Abstract: A ground-to-air telephone calling system is provided including a computer for receiving an airborne telephone number and a call-back number from a calling party and forming the telephone numbers into a data signal comporting with existing protocol filed in the FCC, an uplink unit for uplinking the data signal to a satellite and a plurality of downlink stations for receiving the data signal from the satellite; a plurality of ground stations corresponding to each of the downlink units for receiving the data signals and passing a call signal identifying the airborne telephone and particular ground station to a corresponding transmit/receive unit for subsequent transmission to the aircraft; a call being initiated from the ground station to the calling party over the public switched telephone network if the aircraft responds to the call signal.

Abstract: In a communications network between fixed stations and fixed terminals, the said fixed stations being linked to the telephony channels while the fixed terminals include an antenna for mutual interaction over distance with independent stations, connection means to the telephony channels of the network are provided, and there is established a telephony relationship between an independent station and another station linked to the telephony channels of the network, by an intermediary of a primary link between the independent station and the connection means, via antennas of a primary fixed terminal. A secondary fixed terminal is chosen on the basis of predetermined selection criteria, and a secondary link is established between the independent station (SA) and the connection means, via an antenna of the secondary fixed terminal.

Abstract: A communications protocol for a cellular network comprised of a plurality of exchanges each of which includes a software package for providing services to a plurality of subscribers. According to this protocol, efficient communication between two exchanges can be implemented through a handshake procedure in which each exchange identifies the capabilities and features of its software package to the other exchange.

Abstract: In the selection of a control channel of a mobile station in a radio zone to which some control channels are assigned as communication channels, the receiving levels of the control channels are sequentially measured and control channel candidates are selected. A check is made to see if a control signal can correctly be received in each of the selected control channel candidates, and if not, the number of signal reception failures in that channel is incremented by 1 in a memory used by the mobile rotation. A channel in which the number of signal reception failures has reached a predetermined value M (an integer equal to or greater than 1) is excluded from the group of control channel candidates, and the other selected control channel candidates are similarly checked to determine whether or not the reception of the control signal is possible in each of them.

Abstract: A method of handover and route diversity in a mobile radio communication which is less time consuming and capable of improving the frequency spectrum utilization efficiency and securing the high quality of service regardless of the moving speed of the mobile station. In the method, a loop transmission line by which each base station is connected with neighboring base stations is provided; a handover information is transmitted through the loop transmission line, where the handover information is relayed by each base station from one of the neighboring base stations to another one of the neighboring base station; and the handover of a communication of a mobile station from one traffic channel of one base station to an idle traffic channel of another base station is carried out by using the handover information transmitted through the loop transmission line. The method can also be applied to a route diversity reception.

Abstract: A method of tracking subscribers (201, 203) in a networked radio communications system (100, 200). The subscribers (201,203) are able to roam among a plurality of coverage areas (104-106) which are serviced by a plurality of transmitters (107-109). The transmitters (107-109) are coupled to a central processor (CP, 110), which accesses a memory device (112) for storing subscriber records and site records. Subscriber records include location information for each of the subscribers, while the site records include a logical representation of geographical relationships between the coverage areas. The method relies on the subscriber to send an inbound message (330) which includes its current location. Further, the CP (110) records a message time for the inbound message, producing a timestamped location, then updates (405) a corresponding portion of the subscriber record with the timestamped location.

Abstract: A multiple access communications system reuses a set of N carrier frequencies in adjacent communications sites to provide more than N minimally cross-correlated frequency-hopping communications channels. A first set of communications channels is associated with a first of the communications sites. No two of the channels in the first set employ the same frequency at the same time. A second set of communications channels is associated with a second of the adjacent communications sites. No two of the channels in the second set of channels employ the same one of the N carrier frequencies at the same time. One or more sets of the minimally cross-correlated channels are further defined so that none of the channels in such sets employ the same frequency at the same time as more than a predetermined number of the channels in another of the sets of the minimally cross-correlated frequency-hopping communications channels.

Abstract: A universal wireless radiotelephone communication apparatus is operative in both a first radiotelephone communication system including a first base station having a wide area of coverage, transmitting radiotelephone signals at a first band of frequencies and in a second radiotelephone communication system including a second base station having a localized area of coverage, transmitting radiotelephone signals at a second band of frequencies higher than said first band of frequencies. The second band of frequencies is optimally selected with an offset of less than twice a frequency contained within said first band. The wireless radiotelephone communication apparatus has a common baseband circuitry for operating with both the first base station covering the wide area and with the second base station covering the local area.

