Abstract: A subscriber (410) to a radio communication system manages information needed to monitor for potential server sites during an ongoing communication session. Upon switching server sites during an ongoing communication (520, 530, 540, 550), the subscriber uses a modified neighbor site list for subsequent monitoring for potential server sites (570). The modified list is generated from the original list without benefit of new information downloaded from an external source, by replacing information representing the new server site with information representing the old server site (560).

Abstract: A subscriber unit (300) receives an inbound transmission feedback message regarding at least one inbound transmission made by the subscriber unit (401). Based on the inbound transmission feedback message, the subscriber unit updates at least one site ranking factor corresponding to the subscriber unit's current site (402). In another embodiment, a site (600) determines the signal quality information for at least one inbound transmission made by a subscriber unit (702) and, when the signal quality information is unfavorable, transmits a message instructing the subscriber unit to update at least one site ranking factor (704). The subscriber unit can compute new site rankings based on the site ranking factors and select, if necessary, a new site having a preferable site ranking (403-405).

Abstract: A method for setting up a link for a call in a narrowband cellular communication system (100) includes, in a selective call radio (106), determining a transmitter identity and a signal quality (310, 315) of a strongest monitoring channel of a set of N monitoring channels, each of which has propagation characteristics that closely represent propagation characteristics of one of N groups of channels, and transmitting a report (330) of the transmitter identity and a signal quality of the strongest monitoring channel; and includes, in a system controller, receiving the report (405), choosing an available outbound resource (425, 430) in a first group of the N groups of channels, wherein the first group includes the strongest monitoring channel, and establishing the call (555) using the chosen available outbound resource at a bit rate that is a highest bit rate that is compatible with the signal quality.

Abstract: An object of the present invention is to reduce the control time required when a channel handover is performed in a mobile communication system. The conventional system has such shortcomings that a long time is required for re-designating a channel when a channel handover procedure results in failure. Particularly, in the common access type system, there is such a problem that since a channel handover is required to be performed several times during a channel handover procedure, an extra time is required for performing the handover procedure. The present invention has a plurality of base stations for covering the service area, and a mobile station for performing a communication with the base stations through radio channels.

Abstract: In a cellular radio communication system including a plurality of base stations and a plurality of terminals in which one cell is divided into a plurality of sectors, each of the base stations transmits and receives control information by an omnidirectional beam and transmits and receives traffic information by a directional beam. Alternatively, each of the base stations transmits and receives control information by a directional beam with a time difference of the same control information in a plurality of sectors within one cell and transmits and receives traffic information by a directional beam.

Abstract: A method is disclosed whereby a cellular network's Broadcast Control Channel Allocation BA lists are modified so that the mobile terminals in the network can measure downlink interference on predetermined Broadcast Control Channel Frequencies BCCH frequencies. These measurements can be made in all cells where the mobile terminals are located and then reported back to the base station. The base station maps the reported measurements to corresponding cells, and uses the mapping to produce a cell-to-cell interdependency matrix. For the preferred embodiment, the matrix describes the difference in path loss between cells. This path loss information can be used to derive downlink Carrier to Interference Ratio C/I Carrier to Adjacent Ratio or C/A ratios between cells (or combinations of those ratios) and thus an estimate of the downlink interference in the frequencies assigned to the same cells.

Abstract: In a base station of a wireless telecommunications system for communicating with mobile terminals, a radiowave is received on a transmission channel and compared in field intensity with a threshold value. The threshold value is considered to be received while unused, in view of the receiver characteristics of the base station, and the base station selects a channel with the field intensity below the threshold value as an idle channel to form an idle channel list. To communicate with a mobile terminal, a channel is selected at random among the channels listed in the idle channel list. This makes it possible to reduce the probability that the same channel as that of a contiguous base station, will be selected and enables the channel selection to be achieved quickly and positively in the base station of the wireless telecommunications system sharing transmission channels of the same frequency band as that of contiguous base stations.

