Abstract: Methods and systems for secure data offload in a sensor network. The method comprises offloading data indicative of sensor measurements from a wireless sensing device to a gateway device through a first secure communication channel; and storing the data at the gateway device if there is not currently a second secure communication channel established between the gateway device and the management server. The method continues with offloading the data to the management server when the second secure communication channel is established; and reconciling the data at the management server to generate reconciled sensor measurements in which duplicates have been removed.

Abstract: Methods and systems for secure data offload in a sensor network. The method comprises offloading data indicative of sensor measurements from a wireless sensing device to a gateway device through a first secure communication channel; and storing the data at the gateway device if there is not currently a second secure communication channel established between the gateway device and the management server. The method continues with offloading the data to the management server when the second secure communication channel is established; and reconciling the data at the management server to generate reconciled sensor measurements in which duplicates have been removed.

Abstract: The invention relates to devices and methods for signalling control information associated with transmission of data over a wireless channel. A second communication device receives (S2) data from a first communication device, wherein the data comprises an indication of recommended precoders and a recommendation of a first transmission rank to possibly use during transmission. The second communication device determines (S4) a second transmission rank to use for transmitting data, and transmits (S6) a confirmation message to the first communication device. The confirmation message comprises a confirmation that transmission of data from the second communication device is using at least parts of each recommended precoder associated with a frequency resource that falls within the transmission of data and an indicator of the second transmission rank to use.

Abstract: In one illustrative example, a mobile communication device receives and decodes a plurality of packet data bursts over a packet data channel of a serving cell. While receiving and decoding the packet data bursts, the mobile communication device also receives and decodes a plurality of broadcast data bursts over a broadcast control channel of a neighbor cell. When a time conflict exists between receiving and decoding at least one of the packet data bursts and receiving and decoding at least one of the broadcast data bursts, the mobile communication device receives and decodes the at least one packet data burst instead of the at least one broadcast data burst when no imminent call drop between the mobile communication device and the serving cell is identified.

Abstract: A software-defined radio (SDR) system that operates under a plurality of wireless communication standards. The SDR system comprises a reconfigurable maximum aposteriori probability (MAP) decoder capable of being configured under software control to decode a received data block according to a select wireless communication standard and a reconfigurable interleaver associated with the reconfigurable MAP decoder. The reconfigurable interleaver comprises a reconfigurable interleaver core circuitry capable of being configured under software control to operate according to the selected wireless communication standard and a unified interleaver interface for coupling a defined set of control and bus signals from the reconfigurable MAP decoder to the reconfigurable interleaver core circuitry.

Abstract: A base station apparatus is disclosed for use in a mobile communication system including multiple cells having multiple sectors. The base station apparatus includes a synchronization channel generation unit configured to generate a synchronization channel for use in cell search by a user apparatus and a transmitting unit configured to wirelessly transmit a signal including the synchronization channel. The synchronization channel includes a primary synchronization channel and a secondary synchronization channel. The primary synchronization channel includes multiple types of sequences, and the secondary synchronization channel transmitted in a sector of a cell includes a code derived from a predefined generation polynomial equation corresponding to the primary synchronization channel.

Abstract: Apparatus (40) comprising a voltage input (49) for applying an unfiltered voltage (V_unfil) and a current input (48) for receiving a bias current (Ib) from a current source. The apparatus (40) further comprises a differential filtering resistive circuit with a first current mirror (44) and a second current mirror (43), being situated between a common output node (50) and said voltage input (49). A first mirror circuit (42) for mirroring the bias current (Ib) to said first current mirror (44), and a second mirror circuit (41) for mirroring a current (Ix) to said second current mirror (43) are employed. A filter capacitor (51) situated at the output side of the apparatus (40), said filter capacitor (51) being connected on one side to said common output node (50) and on the other side to ground. The apparatus (40) provides a filtered output voltage (V_fil) at said common output node (50).

Abstract: An apparatus and a method for routing data in a radio data communication system having one or more host computers, one or more intermediate base stations, and one or more RF terminals organizes the intermediate base stations into an optimal spanning-tree network to control the routing of data to and from the RF terminals and the host computer efficiently and dynamically. Communication between the host computer and the RF terminals is achieved by using the network of intermediate base stations to transmit the data.

