摘要:
In a communication system (10) having at least one control center (24) and multiple satellites (12), the satellites (12) operate according to tables (80), wherein each satellites table becomes obsolete at a known time referred to as the exhaustion time. The earliest exhaustion time of all satellites (12) is determined and sent to the satellites (12) in the form of a message or a time-tagged update table (150). When the earliest exhaustion time is reached without updating the satellite (12), the satellites (12) enter default operation at that earliest exhaustion time. The satellites (12) continue default operations until otherwise instructed by the control center (24).
摘要:
A satellite cellular communication system includes satellites in motion that project cells upon the surface of the Earth. These cells are in motion and pass over individual subscriber units (26) engaged in communications, thus requiring individual subscriber units (26) to perform handoffs as an active current cell (300) currently servicing them advances. Selection of a subsequent servicing cell requires evaluation of active neighboring cells. A pre-computation of candidate cells is performed in advance according to a cell activation schedule. Active neighboring cells of an active current cell (300) are evaluated and prioritized in advance of individual subscriber unit's need for them. A candidate handoff cell list is then delivered to a satellite (12). A candidate handoff cell list is broadcast to all individual subscriber units (26) located within active current cell (300) for use in handoff decisions.
摘要:
The system (10) and method (100) adjust reuse units when nodes (e.g., satellites (20, 22)) move in a communication system (10), such as satellites (20,22) moving in their orbits around the earth in a space-based communication system (10). The method (100) and system (10) computes interference potentials between a reference reuse unit in a first reuse unit table of a first satellite (20) and reuse units being used in second reuse unit tables in second satellites (20) that are adjacent to the first satellite (20); and when the interference potentials is less than a predetermined threshold, then assigns the satellite a non-interfering reuse unit for the specific time interval.
摘要:
A cellular communications system may include one or more cellular base stations and a plurality of mobile cellular communications devices for communicating therewith. More particularly, the cellular base station and the mobile cellular communications devices may each include an encoder for generating an information signal. Furthermore, a modulator may generate a modulated waveform based upon the information signal, a carrier signal having a frequency and phase associated therewith, and at least one carrier phase reference symbol. The modulator may also include an offset circuit so that the modulated waveform includes a carrier frequency indicator. A transmitter may also be included for transmitting the modulated waveform to the desired cellular base station or mobile cellular communications device.
摘要:
A packet data communication system (10) where multiple users (87) can access the same channel (22) to maximize an efficiency of the communication system (10). Each channel (22) is divided into time slots. Each time slot is allocated to a user based on the user's request (303) for time slots and the availability of time slots. If time slots are available, then the system (10) will inform the user (87) and allocate the time slot to the user (87, 305). If there are no available time slots, then the system (10) will inform the user (87) that no time slots are available and access to the system's channel is denied. The user (87) will continue to request access (303) to the system (10) as long as the user has data packets to send.
摘要:
A laser transmitter (200, 300) includes a femptosecond pulse forming circuit (214, 308) and an ultra high-speed optical switch (218, 304) which enable the transmitter (200, 300) to generate a modulated pulse stream having pulses with widths of under 200 femptoseconds. The transmitted pulse stream is processed by a laser detector (500), including a wideband optical detector (504) and pulse stretching circuit (506), that regenerates information included in the modulated pulse stream.
摘要:
A MANET may include a plurality of MANET nodes each comprising a wireless transceiver and a controller cooperating therewith for establishing a wireless communication link with an adjacent MANET node based upon a time division multiple access (TDMA) implementation. The TDMA implementation may use a repeating scheduling of a plurality of temporally spaced-apart time slot units within a control epoch to thereby reduce a latency of communication.
摘要:
A MANET may include a plurality of MANET nodes each including a wireless transceiver, a position determining device, and a controller cooperating with the wireless transceiver and position determining device for establishing a wireless communication link with an adjacent MANET node based upon a time division multiple access (TDMA) implementation. The TDMA implementation may use time slots without using a range dependent guard time therein. The controller may further determine a range to the adjacent MANET node, and schedule time slots to offset a link delay in a received signal from the adjacent MANET node based upon the determined range.
摘要:
A method and apparatus have been described for combining multiple satellite constellations into a cooperative network. A GEO tier of satellites receives information to be broadcasted to earth. The GEO tier receives the information from global hubs, regional hubs, and local hubs. Local program material is combined with regional and global program material by either the regional hub or a GEO satellite.
摘要:
A channel management process (68) is performed by a parent base station (36) of a radio telecommunications system (20) that exchanges channel usage data with neighbor base stations (38) within its local group (34). When channel usage data indicates a channel assignment conflict, that conflict is resolved in the base station (22) having the lesser loading of the pair of conflicting base stations (22). Channel usage requests received by a base station (22) are prioritized and sequentially processed, channels (58) being assigned for inter-cell handoff requests, then intra-cell handoff requests after inter-cell handoff requests, even when that assignment creates a conflict, and then channels (58) being assigned to new call requests after handoff requests if that assignment does not create a conflict.