize one or more directional beams that can be directed towards an infrastructure component or wireless device to communicate with the infrastructure component or wireless device. Infrastructure components can adapt to communicate with the same destination through different intermediary infrastructure components. Since the signal strength of a directional beam can be greater than that of an omni-directional antenna of the same gain, infrastructure components can be separated by greater distances.

Abstract: The principles of the present invention provides for using directional antennas to increase signal strength and enhance throughput in a wireless network. An antenna device includes an omni-directional antenna and at least one directional antenna. Each directional antenna (e.g., an electronically steered phased array antenna) can have one or more feeds for directing beams to wireless devices. The antenna device utilizes the omni-directional antenna to send and receive control data that facilitates locating wireless devices and determining when a wireless device is to send program data to or receive program data from the antenna device. The antenna device utilizes the directional antenna to send program data to and receive program data from wireless devices. Since the directional antennas use directional beams, the range and barrier penetration of directional antennas is greater than that of the omni-directional antenna.

Abstract: The principles of the present invention provides for using directional antennas to mitigate the effects of interference in a wireless network. An antenna device includes an omni-directional antenna and at least one directional antenna. Each directional antenna (e.g., an electronically steered phased array antenna) can have one or more feeds for directing beams at wireless devices. The antenna device utilizes the omni-directional antenna to send and receive control data that facilitates locating wireless devices and determining when a wireless device is to send program data to or receive program data from the antenna device. The antenna device utilizes directional antennas to send program data to and receive program data from wireless devices. Since directional antennas use directional beams, directional antennas can be tuned channels with reduced interference based on the location of wireless devices relative to the antenna device.

Abstract: The principles of the present invention provides for using directional antennas to mitigate the effects of interference in a wireless network. An antenna device includes an omni-directional antenna and at least one directional antenna. Each directional antenna (e.g., an electronically steered phased array antenna) can have one or more feeds for directing beams at wireless devices. The antenna device utilizes the omni-directional antenna to send and receive control data that facilitates locating wireless devices and determining when a wireless device is to send program data to or receive program data from the antenna device. The antenna device utilizes directional antennas to send program data to and receive program data from wireless devices. Since directional antennas use directional beams, directional antennas can be tuned channels with reduced interference based on the location of wireless devices relative to the antenna device.

Abstract: The principles of the present invention provides for using directional antennas to increase signal strength and enhance throughput in a wireless network. An antenna device includes an omni-directional antenna and at least one directional antenna. Each directional antenna (e.g., an electronically steered phased array antenna) can have one or more feeds for directing beams to wireless devices. The antenna device utilizes the omni-directional antenna to send and receive control data that facilitates locating wireless devices and determining when a wireless device is to send program data to or receive program data from the antenna device. The antenna device utilizes the directional antenna to send program data to and receive program data from wireless devices. Since the directional antennas use directional beams, the range and barrier penetration of directional antennas is greater than that of the omni-directional antenna.

Abstract: The principles of the present invention provide for using directional antennas to adaptively communicate in a wireless mesh network. A number of infrastructure components are included in a wireless mesh network environment. Each infrastructure component includes an omni-directional antenna and one or more directional antennas (e.g., electronically steered phased array antennas) that can be used to communicate with other infrastructure component and wireless devices. Directional antennas can utilize one or more directional beams that can be directed towards an infrastructure component or wireless device to communicate with the infrastructure component or wireless device. Infrastructure components can adapt to communicate with the same destination through different intermediary infrastructure components. Since the signal strength of a directional beam can be greater than that of an omni-directional antenna of the same gain, infrastructure components can be separated by greater distances.

Abstract: A transmitter receives information for transmission to a receiver over a communication channel. A cyclical redundancy checking (CRC) code circuit encodes the information with CRC code for error detection purposes. The CRC coded information is provided to a code switch. The code switch provides the CRC coded information to either a first code circuit or a second code circuit for forward error correction (FEC) coding. The first code circuit may, for example, encode the information using a FEC Code 1, such as convolutional coding, and the second code circuit may encode the information using a FEC Code 2, such as repetition coding. The code switch selects either the first or second code circuit based on detected characteristics of the channel. The channel characteristics may be obtained from a channel estimation circuit, may be obtained from an error feedback signal I.sub.3 from the receiver or may be obtained from a combination of both.