Abstract: In a multi-carrier and multi-rate CDMA system, a base station transmits an index tag to a number of mobile stations. The index tag has a length indicating a transmission rate and all index tags are nodes in a code tree. In the code tree, mother nodes and their child nodes block each other and are not assigned to the mobile stations at the same time. At the same time, index tags of nodes in the same level of the code tree map are orthogonal to each other. The mobile station constructs an index tag matrix according to the index tag. Then, the index tag matrix is multiplied with a generating matrix that is stored in every mobile station to generate a spreading factor matrix whose rows respectively correspond to different carriers.

Abstract: When a multi-directional antenna is connected to a digital TV broadcast signal receiver, the digital TV broadcast signal receiver measures a term suitable for switching or changing an effective signal receiving direction of the multi-directional antenna corresponding to kind or specification of the multi-directional antenna. Control signals are outputted at an interval suitable for switching or changing the effective signal receiving direction of the multi-directional antenna corresponding to the measured term so as to switch the effective signal receiving direction of the multi-directional antenna to an optimum signal receiving direction of a channel chosen by a user. Consequently, it is possible to shorten a term necessary for switching or changing the effective signal receiving direction of the multi-directional antenna to the optimum signal receiving direction of the channel chosen by the user.

Abstract: An RFID events processing system includes a rules database having filtering rules and complex event rules, a primitive event filtering unit for receiving a plurality of primitive events to generate filtered events based on the filtering rules, and a complex event detection engine which receives the filtered events and detects complex events based on the complex event rules.

Abstract: A radio LAN (Local Area Network) system includes an access point and a mobile or a fixed station each having a physical layer implemented by a direct spread spectrum system. The LAN system uses different spread codes, maintains transmission power semi-fixed, and selects a frequency and a frequency band in accordance with the kind and amount of information. A data link layer above each physical layer includes an LLC (Logical Link Control) sublayer and an MAC (Media Access Control) sublayer. The MAC sublayer uses a CDMA (Code Division Multiple Access) system as an access system for thereby implementing a data structure in accordance with the kind and amount of information.

Abstract: A medium access control (MAC) entity first computes an achievable rate region based on a total transmit power limit and a channel gain of each of a plurality of WTRUs. Next, the MAC entity selects an order of DPC among the WTRUs. A rate set for use in transmitting to the WTRUs is then selected, said rate set being within the computed achievable rate region. Then, based on the selected DPC order and rate set, a DPC entity performs DPC on a plurality of data streams intended for the plurality of WTRUs. If nested lattice-based DPC is utilized, rate compatibility is achieved by selecting proper nesting ratios corresponding to a desired data rate set. Otherwise, if binary-code based DPC is utilized, rate compatibility is achieved via selecting appropriate message input sizes for input to point-to-point coding units prior to performing DPC.

Abstract: An apparatus and a method for routing data in a radio data communication system having one or more host computers, one or more intermediate base stations, and one or more RF terminals organizes the intermediate base stations into an optimal spanning-tree network to control the routing of data to and from the RF terminals and the host computer efficiently and dynamically. Communication between the host computer and the RF terminals is achieved by using the network of intermediate base stations to transmit the data.

Abstract: An apparatus and a method for routing data in a radio data communication system having one or more host computers, one or more intermediate base stations, and one or more RF terminals organizes the intermediate base stations into an optimal spanning-tree network to control the routing of data to and from the RF terminals and the host computer efficiently and dynamically. Communication between the host computer and the RF terminals is achieved by using the network of intermediate base stations to transmit the data.

Abstract: A signal analyzer and a method for displaying code-channel power levels of CDMA (Code Division Multiple Access) signal that contains code changes having different spreading factors. The individual code-channel power level is measured from a received signal and displayed in a diagram for a specified base spreading factor. The code channels having an alias power level are indicated. A code channel, with regard to the specified base spreading factor, has an alias power level when the code channel having the base spreading factor is inactive and when a code channel of a higher spreading factor (corresponding to the former code channel) is active, or, in the event of orthogonal transmit diversity, the power level of a code channel is mapped onto the code channel of the base spreading factor.

Abstract: The present invention is directed towards a look-up table implementation of a WCDMA frame synchronization and a cell group ID detection (both of which are comprised within a “secondary search” process). The secondary search process receives a signal (which is formatted as slots within a frame) and determines (“decides”) information encoded in the received signal according to the slots of the received signal. The determined information is used to produce a sequence of values. A sequence of values (which have been determined from successive slots) is used to produce an index into a table that stores secondary search results. The secondary search codes are arranged such that a minimum sequence of values can be used to determine frame synchronization and group identification. The table is configured to return information that is sufficient for determining frame synchronization and the group ID of the received signal.

