Abstract: A method and system for conducting rapid control traffic in a time division multiple access (TDMA) communication system comprises a base station communicating with a plurality of user stations in assigned time slots of a time frame. For bearer traffic, time slots are assigned to particular user stations for an extended duration. In unassigned time slots, the base station transmits a general polling message indicating availability of the time slot. A user station desiring to hand off communication from one base station to another uses multiple available time slots at the target base station for exchanging control traffic messages with the target base station. The next available time slot is indicated by a slot pointer in the header of each general polling message to facilitate rapid exchange of control traffic messages. During handover, the user station may establish a new link with the target base station before relinquishing the existing communication link with the old base station.

Abstract: Expanded storage is provided to portable electronic devices of the type that typically incorporate compact flash memory cards or a similar local replaceable memory device. A transceiver assembly is provided within the form factor of the local replaceable memory normally used in the local storage device. The transceiver assembly communicates with the portable electronic device over the connections and using the same communication protocol as the portable electronic device conventionally uses to communicate with the local replaceable memory device. Data are written to the transceiver assembly as if the transceiver were the conventional memory device. The data are buffered and transmitted over a wireless link to a corresponding wireless link associated with a remote mass storage device.

Abstract: A method and system for conducting rapid control traffic in a time division multiple access (TDMA) communication system comprises a base station communicating with a plurality of user stations in assigned time slots of a time frame. For bearer traffic, time slots are assigned to particular user stations for an extended duration. In unassigned time slots, the base station transmits a general polling message indicating availability of the time slot. A user station desiring to hand off communication from one base station to another uses multiple available time slots at the target base station for exchanging control traffic messages with the target base station. The next available time slot is indicated by a slot pointer in the header of each general polling message to facilitate rapid exchange of control traffic messages. During handover, the user station may establish a new link with the target base station before relinquishing the existing communication link with the old base station.

Abstract: A mobile communication system having a layered architecture communicates user and signaling data among components of the communication system in the form of information elements which are encapsulated within packets and which may be passed across one or more system interfaces. The mobile communication system may comprises mobile user stations, base stations, and base station controllers and operates as a transparent data pipeline between application end users, such as a telephone service, connected at base station controllers and mobile user stations. Each system interface functions as a communication channel between system components, providing the lower layers of a layered communication system architecture. In a particular embodiment, the interface between the base station and the user stations is a TDMA interface, and the interface between a base radio transceiver and a line card processor comprises a dual-port RAM which is used as a shared resource across the interface.

Abstract: A system for accessing a telephone system, in which a set of user stations are matched with a set of base stations for connection to a telephone network. Each base station may be coupled directly or indirectly to the telephone network and may be capable of initiating or receiving calls on the telephone network. Each user station may comprise a spread-spectrum transmitter or receiver and may be capable of dynamic connection to selected base stations. A plurality of base stations may be coupled to a private exchange telephone system for coupling user stations in calls outside the telephone network. User stations may use CDMA, FDMA, TDMA or other multiple-access techniques to obtain one or more clear communication paths to base stations. User stations may make and break connections with base stations as the user station moves between service regions, or is otherwise more advantageously serviced by, base stations.

Abstract: A system for accessing a telephone system, in which a set of user stations are matched with a set of base stations for connection to a telephone network. Each base station may be coupled directly or indirectly to the telephone network and may be capable of initiating or receiving calls on the telephone network. Each user station may comprise a spread-spectrum transmitter or receiver and may be capable of dynamic connection to selected base stations. A plurality of base stations may be coupled to a private exchange telephone system for coupling user stations in calls outside the telephone network. User stations may use CDMA, FDMA, TDMA or other multiple-access techniques to obtain one or more clear communication paths to base stations. Base stations may be placed at convenient locations or may themselves be mobile. User stations may make and break connections with base stations as the user station moves between service regions, or is otherwise more advantageously serviced by, base stations.