Abstract: Downlink interference on highly uplink interfered allocated frequencies and corresponding candidate frequencies for reallocation is estimated. The estimates are then utilized to narrow the number of candidate frequencies and highly interfered frequencies to be considered for reallocation. The estimation of downlink interference on a selected frequency is made by having a mobile station measure signal strength on the control channel frequencies of neighboring cells which are allocated that selected frequency. From these measurements, a signal strength histogram is generated for each neighboring cell, and a percentile value is calculated for each histogram. These percentile values for the neighboring cells, minus a selected delta value (where appropriate), are then summed to generated a value estimating the downlink interference for the selected frequency. The selected delta value is applied where the selected frequency in the neighboring cell comprises a traffic channel frequency.

Abstract: A method and a system assign a speech channel difficult to cause interference in a radio mobile station and in both in the radio mobile station and a radio base station. A channel number is set, a usability judgment threshold value is read out to be compared with a reception field intensity of a selected speech channel. If the reception field intensity is relatively high, a preference of the speech channel is lowered. If the reception field intensity is relatively low, the channel is notified to the radio mobile station. If interference is present in the radio mobile station, the preference is again lowered and otherwise, process of establishing call connection is initiated.

Abstract: The establishment of digital connections is avoided if the power level compensated uplink signal strength transmitted by a dual-mode mobile station is below a threshold value. In such cases, a dual-mode mobile station is instead preferably connected to an analog traffic channel. The threshold value can be selected to provide a statistically acceptable probability that the digital connection will be successful. Different threshold values can be used for different connection situations to take into account the different techniques used to determine a best serving base station.

Abstract: The present invention relates to a method and a mobile station for use in a communications network of GSM type, or a type derived from GSM. According to the invention the identification (307) of an unidentified BCCH carrier is initiated in the mobile station when said BCCH carrier on the basis of measured signal strengths is foreseen (321) soon to be one of the strongest BCCH carriers with regard to the signal strength average value over a measuring period. The delay from the point in time when the BCCH carriers becomes one of the strongest BCCH carriers, taking into account the signal strength average values over a measuring period, to the point when the BCCH carrier has been identified can in many cases be reduced or in some cases eliminated. Thus the mobile station can report measurement data for the BCCH carrier to the network at an earlier stage so that handover to the corresponding cell may be made faster.

Abstract: In a mobile communication system comprising a control station, a plurality of base stations each for defining a service area, and a plurality of mobile stations, in a standby mode, each of the mobile stations monitors reception levels and interference levels of traffic channels from the base stations and transmits first priority lists of traffic channels via the base stations to the control station. Also, the control station renews and stores second priority lists of traffic channels for the base stations in accordance with first priority lists of traffic channels from the base stations and further transmits these second priority lists to the base stations upon receipt of a request for call connection. In a call connection mode, each of the base stations allocate optimum traffic channels to the mobile stations under the control of each of the base stations in accordance with one of the second priority lists of traffic channels.

Abstract: A cordless telephone set having a base unit and handset units and enabling communications using a channel selected from a plurality of channels. The cordless telephone set comprises apparatus for storing a specified number of channels selected by the telephone apparatus and storing historical channel use data. Whether or not a channel is unused is determined and channels used with high frequency with the data stored in the first storage are changed to those used with low frequency according to the historical use data. Channels that are stored are progressively specified prior to a start of call and a specified channel is selected, if it is determined that the channel is an unused one.

Abstract: In order to detect a base station for a call connect or handover in almost real time while a mobile communication apparatus is moving, the measured base station selecting unit 110 refers to the measured base station table 101 and selects a next base station to be measured. The measuring unit 111 measures the signal quality for the selected base station. The measuring result judging unit 112 compares the measured signal quality with a predetermined threshold and judges whether the measurement of the signal quality of the present base station should be continued or whether a switch to measuring a next base station should be performed. The periphery base station table updating unit 113 rearranges the content of the periphery base station table 102 in descending order of signal quality, based on the information stored in the periphery base station table 102 and on the averages of the signal quality measurements.

Abstract: A method and system for locating control channels, particularly digital control channels, are described. By grouping the channels which are candidates for carrying supervisory messages in blocks indicative of their relative likelihood for being used as control channels, a mobile station can begin its search for a control channel with channels which are most likely to actually be control channels. Placing location information on other channels allows the mobile station to be redirected to a control channel when it reads one of these other channels. Similarly, by placing information describing the location of a control channel in a message associated with handoff, a mobile station avoids the necessity of having to relocate a new control channel associated with the base station to which the mobile has been handed off.