Abstract: In a service area of a mobile telephone system, there are plural base radio stations. A mobile radio station in the service area broadcasts a request signal of zone registration. All the base stations in the service area receive this request signal, measure the field intensity of the signal, and transmit the value of the measured intensity to the mobile radio station. The mobile radio station transmits a response signal to a base radio station where the field intensity is the highest. This response signal is reported to a radio channel control unit where the contents of the zone register is revised in accordance with the reported response.

Abstract: In a mobile radio communication system in which a plurality of base stations, each having at least one communication channel, are arranged in a service area, and communication between mobile stations and the base stations is performed by using the communication channels, a base station coverage area control system includes noise sources. The noise sources are either arranged inside base stations or inside the service area to be located around the respective base stations. The noise sources generate noise having the same frequency as that of a communication signal from each of the base stations or at the selected frequency of one of the base stations. The coverage areas of the base stations are controlled by transmitting the controlled noise from the noise sources.

Abstract: The radio transmission system includes at least one base station (RA or RB) and at least one satellite station (M1, . . . , M7) situated in a coverage zone (ZA, ZB) of the base station in which the base station can send information to a satellite station by a down transmission channel (F.sub.RAM), while one transmission channel is used in which the satellite stations are authorized to transmit. For establishing a group call at the request of a satellite station, the base station allocates a group call channel to the requesting station so that exchange of information can take place directly between the mobile stations which are included in the group call.

Abstract: A control channel monitoring system is for a mobile communication system in which base stations independently control radio zones which are arranged in a cellular array. A mobile station accesses the base station using at least one control channel. Each of the base stations constantly transmits using the control channel in common according to a time division multiple access. A voice signal is transmitted between an arbitrary base station and the mobile station according to the time division multiple access via a speech channel. The control channel monitoring system includes a monitoring part for carrying out a monitoring operation in which a transmission quality of the radio zones is monitored by monitoring the control channel. A selection standard is obtained for the radio zone as the mobile station moves. A silence judging part determines whether the voice signal indicates a silent state based on a level of the voice signal.

Abstract: When remote control data has been input during calling in analog mode, a mobile radio communication apparatus according to the invention outputs a predetermined first voice frequency signal indicative of the remote control data and transmitting the signal to a radio link, and outputs the first voice frequency signal. Further, when remote control data has been input during calling in digital mode, the mobile radio communication apparatus outputs message data indicative of the remote control data and transmitting the message data to a radio link, generates a second voice frequency signal corresponding to the input remote control data and also the first voice frequency signal, and outputs the second voice frequency signal before the message data is transmitted.

Abstract: A channel assignment system assigns channels to various cells by the optimal partitioning of the available radio frequencies into non-overlapping sets, the optimal grouping of co-user cells, and the best assignment of the former to the latter. The objective is the maximization of traffic handling capacity which, given the multitude of cells, is expressed as the maximization of a bottleneck capacity ratio. The capacity ratio for a cell is defined as the ratio of the number of radio frequencies assigned to the cell over the number of radio frequencies needed to meet blocking probability requirements. The solution to attain an optimal non-regular channel assignment is decomposed into two mathematical programs designated a Master Program and a Subprogram. These are solved iteratively with assistance from a channel set augmentation technique impelmented between solutions of the Master and Subprogram.

Abstract: The present invention provides a method for transmitting information on a communications channel, e.g. , a digital control channel between a base station and a mobile station in a cellular system. The method includes the steps of grouping the information into a plurality of information elements, providing at least one change flag to indicate whether the value of at least one of the information elements has changed and transmitting the change flag and the information element over the communications channel.

Abstract: A satellite based paging communication system includes at least one satellite that communicates paging information to at least one terrestrial receiver some of which transmit an acknowledge signal so that message reception may be verified and satellite traffic controlled.

Abstract: A wireless communication system including a repeated pattern of cells, in which base station transmitters and user station transmitters for each cell may be assigned a spread-spectrum code for modulating radio signal communication in that cell. Radio signals used in that cell are spread across a bandwidth sufficiently wide that both base station receivers and user station receivers in an adjacent cell may distinguish communication which originates in one cell from another. Adjacent cells may use distinguishable frequencies and distinguishable codes, but it is sufficient if adjacent cells use distinguishable frequencies and identical codes. A repeated pattern of cells allows the codes each to be reused in a plurality of cells.