Abstract: The accuracy of location estimates based on time-of-arrival measurements may be improved using a variety of different approaches. In some approaches, accuracy predictions are made before a location estimate is computed, and the location estimate is only computed when a high accuracy is predicted. In other approaches, a plurality of preliminary location estimates are computed, and the accuracy of each preliminary estimate is determined. A final location estimate is then based on the preliminary location estimates with the best determined accuracy. In some approaches, the accuracy predictions and determinations are based on geometric dilution of precision (GDOP) or a known topography of a region. In another approach, a subset of time-of-arrival measurements is fed into a closed-form algorithm to produce a preliminary location estimate. This preliminary location estimate is then used to initialize an open-form location algorithm. Optionally, more than one of these approaches may be combined.

Abstract: A portable computer or a similar electronic device having a wireless data communication device such as a Bluetooth transceiver is provided with a power down procedure activated by a remote control device. For example, a single key remote control device emits a radio frequency signal bearing a power down control signal that is transmitted to the portable computer. The control signal is received by a receiver separate from the wireless communication device and initiates a power down process that first causes the portable computer to wake up from a sleep state, if the computer is in a sleep or similar state. The communication device or the computer then invokes a driver that either directly initiates a power down sequence or that invokes another program that initiates a power down sequence. A log file is written during power down that indicates the state of the computer at the time that the power down control signal was received.

Abstract: A technique for spread-spectrum communication which uses more than one mode and more than one frequency band. Selectable modes include narrowband mode and spread-spectrum mode, or cellular mode and microcellular mode. Selectable frequency bands include both licensed and unlicensed frequency bands, particularly frequency bands including the 902-928 MHz, 1850-1990 MHz, and 2.4-2.4835 GHz frequency bands. Spread-spectrum communication channels are 10 MHz or less in width. The frequency band onto which spread-spectrum signals are encoded may be changed upon a change in environment or other control trigger, such as establishment or de-establishment of communication with a private access network.

Abstract: A system and method for time division duplex communication over a single frequency band wherein guard time overhead is reduced by active adjustment of reverse link transmission timing as a function of round trip propagation time. A time frame is divided into a plurality of time slots, during each of which the base station transmits to a user station and the user station transmits to the base station. Communication is initiated by a round trip timing transaction. In response to a general polling message from the base station, a user station seeking to establish communication transmits a short reply message. The base station calculates the distance of the user station by measuring the propagation delay with respect to receipt of the reply message. The base station sends a timing adjustment command to the user station instructing the user station to advance or retard its timing according to the calculated distance, so as to minimize guard times between time slots.

Abstract: An RJ-45 standard modular plug receptacle is defined by walls including a wall defining a plurality of contact wire positions including a pair of outermost contact wire positions. A pair of stops project into the receptacle from a surface of the wall, the stops being in longitudinal alignment with the outermost contact wire positions. An RJ-45 plug is thereby fully insertable in the receptacle with the stops entering the outermost contact pin grooves on the plug during insertion. However, full insertion of an RJ-11 plug is prevented by said stops which engage front faces on the RJ-11 plug flanking the contact pin array of the RJ-11 plug.

Abstract: A forward error correction (FEC) method is provided that operates in a multiple access format, such as, e.g., a Time Division Multiple Access (TDMA) format. An FEC transband central station and a plurality of FEC transband remote stations transmit data and corresponding error correction data therebetween during time frames. The time frames are divided into in-band time slots during which the traffic data is transmitted and out-of-band time slots during which the error correction data may be transmitted. The FEC transband remote stations that are assigned to the out-of-band time slots are efficiently and dynamically adjusted during communication.

Abstract: The present invention is embodied in a system and method for protecting an electronic device connected to a telephone line. The system includes a detector, sensor and protector. The detector determines a resistance built-in to the telephone line, the sensor utilizes the resistance of the telephone line to determine if the telephone line is a digital line and the protector prevents the electronic device from prolonged connection with the telephone line if it is a digital line.

