US Government As Represented by the Secretary of the Army

Avaya Technology LLC

Lucent Technologies Inc.

Canadian Marconi Corporation

Charles M DeSantis

Louis J Jasper, Jr

Raymond Abbott Sackett

John R Wills

Donn V Campbell

Felix Schwering

Watson P Czerwinski

Albert H Zannella

Michael W Begala

Shabbir Amirali Khakoo

Kevin William Gould

Steve J Nossen

James J Arnold, Deceased

James F Baxendale

David J Helmkamp

Sydney D Bridges

Jane Klein

Susan L Klein

Robert M True

Christine T Read

John Marinho

Bruce Linick

Jeanne Weise

Thomas Ralph Smeraldi, Jr

Donald Jacoby

Dennis Mastriani

The present invention provides an apparatus and system for accurately predicting and evaluating cellular system performance before an actual system is installed at a site. In accordance with an embodiment of the invention, only two persons (or under certain conditions, as few as one) are required to operate the portable measurement and antenna placement (MAP) tools of the invention, and evaluate system performance (e.g., voice quality) at varied locations of a site without the system being in place. A user can measure out the size of cells using a bar graph display that shows the range of acceptable signal levels for the system, and an audible warning tone that signals the user when the cell edge has been exceeded. In addition, other quality determinative system parameters (e.g., bit error rate (BER), etc.) can be evaluated simultaneously with voice quality and average received signal strength.

Measurement and antenna placement tool for establishing a cell site

An ongoing communication with a mobile in a current cell of a wireless cellular system is handed over to another cell using information regarding a set of potential handover candidates. This information is transmitted from a base station in the current cell or from another fixed part transmitter in the system. The set of handover candidates for a given mobile in the current cell is determined based on stored adjacency information regarding the cells which are adjacent to the current cell. This adjacency information may be stored after an initial system configuration, based on the actual physical layout of the cells, and may be altered during system operation to reflect the success or failure of particular attempted handovers. The set of potential handover candidates may be in the form of a list of beacons associated with the cells adjacent to the current cell, and may include corresponding channel identifying information such as frequency and time slot. The potential handover candidate information may be transmitted upon receipt of a handover assistance request from the mobile, or may be periodically broadcast throughout the system.

Assisted handover in a wireless communication system

The present invention provides a method and apparatus for transmitting a synchronization beacon from a wireless base station to a wireless terminal in a wireless communication network installed in a building. The wireless network comprises a private branch exchange (PBX) connected to a wireless fixed base station (WFB) having a plurality of cell antennae units (CAUs) connected thereto. In a first embodiment, the plurality of CAUs are located in a single cell of the wireless network and are configured to receive two synchronization beacons from the WFB. In a second embodiment, each CAU is located in a separate cell in the network and is configured to receive a single synchronization beacon from the WFB. The synchronization beacon(s) is/are managed by the WFB and WT to virtually eliminate loss of synchronization between the WFB and WT if the frequency-timeslot at which the beacon is transmitted is changed or if transmission of the beacon is temporarily discontinued. In addition, synchronization between the WFB and WT is also maintained when the WT is moved to another cell in the wireless network.

Method and apparatus for transmitting a synchronization beacon in a wireless communication network

A method for improving the display of the interaction between cells in wireless environment by a computerized site layout system is presented. Each cell has a cell boundary threshold signal level and a hand-off trigger threshold signal level. After the signal strengths of the cells throughout the environment are calculated, the signal strength data is examined to determine for a primary cell and each of its neighbor cells, in turn, a handoff region where the signal strength of said primary cell is at least equal to its cell boundary threshold signal level and the signal strength of the particular neighbor cells is at least equal to its hand-off trigger threshold signal level. The position of the primary and neighbor cells and the identified handoff regions are graphically displayed. Preferably, each cell is assigned a unique display indicium and the handoff regions are displayed using a combination of the indicia for the primary and respective neighbor cell.

System and method for laying out wireless cells to account for cell handoff

Increased coverage and macro diversity from a single base station in a wireless communication system by having a base station coupled to N antennas is described. Increased coverage and macro diversity are achieved by transmitting from the base station N control messages each via one of the antennas, and transmitting a data message addressed to a mobile unit via a particular one of the antennas previously assigned to the mobile unit for an active call. The mobile unit receives the control messages and the data message and analyzes the control messages to identify from the antennas a best antenna. The mobile unit then transmits to the base station a new antenna request identifying the best antenna in an uplink control slot of a frame. The uplink control field is associated with the particular one of the antennas. The base station uses the best antenna to transmit subsequent data messages addressed to the mobile unit. A random access technique, to allow mobile units that are going from an inactive status to an active status, is provided by connecting all base station antennas together during non-call-affiliated slots in the uplink portion of the frame.

Wireless communication system using distributed switched antennas

A traveling wave type amplifier. The device features a pair of short helical input and output couplers through which an electron beam is projected. Application of an RF signal to the couplers serves to modulate the electron beam. A drift tube to be positioned between the couplers is dimensioned to attenuate the RF signal while permitting the modulated electron beam to pass through. An amplified output signal is extracted from the output helix. Gain of the tube is enhanced by a linearly decreasing magnetic focussing field.