Abstract: A reception apparatus includes a plurality of antennas for receiving modulation signals of channels in the same frequency band, a received signal strength intensity estimation unit for estimating the reception received signal strength intensity of each reception signal, transmission path fluctuation estimation units for estimating a transmission path fluctuation of each channel of the reception signal, phase difference estimation units for calculating a phase difference of the transmission path fluctuation estimation signal of a predetermined channel of each antenna and outputting it as a phase difference signal, and a signal selection unit for selecting and outputting a reception quadrate baseband signal for isolating a signal of each channel from the reception signals and a transmission path fluctuation estimation signal of each channel. Thus, by isolating and demodulating a plurality of multiplexed modulated signals received, it is possible to improve the data transmission rate.

Abstract: A control section (110) recognizes the type of data included in a transmission signal and outputs a control signal (C1) to an S/P conversion section (101) and a spreading control section (107). The S/P conversion section (101) apportions a specific type of data output from the control section (110) to different transmission systems. Spreading sections (102, 103) carry out spreading processing on the specific type of data output from the S/P conversion section (101) with different spreading codes assigned thereto under the control of the spreading control section (107). The data output from the spreading sections (102, 103) is transmitted by radio through addition sections (104-1, 104-2), transmission sections (105-1, 105-2) and antennas (106-1, 106-2). In this way, it is possible to improve the reception performance on the receiving side for specific data while maintaining the transmission efficiency of an MIMO communication system.

Abstract: In a cell phone position measurement system, a position measurement unit performs position measurement using a (GPS) satellite. A cell phone terminal notifies the position measurement unit of a (GPS) signal received from the satellite and receives a position information service. In the cell phone terminal, a receiving unit receives the signal from the satellite. A radio phone unit notifies the position measurement unit via a radio channel and a cell phone network of position measurement data obtained from the signal received by the receiving unit. A controller controls the radio phone unit and temporarily interrupts communication via the radio channel in position measurement through the receiving unit. A position measurement method is also disclosed.

Abstract: An apparatus and a method for routing data in a radio data communication system having one or more host computers, one or more intermediate base stations, and one or more RF terminals organizes the intermediate base stations into an optimal spanning-tree network to control the routing of data to and from the RF terminals and the host computer efficiently and dynamically. Communication between the host computer and the RF terminals is achieved by using the network of intermediate base stations to transmit the data.

Abstract: A CDMA mobile communication system is disclosed in which a reference value that is used in a closed-loop transmission power control is updated in base transceiver stations. The updating of an uplink signal target SIR value that serves as the reference in closed-loop transmission power control is performed independently at base transceiver stations and is not performed at the base station controller. At the base transceiver station, when a decoder detects a loss of synchronization of a user signal from a mobile station, a demodulator adds a step value ASIR that has been set in advance to the uplink signal target SIR value that has been reported from the base station controller to obtain an uplink signal target SIR provisional value, and when this uplink signal target SIR provisional value is smaller than an uplink signal target SIR maximum value that has been set in advance, the uplink signal target SIR value is updated to the uplink signal target SIR provisional value.

Abstract: There is provided a radio station and a radio network controller performing communication by CDMA, able to change transmission speed in response to the propagation environment, and carry on communications without communication quality degradation. The radio station comprises a signal quality reception unit for receiving information of quality of the signals having been transmitted by the radio station, received by a party thereof, and sent to the radio station by the party, in which the information is measured from the received signals by the party, and a code multiplicity determination unit configured to determine a code multiplicity of signals transmitted from the radio station to the party based on the received information of signal quality. The radio station transmits the signals to the party using the determined code multiplicity.

Abstract: A received low-frequency standard radio wave, which is an amplitude modulation signal, is converted to an intermediate frequency signal Sa, and is output to a detection circuit and an AGC circuit. The detection circuit and AGC circuit generates an RF control signal Sf1 and IF control signal Sf2 from the input intermediate frequency signal Sa, and controls an RF control circuit and IF control circuit by outputting the generated RF control signal Sf1 and IF control signal Sf2 to the RF control circuit and IF control circuit. By this a radio wave reception device can speed up AGC operation.