Abstract: An antenna system for use in cellular and other wireless communication includes a dual polarized compact antenna array. In one embodiment, the antenna system includes four T-shaped dipole antenna elements mounted on a ground plane, forming a side of a square shaped array. In another embodiment, the antenna system includes seven T-shaped dipole antenna elements mounted on a ground plane to form two side by side square arrays, wherein the square arrays share a common T-shaped dipole antenna element.

Abstract: A method of communicating FSK-modulated Caller ID signals through a network incompatible to the transmission of these signals is presented. A first network component couples between the incompatible network and a Central Office, and a second network component couples between the incompatible network and the telephone. In one embodiment, the call flow proceeds until the second network component would ring the line of the called party. The second network component seizes the line but does not apply a ringing signal. The second network component continues with the call flow as though the second network component had entered the silent interval after the first ring cycle at the called party. Subsequently, the CO transmits the FSK Caller ID information to the first network component which detects the FSK transmission and converts it into an out-of-band message and transmits the out-of-band message over the incompatible network to the second network component.

Abstract: A system for time division multiplexed communication over a single frequency band in which guard time overhead is reduced by active adjustment of reverse link transmission timing as a function of round trip propagation time. In one embodiment, during a first portion of a time frame, a base station issues a single burst segmented into time slots comprising data directed to each user station. After a single collective guard time, the user stations respond, one by one, in allocated time slots on the same frequency as the base station, with only minimal guard times between each reception. In order to prevent interference among the user transmissions, the base station measures the round trip propagation time for each user station and commands the user stations to advance or retard their transmission timing as necessary.

Abstract: A communications bridge for simulating circuit switched call links to user equipment is provided. According to one embodiment, the communications bridge receives data from the user equipment over a serial data interface. The communications bridge simulates circuit switched call link responses back to the user equipment so that the user equipment believes that a circuit switched call link has been made. Once the simulated circuit switched call link is established, data from the user equipment is packetized into short message service or general packet radio service packets for transmission over a non-circuit switched call link.

Abstract: A low profile, multi angle, adjustable mounting bracket that allows an antenna or other device to be secured to a mounting surface and rotated through a substantially 180° arc with minimal protrusion from the mounting surface. A mounting bracket in accordance with the present invention comprises a bracket support and a rotational slide support. The slide support provides two degrees of freedom in its adjustment by allowing both rotation and translation about a single point on the bracket support.

Abstract: In a first embodiment of the invention, a concatenated preamble code is formed by a kronecker product between two subcodes of the same or different lengths. The subcodes have favorable correlation properties and may be Barker codes, minimum peak sidelobe codes, Gold codes, Kasami codes, Boztas codes, or other codes. At the receiver a two-stage processor is used to detect the concatenated preamble code. The two-stage processor comprises a series of two filters, one of which is preferably a mismatched filter. In another aspect of the invention, a repeated codeword preamble is formed from a series of the same repeated short subcode. The short subcode may be an augmented or truncated odd-length code. At the receiver a single matched filter is preferably used to generate a series of spikes separated by the period of the subcode. An alert/confirm detector non-coherently adds together individual correlation spikes and reject false alarms.

Abstract: A method and apparatus for an authenticated electronic userid is provided. According to one embodiment, an adapted digital signature is generated for an outbound message from a local user that authorizes a remote user to reply to the message. The adapted digital signature becomes part of an authenticated electronic userid and, when a reply from the remote user is made, the reply message includes the authenticated electronic userid. A one-way hash function is employed to generate the adapted digital signature. According to one embodiment, if an inbound message to a local user from a remote user does not have an authenticated electronic userid, in particular the adapted digital signature, then the inbound message is rejected. An advantage of the method and apparatus described herein is that unsolicited bulk electronic messages and other non-authorized communications to a local user of an electronic message system are reduced.