Abstract: The foregoing objects are achieved as is now described. Provided are a method and system for utilization with wireless communications systems having a cellular architecture covering a geographic area. The method and system accomplish their objects via the following. The geographic area is defined. One or more pairs of the sectors within the defined geographic area wherein a weak connection zone exists are determined. The geographic area is decomposed into two or more sub-areas wherein each sub-area is isolated from other sub-areas by the determined one or more pairs of sectors having a weak connection zone. A first of the sub-areas is selected. Frequency groups are assigned to each sector within the first selected sub-area such that signal to noise ratio is optimized. Thereafter, a second of the sub-areas is selected. One or more sectors within the second selected one of the sub-areas which are linked to sectors within the first selected sub-area are selected.

Abstract: A method and apparatus for designing a communication system where user call demand is estimated based on spatial and temporal distributions. Base stations and cell grids are then designed to accommodate the estimated user call demand, while user mobility demand is estimated based on spatial and temporal distributions developed for geographic subregions with self-similar mobility patterns. An MSC network is then designed to service both the base stations and cell grids, and the estimated user mobility demand.

Abstract: A robust method for determining the boundaries of cells and the associated reliability of the RF coverage within these boundaries is presented. The invention accurately determines the average range from the base station to the cell edge from RF signal strength measurements with a linear regression approach. The accuracy of this estimate is quantified both as a range uncertainty (e.g. .+-.100 meters) and as a cell coverage reliability (i.e. area/edge) through 1) simulation, 2) analysis of real data, and 3) theoretical analysis. It is shown that if the estimate of the cell radius meets the desired accuracy, then the corresponding estimates of coverage reliability (both area and edge) are more than sufficiently accurate. It is recommended that radio survey analyses incorporate this test as part of the coverage validation process.

Abstract: In an optical transmission system, an optical signal is transmitted to an optical element which is sensitive to changes in the optical power of the signal. Changes in optical power are anticipated and damped by controlling the transmitter output power, or an external damping element. For WDM systems, wavelengths can be added or removed without causing rapid changes in total power which would otherwise disturb the output of downstream optical amplifiers, and cause bit errors.

Abstract: The low profile antenna assembly comprises a generally rectangular frame member housing a planar antenna. A radar absorbing material is attached to the front side of the housing with a radome covering the front side of the planar antenna and attached to the frame member. The planar antenna is a microstrip array fed by a beam forming network that uses either delay lines or phase shifters to electronically steer the antenna pattern horizontally and vertically. The antenna assembly is weatherproofed, painted and flush mounted against a building surface for camouflaging the antenna assembly from observers at a distance.

Abstract: A plurality of bit stream formatters formats and codes the digital information signals that are to be transmitted. A symbol generator generates I and Q symbols from the formatted information signals. These symbols are input to the beamforming matrix that is connected directly to the symbol generators. The beamforming matrix generates baseband beam signals from the I and Q symbols. Baseband, pulse-shaping, low-pass filters are connected to the beamforming matrix. The low-pass filters each generate an antenna feed signal from each of the baseband beam signals.

Abstract: The method and apparatus of the architecture of the present invention is accomplished in an embodiment of the present invention by establishing a high speed network interconnection layer between the base station and the mobile switching office. This high speed interconnected network may be an asynchronous transfer mode (ATM) switch. This architecture allows for a dynamic virtual cell area to be configured around a mobile subscriber as a mobile subscriber moves within the network. As a subscriber leaves a previously defined virtual cell area into a new virtual cell area, the high speed switching network sets up a new virtual cell area around the mobile subscriber in his new area. The network is designed to anticipate a user's mobility pattern and to set up the new virtual cell area in advance of the mobile subscriber moving into the that new area.

Abstract: A method and apparatus for monitoring the performance of an echo canceler within a telephone communications network is disclosed. In accordance with the method and apparatus of the present invention, an embedded echo-cancellation performance monitoring circuit comprises three separate units, namely, a test data injection unit, an echo path simulator unit, and a test data extraction unit. The test data injection unit is utilized to inject test data into a serial data stream intended for an echo canceler. The echo path simulator unit is utilized to simulate an echo path by attenuating the test data in the serial data stream and to loop the test data in the serial data stream back to the echo canceler. The test data extraction unit is utilized to extract the test data from a send-out data stream exiting from the echo canceler.

Abstract: A method and system for use with wireless communication systems having a cellular architecture with at least a first and a second cell. The method and system provided ensure near uniform capacity and quality of channels within the second cell via the following steps. The noise signal power in unused data channels within the second cell is monitored. When a request for channel access is received, a determination is made whether the request for channel access is either a request for handoff from the first cell into the second cell, or not. In the event that the request is not a request for handoff, a determination is made whether idle channels exist to satisfy the request for channel access. In the event of a determination either that the request for channel access is a request for handoff, or both that the request is not a request for handoff and that idle channels exist to satisfy the request, a measured received signal power of a mobile unit subscriber unit making the request is determined.