Abstract: A locomotive communication system for communicating between a locomotive and a fixed site. A communication system commissioning process is utilized to ensure that the locomotive phone number and locomotive road number are paired at the fixed site so that data downloaded from the locomotive, in response to a call from the fixed site using the locomotive phone number will be identified with the correct locomotive road number.

Abstract: Conventionally, there is a problem that a block error rate cannot be measured when packet data does not exist during packet data transmission and therefore, output adjustment cannot be performed at an outer loop.

Abstract: A self-tuned millimeter wave transceiver module includes a microwave monolithic integrated circuit (MMIC) having at least one amplifier. A controller is operatively connected to the MMIC for sensing amplifier operating conditions and tuning the at least one amplifier to an optimum operating condition. The controller includes a surface mounted microcontroller chip operatively connected to the MMIC.

Abstract: Slot quality detector 121 detects reception level, and power controller inversely corresponding to reception quality 122 outputs power control information indicative of increasing transmission power in the case where the detected reception level is higher than a threshold value and of decreasing the transmission power in the case where the detected quality is lower than the threshold value. Transmission power setter 108 performs the setting of transmission power corresponding to the power control information and provides a control to transmit by the set power. That allows improving of a battery saving and moderating of the specification of amplifiers in a transmission/reception apparatus, thereby resulting in decreased interference to signals of other users in the CDMA communication.

Abstract: A system and method for accurately determining the position of a mobile unit operating within a predefined service area is disclosed. Three embodiments of the present invention are disclosed which teach the use of one, two and three narrow beam base transceiver stations in the determination of a mobile unit's position. Where one base station is utilized, an information map of signal attributes is used in the position determination. Where two and three base stations are used, signal strength measurements in combination with the time difference of arrival of a signal at the various base stations are used in the position determination.

Abstract: An interference analyzing system and method analyze interference in a dual mode system having a digital network overlaid on an analog network. The digital network includes portable units operating within digital cell sites; whereas, the analog network includes mobile units operating within analog cell sites. The interference analyzing system measures the amount of interference caused by and to the portable units, and the amount of interference caused by and to the digital cell sites. The system individually compares these interference amounts to a predetermined threshold. If either of the interference amounts exceeds the predetermined threshold, the system selects one of the analog cell sites for spectrum clearing and determines the amount of spectrum to be cleared from the selected analog cell site.

Abstract: A cellular communication system has a plurality of cells and a plurality of channels. The plurality of channels includes a plurality of measurable channels for which interference can be measured in both uplink and downlink directions and a plurality of unmeasured channels for which interference are not made in both uplink and downlink directions. The measurable channels, designated probe channels, may be channels for use in a digital system. The unmeasured channels may be channels for use in an analog system, or broadcast channels. A method and apparatus for allocating the plurality of channels comprises initially organizing the plurality of channels into a plurality of channel groups, wherein each channel group includes at least one probe channel, and wherein at least one of the channel groups further includes at least one unmeasured channel.

Abstract: A wireless computer network communication system for use in an environment in which plural groups can perform network communication at the same time. A channel controller receives a requirement of starting network communication from a computer, controls a wireless channel sensor, and detects a received signal. The wireless channel detector detects which wireless channel is employed by one or more other networks and the channel controller determines the wireless channel to be employed by its own group and also controls the transceiver. The computer starts the network communication through a network controller. The network controller controls the transceiver for transmitting and receiving data by use of the wireless channel, and the same further controls the transmitting/receiving of the requirements and the data from the computer.

Abstract: To perform control of a mobile telephone system which uses a dedicated control channel type multichannel access system, when an emergency telephone call is made from a mobile telephone to the police or fire department, the mobile telephone references a memory into which is stored the identification code of a service area within which calling is permitted, the base station having the highest received field strength of the control channel radio signals of base stations in this service area is selected and the emergency call is made to the thus selected base station. When doing this, the mobile telephone stores the identification code of the base station to which the emergency call was made, and when a next call is made after the emergency call is completed, the call signal is sent on the control channel of the base station to which the emergency call was made, based on the thus stored identification code of the base station.

Abstract: The minimum CIR value that permits a channel allocation to a call is defined as a threshold value .LAMBDA..sub.c1 and a CIR value a little larger than it is defined as a threshold value .LAMBDA..sub.c2. The CIR value in each idle channel is measured. When the measured CIR value is below the threshold value .LAMBDA..sub.c1, the priority of that channel is decreased; when the CIR value is between the threshold values .LAMBDA..sub.c1 and .LAMBDA..sub.c2, the priority is increased; and when the CIR value is above the threshold value .LAMBDA..sub.c2, the priority is held unchanged. When a call occurs in a base station, the highest-priority one of idle channels with the CIR values larger than the threshold value .LAMBDA..sub.c1 is allocated to that call and the priority of the allocated channel is increased.