Abstract: A cellular or non cellular radiotelephone system consisting of a plurality of base station radios at one or more radio base station sites including method of connection of such base station radios to the Mobile Switching Center by the use of standard public telephone circuits whereby connections on these public telephone circuits are established only when required to provide communications to a mobile subscriber served by the radio base station.

Abstract: A cellular mobile communication system in which each of one or more cells is provided with a base radio station, and mobile terminals communicate with the base radio stations. Base radio stations (21, 22 and 23) are connected to a central base station (100) by optical fibers. The central base station is connected to a mobile switching center (50). Each of the base radio stations is provided with an O/E converter (201) and E/O converter (207). The O/E converter converts a optical signal containing speech signals and a call connection control signal into RF signals. The E/O converter (207) converts RF signals, received from a mobile terminal (11) via an antenna (204), into optical signals and transmits the optical signals to the central base station.

Abstract: A manually-movable, portable, cellular-system signal-strength analyzer for measuring, recording and displaying geographically-located, downlink, cellular-communication-channel signal strengths in non-vehicular pedestrian areas and also inside buildings. The analyzer has a cellular-telephone scanning receiver housed within a backpack that is worn by a human operator who traverses the areas to be analyzed. A height-adjustable antenna mast formed from a set of telescoping tubes is fixed to the exterior of the backpack. This mast supports a self-resonant antenna of fixed length whose elevation height may be varied to determine signal-strengths at different pedestrian heights. The backpack also houses a controller. A laser rangefinder which has a built-in compass inputs data to the controller concerning the geographic locations of various points traversed by the analyzer. An arm-held computer is also connected to the controller.

Abstract: Apparatus operable with different cellular telephone systems and signalling protocols is described. Signalling messages, both data messages and supervisory related signals between a cellular telephone microcontroller (4) and a base station are transferred via a baseband signalling circuit (10). The baseband signalling circuit is operable to employ different signalling protocols, the protocol being selected by control bits provided from the microcontroller to the signalling circuit. In a preferred embodiment, the signalling protocol selection is made between an AMPS/TACS signalling protocol and a NAMPS/NTACS subaudible signalling protocol.

Abstract: A cellular telephone system includes a packet-switched digital data communication subsystem overlaying a circuit-switched (e.g., voice) communication subsystem, with voice and data services sharing the same voice channels. The voice communication subsystem provides voice services independently of the operation of the data communication subsystem. On the other hand, the data communication subsystem monitors use of the voice channels for voice communication, and, in response thereto, temporarily allocates one or more of the available voice channels for data service. In a preferred embodiment, each data basestation transmits, from time to time, an available-channel signature to identify those, if any, of the data-allocated channels that are not then being used to transmit voice or data.

Abstract: A method and system of communicating between moving participants such that each participant is provided with a first time slice and a respective priority listing containing the name of each participant once only, each participant thus having the top priority for one first time slice only. Also allocated to each participant is a second time slice during which he must transmit his identity as well as the identities of all his near neighbors within a radius R thereof. For each participant A there is stored the identity of all near neighbors B(A) and all far neighbors C(A) being within a radius R of his near neighbors B(A) and who are not also near neighbors B(A) of A. During each first time slice, any participant having a higher priority for the respective first time slice than all of his near and far neighbors may transmit data including the identities of at least those of his near neighbors who became near neighbors since his previous transmission.

Abstract: An RF communications system for providing wireless telecommunication service to sixteen contiguous geographic sectors or cells. The system includes an antenna array having a plurality of antenna sites located at the corners of contiguous geographic sectors. The central antenna site has four directional antennas. The four corner towers each have three directional antennas. Each directional antenna illuminates an entire sector. The location of the antenna sites and the allocation of a frequency group for each sector minimizes RF interference.

Abstract: In a trunked communication system that supports roaming communication units, communication capabilities in support of the communication activities of the communication unit may be varied from system to system in a controlled manner. This control may be initiated at the instance of the communication unit itself, on a system by system basis (wherein each system maintains a data base and/or retains the capability of contacting a home system for the communication unit), or by a hub that interconnects with each of the trunking systems and which either maintains a data base of preauthorization information or that contacts home systems in order to obtain authorization information.