Abstract: A system and method for providing dynamic channel assignments in a microcellular system surrounded by a macrocellular system. The method characterizes the RF environment of the microcellular system and the macrocellular environment. Channels are then ranked according to the signal-to-impairment ratio computed from the measured RF characteristics. A call is assigned to a highest ranked idle channel. All active calls are monitored to ensure voice quality and call performance by forcing hand-off to another channel before degradation occurs. In another embodiment, the system is self-configurable to changes in the macrocellular configuration by including remote power adjustment and remote Supervisory Audio Tone assignment functionality.

Abstract: A method of selecting a voice channel in a radio telecommunications network. The method begins by seizing a first digital traffic channel (DTC) having a carrier signal strength (C) and an interference strength (I), and calculating an expected ratio of the carrier signal strength to the interference strength (C/I) on the first DTC. From this calculation, it is determined whether the first DTC is disturbed. This is followed by utilizing the first DTC for a call upon determining that the first DTC is not disturbed, and seizing a second voice channel upon determining that the first DTC is disturbed. The second voice channel may be a second DTC or may be an analog voice channel (AVC). If a second DTC is seized, the C/I is determined for the second DTC, and the DTC with the higher C/I is retained. If the second DTC is also disturbed, another reselection and comparison may be performed. Reselections continue until a channel with good C/I is found, or a maximum number of reselections is performed.

Abstract: Optimal handover margins in a cellular communication system (100) are determined by computing a power budget (701) for each base station/neighbor combination in the communication system (100) and determining a probability distribution function (703) for each base station/neighbor combination in the communication system (100). Once the probability distribution function for each base station/neighbor combination is known, optimal handover margins are determined by maximizing communication system traffic over all base stations while at the same time holding call quality to acceptable levels.

Abstract: A communication channel is dynamically assigned to a mobile station in autonomous decentralized channel assignment in TDMA/TDD communications system. An interference detection criterion is determined depending on a signal strength of a call request signal. It is determined whether interference occurs in a transmitting time slot relative to the interference detection criterion in a selected channel, and further determined whether interference occurs in a receiving time slot relative to a predetermined interference detection criterion in the selected channel. When it is determined that no interference occurs in the selected transmitting and receiving time slots, the selected channel is assigned to the mobile station.

Abstract: Methods of and corresponding apparatus for scheduling messages on an operating channel (223) in a selective messaging system (200) for a messaging unit (235) include scheduling a first message, including a channel priority indication (511), addressed to the selective messaging unit on a first channel, and then scheduling a second message for the selective messaging unit on a second channel (225) selected as an alternative operating channel. Analogously at the selective messaging unit a method of selecting an operating channel includes monitoring the first channel for a message addressed to the selective messaging unit; detecting as part of the message the indication; and responsive thereto discontinuing monitoring the first channel and then scan for the second channel.

Abstract: In a telecommunications network, a method and apparatus for allocating channels include making signal quality measurements for channels that are in use or available for use and for channels that may become available for use. Spectral efficiency is enhanced by considering the exclusionary bandwidths associated with combiner filters tuned to currently allocated frequencies.

Abstract: A method and system for use with wireless communication systems having a cellular architecture with at least a first and a second cell. The method and system provided ensure near uniform capacity and quality of channels within the second cell via the following steps. The noise signal power in unused data channels within the second cell is monitored. When a request for channel access is received, a determination is made whether the request for channel access is either a request for handoff from the first cell into the second cell, or not. In the event that the request is not a request for handoff, a determination is made whether idle channels exist to satisfy the request for channel access. In the event of a determination either that the request for channel access is a request for handoff, or both that the request is not a request for handoff and that idle channels exist to satisfy the request, a measured received signal power of a mobile unit subscriber unit making the request is determined.

