International Business Machines Corporation

Lenovo (singapore) Pte. Ltd.

Claus Michael Olsen

Mahmoud Naghshineh

Chandrasekhar Narayanaswami

Parviz Kermani

Babak Rezvani

Marcel-Catalin Rosu

Peter Dirk Hortensius

Danny N McKay

Lorraine M Herger

Fritz R Gfeller

Guruduth Somasekhara Banavar

Arvind Krishna

Thomas Richard Hildner

Chandra Narayanaswami

Patrick K Kam

Jeffrey Clark

Lewis Alexander Morrow

Timucin Ozugur

To conserve energy, components in mobile devices normally have to transition less frequently between 'active' and 'sleep' modes, and to sleep for longer intervals. In accordance with at least one presently preferred embodiment of the present invention, there is broadly contemplated herein an approach to reduce energy consumption by using HTTP proxies to shape incoming WLAN traffic. Proxies contemplated herein use techniques specific to the HTTP payload to compensate for any negative impact that shaping may have. Thus, there is described herein the architecture of a &#x201c;PowerAware Streaming Proxy&#x201d; (PASP), built on a PowerAware x-Proxy (PAxP) framework. PASP preferably uses RTSP/RTP semantics to effectively schedule media streams across the WLAN. Herein, PASP is compared with PAWP, which is a PAxP extension for web traffic, and problem areas are identified.

Method and apparatus for scheduling wireless LAN traffic

A computer program product includes instructions for causing a processor to: alert a client of the configuration of said computer program product; use a memory space for buffering the network application data destined for the client; release the network application data to the client, based on at least one occurrence of a specified condition that promotes energy savings; and purposely delay at least some of said data with an amount of time greater than zero to promote energy savings.

System for low power operation of wireless LAN interfaces

A method, system, and computer program for a) buffering instant messages to an intended recipient while the recipient is currently not logged on to an instant messaging system, and b) delivering buffered messages to the intended recipient after the recipient connects the instant messaging system. Thus, users are enabled to initiate instant messaging sessions with other users who are not currently online. An instant messaging device buffers messages and delivers them to the recipient when the recipient comes online. To the recipient, the method of delivery appears identical to the case where the recipient was continuously connected to the system. The main difference is the time delay, i.e. the elapsed time between the time the sender sent it and the time the recipient connected. The recipient is further able to configure the instant messaging device to be selective about which senders are allowed to buffer messages to the recipient while the recipient is disconnected. Sender specific pop-up windows, including the sender's buffered messages, will appear on the recipient's screen after the recipient connects to the system. The recipient can then respond to the instant message and resume the conversation in a real-time (though delayed) manner if the sender is presently online.

System and method for supporting instant messaging in disconnected modes

To conserve energy, components in mobile devices have to transition less frequently between 'active' and 'sleep' modes, and to sleep for longer intervals. In accordance with at least one preferred embodiment of the present invention, there is broadly contemplated herein an approach for remote discovery of wireless client and access point configurations, especially those settings associated with the power consumption of the client's wireless interface. Methods contemplated in the preferred embodiment use packet probing techniques to determine the client and access point configurations remotely. The probing techniques include sending packets to the client device, over the wireless LAN, at intervals calculated using data publicly available on the wireless LAN technology in use and results of previous packet probing measurements. Measurements from several packet probes and methods for statistical data processing are used to make a determination.

Method and apparatus for remote discovery of client and access point settings in a wireless LAN

A computer and method that control access to a network. The computer includes an application that shrinks the window of opportunity for a network attack and reduces power consumption by automatically causing a computer to connect to the network when access is needed and to disconnect the computer from the network when access is not needed. The computer is automatically disconnected when it is deemed that network access is no longer needed, such as after a time period of no network activity. In turn, when the user, or the system, needs access to the network, the computer is automatically reconnected to the network. A software daemon on the computer may temporarily reconnect the computer to the network to access a server on the network to determine if attempts have been made to access the computer.

Computer and method for on-demand network access control

A method and apparatus for managing power consumption of a processing unit having an operating system (OS) or software system and access to at least one hardware timer saves power by putting the processing unit into one of at least two low power states when the OS or software system is not expected to do work. A time period for which the software system is not expected to perform work is determined, and a determination is made as to which one of at least two low power states to put the processing unit in, in response to the time period. The hardware timer is configured to facilitate waking up the software system or OS in time for it to perform expected work. The processing unit and software system are transitioned into the chosen low power state. They are transitioned out of the low power state in response to a hardware interrupt.

