Hong Kong Applied Science and Technology Research Institute Company, Limited

Soung Liew

Vincent Lau

Kar-Wing Edward Lor

Yan Wang

Meixia Tao

Ross David Murch

Kin Nang Lau

Kang Heng Wu

Douglas Ronald George

Cheong Yui Wong

Sammy Ming Kit Chau

Vincent Wong

Kent Chen

Cheong-Yui Wong

Pui Bill Wong

A method of error correction for a multicast message sent over a wireless network includes encoding a message into N data packets using a forward error correction code and multicasting at least L data packets of the N data packets over a wireless network to recipients. Recipients not receiving the at least L data packets send a reply to the sender. The sender then selects a second subset of X data packets from the N data packets, and multicasts the X data packets over the wireless network to the recipients.

Method of error correction for a multicast message

Disclosed are systems and methods which provide high bandwidth data communication with respect to a large coverage area using smart antenna and/or directional antenna (referred to herein as multi-beam antenna) technology. Circuitry may be provided at a WLAN AP to provide selection of particular antenna beams used in the downlink and/or uplink, control of multicast transmission, control of unicast transmission, and to provide antenna pattern shaping techniques. Embodiments implement multi-beam antenna technology with little or no hardware modifications to AP circuitry. Other embodiments implement multi-beam technology using radio front-end and/or radio hardware modifications to AP circuitry. Various diversity techniques may be implemented, such as selection diversity, maximum ratio combining, and equal gain combing. To provide desired antenna pattern shaping, phase offsets with respect to a signal as transmitted in each antenna beam may be employed.

WLAN access point with extended coverage area

A method of providing data to two client devices on a first network having a shared cache from a server device on a second network. An instance of substantially simultaneous requests for data being made to a server from two client devices on a same network is identified. In response to a first request for the data being received at a first point in time a first one of the two client devices is served with the requested data from the server such that the data is stored in the shared cache. The second one of the two client devices is directed to make a second request for the data at a second point in time, later than the first point in time, so that the requested data is available in the stored cache.

Method of simultaneously providing data to two or more devices on the same network

Some representative embodiments are directed to controlling access to a wireless medium using 'credit' periods and 'free' periods. During a credit period, credits are initially assigned to the stations and each station is repetitively polled as long as the station has credit remaining and data is available to communicate. During the free periods, stations are polled using a start-time fair queuing algorithm. By dividing the access to the wireless medium in this manner, real time applications may use the credit periods to prevent communication latency from deteriorating application performance. Specifically, the repetitive occurrence of the credit periods and the assignment of credits to the stations ensures that each station will communicate at least at a minimum data rate. Additionally, controlling access to the wireless medium in this manner prevents frame collisions and, thereby, increases network throughput.

System and method for controlling access to a wireless medium

Disclosed are systems and methods which provide a busy tone or signal for use in communication collision avoidance in a wireless network, such as a WLAN, a cellular network, or other point-to-multipoint wireless network. An intelligent busy tone generator, upon the proper conditions, transmits a busy tone or signal to one or more wireless device which may otherwise be hidden from particular communications. According to embodiments the busy tone mimics a carrier sequence of an actual transmission to facilitate the wireless devices recognizing the channel as busy. Because the original uplink packet may be interfered by transmission of a busy tone carrier-sense sequence, embodiments are provided with interference cancellation capability. Interference cancellation circuitry of embodiments may operate in a plurality of modes, including a training mode (including an online training mode, an offline training mode, and a hybrid or combined mode) and an operating mode.

Busy tone for wireless networks

Disclosed are systems and methods which provide high bandwidth data communication with respect to a large coverage area using smart antenna and/or directional antenna techniques. Embodiments provide extended wireless local area network (WLAN) coverage areas using a directional antenna, with the cooperation of a cellular system or proprietary WLAN infrastructure to perform best antenna beam pattern estimation and signaling. Stations disposed beyond a WLAN coverage area may establish contact and exchange signaling information with an access point through a secondary control channel. Such a secondary control channel signaling may be relatively low bandwidth and may be utilized to identify the need to communicate data, to identify a 'best' directional antenna beam through which to communicate data, etcetera. Payload data may then be transmitted at a high bit rate through one or more smart antenna beams targeted at the appropriate stations.

Growing community of inventors

Hong Kong, China

Soung Liew