Abstract: A process for assuring secure communication over a radio link and apparatus to perform the process includes a scrambler-descrambler installed at a multiple line input multiple line output telephone switch. Individuals equipped with compatible scrambler-descramblers can place calls to the switch and automatically transmit unique identity code information which, if recognized, opens an audio circuit and connects an available output telephone line. The individual can then place a telephone call to third party and all audio transmission over the radio link will be scrambled. Scrambled audio signals received at the switch are descrambled and passed to the third party. Audio signals received at the switch from the third party are scrambled and transmitted to the individual whose instrument descrambles the signal.

Abstract: A satellite based paging communication system comprises at least one satellite capable of communicating the paging information to at least one terrestrial receiver some of which are capable of transmitting an acknowledge signal so that message reception may be verified and satellite traffic controlled.

Abstract: A dual mode cellular radio communication apparatus having a received signal strength measuring function is disclosed. The measured strength of the signal may be corrected when the apparatus operates in the digital mode. The value of corrected strength may be used for indicating the received signal strength to a user of the apparatus and for reporting the received signal strength to a base station. Similarly, the measured strength of the signal may be corrected for indicating the received signal strength to a user of the apparatus when the apparatus operates in the analog mode.

Abstract: A method of tracking mobile stations in a cellular network. A mobile station will report to a base station only when the mobile station is turned on and only after having made a minimum number of intercellular movements. When communications with a mobile station is desired, the mobile station is searched for only in the neighborhood of the most recent current cell, which is the last cell from which the mobile station reported to the base station.

Abstract: Methods for carrying out an authentication check in a mobile telephone system in which an authentic base station serves a plurality of mobile stations. A prior method carried out a unidirectional check from the base to a calling mobile, permitting a false base to carry out a false authentication check by collecting a number of so-called RAND-Response pairs. To avoid this problem, another unidirectional, base-to-mobile, authentication check and an authentication check from the mobile to the base are carried out. In one embodiment, only the bi-directional authentication check is carried out.

Abstract: The invention relates to a method of controlling, in a cellular mobile radio communication system, the output power of radio signals transmitted from a transmitter to a receiver located in the same cell as the transmitter.

Abstract: In a two-way interactive communication video network having a network switching center for point-to-point communications between subscribers at different geographic locations, a local base station configuration is provided for facilitating low power battery operated portable subscriber units. The local subscriber units surrounding a base station are adapted for multiplex transmission of digital messages synchronously related to a broadcast television signal for system coordination. Digital messages are transmitted from the local subscriber units to the base station data processing facility through a set of receive only cell site subdivision zones distributed over the base station transmitter geographical range, which communicate with the base station data processing facility over a communication link such as wired cable. Messages are compiled and relayed by satellite to a network switching center transmitter site for nationwide point-to-point communications.

Abstract: In order to provide for a mobile communication network of a cellular type a transmission power control system capable of keeping a signal quality constant, an average bit error rate y is measured on a receiving side in connection with a communication channel being in use (step 100). If the average bit error rate y is not greater than a first rate threshold value LV1, transmission power is decreased by a predetermined amount on a transmitting side (step 102). If the average bit error rate y is not less than a second rate threshold value LV2 which is greater than the first rate threshold value LV1 (step 103), the transmission power is increased by the predetermined amount on the transmitting side (step 104). Preferably, an average reception level is additionally measured to adjust the transmission power when the bit error rate is less or greater than the first or the second rate threshold value.

Abstract: A radiotelephone communication system is provided, in which radio communication channels including control channels and a plurality of communication channels are set between a plurality of base stations and a plurality of mobile stations provided within radio zones of the base stations, an outgoing call and an incoming call are controlled and the communication channels are designated via the control channels, a telephone conversation is made via the communication channels, channels of different frequencies are allocated to adjacent radio zones of the radio zones, each base station includes a circuit for detecting receiving electric field intensity of mobile station and the channel, the base station and operation of radio transmitter and receiver of the mobile station are set such that, when the mobile station is moved between the radio zones, the mobile station is constantly connected to the base station whose communication state is satisfactory.

Abstract: A method for carrying out a location updating from a mobile cellular radiophone system, such as a DECT system, to another cellular radiophone system, such as the GSM mobile phone system.