Method and apparatus for managing low power processor states

The energy consumption of a computing system is reduced by incorporating two or more processing units with diverse energy efficiencies and diverse processing capabilities. A scheduler intercepts an interrupt(s) from I/O space, resolves the interrupt to a task, retrieves energy and performance attributes for the task, and schedules the task for execution on the processing units such that the task will consume the least amount of energy while executing in a timely fashion.

Computer system having low energy consumption

Rate management in adaptive data rate wireless communication systems in which communicating stations move with respect to one another implements algorithms for calculation of the repetition rate. A rate management module is used for selecting a proper value of repetition rate to be communicated back to sending station and for a selecting proper value of repetition rate to encode the data at the sending station. The repetition rate calculation procedure enables each station to dynamically calculate the optimum rate with which each station should be receiving information from another station. The repetition rate calculation procedures take into consideration past and present measurements of the link quality, age of the link quality measurements, speed of change in the link quality, packet types, packet lengths, received signal strength, and pattern and correlation in the link quality measurements. The rate management module utilizes one or more tables which are accessible from either hardware or software.

Rate selection in adaptive data rate systems

A repeater that has a receiver for receiving a signal. A validation module determines whether a signature is present in the received signal. An invalidation module determines whether undesired signal components are present in the received signal. The received signal is transmitted if the signature is present and if the undesired signal components are not present.

Wireless communication system

Fairness algorithms and access methods enable non-zero channel access for wireless communication systems operating in a random access channel environment. Fair access to a random access channel for each station in a wireless network is assured by each station calculating a priority or probability for accessing the channel based on logical connections among certain stations, based on other stations perception of the channel and based on each calculating station's own perception of the channel properties.

Balanced media access methods for wireless networks

The throughput of a Request-to-Send and Clear-to-Send (RTS/CTS) based distributed media access control protocol is improved by reserving the medium in a hierarchical fashion. The shared medium is reserved for two stations called the participants. During the reserved period, a master (or primary) attribute and a slave (or secondary) attribute are given to the participants and the medium is shared between them using any suitable coordination algorithm. During the reserved time, the secondary can signal the primary station that it has data to send to the primary station and request that the primary and secondary roles or attributes be exchanged. In the case that a role exchange takes place, control of the medium is transferred from one station to another and data transfer in an opposite direction can take place without requiring another reservation. Observing stations which are not participating in the reservation can be invited to join the reservation as additional secondary stations if this does not cause any interference to any other existing reservations. The efficiency of the medium reservation may be improved also by piggy-backing any reservation specific signals onto data packets and by defining new response frames such as Hold-to-Send (HTS) and Free-to-Send (FTS) for flow control when there is a congested receiving station.

Extensions to distributed MAC protocols with collision avoidance using

In a wireless multi-rate communications system, a method for extending the range of communications in the system by dividing the physical layer frame into two portions: a robust header portion and a body, where the repetition rate of the data symbols in the header portion is greater than or equal to the repetition rate of the data symbols in the body of the frame. In this way the header can be received and decoded by all stations in the system with a high probability, while the body of the frame need only be received and decoded by the destination station to which the body of the frame is intended to be received and decoded.

Media access control protocols in a wireless communication network

A method and apparatus for expanding the physical coverage area of a wireless communications network. More specifically, a number of transceivers are connected in a series configuration to a single base station, and each transceiver transmits signals to selected portions (subcells) of the physical coverage area. Each transceiver is connected to a delay unit where all of the delay units are adjusted so that downlink signals transmitted from the single base station will be transmitted from the transceivers to their respective subcells in phase with each other. Since all of the downlink signals from each of the transceivers result from the same downlink signal from the base station and since they are in phase with each other, a wireless unit anywhere in the physical coverage area will receive a downlink signal which is error free. Further, with this invention, when uplink signals are transmitted simultaneously from a number of wireless units in different subcells of the physical coverage area to the transceivers, the selection units will instantaneously select one and only one uplink signal to be received by the base station. Any one of the other simultaneously transmitted signals will be rejected throughout the duration of their signal.

Growing community of inventors

Cortlandt Manor, NY, United States of America

Claus Michael Olsen