Abstract: A single semiconductor chip (10) includes both wireless modem (30) which may be fabricated from group III-V compounds and a digital modem (20) or router/gateway (25) which may be fabricated using standard CMOS semiconductor technology. This single semiconductor chip provides wireless access from computers or wireline access from computers to the internet or for small business or home LAN operation.

Abstract: A satellite-based, world-wide cellular messaging system transmits paging messages to pagers. The messages are transmitted at unique times, on unique frequencies, and into uniquely identified cells according to a plan which is periodically revised and transmitted in advance to the pagers. Battery resources in the satellites and pagers are thereby conserved, and interference between transmissions to adjacent cells is minimized.

Abstract: A satellite-based, world-wide cellular messaging system transmits paging messages to pagers. The messages are transmitted during a guard-band time-slot of a compatible world-wide cellular telephone system. In order to achieve better penetration, the satellites boost their transmit power for paging messages. One or more paging carrier frequencies may be used to accommodate differences in paging demand among different terrestrial cells.

Abstract: A satellite-based, world-wide cellular messaging system transmits paging messages to pagers via multiple beams. A message unit monitors multiple beams, recording the visit information for each beam, and ultimately determines the optimum beam to monitor for messages. The message unit, which conserves battery resources by entering into a sleep mode, synchronizes quickly to its message block when it awakes.

Abstract: A distribution network 108 receives simplex communications or pages from any number of user interface nodes (UINs) (202) and distributes the pages to one or more paging outlets provided by page termination nodes (PTNs) (110) and delivery systems (102). The UINs (202) perform the bulk of the processing related to the distributed system of the present invention. Originator services (1000) are provided through UINs (202). Through originator services (1000) callers may place pages or inquire about previously placed pages. In placing pages, page originators can specify options (1102-1104) related to the delivery of pages. Subscriber updating services (1100) are also provided through UINs (202). The updating services (1100) allow a subscriber to alter (802-812) the services provided by the distribution network (108). For example, the subscriber may change delivery addresses (402) which identify the delivery systems (102) through which pages are to be delivered.

Abstract: A hierarchical communication network includes primary, secondary, and tertiary communication systems. The primary system uses orbiting satellites as communication nodes and forms a pattern of cells that may cover the entire earth and that move over the earth. A given spectrum is divided among the cells in accordance with a reuse plan. Any number of secondary, terrestrial-based systems have secondary region areas of coverage that are substantially smaller than the distance to the orbits of the satellites used by the primary system. Secondary systems monitor the primary system to determine which channels of the spectrum are available for use in their secondary regions. Any number of tertiary, terrestrial-based systems reside within a secondary region and have tertiary region areas of coverage that are substantially confined within buildings. Tertiary systems use channels concurrently used by the primary system in the same area where their tertiary regions are located.

Abstract: A controller operates with a cellular communication system that transmits primary communications. The controller recovers a portion of the spectrum assigned to the primary communications for reuse in transmitting secondary communications. The primary communications' cells move in a predictable manner relative to a site at which the controller is located. The controller monitors primary communications to determine the current active cell. The identities of past active cells are saved so that a historical sequence of active cells is available. A map defining the relative orientation of cells is used with the historical sequence information to predict tracks through newly entered active cells. Based on this prediction, a recoverable cell is selected. Communication link parameters of the recoverable cell are used for secondary communications. The identity of the recoverable cell changes in response to changes in the identity of the active cell.

Abstract: A synchronizer operates to achieve initial synchronization with a TDMA acquisition signal exhibiting a potentially large Doppler. The synchronizer collects samples of a baseband signal during a timing window. A fast Fourier transform (FFT) is performed on the samples to generate a set of spectral data. The window is moved to an identical point in a subsequent frame and the FFT repeated until a high-confidence spectral data set is obtained. If the spectral data set indicates energy concentrated around a discrete frequency, then that discrete frequency represents an estimate of the acquisition signal's frequency. The timing window's timing parameters represent a time slot estimate of the acquisition signal. If the spectral data set indicates energy spread more or less uniformly over the spectrum, then no estimates are indicated and a new window is positioned at a different point in subsequent frames.

Abstract: A network of satellites delivers communications through bi-directional communication links between individual ones of the satellites. Each satellite terminates a plurality of links. All satellites are synchronized to recognize a constant duration frame structure. For each link in the network, satellites at both ends of the link simultaneously transmit data communications into their respective ends of the link using the same frequency band. Transmissions into all links supported by a satellite occur simultaneously. The transmissions continue for a duration that is responsive to the distance between the satellites. Transmissions cease for all links supported by a satellite when the communications from the opposing link nodes have nearly propagated the entire distances between the satellites. After ceasing transmissions, each satellite receives the communications previously transmitted from the opposing satellites into the links therebetween.