Abstract: A cellular/wireless foreign subscriber is enabled to use her/his own cellular/wireless telephone instrument in a local cellular/wireless (C/W) network/system by entry of a code and a PIN into the local network/system desired to be used. The local C/W network/system algorithmically responds to the code and PIN by changing characteristics of the radio equipment of the local C/W network/system to accommodate operation of the subscriber's cellular/wireless telephone instrument with the network/system desired to be used.

Abstract: An apparatus that provides a redundant path for providing service using existing or original equipment when failure or degradation of performance of new equipment is detected in a communication network. A controller module monitors the performance of new equipment used to provide improved services to service provider customers. When a failure in the new equipment is detected, the controller module outputs a control signal to switch processing from the new equipment to the existing equipment that is still available for use. In addition, processing may be switched from the new equipment to the existing equipment when the controller detects degradation in the performance of the new equipment so that loss of service is prevented. Therefore, the existing equipment acts as a redundant path for processing.

Abstract: A cellular/wireless foreign subscriber is enabled to use her/his own cellular/wireless telephone instrument in a local cellular/wireless (C/W) network/system by entry of a code and a PIN into the local network/system desired to be used. The local C/W network/system algorithmically responds to the code and PIN by changing characteristics of the radio equipment of the local C/W network/system to accommodate operation of the subscriber's cellular/wireless telephone instrument with the network/system desired to be used.

Abstract: A system and method in which a dual image-reject mixer arrangement receives an RF signal having at least one channel. The dual image-reject mixer arrangement generates first and second signals corresponding to each channel of the RF signal. Each first and second signal includes a desired signal, an image frequency signal and an intermodulation signal. A feed-forward arrangement receives the first and second signals corresponding to each channel and outputs a third signal that is formed by constructively combining the desired signals corresponding to each channel and substantially cancelling the intermodulation signals corresponding to each channel. An in-phase and quadrature hybrid network receives the third signal and outputs an in-phase baseband signal and a quadrature baseband signal corresponding to each channel of the RF signal.

Abstract: A power amplifier includes a first amplifier, a second amplifier, a transfer switch and a controller. The first amplifier amplifies a first frequency bandwidth, and the second amplifies a second frequency bandwidth. The second frequency bandwidth is less than the first frequency bandwidth. The transfer switch includes a first input port, a second input port, a first output port and a second output port. The first input port is connected to a primary power source, while the second input port is connected to a battery. The first output port is connected to the first amplifier and the second output port is connected to the second amplifier. The controller controls the transfer switch to connect the first primary power source to the first amplifier in a primary mode of operation. The controller also controls the transfer switch to connect the battery to the second amplifier in a second mode of operation.

Abstract: An RF power amplifier includes a first monitoring circuit that is coupled to an output signal of the power amplifier, and generates a first control signal based on a level of intermodulation distortion in the output signal. The first control signal has a first value when the level of intermodulation distortion in the output signal is less than a predetermined level of intermodulation distortion and second value when the level of intermodulation distortion in the output signal is greater than or equal to the predetermined level of intermodulation distortion. A second monitoring circuit is coupled to the output signal and generates a second control signal based on a power level of the output signal. The second control signal controls a level of the input RF signal so that the power level of the output signal is less than a predetermined power level. A phase shift/hybrid network is coupled to a primary signal path and an auxiliary signal path of the power amplifier.