Abstract: Echo canceling method including the steps of determining an Euclidean norm of an echo-replica signal, determining an Euclidean norm of an input signal, determining a gradient step size, correcting the coefficients of an adaptive filter, deriving an updated echo-replica signal, and determining an updated error signal by subtracting the updated echo-replica signal from the input signal.

Abstract: A display-based terminal (101) employs a method and apparatus for dynamically grouping communication units (105-113) operating in a communication system (100). The display-based terminal displays a map (300, 400) to a user of the terminal that indicates, among other things, locations of communication units in at least a portion of the communication system. The terminal receives the user's selection of communication units from the map and an identification of at least one talkgroup with which the selected units are to become members. The communication units may be selected individually, as a group (e.g., using “click and drag” rectangling techniques), or both. After communication units have been selected from the map, the terminal automatically groups the selected units into the indicated talkgroup.

Abstract: A portable data device employs an integrated circuit having a signal processor that receives a power signal from an external source via a power node. A decoupling device is placed between the power node and the signal processor. An energy reservoir is placed in parallel with the signal processor, which acts in concert with the decoupling device to isolate the effects of the signal processor from the rest of the integrated circuit.

Abstract: In a communication system a method for selecting a set of preferences for use during transmission of information to a particular destination anticipates selecting a list of one or more destinations, each destination having a key and a set of preferences, each preference further having a value. A historical database is indexed via the key to retrieve a set of database entries, each entry having a set of preferences, each preference further having a value. The retrieved database entries are filtered in order to identify those entries exhibiting a predefined set of criteria. After filtering, the preference values within the identified database entries are applied during transmission and subsequent processing of the information.

Abstract: A packet delivery method for assuring the delivery of packets in an wireless local area network (LAN) having a service access point (AP) and a plurality mobile user devices, said user devices in communication with each other and with the access point. The access point determines when a destination device is in the sleep mode of operation and stores data packets intended for that device in memory. Thereafter the access point determines when the destination device enters the active mode of operation, delivers the data packets to the destination device and informs the source device of delivery of the data packets to the destination device.

Abstract: A power management technique for use in an wireless communication system having a service access point and a plurality mobile battery powered user devices, user devices in communication with each other and with the access point, power management technique for determining when a user device may transition from an active mode of operation to a sleep mode of operation and further for determining when a user device in the sleep mode of operation should transition to the active mode of operation.

Abstract: A data processing system in which a plurality of processors or other memory access devices operate either synchronously or asynchronously with a memory interface device, which in turn provides access to one or more memory units on a time-division basis. This is accomplished by providing each memory unit a series of time-divisioned access opportunities and controlling the phase relationship between these time-divisioned access opportunities. Accordingly, two or more access devices can address an equal number of memory units simultaneously.

Abstract: A communications device 100 employs an averaging filter 112 at the output of a demodulator circuit 110 to remove unwanted components introduced by in-channel interfering signals.

Abstract: A method used in a communication system (10) having central controllers (14) in communication with a plurality of user devices (12) where synchronizing data (34) and user data (35) are transmitted for a predetermined period of time defining a dwell (30). The method for delivering data to more than one user device (12) simultaneously includes the steps of providing an indicator (34) associated with at least a portion of a dwell indicating that the transmission of user data (35) is directed towards more than one user device (12), and informing the user devices of the repetition rate at which the indicator is transmitted. The user device schedules periods of time during which it is enabled and disabled respectively, based upon the repetition rate of the indicator received such that the user device is enabled and receives the data directed towards more than one user device.

Abstract: A packet transmission system (100) with reduced transmission delays includes a communications controller (110) and a plurality of remote requesting units (112) requesting packet transmission services. Each remote unit (112) sequentially stores transmitted access requests (302) in a memory queue (500) and awaits a resource grant (306) from the communications controller (110). Upon receipt of a granted resource the remote unit (112) will apply the granted resource to the oldest request (502) stored in the queue (500) in order to transmit data (310) to the communications controller (110). A separate and distinct aspect of the transmission system (100) resides within the communications controller (110).

Abstract: User device (12) classes are established in a communications network (100). An access point (10) utilizes a first password to create an encryption key, then generates a plurality of secondary passwords for use by devices (12). User device (12) classes are established by assigning a secondary password to a respective class of users, determining the network access permitted the class, determining the network services provided to the class and finally assigning the secondary password to a device (12') seeking to communicate within the network (100).

Abstract: A method for prioritizing data transmissions in a frequency hopping communication system (10) includes defining a predetermined number of time slots at the beginning of a dwell or end of a transmission, each time slot having a duration and a data type, the communication device attempting to transmit data if the data type of the data corresponds to the data type of the slot, the attempt being based on at least one of the first and second assigned probability of transmission values, assigning the second probability of transmission value to the communication device if the attempt succeeds, reassigning the first probability of transmission value to the communication device if the transmission of data is complete.

Abstract: A method and apparatus for routing information within a communication system (100) is based upon evaluating various attributes (310) of the information to be routed. The methodology employs processing steps including, but not limited to receiving a message (300) having a key (304) and a first set of message attributes (310), each attribute having a value. Extracting the key (304) from the message to index a data base (400) in order to retrieve records (410) having the key and containing a representation of a logic function (406) that describes a second set of message attributes. The first set of attributes values are applied to the logic function (406) of the first retrieved record to determine whether the function is true or false. If true, that data base record is selected for use in routing the information. Otherwise, the first set of attribute values are applied to the logic functions of each indexed data base record (410) until a true condition is encountered.