Abstract:
In embodiments, a one-to-one association is established between a client and a host in a wireless network, such as a wireless local area network or a wireless personal communication network. The client may be a display device. The host may be a cellular telephone. Active association corresponds to the host exclusively using a shared resource of the client. When the association is solid, requests from other hosts to establish an active association are denied. When the association is fragile, such requests are granted. In the case of a semi-solid association, a request from another host to establish an active association causes the client to generate a query to the host currently owning the active association. If the host currently owning the association grants a release, a new active association is established between the requesting host and the client. Otherwise, the request from the other host is denied.
Abstract:
A novel power conservation scheme is provided for conserving power in client terminals by using a proxy server. The client terminal, having a low-power communication interface and a high-power communication interface, may power down its high-power communication interface, to conserve power. Prior to shutting off its high-power communication interface, the client terminal may assign a host terminal to act as a proxy for the client terminal. The host terminal monitors the paging channels for the client terminal via a high-power communication interface. If the host terminal detects a paging message for the client terminal, it forwards at least a portion of the paging message to the client terminal via a low-power communication interface. Upon receipt of the paging message from the host terminal via its low-power communication interface, the client terminal may power up its high-power communication interface and directly respond to an access terminal that initiated the paging message.
Abstract:
A system and method are provided for using frequency domain spreading to generate real signals in the time domain. The method supplies a first complex frequency domain symbol (α) and a second complex frequency domain symbol (αi), and maps (α+jαi) onto a subcarrier (+f). Further, (α−jαi)* is mapped onto a mirror subcarrier (−f). The mappings are converted into a complex time domain symbol carrying α and jαi in a single inverse fast Fourier transformation (IFFT). The real component of the complex time domain symbol (α) is initially supplied, and subsequently supplied is an imaginary component of the complex time domain symbol (αi). The real symbol component (α) is supplied by carrying a on the subcarrier (+f), and carrying (α)* on the mirror subcarrier (−f). The imaginary symbol component αi is supplied by carrying αi on the subcarrier (+f), and carrying (αi)* on the mirror subcarrier (−f).
Abstract:
A method of and system for calibrating a repeater in a wireless communications system are provided. The one or more calibration parameters for the repeater are derived from (a) time measurements derived from one or more signals relayed by the repeater and received at a plurality of different measurement positions, and (b) the positions of the measurement locations. In one application, the one or more parameters are used in determining the positions of subscriber stations in the wireless communications system.
Abstract:
Compact antennas for ultra wide band applications are disclosed. The compact antenna may be an elliptic dipole antenna with a poise and counterpoise both having an elliptical shape. A substrate may be used to support the poise and counterpoise with the substrate having a closed three-dimensional shape.
Abstract:
A method of identifying whether a first signal received at a subscriber station has been relayed by a repeater. The method involves measuring at the subscriber station a time difference of arrival between the first signal and a second signal. A hyperboloid or other potential solution surface is then formed from the measured time difference of arrival. A determination is then made whether or not the first signal was relayed by a repeater based on information derived from the potential solution surface.
Abstract:
A wireless remote telemetry system uses low-cost, low-power ad-hoc networks to provide flexible reading and control of remote devices. In an embodiment applicable to a utility service, consumption of electrical power among a population of customers is measured by a utility metering system having ad-hoc network communication capability. The remote metering unit transmits information over an ad-hoc network to one or more intermediate communication units or hops. The intermediate communication units or hops include a mobile unit, a mobile base unit, a subscriber home computer, and a home base unit. Each of these hops may co-exist in the same large-scale system. The intermediate communication units transfer the received information to a central controller through multi-hop ad-hoc networks or cellular networks, according to intelligent planning by the wireless infrastructure or the central unit.
Abstract:
A method and apparatus for detecting forward and reverse link imbalances in a digital cellular communication system. The method preferably uses an indication of “maximum access probes” to determine whether a link imbalance caused a reverse link failure to occur. The maximum access probes condition indicates that a wireless unit has attempted to access a base station a pre-defined maximum number of times. The method preferable uses an indication of a lost paging channel and a traffic channel initialization (TCI) time out to determine whether a link imbalance caused a forward link failure to occur. If the wireless unit did not lose the paging channel, the method determines whether a TCI time out occurred. If the wireless unit lost the paging channel, or it did not lose the paging channel but a TCI time out occurred, the method determines the cause for the forward link failure. There are two potential causes in this scenario: (1) either the wireless unit is a significant distance from the base station; or (2) the paging channel suffers from significant interference. The method determines the cause and either instructs the wireless unit to perform an idle handoff to a neighboring base station or to exit the digital system.
Abstract:
A system and method for monitoring the load on a CDMA communication system having a base station and a plurality of users. A measure of voice activity in the communication system is determined, and a current value of frequency reuse efficiency equal to an initial value of frequency reuse efficiency is provided. A power determination is made according to the measured voice activity and the current value of frequency reuse efficiency. The current value of frequency reuse efficiency is updated using the power determination to provide a new current value of frequency reuse efficiency. The power determination and the update of the frequency reuse efficiency are iteratively repeated until convergence to provide a converged value of frequency reuse efficiency. The load on the communication system is then determined according to the converged frequency reuse efficiency value.
Abstract:
A method and apparatus for determining the position of a wireless communication device using global positioning system (GPS) satellites, base stations synchronized to GPS time and base stations that are unsynchronized with GPS time. The unsynchronized base stations are synchronized with one another. Time of arrival information is adjusted to take into account the fact that wireless communication devices that received GPS time information from a base station receive that information biased by the one-way delay that is encountered by the signal that communicates that information to the wireless communication device. In addition, time difference of arrival information for base stations that are not synchronized to GPS time allows the bias between these base stations GPS time to be eliminated.