Abstract: Characteristics of a communication channel are used to establish key sequences for use in encrypting communicated information. In one embodiment, these characteristics are the impedances of the channel viewed from one transceiver to the other and vice versa. The keys can be established with computations equivalent to a bounded distance decoding procedure, and the decoder used to establish a key may be used for processing the subsequent data transmission. Compared to classical and public-key cryptographic systems, an alternative mechanism for establishing and sharing key sequences that depends on a physical process is provided in which each party need not generate a pseudo-random quantity because the necessary randomness is provided by the properties of the communication channel itself. By using a channel decoder, the probability of two users establishing the same secret key is substantially unity, and the probability of an eavesdropper establishing the same key is substantially zero.

Abstract: Characteristics of the radio channel are used to establish pseudorandom sequences for use in communicating information. These characteristics are the short-term reciprocity and rapid spatial decorrelation of phase of the radio channel. Due to the reciprocal nature of these radio channel characteristics, the transceivers which are communicating via the radio channel will generally both determine the same sequence. Although the determined sequences are not always sufficiently random for use in pseudorandom functions, a randomness tester can be provided to discard those sequences which are not sufficiently random. Exemplary pseudorandom communication functions include the selection of a spreading sequence in CDMA systems and the selection of a hopping sequence in a TDMA or CDMA system.

Abstract: Exemplary embodiments of the present invention describe terminal position location methods and systems. Relative powers of nearby spot beams which are generated by array antennas are determined. For example, powers from six neighboring spot beams relative to a center spot beam within which a mobile station is currently operating, can be measured relative to the power of the center spot beam. Using information from these measurements, the mobile stations position can be determined using, for example, an exponential model of the spot beam pattern.

Abstract: A method and an apparatus for establishing a key sequence for secure communication through a communication channel between a first transceiver and a second transceiver. Each transceiver transmits to the other transceiver a plurality of tones having predetermined phases and frequencies. Each transceiver transmits back to the other transceiver, without substantial change, the plurality of tones transmitted by the other transceiver. The transceivers determine a key based on the differences in the phases of transmitted and received plurality of tones.

Abstract: A mobile-link system for a radio communication system including a first mobile-link assembly, a second mobile-link assembly, and a satellite feeder-link assembly located in a satellite; and an earth feeder-link assembly located in an earth station. The first mobile-link assembly receives mobile uplink signals including zone-one uplink signals transmitted from mobile stations located in a first zone of a coverage area and zone-two uplink signals transmitted from mobile stations located in a second zone of the coverage area, and outputs received zone-one uplink signals and received zone-two uplink signals. The second mobile-link assembly receives mobile uplink signals transmitted from mobile stations in the coverage area, and outputs received zone-two uplink signals and not zone-one uplink signals. The second mobile link assembly also transmits mobile downlink signals to at least the first and second zones of the coverage area.

Abstract: A coding system for error protecting both insignificant and significant symbols of a digital message to be transmitted from a transmitter to a receiver of a digital system. Error protection for both insignificant and significant symbols is provided by coding at the transmitter both significant and insignificant symbols of message blocks forming the digital message. The symbol rate of the coded signal to be transmitted is reduced and unequal error protection is provided to the significant symbols by puncturing a selected number of insignificant symbols of each codeword of the coded signal. At the receiver, a correction determination is made for each received codeword as to whether the erasures and errors of the received codeword are correctable. The correction determination is a function of the number of errors, number of erasures, and the minimum distance of the code. Based on this correction determination, the received codeword is depunctured and decoded.

Abstract: Apparatus for monitoring the health and response of critical electromechanical control valves to detect the likelihood of future valve malfunction including the use of wavelet decomposition to selectively enhance portions of the valve response signal for comparison with a normal valve response signal.