Abstract: Monitored calls are intercepted and rerouted to plural selected monitoring stations by intervention of an IP phone monitor center (IPMC) which duplicates the voice to a monitoring location and automatically identifying the types of networks to be traversed and adapting the voice message to such a network type to communication with monitoring stations connected to these networks. Surveillance is, therefor, enabled to be conducted at more than one monitoring location each of which many are widely separated from the other. In a particular embodiment an authorized surveillance agent transmits a valid request to an IP phone monitor center (IPMC) which in response intercepts voice packets to and from the targeted IP phone. The duplicated voice packets are transmitted to the designated monitoring location. The IPMC determines the type of voice signal to be transmitted to the terminal monitoring station.

Abstract: An entry access system includes a locking mechanism enabling authorized entry at a secured entry point to a closed access area or computing device. Entry is approved in response to an interaction between an intended entrant and the entry access system that involves an interchange of multidigit numbers and use of ID and PINs for generation of a multidigit check number to establish authenticity of a request for entry.

Abstract: In a code division switch in a satellite communication system each of a plurality of uplink CDMA modulated RF beams, each including a plurality of uplink traffic channels, are down converted to IF and overspread with a new orthogonal code having a spreading rate N times that of the spreading code of the uplink CDMA modulated RF beam. All of the overspread beams are combined into a single combined IF stream. The individual traffic channels are extracted from the combined IF stream by de-overspreading the stream with orthogonal codes and despreading with beam and traffic channel specific orthogonal codes. All traffic channels are respread with downlink beam codes and downlink orthogonal traffic channel codes and joined onto selected ones of downlink CDMA modulated IF beams having common destinations with the included traffic channels. Downlink CDMA modulated IF beams are up converted to RF frequency and transmitted to selected destinations.

Abstract: In a transition phase of a cellular cell from analog-to-digital radio service it must be determined how many of the base station radios in a cell must be changed over from analog to digital, given the proportion of mobile phones with dual-mode capability to analog phones. A dual-mode mobile phone has the capability to interface with both analog and digital radios. In determining the radio mix, it is desirable to maximize the call handling capacity of a cell, or minimize the blocking experienced by the mobile subscribers. To address these questions, an analytical model is developed to compute the blocking rate experienced by mobile callers in a cell, given the cell's offered load, the mix of analog and dual-mode mobiles, and the analog-digital split of the RF channels available to the cell.

Abstract: In a satellite communication system a CDMA uplink signal including user data is transmitted in a packetized manner, the packets are switched on board the satellite by a packet switch before its downlink delivery. The packet switch routes the packets to the appropriate one of several outgoing downlink beams based on address information included in the packet header. Time Division Multiplexing (i.e., TDM) is used for downlink transmission. This invention constitutes an efficient multi-user satellite based communication system.

Abstract: An antenna structure includes a plurality of vertical directed antennas mounted on an insulated cylindrical substrate. A parabolic reflecting antenna is mounted at one end of the cylindrical substrate cavity and a dielectric lens admits radiation through the cylindrical cavity to the parabolic reflector. Optical detectors are located on the cylindrical substrate periphery and exposed to optical signals through an InfraRed (IR) optical filter.

Abstract: Synchronization of a terrestrial transmitted CDMA signal with despreading and respreading in a remote satellite, for transmission to a second terrestrial site, is achieved in accord with the processes recited in the appended claims. Uplink access and synchronization signals are acquired at a satellite switch and a reference propagation delay time is established in terms of quantified timing marks with intervals within a size range of chip intervals used in the CDMA spreading codes of the system. The propagation delay is defined in terms of one of the quantified timing marks defining when a first signal from a terrestrial subscriber unit is received. This propagation delay is transmitted to a terrestrial subscriber unit and utilized to adjust the timing of uplink CDMA code chips.

Abstract: An integrated radio frequency transceiver comprising a diversity receiver and transmitter capable of performing a self test operation to determine if the receiver and transmitter paths are properly operational. The diversity receiver includes two receiver paths, a first path for receiving radio communications having a permitted bandpass, and a second receiver path for receiving radio signals from other radio port channels in use to assist in constructing its own neighbor list.

Abstract: Switching of traffic channels within spread spectrum beams is performed in a satellite without buffering of the individual signals. Individual satellite beams carrying spread spectrum user RF signals from a plurality of customer premise equipments are received by radio receivers of a satellite switch and downconverted to IF signals. Traffic channel recovery is performed immediately after the down conversion, and digital encoding and decoding is performed to route each channel to an appropriate outbound satellite beam. Traffic channel recovery is by despreading and filtering followed by respreading to uniquely identify each user signal so it may be recovered at its end destination. Further spreading uniquely identifies the user signal with an outbound satellite beam going to the intended destination of the user signal.

Abstract: The present invention is a system and method for providing wireless packet data transmission without dependence on a fixed time slot access method or central timing mechanism. An available radio frequency (RF) channel in a communications network is divided into time frames which are further divided into time slots, wherein corresponding single time slots in each frame define a logical channel for carrying user packet data. The network includes a plurality of nodes divided into at least two time domain groups, wherein the time domain groups are divided into segments. Each of the time domain groups includes an independent timing source for synchronizing the time slots of logical channels within a time domain, wherein communication between nodes is accomplished through a data messaging scheme, such as a token passing scheme. Buffer segments interface between the time domain groups.