Abstract: A method of reducing interference within a cellular system (10) by partitioning a designated frequency spectrum within a service coverage area (11, 12, 13, 14, 15, 16, or 17) into a first and at least second spectrum inclusive of the designated frequency spectrum and each with an associated power level. Assignment of communication units to a spectrum and power level are based upon distance from the base site (as determined through signal strength measurements). The spectral content of spectra in adjacent service coverage areas is adjusted to include non-coincidental frequencies.

Abstract: A synchronization device for a terminal of a radio communication system, adapted to identify a control channel constituting one of a plurality of receive channels by means of a receiver (2) comprises means (3) to measure the power of the receive channels and means (4) for attempting synchronization to at least some of said channels identified in a list (5), and is characterized in that, the system being such that a reference channel (C.sub.r) of nominal power (P.sub.r), its ith predecessor (C.sub.r-1) and its ith successor (C.sub.r+1) have an ith attenuation (A.sub.i) when the receiver (2) is tuned to the reference channel (C.sub.r), it comprises selection means whereby the ith predecessor (C.sub.r-i) or the ith successor (C.sub.r+1) do not appear in the list if its power is less than the nominal power (P.sub.r) of the reference channel (C.sub.r) reduced by the ith attenuation (A.sub.i).

Abstract: A radio calling method and apparatus for removing a near-far problem in a radio switching system groups a plurality of cordless fixed parts distributed in various areas into at least two groups. If a cordless portable part attempts an outgoing call, a channel is scanned by the cordless fixed part, a received field strength is compared with a communication field strength. If the received field strength is more than the communication field strength, the received field strength is stored and a determination is made as to whether or not link-request data has been received during a given period of time. If the link-request data has been received during the given period of time, a determination is made as to whether or not the received field strength is more than a near-far field strength and if received field strength is more than the near-far field strength, a link-grant is transmitted to the cordless portable part.

Abstract: A method and system for controlling overhead information transmission in a radicommunication system is described. By desynchronizing information trasmitted in two streams on a control channel, loads on the reverse control channel are more evenly distributed to minimize overload situations. Similarly, blocked calls can be prevented by judicious transmission timing of control filler messages relative to the overhead message trains. The relative timing of various registration parameters is also described to reduce extraneous registrations.

Abstract: A wireless communication system includes a plurality of wideband base stations and a cluster controller that dynamically controls channel allocations among the base stations. When a base station can not service a radio telephone terminal within its cell site, the base station polls the channels and sends a request for a channel to the controller, listing in the request the channels the station determines at the cell site to be inactive. The controller consults a load statistics table to determine if a first listed channel is free over the system. If so, the controller allocates the channel to the base station, if not the controller searches the table for a free channel. The controller may also include channel usage rates in the table. These rates indicate for a predetermined period of time for each base station the rate at which the base station assigns channels to the terminals and the number of channel in use simultaneously.

Abstract: When frequencies are being scanned to seize a control channel immediately after the end of a call, if there arises a call request, the call request is stored, and a calling operation is automatically initiated after a control channel has been seized. When a call request is stored, if a predetermined length of time has elapsed before a control channel is seized, the stored call request is discarded.

Abstract: A communication apparatus to which communication units for communicating in accordance with a multichannel access method are connected comprises a receiver to receive ID information of a communication channel to be used from the plurality of communication units, and a selector to select the communication channel in accordance with the ID information received by the receiver. Namely, the selector selects the communication channel other than the communication channel such as to exert an influence on a control channel or other communication channels if it is used together with the in-use communication channel. Or, now assuming that a frequency of the in-use communication channel is set to f.sub.A, the selector selects the communication channel other than the communication channel of a frequency f.sub.B such that (2f.sub.A -f.sub.B) or (2f.sub.B -f.sub.A) is equal to the frequency of the control channel or the frequency of the other communication channel.

Abstract: A method for facilitating communication between parent telephones and child telephones in a cordless telephone system. The method includes steps of dividing a plurality of channels into groups and assigning each parent telephone to one of the groups. When a child telephone is registered with one of the parent telephones, the child telephone may scan only the channels in the group assigned to the parent telephone with which the child telephone is registered, rather than the entire plurality of channels in the cordless telephone system.