Abstract: A cellular switching system and architecture is described in which the switching associated with a call originated within one cell but now serviced within another cell is distributed among base stations which are interconnected with each other through a local area network or a packet switch. The routing procedure associated with the point of origin for a given call is stored in the memory of a switch of public switched telephone network. As an active subscriber crosses a cell boundary, the switch routes all packets of information for the given call to the originating base station for the duration of the call. Importantly, each base station then forwards each packet to the subscriber's current base station via the local area network or a packet switch.

Abstract: A resynchronization method for use in a communication system, such as a second generation cordless telephone system 800, begins by determining that synchronization has been lost by a receiving unit (830). The receiving unit than mutes any transmit data and generates zero data which is combined with a pattern generated by pattern generator (812). The transmission is then received by handset (830), which detects the pattern generated by pattern generator (812) using pattern detector (850). Pattern detector (850) then generates a pattern detected signal (852) which causes handset (840) to also stop sending data and generate a pattern accompanied by zero data. Base station (830) detects the pattern and again generates another pattern accompanied with zero data which is transmitted to handset (840). Handset (840) after decoding the pattern for the second time begins to resumes the normal transmission of data to base station (830).

Abstract: In a system for monitoring and collecting data on the viewing habits of television viewers or radio listeners, to enable operators of networks or television stations, programmers and advertisers to determine the numbers of viewers watching particular programs, a portable personal data collection device comprises a detector for providing a station identifier identifying the particular broadcast signal being received by the receiver, a clock for providing a signal representing time, a memory for storing data, a cellular telephone module for communicating with a central location, a control for the cellular telephone module, and a microprocessor. The microprocessor stores in the memory data comprising the station identification, and the time at the beginning and end of receiving signals from that station. The control is arranged to control operation of the cellular telephone module to transmit the stored data to the central location.

Abstract: A system for separating mixed signal sources by processing a received signal through the combination of a beamforming network and an adaptive Herault-Jutten network. The conventional Herault-Jutten network is useful for separating independent signals that have been linearly mixed, but cannot separate a mixture of several independent signals in free field conditions because of the propagation time delays between sources and sensors. The system of this invention combines planar beamforming techniques with a conventional HJ network to adaptively distinguish among signals having delays introduced by the propagation medium. A new sensor filter scheme is introduced to eliminate beamforming variation with frequency over the band of interest. The resulting system has application to adaptive interferer rejection and to acoustic and cellular communications receivers.

Abstract: In a communication system network that includes a central controller that is operably coupled to a processing multiplexer switch, system configuration information may be transferred between the central controller and the processing multiplexer by establishing a communication link between the central controller and the processing multiplexer switch. Once the link is established, the central controller requests site interface configuration information from the processing multiplexer. The site interface information indicates the status of the interfaces and the type of site coupled to the interface. Once this has been relayed to the central controller, the central controller determines the particular type of site coupled to the site interface. If the site is of a first site type, the central controller assigns the link between the site and the site interface a unique link address.

Abstract: A cellular communication system hops both signalling channels and traffics channels in a common hopping sequence. To obtain system information from the frequency hopping signalling channel, a subscriber unit waits on a predetermined frequency, or carrier, until the frequency hopped signalling channel arrives at the predetermined frequency. Once arrived, the subscriber unit obtains synchronization information, and information related to the hopping sequence, from the signalling channel during the hop. The subscriber unit may then hop in tandem with the system, obtaining further system information in subsequent hops. The cellular communication system supports mobile assisted handoff (MAHO) by allowing a subscriber unit to measure signalling channel of neighboring cells in a similar manner, and using the measurements to assist in communication handoff from a source cell to a neighboring cell.

Abstract: A method of establishing a telecommunications call connection in a cellular wireless system. If a mobile station is near the border between areas served by two mobile switching center (MSCs) then the mobile is paged from appropriate base stations of one of the MSCs while the other MSC is alerted to listen for page responses from the paged mobile station. Advantageously, the number of paging orders is substantially reduced thus increasing the call handling capacity of the base station systems. The second MSC is initialized to be prepared to process a page response from the mobile station being paged from the base stations of the first MSC. Advantageously, this permits straightforward recognition of a valid paging response and a record of the call with which that response is associated.