Abstract: An enhanced, deferred messaging service ensures a message is received even when an answering machine is connected to a line and receives the call. In such a case, the service notes the number of rings n necessary to activate the recipient's answering machine. The service then resumes redialing and lets the phone ring n-1 times for each attempted call until either the phone is answered or a time-out occurs. If the recipient's answering machine, however, is in toll-saver mode, then the answering machine may answer a second time in less than n-1 rings. If the toll-saver feature is activated, then the service notes the number of rings m which caused the answering machine to be reached in toll-saver mode. The service then resumes redialing and lets the phone ring m-1 times for each attempted call until either the phone is picked up or a time-out occurs. Thus, even after leaving a message on an answering machine, the service will attempt to reach a human.

Abstract: A digital switch included within a satellite, processes uplink beams and the included traffic channels at a symbol level instead at a bit level. In this system the switch performs as a repeater on the per user basis and as a switch at the beam level. Individual user signals (i.e., channels) are separated from the uplink beam and recombined into the appropriate downlink beam.

Abstract: A low cost solution for providing wireless multi-rate packet data communications between a transmitting unit and a receiving unit on a single spread spectrum channel. The transmitting unit and receiving unit are operable to change communications modes at any given time to provide packet data communications at any given data rate for any given duration. In general, the transmitting unit is operable to change the coding gain of the transmitted spread spectrum to establish a communications mode providing a given data rate for communication to the receiving unit. In one embodiment, the transmitting unit first establishes a regular communications mode, wherein the transmitting unit generates a spread spectrum packet data signal having a high coding gain, thus providing low rate, highly reliable communications over the channel.

Abstract: Communication systems, terminals and methods are provided which are capable of supporting, and/or being used in conjunction with, communication session scheduling. The communication systems include a plurality of terminals, ones of which are operative to receive and transmit communication signals among a plurality of parties. At least one terminal includes both an interface operative to receive a scheduling signal and a circuit. The circuit is operative in response to the received scheduling signal to modify selectively one of either a first data set or a second data set. The first data set represents the availability of a first party to respond to a received communication signal. The second data set represents the priority associated with a particular communication signal transmitted from the first party to at least a second party.

Abstract: In a channel assignment system novel methodologies are utilized for managing channel interference in a cellular wireless communications system as a function of a service-quality factor for a communications channel within such a system. Those methodologies and their essential functions include: (1) Mixed Power Control for overcoming interference problems associated with conventional power control methods; (2) Directed Assignment for reducing channel conflicts between neighboring cells in non-congestion conditions; and (3) Mixed Power Control with Directed Assignment for reducing channel interference between neighboring cells.

Abstract: A system is provided for tracking a free-space optical communications beam. The incoming beam is split by a beam splitter. One portion of the incoming beam is focused onto a high-speed photodetector. Another portion of the incoming beam is passed through a target pattern optical element. A resulting target pattern is formed on a two-dimensional active pixel sensor array. The alignment of the system can be adjusted based on the position of the target pattern on the sensor array.

Abstract: A system wherein audio samples are added to a video signal, but within the time-frame allocated to video information, thereby displacing video data. Two audio samples are preferably placed in each video line: at the beginning, and at the end. When the video lines are "stacked" to form a video image, the audio forms noisy vertical stripes at the sides of the image, each of which is about 6 percent of the width of the image. The invention stretches the video image, to cover the stripes.

Abstract: A message distribution system having multiple message processors provides integrated overload control and message distribution. An additional "dummy" message processor is established by the system, to which a certain fraction of messages is assigned as though it were a real processor, thereby accomplishing rejection of that fraction of messages. The fraction to be rejected is determined in real time based on the states of the various processors, which also is the basis for the allocation among the processors of those messages that are not rejected.

Abstract: Novel methodologies are provided for managing neighbor channel interference in a cellular wireless communications system as a function of a service-quality factor for a communications channel within such a system. Those methodologies, and their essential function are characterized as:Even/Odd Cell Designation--for eliminating adjacent-channel conflicts within a cell;Vertical Channel-Set Construction--for eliminating adjacent-channel conflicts between abutting sectors in sectorized cells; andMinimum Adjacency Circuit Method--for reducing the number of adjacent edges between abutting cells or sectors in a regular channel assignment.

Abstract: A method and apparatus for allowing a caller to leave a message for an unreachable called party. The method and apparatus provides the caller with an option for a pre-paid return call that is billed to the caller. When the intended recipient of the call is unreachable, the call is transferred to a message server that gives the caller the option for a pre-paid return call for the recipient. The recipient is then notified of the available pre-paid return call through periodic callbacks to the intended recipient or by alerting the recipient the next time the recipient makes a call. The receiver of the message has the option of returning the call immediately or at a later time within a time duration set by the caller.