Abstract: The method of selecting one of the resources for servicing a call includes determining a load level and a relative load capacity for each of candidate resources. The relative load capacity is based on a ratio of each candidate resource load capacity and total load capacity of all candidate resources. The candidate resource is selected by a relative ranking based on multiplication of each resource with each respective load level and each relative load capacity determination.

Abstract: A mobile station for measuring signal strength of a set of channels includes a synthesizer, a controller and a transceiver. During an idle period, the controller loads channel data of the set of channels contained into a memory block in the synthesizer. The synthesizer automatically selects the channel data for each channel stored in the memory block and generates a frequency signal corresponding to the selected channel data. The transceiver measures the signal strength data of the selected channel data and stores the signal strength data in a buffer. Once the signal strength data for the entire set of channels has been measured and stored in the buffer, the transceiver transmits the signal strength data to the controller. The set of channels may include a set of channels from a neighbor cell list or measurement order transmitted by the radio base station. The set of channels may also include a set of control channels that the mobile station measures at power-up.

Abstract: A distributed processing telephone system for providing "plug-and-play" capability. In particular, a key telephone system comprises a plurality of telephone sets. Each telephone set is coupled to a least one common communications channel, or telephone line, and includes at least one tunable RF modem. There is no key service unit (KSU). That is, the system is KSU-less. Resources of the telephone system are allocated using a peer-to-peer protocol. For example, as each telephone set is newly added to the system, the new telephone set adaptively determines its own allocation of resources, e.g., intercom numbers, etc. During operation, each telephone set requests the appropriate resources from its peers.

Abstract: A method and system for locating control channels, particularly digital control channels, are described. By grouping the channels which are candidates for carrying supervisory messages in blocks indicative of their relative likelihood for being used as control channels, a mobile station can begin its search for a control channel with channels which are most likely to actually be control channels. Placing location information on other channels allows the mobile station to be redirected to a control channel when it reads one of these other channels. Similarly, by placing information describing the location of a control channel in a message associated with handoff, a mobile station avoids the necessity of having to relocate a new control channel associated with the base station to which the mobile has been handed off.

Abstract: Each base station in a cellular telephone system includes a signal strength measurement device operable to tune to and make signal strength measurements on not only the frequencies allocated to other cells, but also on its own allocated frequencies. Measurements are made by the device on those of its own frequencies having idle traffic channels to obtain an indication of injected uplink interference. An interference penalty is then assessed against the measured uplink interference for those frequencies having more than a threshold number of idle traffic channels. The adjusted measurements for the frequencies allocated to the cell are then sorted in relative order of idle traffic channel (adjusted) measured uplink interference from a least (adjusted) interfered frequency to a most (adjusted) interfered frequency. An idle traffic channel is then selected for assignment at either call set-up or hand-off from the least (adjusted) interfered frequency.

Abstract: In a wireless communications system (20), a beacon having a first radiation pattern (28) covering a portion of a subscriber service area (34) covered by a base station is transmitted. A subscriber (36) reception quality is then measured to produce a first beacon quality measurement (210). Thereafter, the first radiation pattern is changed to a second radiation pattern (32, 212), and a subscriber reception quality of the beacon transmitted with a second radiation pattern is measured to produce a second beacon quality measurement (214). In response to the first and second beacon quality measurements, a traffic channel radiation pattern (32) is selected (218), wherein such radiation pattern covers a portion of the subscriber service area. In a preferred embodiment, the beacon carrier frequency is the same as the traffic channel carrier frequency.

Abstract: 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.

Abstract: A channel is selected first, and immediately the received field is measured and digital Manchester code data are searched for. The digital signals are 100% Manchester code signals. After a predetermined first delay, the carrier level is tested and recorded in a memory. The smallest value among the various recorded values is selected; a fixed value is added thereto; and the value thus obtained is used as a threshold value for the level test. If the channel is free, another channel is selected. If the channel is occupied, one will wait for a second delay period, after which a test is performed to know whether data have been recognized. If nothing has been recognized, another channel is selected.

