University of Illinois

Qualcomm Incorporated

Lucent Technologies Inc.

At+t Corp.

Rayadurgam Srikant

Ward Whitt

Sundar Subramanian

Xinzhou Wu

Albert Gordon Greenberg

Nilesh Nilkanth Khude

Mathieu Leconte

Songwu Lu

Vaduvur Bharghavan

A method of operating a wireless device is provided in which a number of neighboring nodes is estimated, a medium access priority to access a communication resource in a current timeslot is determined, and whether to transmit a scheduling control signal in the current timeslot is determined based on the number of neighboring nodes and the medium access priority.

Methods and apparatus for preemptive backoff for medium access in wireless peer-to-peer networks

A wireless shared channel network packet communication method emulates fluid flow fair scheduling. Errors inherent in wireless communication and unaccounted for in fair scheduling for wired networks are accounted for according to the method. Lagging communication flows, typically caused by burst errors in wireless communication systems, make up for their lag by causing leading flows to give up their lead. The method is independent of the pattern of channel error. In a preferred embodiment, lag compensation is accounted for by a service tag which identifies a precedence for contention based upon the previous denial of access for channel error. This precedence allows compensation when channels become error free. A modified preferred embodiment first attempts intraframe compensation by swapping slots when a host predicts an error for its assigned slot and another host assigned a later slot is able to transmit in the slot. Interframe compensation, when needed, is accomplished preferably by a round robin contention among backlogged flows. Errors are predicted by hosts for a subsequent slot when activity is sensed in a current slot but no good packet is received. Preferred packet structures include data and control slots, with data slots partitioned to provide necessary error status and backlog information piggybacked with data so a base has sufficient information to implement compensation in contention resolution.

Fluid flow fair scheduling emulation in wireless shared channel packet communication network

Because it is difficult to provide adequate quality of service to large-bandwidth calls in integrated-services networks, service providers may allow some customers to book ahead their calls. The present invention provides a scheme resource sharing among book-ahead calls (that announce their call initiation and holding times upon arrival) and non-book-ahead calls (that do not announce their holding times and enter service immediately, if admitted). The basis for this sharing is an admission control algorithm in which admission is allowed if an approximate interrupt probability (computed in real time) is below a threshold. Simulation experiments show that the proposed admission control methodology is superior to alternative schemes that do not allow interruption, such as a strict partitioning of resources.

Resource sharing for book-ahead and instantaneous-request calls

A system for, and method of operation of, estimating a blocking probability for at least a portion of a network and a model of the same are provided. The blocking probability represents a likelihood that a transmitted signal will arrive at least at the portion of the network. The system includes an estimator controller and a processing controller. The estimator controller derives both a direct and an indirect estimator. The direct controller is derived as a function of a number of losses and arrivals occurring with respect to at least the portion of the network during a period of time, and the indirect estimator is derived as a function of an offered load with respect to at least the portion of the network during the period of time. The processing controller, that is associated with the estimator controller, applies a weighting factor to the direct and indirect estimators to derive the blocking probability. The weighting factor minimizes variance of combined estimates.

Systems and methods for estimating a blocking probability

Growing community of inventors

Urbana, IL, United States of America

Rayadurgam Srikant