Circuitless electron beam amplifier (CEBA)

A method for effecting communication between first and second antennas, includes the steps of (a) mutually displacing the antennas and determining received signal strength at each antenna and positioning said antennas accordingly to obtain a first quality level of communication therebetween; and (b) effecting a second quality level of communication as between the antennas, exceeding the first quality level, by defining a plurality of succeedingly diminishing search movement patterns for each of the first and second antennas, transmitting from the first antenna while displacing the second antenna in one such pattern and detecting the level of receipt of such transmitted energy. The second antenna is now placed in its location of maximum received signal level and transmits while the first antenna is displaced in one of the patterns and its level of receipt of transmitted energy is monitored. The first antenna is now placed in its location of maximum received signal level. This practice of transmitting from one antenna and moving the other in succeedingly diminished patterns and replacement in accordance with received signal strength continues until the desired second quality level of communication is attained. Maintenance of the second quality level of communication is practiced by quite small antenna search patterns on given lessening of communication quality. The antennas are supported on masts and preferred practice includes the further step of sensing movement of the masts and displacing the antennas responsively to such sensed mast movement in excess of a given threshold level. A system is disclosed for implementation of the practice.

Antenna alignment system and method

A transverse field interaction multi-beam amplifier device comprising a structure having, for example, a plurality of discrete cathodes cylindrically located in succession along a central axis of RF propagation. In registration with the cathodes are a respective number of annular collectors located within an outer cylinder which also acts as the structure housing. Intermediate the cathodes and collectors are two additional coaxial cylinders, one having a relatively smaller diameter than the other, with the smaller diameter cylinder including respective number of discrete grids, while the larger cylinder comprises a structure preferably having a rippled or undulating slow wave wall surface and a respective number of annular slots formed therein. The cathodes emit radial beams of electrons which pass through and are bunched by the grids and then accelerated by the slots to the collectors while interacting with and being modulated by an input RF beam propagating along the central axis of the coaxial structure between a first pair of cylinder walls including the grids and cathodes and inducing an output beam in a second pair of cylinder walls including the slots in the slow wave wall surface and the grids.

Transverse field interaction multibeam amplifier

A low-profile survivable antenna suitable for military use is described. pite its small size, which might be one tenth of a wavelength, the antenna has reasonable transmission range for these applications. Very little operator attention is needed in use, since a special matching circuit within the antenna network enables effective impedance matching, over a 3:1 frequency range, without necessity of switching to different matching circuits over different frequency bands. By including resistive components along with other passive inductive or capacitive elements, the reactance of the single matching circuit is made to effectively compensate the antenna's impedance over the entire frequency range. The impedance of the circuit has a decreasing positive reactance which compensates for the decreasing negative reactance, with frequency, of the antenna. Although the transmission efficiency of the matched antenna network is somewhat diminished by resistive losses, it is still satisfactory, and band switching with this matching circuit is completely eliminated. By including a slender whip screwed into the top, the range can be doubled with no further changes. The matching techniques to be described are most easily realized in the HF through VHF range (1-200 MHz).

Lossy matching for broad bonding low profile small antennas

A high power, broadband, active transmitting antenna for operation in the frequency range below 1 GHz which is in the order of 0.15 wavelength in electrical size. The relatively small antenna is coupled across an electron bombarded semiconductor device in the form of a diode which is penetrated by high energy electrons from an electron gun modulated with the RF signal to be transmitted.

Active transmitting antenna employing an electron beam bombarded

A circuitless particle beam device for relatively high frequency amplifier r oscillator applications that eliminates the requirement for an internal RF slow wave structure. A circularly polarized RF energy wave propagates on a relatively high density particle beam within an oversized waveguide and interacts with the beam which exhibits a relatively high dielectric constant. The high density beam acts as an active dielectric waveguide serving the dual purpose of a slow wave circuit and amplification source, and accordingly guides and amplifies the RF energy when a condition of beam and wave synchronism is met.

Active dielectric waveguide amplifier or oscillator using a high density

A broadband RF isolator system for connection between RF devices such as inear antennas is disclosed. In accordance with this invention, two or more antennas are spaced several wavelengths apart, connected to coaxial feeds and choked at their adjacent ends to establish the electrical length. In one embodiment of the invention, the isolator is formed by placing a second line adjacent the coaxial line connected to the upper antenna. The addition of this second line forms a balanced transmission line having a given characteristic impedance. The second line is terminated at one end by a resistor having a resistance equal to the value of the characteristic impedance. In a second embodiment the second line is replaced by a coaxial sleeve which is also terminated at one end with a resistor having a resistance value equal to the characteristic impedance. In four additional embodiments, which are essentially variations of the second basic embodiment, coaxial sleeves are also utilized to form the isolation system.

Broadband RF isolator

A phase sensing device is described which is useful for indicating the reance condition of a complex load impedance (such as an antenna), with a high degree of accuracy over the frequency range from 3 to 100 MHz. The device uses readily available transmission line and solid state components to provide a .+-. indication of the phase condition of the load; a zero crossing indicates resonance. Such a signal is useful for controlling an automatic turning mechanism that could be used in a tunable antenna. The extremely broadband operation and no physical connection to the main RF line are salient features of the device. The components are a transmission line coupler with a short pick-up wire mounted adjacent to the center conductor, two diodes with like electrodes (cathodes) connected to opposite ends of the pick-up wire, a carbon resistor between the other electrodes of the diodes, and a zero center meter across the resistor.

Phase sensor for R.F. transmission lines

Small broadband antennas using lossy matching networks

A VHF monopole antenna unit, particularly adapted for operation in the 30 MHz frequency range, yet capable of embodiment in a compact structure only approximately 11/2 feet in height is described. Coarse tuning is accomplished in a number of switched bands, for each of which is provided a specially designed matching network comprised of inexpensive L-networks of inductors and capacitors. Tuning is accomplished through adjustment of inductor elements. The simple, inexpensive design of the matching circuits eliminates need for intricate mechanisms typically used for automatic impedance matching over a wide band and also for a broadband impedance matching transformer. The compactness made available by the unique top-load structure design is further made possible by provision of a specially designed dielectric filled vertical antenna element, accomplishing the same range and efficiency in an even more compact antenna.

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Neptune, NJ, United States of America

Charles M DeSantis