Abstract: Cells in a radio telephone scheme are covered by beam-spots generated by multi-beam antenna system. Forward communication channels follow mobile units as they move between beam-spots. Additionally, each cell is divided into zones based on the mobile traffic patterns within the cell. Typically, there will be a high density zone covered by many, small area beam-spots, a medium density zone covered by two or three medium sized beam-spots, and a low density zone covered by one large beam-spot. As the mobile traffic patterns change throughout the day, multi-beam antenna dynamically reconfigures the zone and beam-spot layout for each cell, thereby keeping a nearly optimal zone and beam-spot configuration despite varying mobile traffic patterns.

Abstract: A radio (1) for radio communication supportable with repeaters. The radio (1) has a transceiver (2) for receiving information on either a repeater channel or a talkaround channel. A monitor (3) is coupled to the transceiver (2) to provide output signals indicative of channel strengths of the two channels. The output signals are compared by a controller (4) to provide a selected channel from the two channels. Information is then received by radio (1) on the selected channel. When receiving the information, the controller (4) periodically controls the transceiver (2) to receive on an unselected channel of the two channels. The monitor (3) then provides a new output signal corresponding to the unselected channel for the controller (4) to re-compare and re-select the selected channel.

Abstract: An allocation method and system for allocating a least-interference communications channel between a cellular system and a private radio system within the cellular system. A set of candidate channels are first selected and ordered by the amount of interference present within the cellular system, and a subset thereof is selected. A second set of candidate channels are then selected from the subset and ordered by the amount of interference present in the private radio system environment, and a safe channel subset thereof is selected. That channel exhibiting the least amount of interference is then selected from the safe channel subset as the communications channel.

Abstract: In a multi-carrier system, the pilot carrier which is transmitted between two stations for synchronisation purposes, is re-allocated to a new frequency whenever it is disturbed by noise or a single frequency disturber in the vicinity thereof. A less noisy frequency is selected by means of a specific criterion to be fulfilled, for instance based on signal to noise ratio measurements performed for all carriers in the multi-carrier system.

Abstract: A mobile communication system is provided in which a base station commands a mobile station (or field monitor) to measure the field strength for a specific channel. The mobile station reports the measured results to the base station. The measured results are used in conjunction with base station identification codes to obtain a single representative value which is used to determine what channels can be selected and used by the system. This enables an existing cellular system to be utilized as a first mobile communication system, and makes it possible to construct a second mobile communication system in the same area as the service area of the first system.

Abstract: An apparatus (101, 110) and method for channel acquisition in a communication system (100) provides for selecting a channel, from a multiplicity of available channels (205), and determining whether the selected channel is the properly assigned channel for data and other information to be received by the apparatus (101, 110). The selected channel is monitored for a predetermined or adaptive energy level (210), a predetermined modulation mode (215), for a protocol signal, and for a protocol signal having an identification specifying the particular apparatus (225), such as a protocol frame containing a serial number corresponding to the apparatus. When a protocol signal having an identification specifying the particular apparatus (225) is received, the selected channel is acquired (250) for reception of data and other information.

Abstract: A controller (152) in a frequency hopped spread spectrum system (100) operating to assign a best available frequency hopping sequence among a plurality of sequences to at least one of a plurality of subscriber units (156) having predefined transmission intervals (12) and predefined transition intervals (14) comprises a power detector (50) that estimates a combination of a noise level and an interference level by measuring signal strength during a series of transition intervals for at least one sequence of channels among the plurality of sequences and a processor that computes an average noise and interference level for the at least one sequence of channels and ranks the at least one sequence of channels in accordance with the average noise and interference level computed.

Abstract: In a data communications system operating on a registered data channel and including an infrastructure 100 and a subscriber terminal 115, a method of making a channel exit decision at the subscriber terminal includes: sampling 201 the registered data channel for a time period, preferably a signal time period and a data time each of which may be an adaptable time period to obtain a plurality of quality values, preferably signal values and data quality values; comparing 203, 213 each of the plurality of quality values to a threshold; and initiating 225 an exit procedure, preferably including a quick scan for a possible data channel, when a first number of the plurality of quality values obtained during the time period does not satisfy the threshold.

