摘要:
The present invention provides a bandwidth efficient system and method of measuring the range between nodes (102, 106, 107) in a wireless communications network (100) with one-way data transfer, where each node (102, 106, 107) periodically transmits a message that contains information regarding neighboring nodes (102, 106, 107) from which any prior messages have been received by the transmitting node (102, 106, 107). A node (102, 106, 107) receives the messages transmitted from neighboring nodes (102, 106, 107) in the network (100), and records the times of arrival of the received messages. The node (102, 106, 107) receiving those messages can thus determine the respective distances between itself and the neighboring nodes (102, 106, 107) based on the respective time of arrivals of the received messages and the respective information included in the respective messages.
摘要:
Techniques are provided for reliably distributing network management information in and ad hoc multi-hop wireless network which includes a number of existing nodes. A first node selects a particular timeslot in a dedicated channel based on the network management information received from the neighbor nodes and determines, via a contention channel, if the particular timeslot is being used by any neighbor nodes of the first node. If the particular timeslot is determined to be unused, then it is assigned to the first node for periodically transmitting network management information.
摘要:
A wireless communication device (e.g., 102) employs a method and apparatus for determining distances between wireless communications devices in a wireless communication network (100). The wireless device receives an incoming message signal (117) from at least one other wireless device (e.g., 101, 103-104) in the network. The message signal(s) includes a time of arrival of a ranging signal (121) previously transmitted by the wireless device. Responsive to receiving the message signal(s), the wireless device receives one or more incoming ranging signal(s) (120) from the other wireless device(s). Each ranging signal is received in a frequency range that is substantially less than the frequency range in which the messaging signal(s) was received. Having received the message signal(s) and the ranging signal(s), the wireless device then determines the distance between itself and the other wireless device(s) based at least on receipt of the ranging signal(s) and, more preferably, further based on the contents of the message signal(s).
摘要:
A system and method for transmitting packets in a network (100). A node (102, 106, 107) in the network (100) accesses uses one of a plurality of medium access techniques for transmitting packets on the network (100). The node (102, 106, 107) separates packets to be transmitted into classes based on at least one characteristic of the packets and selects one of the medium access techniques for each class of packets based on whether the medium access technique provides improved transmission efficiency for the at least one characteristic of the packets in the class. The node (102, 106, 107) transmits the packets in each respective class using the respective selected medium access technique.
摘要:
A technique for allowing a first and second group of users to share access to a communication channel such as a wireless radio channel is disclosed. The first group of users can be a group of legacy users such as those that use digital CDMA cellular telephone equipment based on the IS-95 standard. The second group of users can be a group of web surfers that code their transmissions using one of multiple formats. The first group of users can share one modulation structure such as, on a reverse link, using unique phase offsets of a common pseudorandom noise (PN) code. The second group of users can share another modulation structure, but in a manner that is consistent and compatible with the users of the first group. Specifically, the users of the second group may all use the same PN code and code phase offset. Each channel used by the second group of users can be uniquely identified by a corresponding unique orthogonal code.
摘要:
A technique for distributing channel allocation information in a demand access communication system. Multiple access codes are used that have a defined code repeat period or code epoch. For each such epoch duration, a schedule of assignment of traffic channels to active terminals for each epoch is determined. For each terminal designated as active during the epoch, a list of active channels for such terminal unit is assigned. Prior to the start of each epoch, a channel set up message is sent on one of the forward link channels, such as a paging channel, indicating the lists of active channels for epochs of the associated traffic channel(s) that are to follow.
摘要:
A system and method for cognitive communication device operation. In accordance with the system and method, a node (102, 106, 107) that communicates in a wireless multihopping communication network (100) uses a receiver (302, 402, 502, 602) to acquire a digital sample of a communication signal, and extracts at least one feature of the digital sample. The node (102, 106, 107) employs a classifier (306, 406, 506) to determine the signal type, and a transmitter (108) to send feature vectors including information representing the signal type to other nodes (102, 106, 107) in the network (100).
摘要:
A system and method for providing position information of mobile user terminals (103) in a portable voice and data wireless communications network, such as an ad-hoc wireless communications network (100). More particularly, the present invention relates to a system of locating persons or assets using a centralized computing device, such as a server (125), that computes the respective locations of the terminals (103) from the respective information provided by the terminals (103) relating to their respective locations. A graphical display (121) that retrieves the location information from the centralized server (125) and generates a graphical display (121) of the location of all or selected terminals (103) based on their locations as computed by the server (125).
摘要:
This invention describes a cognitive radio receiver architecture where multiple specialized receiver algorithms are executed in parallel. For example, maximal ratio combiner and beam forming algorithms may be running parallel. The receiver system computes solutions using different hypotheses of channel conditions and chooses the best result, i.e. is able to decode data from one of the parallel receivers.
摘要:
A system and method for medium access control (MAC) protocol which controls transmissions in wireless devices to at least substantially comply with specific absorption rate (SAR) limits. The system and method of MAC protocol uses “source-based” time averaging measurements of transmitter “on-times” and an integral of transmission power to direct transmitter duty-cycle such that SAR limits are met. The system and method monitors and controls topology-dependent functions of a node transceiver, including transceiver duty cycle, transceiver transmit power levels and transceiver power-time products, using a automatic transmission control protocol (ATP) to vary functions to maintain specific absorption rate (SAR) limits for handheld and portable devices which are used close to human bodies. In cases in which SAR limits are approached, the ATP can direct the transceiver at the device to adjust each function, or combination of functions, to maintain an acceptable SAR limit.