A remote apparatus includes: a plurality of sub amplification units amplifying radio frequency (RF) signals of different frequency bands, respectively; a test signal generation unit generating test signals of a frequency band for any one sub amplification unit among the plurality of sub amplification units; a conversion unit converting intermodulation (IM) signals generated in response to the test signals into a plurality of conversion IM signals by using a conversion signal of which a frequency is swept; and a control unit determining a degree of an intermodulation distortion by the any one sub amplification unit based on signal levels of the plurality of the conversion IM signals.

A remote apparatus includes: a plurality of sub amplification units amplifying radio frequency (RF) signals of different frequency bands, respectively; a test signal generation unit generating test signals of a frequency band for any one sub amplification unit among the plurality of sub amplification units; a conversion unit converting intermodulation (IM) signals generated in response to the test signals into a plurality of conversion IM signals by using a conversion signal of which a frequency is swept; and a control unit determining a degree of an intermodulation distortion by the any one sub amplification unit based on signal levels of the plurality of the conversion IM signals.

System and method for implementing a Vector Network Power Meter (VNPM) as a new class of electronic test instrument that uses a novel topology based upon a reflectometer to combine the functionality of a Power Meter with that of a Vector Network Analyzer (VNA). The VNPM overcomes application limitations of the two existing classes of test instruments, including parallel and simultaneous measurement capability, in-circuit operation, and improved accuracy and repeatability by eliminating the calibration of interconnecting cabling. Also provided are alternate implementations of a correlator for the reflectometer which reduce the size and complexity of the correlator while extending its frequency range without limit.

A monitoring system 22 for a distributed antenna system (DAS) 10 is provided. The DAS comprises central transmitter 12 which is connected by a signal transmission network 14 to a plurality of distributed antenna devices (DAD) 16.1 to 16.n. The network comprises physical branches. Each of the DAD's is connected to a respective sub-branch 14.11 and comprises at least one antenna 18. The antenna is associated with a frequency band having a centre frequency f.sub.c and an associated wavelength Ac. The monitoring system comprises a central monitoring unit (CMU) 24 which is coupled to the network 14. A monitoring device 28.1 is associated with at least one of the DAD's and permanently mounted a distance d<2 λ.sub.c away from the antenna of the DAD. The monitoring device comprises a controller 30, a transceiver 32 and an antenna 34. The controller being configured, upon being polled by the CMU 24 with a monitoring signal via the network and the distributed antenna device, to cause the transceiver 32 to respond by transmitting a response signal to the CMU 24 via the distributed antenna device 16.1 and the network 14.

A monitoring system 22 for a distributed antenna system (DAS) 10 is provided. The DAS comprises central transmitter 12 which is connected by a signal transmission network 14 to a plurality of distributed antenna devices (DAD) 16.1 to 16.n. The network comprises physical branches. Each of the DAD's is connected to a respective sub-branch 14.11 and comprises at least one antenna 18. The antenna is associated with a frequency band having a centre frequency f.sub.c and an associated wavelength Ac. The monitoring system comprises a central monitoring unit (CMU) 24 which is coupled to the network 14. A monitoring device 28.1 is associated with at least one of the DAD's and permanently mounted a distance d<2 λ.sub.c away from the antenna of the DAD. The monitoring device comprises a controller 30, a transceiver 32 and an antenna 34. The controller being configured, upon being polled by the CMU 24 with a monitoring signal via the network and the distributed antenna device, to cause the transceiver 32 to respond by transmitting a response signal to the CMU 24 via the distributed antenna device 16.1 and the network 14.

For wireless cellular communications, a “smart” multi-band combiner system has a multi-band combiner and a passive inter-modulation (PIM) detection sub-system. The multi-band combiner combines multiple transmit signals in different downlink frequency bands into a single, multi-band transmit signal for transmission from a cell tower antenna. The PIM detection sub-system characterizes the frequency components in the multi-band transmit signal to predict PIM products and determine if any predicted PIM products might interfere with any receive signals in any uplink frequency bands. If so, the PIM detection sub-system generates a signal indicating the presence of such predicted interfering PIM products, and the system installer and/or the network administrator can take remedial action to prevent the PIM products from interfering with user communications.

A unique method/device for isolating the over-the-air segment within a mobile communications network is provided. A coordinated set of tests is run to isolate problems in an end-to-end network including over-the-air segment, wired, and core network segments. Test results are compared to identify which segment or components within a segment is failing. The testing device executes the same test in two differentiated modes. In one mode, the device acts as a mobile client device identified by subscriber identification data that communicates with the network base station over-the-air using the standard control and data protocols of the mobile network. In another mode, the testing device, identified by the same subscriber identification data, acts like the combination of the same Mobile Client Device(s) and a Network Base Station using a wired interface that is equivalent to the wired interface that connects the network base station to the rest of the wired network.

A unique method/device for isolating the over-the-air segment within a mobile communications network is provided. A coordinated set of tests is run to isolate problems in an end-to-end network including over-the-air segment, wired, and core network segments. Test results are compared to identify which segment or components within a segment is failing. The testing device executes the same test in two differentiated modes. In one mode, the device acts as a mobile client device identified by subscriber identification data that communicates with the network base station over-the-air using the standard control and data protocols of the mobile network. In another mode, the testing device, identified by the same subscriber identification data, acts like the combination of the same Mobile Client Device(s) and a Network Base Station using a wired interface that is equivalent to the wired interface that connects the network base station to the rest of the wired network.

An operation test method of a base station to which a plurality of terminal stations are connectable, the method including switching a specific radio communication unit of a plurality of radio communication units to a subordinate mode and setting another radio communication unit of the plurality of radio communication units to a normal mode, the normal mode being a mode in which each of the plurality of radio communication units performs radio communication as a base station, the subordinate mode being a mode in which each of the plurality of radio communication units performs radio communication as a virtual terminal station, each of the plurality of radio communication units being switchable between the normal mode and the subordinate mode, and conducting an operation test of the base station by performing, based on a test policy that sets the operation test, radio communication between the specific radio communication unit switched to the subordinate mode and the other radio communication unit in the normal mode.

An operation test method of a base station to which a plurality of terminal stations are connectable, the method including switching a specific radio communication unit of a plurality of radio communication units to a subordinate mode and setting another radio communication unit of the plurality of radio communication units to a normal mode, the normal mode being a mode in which each of the plurality of radio communication units performs radio communication as a base station, the subordinate mode being a mode in which each of the plurality of radio communication units performs radio communication as a virtual terminal station, each of the plurality of radio communication units being switchable between the normal mode and the subordinate mode, and conducting an operation test of the base station by performing, based on a test policy that sets the operation test, radio communication between the specific radio communication unit switched to the subordinate mode and the other radio communication unit in the normal mode.