Abstract: A two-way communications system that provides ubiquitous wireless data communication services, such as throughout the continental United States, by using a network of only a few, widely distributed radio base station (RBS) sites and the existing paging network infrastructure. The paging network infrastructure is used as an outbound link to request data from the remote field units. The outbound page message indicates a time and frequency at which the RBSs can expect to receive data from the field units. A network hub or message operations center (MOC) coordinates the operation of the paging systems and RBSs from a central location. For example, the MOC determines an available HF frequency and time for a particular field unit to transmit, and then issues the request for data to the field unit using the existing paging network infrastructure. The field units make use of paging receivers, and an HF transmitter to report remote data such as a geoposition or other sensor data when requested to do so.

Abstract: A method and apparatus for accessing a communication system relies on the use of varying access probabilities for subscribers or messages of varying priority. A serving infrastructure entity (e.g., a base station) determines access probabilities (e.g., p.sub.hi and p.sub.lo where there are two classes of subscribers) in response to known system parameters like the current rate of access attempts for each priority class of user/message. Values representative of these access probabilities are then transmitted to the subscriber unit(s), for example by use of a system broadcast channel or control channels. These values are then used by the subscriber units in determining when to access an uplink channel. A temporal and/or proportional priority distribution approach is preferably used in determining the access values. As a result of this contention-based prioritization, an expedited access is achieved by higher priority units/traffic, thus increasing their throughput.

Abstract: A method and system for locating control channels, particularly digital control channels, are described. By grouping the channels which are candidates for carrying supervisory messages in blocks indicative of their relative likelihood for being used as control channels, a mobile station can begin its search for a control channel with channels which are most likely to actually be control channels.

Abstract: In a cellular telephone system, mobile station measurements of received signal strength on each reference frequency are made in order to select a cell. At call set-up in or handoff to that cell, a voice frequency is selected by the system to carry the communication. A determination is then made as to whether the antenna used for the reference frequency is the same as that used by the selected voice frequency. From this determination, actions are taken as needed to address concerns over potential differences in broadcast coverage areas for the antennas. For example, an alternate voice frequency using the same antenna as the reference frequency may be chosen. Further, a test broadcast may be made on the selected voice frequency for comparison to the received signal strength on the reference frequency in order to confirm the selection of the cell and use of the selected voice frequency.

Abstract: A method for selecting a channel and a base station in a mobile radio system, the geographical coverage area of which is divided into radio cells, each radio cell including a main base station indicated by an identifier, and at least one of the radio cells including at least one infill base station. In the method, the main base station signals with subscriber stations on a control channel having a downlink frequency for signalling from a base station to a subscriber station and an uplink frequency for signalling from a subscriber station to a base station. Each infill base station monitors the subscriber stations at the uplink frequency of the control channel of the respective main base station.

Abstract: A telecommunication system includes a number of radio base stations connected to a telephone network, the base stations forming a link to the network for a number of cordless telephones. Each base station determines in which of a number of predetermined signal strength bands the signal strength of a signal produced by a cordless telephone and received by the base station lies. If the received signal strength lies in a lower band, the base station stores an indication of the signal, and scans through the communication channels available between the base station and the cordless telephones to determine whether a new incoming signal lies in the highest signal band, or whether by increasing the rank of the band of a stored signal, the highest signal band is reached.

Abstract: A mobile radio communications network is provided with a system for allocating one or more ranges of transmission frequency to the communications network, in order to prevent the network from interfering with received signals of an incumbent radio system. The allocating system may be provided with a device for receiving and monitoring information indicative of the presence and location of incumbent radio stations. A signal level monitoring system monitors signals transmitted from incumbent radio stations to determine the frequency and degree of RF isolation, with respect to a monitoring antenna of the monitoring system, of the stations. The monitoring system includes monitoring antennas, a spectrum analyzer, a device for controlling the spectrum analyzer, and a device for processing and correcting the data produced by the spectrum analyzer.

Abstract: In an optical communication system, wherein light intensity modulation with no carrier is performed using a light emitting diode with linear relation of the drive signal current vs. optical output power over a range which changes with frequency of the drive signal, the input signal is modulated for relatively larger amplification of frequencies higher than a predetermined frequency, above the thermal response frequency of the light emitting diode, than for frequencies lower than the predetermined frequency.