Abstract: A robust method for determining the boundaries of cells and the associated reliability of the RF coverage within these boundaries is presented. The invention accurately determines the average range from the base station to the cell edge from RF signal strength measurements with a linear regression approach. The accuracy of this estimate is quantified both as a range uncertainty (e.g. .+-.100 meters) and as a cell coverage reliability (i.e. area/edge) through 1) simulation, 2) analysis of real data, and 3) theoretical analysis. It is shown that if the estimate of the cell radius meets the desired accuracy, then the corresponding estimates of coverage reliability (both area and edge) are more than sufficiently accurate. It is recommended that radio survey analyses incorporate this test as part of the coverage validation process.

Abstract: A verification system for a switch or other element in a digital transmission system includes a sample extraction means for tapping a input to the switch, and a similar means for tapping an output of the switch. Analogue features of the signal passing through the switch are tapped off and compared by pattern matching without demultiplexing digital data from the signal passing through the switch. The result of the match can be used to verify the switch has switched correctly, or to monitor other parameters such as cross-talk.

Abstract: A base station arrangement for a cellular radio system comprising an antenna array, is disclosed. The downlink signals transmitted from antennas have a spacing which is scaled in proportion to the transmitted and received wavelengths. A method of operation is also disclosed.

Abstract: An optical logic device is provided by an interferometer having an output which defines a logic state 1 or 0 in dependence upon an interference condition existing in the interferometer. Each arm of the interferometer contains a semiconductor optical amplifier in which the effect of cross phase modulation is utilized to modulate the phase of light transmitted through the respective arms. Optical signals are counter propagated through one or both of the arms in order to provide the cross modulation and thereby enable the interference condition to be set to one or other of the logic states. Automatic level control is provided at inputs to the interferometer and between successive stages of logic device. The method has application to high frequency digital optical communication systems where all optical logic operations are required.

Abstract: In an optical transmission system, multi-path interference is distinguished from the desired signal and other interferences, by measuring light transmitted from a source, using an element of the transmission system. Frequency modulation products are used, and the signature of the interference in the frequency spectrum is derived.

Abstract: This invention relates to an antenna operable in a multi-mode radio transceiver. One aspect of the present invention, provides a radio antenna having resonant frequencies operable to receive and transmit radio signals in different frequency bands according to two operating protocols.

Abstract: A method and system in a wireless communications network for restricting certain communication transactions to specific geographic areas in order to reduce the risk of communications fraud are presented. Initially, a list of communication transactions is stored such that the list includes communication transactions permitted to occur at each of a number of geographic locations. Thereafter, a communications transaction is initiated. In response to an initiation of the communications transaction, a geographic location of an originator of the communications transaction is determined. Next, the list of communication transactions is automatically scanned for communication transactions permitted to occur at the geographic location. If the communications transaction is not found among the list, the initiation of the communications transaction is thereafter terminated. Alternatively, if the communications transaction is found among the list, the communications transaction is thereafter permitted to continue.

Abstract: A system for providing fixed wireless access to standard telephony device is disclosed. A subscriber unit comprising a telephony interface for connecting to a standard telephony device, and a transceiver for establishing a communication link with a wireless network is used for providing telephony service to standard telephony device. Dual tone multiple frequency (DTMF) tones produced by said standard telephony device are sent to the wireless network, either directly or indirectly in the form of digit messages corresponding to the dialed digits, after a call set up message is sent. The subscriber unit sends a special set up message which identifies the subscriber unit as a terminal which sends digits on a digit by digit basis. A wireless network component (e.g. an MSC) is configured to identify such a set up message and upon receiving such a set up message collects and analyses digits sent by a subscriber unit on a digit by digit basis in order to provide a service feature or to connect a call.

Abstract: A robust method for determining the boundaries of cells and the associated reliability of the RF coverage within these boundaries is presented. The invention accurately determines the average range from the base station to the cell edge from RF signal strength measurements with a linear regression approach. The accuracy of this estimate is quantified both as a range uncertainty (e.g. .+-.100 meters) and as a cell coverage reliability (i.e. area/edge) through 1) simulation, 2) analysis of real data, and 3) theoretical analysis. It is shown that if the estimate of the cell radius meets the desired accuracy, then the corresponding estimates of coverage reliability (both area and edge) are more than sufficiently accurate. It is recommended that radio survey analyses incorporate this test as part of the coverage validation process.

Abstract: A system for locating sources of degradation of an optical path of an optical transmission system comprises means for transmitting (1) along the path a test pattern signal having a frequency spectrum predominately in a band below a data traffic rate means (4) for recovering the test pattern at a plurality of separate points in the path means (4) for determining an amount of pattern degradation from the shape of the recovered pattern, and means (5) for comparing the amounts of pattern degradation at the separate points to locate the source. A broad range of types of degradation can be detected efficiently, and the results used to take corrective action.

Abstract: During a telephone call to a call center, in a first portion of the call is placed in a call queue, and the call center apparatus generates a pre-answer signal which is interpreted by a central office apparatus to meter and bill a cost of the call to a receiving party operating the call center. When the call is connected to an interactive device, e.g. a call center agent's telephone handset, the call center generates a call answer signal which is transmitted to the central office apparatus, and interpreted as a signal to meter and bill a second portion of the call, containing interactive communication to a caller.