Abstract: A radio environment measuring system for measuring a propagation state of radio waves includes: a fixed radio apparatus provided in a base station; a mobile radio apparatus operatively connected to the fixed radio apparatus through the radio waves; the mobile radio apparatus having a repeater unit for receiving a transmission signal from the fixed radio apparatus and sending a returned signal to the fixed radio apparatus; and the fixed radio apparatus having a transmission/reception unit for sending the transmission signal to the mobile radio apparatus and receiving the returned signal from the mobile radio apparatus, and a measuring unit for measuring the propagation state of the radio waves, for example, a propagation distance, direction and reception intensity of the radio waves between the fixed radio apparatus and the mobile radio apparatus based on the transmission signal and the returned signal.

Abstract: In a radio transceiver having a microcomputer (11) that controls various hardware-dependent components (220) and functions (240) that form a plurality of radio control processes, a method and apparatus for executing the radio control processes includes providing the microcomputer (11) with a plurality of virtual sources (272). The virtual sources (272) are for collecting and distributing data (440) generated by the hardware-dependent components (220) and functions (240) in the radio transceiver. A plurality of hardware-independent tasks (292, 392) for executing the radio control processes are also provided by the microcomputer. A distribution controlling interface standard (228) for controlling which hardware-independent task (292, 392) will receive from which virtual source (272) is further provided by the microcomputer (11).

Abstract: Improved automatic gain control for an amplifier is obtained by controlling the size of a null zone in a drive signal for the amplifier. The size of the null zone is controlled by estimating strength of an interference signal, and dynamically varying the size of the null zone based on the estimated strength of the interference signal. As a result, the amplifier rarely saturates, regardless of signal strength. The invention is useful to reduce the harmful effects of jamming or interference.

Abstract: A mobile station, operable in a mobil communication system that executes a location registration processing by using the channel quality of a base station and an information concerning a base station the mobile station includes a base station information memory unit for storing therein information concerning a plurality of base stations and an amount in which the channel quality of the base station is changed with time and a location judging unit for judging on the basis of the amount in which the base station information is changed with time and which is stored in the base station information memory unit whether or not location registration processing is to be executed indicating a location in service area.

Abstract: A centralized telephone interconnect system for an RF multisite system. Multiple publicly trunked radio sites are networked together through a multisite switch. The centralized telephone interconnect system couples a series of land telephone lines to the multisite switch so that a mobile radio user anywhere in the multisite system is accessible to telephone communications. The telephone interconnect system supports individual calls, group calls and dispatcher console calls. The system includes a centralized interconnect controller that supervises the operation of the interconnect system and a telephone line switching network that connects telephone lines to the multisite switch. A centralized telephone interface module within the multisite switch connects to the centralized interconnect controller and switching network.

Abstract: A self-contained cellular emergency roadside call box is disclosed without the use of external telephone lines. The call box is solar powered with battery storage and comprises a controller coupled to a cellular transceiver. The controller is also coupled to a solar array and battery which is recharged through the controller. The call box communicates through a radio-telephone link established by cellular transceiver to a cellular telecommunication system. The cellular telecommunication system includes a call site controller and mobile telephone switching terminal. Each call box comprises a plurality of status subcircuits for monitoring conditions such as battery condition and transmitter status. The call box communication and the status are processed by a micro processor which generates appropriate commands required by the cellular transceiver. Information can be transmitted bidirectionally between each of the call boxes and the communication applications processor.

Abstract: The present invention is directed to novel implementation techniques which makes orthogonal CDMA practical in an a short range mobile telephone environment where significant multipath fading exists. Specifically, novel techniques for establishing the time base, frequency, and power control necessary to achieve orthogonality. Use of a high power sounding burst on the outbound link permits: 1) antenna diversity selection to minimize the probability of a faded condition, 2) local frequency locking at the subscriber terminal which avoids the requirement for a costly precision frequency standard, and 3) essentially instantaneous inbound power control based on the outbound receive signal level. This is effective since time division duplexing is used and both transmission and reception take place on the same frequency. With the short frame structure and unique placement of the sounding burst the correlation between the outbound and inbound path losses is very high.

Abstract: The present invention relates to systems and methods for allocating channels in a radiotelephone system wherein local estimation of interference for a potential new connection is achieved by measuring interference on the available downlink channels at a plurality of locations within a cell. The measurements can be made, for example, by already connected mobile stations, mobile stations which are not connected, fixed measurement stations or any combination thereof.