Bell Communications Research, Inc.

Bell Telephone Laboratories

Telcordia Technologies, Inc.

Nokia Mobile Phones Limited

Anthony Robert Noerpel

Li-Fung Chang

Nelson Ray Sollenberger

Li Fung Chang

Hamilton W Arnold

Robert A Ziegler

Vijay K Varma

Ashok Ranade

Pertti S Lukander

Edward Lipper

Adedokun W Sule-Koiki

Vijay Kerala Varma

A method for enabling the integration of the Personal Access Communications System (PACS) which supports low-tier radio, wireless communication devices with a GSM network used to support high-tier, cellular devices to allow connection of the PACS system to public switched telephone networks that do not have Advanced Intelligent Network capabilities. The functions of the conventional PACS Access Manager are redistributed among the various components of the PACS/GSM integrated system. Modifications to the PACS protocol to make it compatible with GSM protocol are detailed.

Method and system for supporting PACS using a GSM mobile switching center

Radio ports (RPs) in an unlicensed personal communications system adaptively, autonomously set their interference threshold and/or transmission power levels. This may be done by the RP measuring the signal level on each of the available channels and then setting the interference threshold and/or power level according to these measurements. In a preferred method, the interference threshold is determined by measuring the signal level on each channel, ranking the channels in order of measured signal level, and using these rankings to determine the threshold. The transmission power level may be set with reference to the adaptive interference threshold level. This level is determined by using the system and FCC power limitations and current conditions to provide a satisfactory transmission level.

Method for unlicensed band port to autonomously determine interference

A number of RPs stagger the times in which they begin searching for available channels. In a preferred method, one of a plurality of RPs in a UPCS system is selected to have a first start time. The system determines which RPs in the system can 'see' the selected RP. Each of these RPs is given a unique stagger start time. This process may be repeated until each RP in the system is assigned a stagger start time. Alternatively, if there are fewer RPs in the system than there are available stagger start times, each RP may be selected to have a unique stagger start time.

Method for assigning band port channels in an unlicensed personal

In a TDM/TDMA portable radio communications system, a portable handset is compatible for operation in both a frequency-division duplexing (FDD) mode for communication in the licensed portion of the Emerging Technologies frequency band, and in a time-division duplexing (TDD) mode for communication in the unlicensed portion of the Emerging Technologies frequency band. In the FDD mode, different frequencies are used to separate a downlink transmission to a portable from a port from an uplink transmission from a port to a portable. In the TDD mode, uplink and downlink transmissions are separated in different time-slots, but at the same frequency. The handset includes common transmit and receive circuitry that operates at fixed IF frequencies that are separated in frequency by the fixed FDD frequency difference between corresponding uplink and downlink signals. In the FDD mode, therefore, a frequency synthesizer (301), which is used to tune to transmit and receive at different frequencies from different ports, does not have to switch its frequency between transmitting and receiving a burst to and from a single port. In the TDD mode, however, even though uplink and downlink signals are at the same frequency, the synthesizer is switched in frequency between transmitting uplink and receiving downlink.

Compatible licensed and unlicensed band portable handset unit for TDMA

A mode coupler for vertically polarized modes comprises a first waveguide (32) having a relatively small rectangular cross-section and a second waveguide (22) having a relatively large rectangular cross-section. The first small cross-section waveguide has a wall (300) formed in common with a portion (400) of a wall (200) of the second large cross-section waveguide. The common wall portion contains a series of circular apertures (202) extending in a longitudinal direction of both waveguides. The centers of the apertures are displaced a first distance (.tau..sub.1) from a center line of a wall of the first waveguide and a second distance (.tau..sub.2) from a center line of the wall of the second waveguide. In this case, a fundamental TE.sub.01S mode of the first waveguide is in phase synchronism and couples equally to the two degenerate TE.sub.11L and TM.sub.11L higher order vertically polarized modes of the second waveguide.

Mode diversity coupler for vertical polarization

During multipath fading in a terrestrial digital radio system, off-axis arrival of signals excites higher-order modes in a horn reflector antenna. In the disclosed system specified ones of these higher-order modes and the fundamental mode are allowed to propagate in a main waveguide connected to the antenna. At least one of the higher-order modes is abstracted from the main waveguide and fed to a standby receiver while the fundamental mode is propagated intact to a main receiver. Error occurrences in the fundamental and higher-order modes due to multipath fading are substantially uncorrelated. Hence, upon detecting an error in the signals delivered to the main receiver, the system switches to the standby receiver thereby to provide in a single-antenna a significant improvement in performance against multipath fading.

Pattern diversity in a microwave digital radio system utilizing a single

The present invention relates to a small hybrid mode feed for dual frequency band use. In the present feed, a helically wound wire structure (10) is bonded to the inner surface of a hollow conducting waveguide structure (12) by a layer (14) of low-loss dielectric material having a predetermined thickness to permit a first frequency band to propagate. Embedded in the dielectric layer between the helically wound wire structure and the inner wall of the waveguide is a periodic tuned grid structure (16) disposed at a predetermined depth from the helical wire structure to permit a second frequency band to propagate. The periodic tuned grid structure can comprise, for example, a Jerusalem Cross grid arrangement.

Small dual frequency band hybrid mode feed

The present invention relates to a hybrid mode waveguide or feedhorn antenna for transforming the TE.sub.11 mode into the HE.sub.11 mode. The waveguide or antenna comprises a first waveguide section of uniform cross-section at the TE.sub.11 mode entrance port which in the antenna arrangement changes to a second section which flares outward toward the antenna mouth, and a spiro-helical projection bonded with a dielectric layer to the inner surface of the waveguide or antenna. The spiro-helical projection comprises a closely spaced helically wound wire structure formed of dielectrically coated wires which in the first section decrease in gauge size in small adjacent portions thereof as the helix progresses away from the TE.sub.11 mode entrance port and in the remainder of the helical projection, the same or decreasing gauge wire in adjacent portions can be used.

Growing community of inventors

Long Branch, NJ, United States of America

Anthony Robert Noerpel