Abstract: A channel allocation method in a cellular radio system. The mobile radios have permanently stored in their memories a first group of radio channels scanned in a normal hunt sequence and a second group of radio channels scanned in a comprehensive hunt sequence. When the control channel of a base station is changed, a channel permanently belonging to the first group is allocated as a new control channel to the base station whenever such a channel is available. If a channel belonging to the second group has to be allocated as a control channel, it is transferred temporarily to the first group and the change of group is announced through control channels to the mobile radios. A channel permanently belonging to the first group is re-established as the control channel of a base station as soon as such a channel is available and the freed channel is returned to the second group.

Abstract: A method and apparatus providing communications between mobile units and other communications devices, is disclosed wherein, in response to a request to call a mobile unit from an originating communications device, a paging signal is sent via a global communications network and received by a mobile unit. The paging signal contains caller and callee identification codes, which are decoded by the mobile unit. A paging response signal, in the form of a reverse call setup signal, is then transmitted from the mobile unit to the originating communications device. Transmission of the paging signal is preferably stopped when a correspondence condition exists such that the caller and callee identification codes of the paging signal correspond to the caller and caller identification codes of the paging response signal.

Abstract: A method as shown in FIG. 2 for allocating resources in a radio communications system having a plurality of communications resources for at least one receiver and transmitter to communicate over where the communications resources have signal levels which vary due to a multipath environment resulting in periods of poor communication quality over at least one particular communications resource including measuring at a first receiver a parameter indicative of a quality of communications between the first receiver and a first transmitter over a currently assigned communications resource and determining whether to allocate a different communications resource based on the measured parameter in order to effectively reduce periods of poor communications quality between the first receiver and the first transmitter.

Abstract: A method of transmitting messages, where transmitting a message requires a plurality of transmissions, includes communicating control information, e.g., a communication resource allocation request (106) and a communication resource assignment (110), between a controller (101) and a communication unit (104) on a control communication resource (114), such that a working communication resource (115-117) is assigned to the communication unit (104). While the communication unit (104) is engaged in a first transmission of the message on the working communication resource, the control information is communicated between the controller (101) and the communication unit (104) on the working communication resource (115-117), such that the working communication resource (115-117) is assigned to the communication unit (104) for a second transmission of the message.

Abstract: A method and apparatus for controlling scanning of radio channels by mobile stations in a cellular radiotelephone system, including transmitting from a base station a control signal, e.g., a battery savings order, to a group of mobile stations for informing the group of mobile stations that no pages will be issued directed to them for a predetermined period, upon receipt of which the mobile stations begin scanning during the predetermined period radio channels to identify which radio channels have superior characteristics, and storing the channels identified to have superior characteristics for later use as respective access and control channels.

Abstract: A method and apparatus for controlling communication channel access in a communication system (10) determines channel allocations (106) which represent limits on communication channel access and conforms operations of the system (10) to the channel allocations. The channel allocations are determined by dividing a surface which emanates signals from communication units (26) into elemental areas, collecting past traffic data (102) describing past communication channel usage by the communication units (26) located in the elemental areas, generating a traffic model (104) for a future time interval based on the past traffic data, and determining the channel allocations (106) based on the traffic model.

Abstract: A traffic information warning system for conveying traffic information from a traffic advisory site to a vehicle is disclosed. The traffic warning site comprises an emergency vehicle, a roadside hazard, or the like. The system comprises a transmitter adapted for placement at the advisory site and a receiver adapted for placement at the vehicle. The transmitter includes a first oscillator for transmitting a first carrier signal having a first carrier frequency and a second oscillator for transmitting a second carrier signal having a second carrier frequency. The first carrier frequency and the second carrier frequency are spaced apart by a predetermined frequency difference. The transmitter also includes a modulator for modulating both carrier signals with an identical modulating signal reflective of a traffic situation.

Abstract: A method of searching for a signalling channel in a radio system including a mobile exchange, base stations connected therewith, subscriber stations that are connected with the base stations and communicate with the radio system via the channels of the base station, i.e. via traffic channels and non-dedicated control channels. The method includes the following steps: a first subscriber station registered in a first base station listens to a signalling channel of the first base station, and the radio system allocates the signalling channel to a second subscriber station for use as a traffic channel since the other channels of the first base station are busy.