摘要:
The invention is directed to a dynamically reconfigurable network comprising a plurality of nodes having respective transmitters and receivers for transmitting and receiving respective signals to and from one another. In one embodiment, the network is adapted to determine whether a first maximum power can be found at which a first node can transmit a first signal that provides a minimum signal-to-noise ratio at a second node without exceeding a maximum signal-to-noise ratio that a third node requires to simultaneously receive a second signal from a fourth node. If the first maximum power cannot be found, the network is further adapted to cause the first, second, third, and fourth nodes to share a single sub-network. Alternatively, if the first maximum power can be found, the network is adapted to cause the first and second nodes to share a single sub-network that the third node is not permitted to share.
摘要:
A method of providing backwards compatibility of a new TDMA system with an existing CSMA/CA system, wherein the CSMA/CA system includes asynchronous packet transmission, and wherein the TDMA system includes synchronous packet transmission, and wherein both systems transmit and receive over the same communication channel, including providing a control coordinator; dividing the TDMA system's frame into sub-frames for use by the CSMA/CA system and the TDMA system; and generating delimiters by the control coordinator to gain, retain and relinquish control of the communication channel from the CSMA/CA system, and wherein the delimiters are transmitted during guard bands of the TDMA system.
摘要:
Small electronic information storage and display devices such as paging devices with a limited number of control buttons allow user navigation of complex data structures by use of a single control button. Where a user has opportunity to branch within the data structure, the duration of control button actuation determines the selected branch. During the predetermined time interval, the user has visual indication of the item to be next displayed if the user maintains actuation of the control button. In this manner, a single control button supports navigation functions as might normally be established by two buttons such as a cursor right button and a cursor down button. Incorporating a second control button under the present invention supports a cursor left and a cursor up button. In this fashion, navigation of complex data structures occurs naturally and intuitively without requiring more than a limited number of control buttons.
摘要:
Pager data is transmitted at different subcarrier frequencies on different FM broadcast channels. The subcarrier frequency of the pager data is selected to avoid conflicts with signals transmitted from other systems. The pager receiver decodes data at any one of the multiple subcarrier frequencies according to the active subcarrier used on the currently tuned broadcast channel. In one embodiment, the subcarrier frequency of the pager data is contained in control packets of a time division multiplexed data frame. The receiver decodes the control packets to determine which broadcast frequencies and associated subcarrier frequencies contain potential pager signals. The receiver accordingly searches the identified broadcast frequency and automatically reconfigures a circuit demodulator to decode data packets at the identified subcarrier frequencies.
摘要:
A receiver operates in both a first polling protocol and in a selectable data acquisition protocol to both conserve power while quickly read long messages in wireless one-way communication systems. The receiver first polls data transmissions at a relatively slow periodic rate to identify messages. When the receiver identifies a corresponding address in the data transmission, a format packet directs the receiver to acquire data using a second data acquisition protocol independent of the polling protocol. The data acquisition protocol enables long messages to be communicated in a fast, highly reliable manner. After the long message is successfully transmitted, the receiver automatically reverts back into a polling protocol to conserve power.
摘要:
Packets are transmitted in different block sizes according to the speed of motion of the receiver. The packet block size is selected to minimize the effects of burst errors that occur at the receiver. The burst errors are disbursed between all packets in the packet block by interleaving the packets together prior to transmission. The receiver then deinterleaves the packets into their original format disbursing burst errors between all packets in the packet block. Since each packet will only contain a small proportion of the burst error, standard ECC schemes can be used to correct for bit errors in each packet increasing the probability that all packets will be transmitted successfully.
摘要:
A wide area paging system is disclosed in which paging messages input to the system in one local area can be broadcast to a receiver in any other local area without necessarily broadcasting the message in all areas. A local area clearinghouse in each area stores resident subscriber data including current location and receiver serial number. This data is used to transfer messages over a data network to the correct clearinghouse. The system uses a TDM data protocol. The data is encoded and transmitted at a very high rate (e.g. , 19,000 baud) in short packets (256 bits/13 milliseconds) via stereo FM sidebands. Receivers are assigned to receive sequentially numbered time slots matching a portion of their address. The addresses of intended receivers are included in the data packets. Battery-powered receivers are deactivated between packets and reactivated in accordance with the sequential time slot number scheme to receive an incoming packet. Messages longer than a packet are segmented and transmitted in two or more packets, linked together by data contained in the packets. A watch pager used in the system employs a wristband antenna which electromagnetically couples to the user's body. The watch pager displays time, telephone numbers and icons representing common types of paging messages.
摘要:
In a time keeping system providing time of day by radio signal to remote time keeping devices, the transmitted time of day is provided in association with a given time zone identification. The time keeping devices receiving the time of day reference and the time zone identification include a time zone preference identification. By comparing the time zone preference and the time zone identification transmitted, the time keeping device can, when necessary, offset the received time of day value according to user preference for display relative to a preferred time zone.
摘要:
A portable communication device which also has an infrared transceiver. A portable communication device can automatically establish infrared communication sessions with another portable communication device or desktop computer having an infrared transceiver. The portable communication device and the other device may exchange textual and graphical information, as well as the current time, and then reconcile the newly received information with that information in possession before the communication session began. Multiple portable communication devices and computers may communicate, while conserving battery power, using a time division multiplexing scheme where the infrared transceivers are active during a short, periodic time slots. Multiple communication session may overlap in time as long as they are not active during the same time slot.
摘要:
The present invention provides a highly reliable radio paging system. The radio paging system of the present invention provides a combination of time, frequency and spacial diversity in order to increase the reliability of the system. Time diversity is provided by broadcasting the same message at a number of different times. Spacial diversity is achieved by broadcasting the same message from a number of different locations. Frequency diversity is achieved by broadcasting the same message at a number of different frequencies. The paging receiver according to the present invention is designed to receive messages on a number of different frequencies; however, the pager only responds to a message the first time that it receives the particular message. The combination of time, frequency, and spacial diversity provided by the present invention results in a highly reliable radio paging system.