A data interface for transferring digital data between a host and a client over a communication path using packet structures linked together to form a communication protocol for communicating a pre-selected set of digital control and presentation data. The signal protocol is used by link controllers configured to generate, transmit, and receive packets forming the communications protocol, and to form digital data into one or more types of data packets, with at least one residing in the host device and being coupled to the client through the communications path. The interface provides a cost-effective, low power, bi-directional, high-speed data transfer mechanism over a short-range “serial” type data link, which lends itself to implementation with miniature connectors and thin flexible cables which are especially useful in connecting display elements such as wearable micro-displays to portable computers and wireless communication devices.

High data rate interface apparatus and method

Pilot signal transmission sequences and methods are described for use in a multi-sector cell. Pilots in different sectors are transmitted at different known power levels. In adjacent sectors a pilot is transmitted while no pilot is transmitted in the adjoining sector. This represents transmission of a NULL pilot signal. A cell NULL is also supported in which NULL pilots are transmitted in each sector of a cell at the same time. Multiple pilot signal measurements are made. At least two channel quality indicator values are generated from measurements corresponding to at least two pilot signals of different power levels. The two values are transmitted back to the base station which uses both values to determine the transmit power required to achieve a desired SNR at the wireless terminal. The wireless terminal also reports information indicating its location to a sector boundary.

Pilot signals for use in multi-sector cells

A mobile station (402) selects (1802) a preferred cell site for transmitting a frame of data to be sent subsequently to the mobile station. A base station (602) of the preferred cell site schedules (1804) a transmission of the frame of data, wherein parameters for the transmission are determined by the base station from recently-measured channel and interference information. Thereafter, the base station sends (1806) the frame of data from the preferred cell site; and an active set of base stations associated with the mobile station at ones of a plurality of cell sites synchronize (1808) their data queues to reflect the transmission of the frame of data.

Method and apparatus for providing a distributed architecture digital wireless communication system

Methods and apparatus for collecting, measuring, reporting and/or using information which can be used for interference control purposes. Wireless terminals measure signals transmitted from one or more base stations, e.g., base station sector transmitters. The measured signals may be, e.g., beacon signals and/or pilot signals. From the measured signals, the wireless terminal generates one or more gain ratios which provide information about the relative gain of the communications channels from different base station sectors to the wireless terminal. This information represents interference information since it provides information about the signal interference that will be caused by transmissions from other base station sectors relative to transmissions made by the base station sector to which the wireless terminal is attached. Based on the signal energy measurements and relative gains generated from the energy measures, reports are generated in accordance with the invention and sent to one or more base stations.

Methods and apparatus for determining, communicating and using information which can be used for interference control purposes

A method and system for optimizing channel access scheduling for multiple wireless computing devices over a wireless network improves channel access efficiency with respect to a primary channel. An access point, or host computer, includes a host transceiver for receiving control information from the wireless computing devices over a low power channel. Upon receiving the control information, the access point applies a scheduling algorithm to schedule channel access for the wireless computing devices to transmit data over the primary communication channel. The wireless computing devices include a low power radio for receiving scheduling information via the low power channel during idle periods. When the scheduling information is received, the wireless computing device activates its primary channel network interface components to communicate data through the primary channel. When the computing device is idle, the device is configured to power down all of its components with the exception of the circuitry required to power the low power channel. As such, the low power channel is maintained in an active state for receiving scheduling information, such as an access schedule, during both idle and non-idle periods.

Power efficient channel scheduling in a wireless network

The present invention provides a transmission control scheme for wireless digital networks comprised of a plurality of access points each communicating with access terminals, which improves data throughput to access terminals located in areas where interference from the neighboring access points are high. Generally, under the transmission control scheme according to the present invention, the access points are controlled so that neighboring access points will not transmit signals simultaneously with transmission parameters providing high robustness. The transmission parameters include, for instance, transmission power, a modulation scheme and a coding rate. Higher power transmission achieves higher robustness. Transmission at a lower modulation level achieves higher robustness. Transmission at a lower coding rate achieves higher robustness. Transmission providing high or low robustness will expand or narrow a virtual communication zone, which is defined in this application as an area within which it is feasible at a given level of error performance for access terminals to communicate with the access point in the zone. The access points may change their transmission parameters according to predetermined schedules, such as at regular intervals.

Transmission control scheme

The present invention provides scheduling algorithms that guarantee minimum data transport service for even ATs with poor channel conditions. Data-requesting ATs are divided into a number (N g1 ) of AT groups according to their channel conditions. Also, a recurring sequence of time slots is defined on the TDMA channel and partitioned into a number (N g2 ) of slot groups, where N g2 is made larger than N g1 . Generally, slot assignment according to the present invention is a two-step process. First, in the sequence, the slot groups are allocated to the AT groups so that AT groups with better channel conditions will receive more slot groups while each AT group will receive at least one slot group. Second, in each AT group, the time slots allocated to an AT group are assigned to the individual ATs in the group. By assigning more slot groups to AT groups with better channel conditions, the algorithm will optimize the overall data throughput. By assigning at least one slot group to each AT groups, the algorithm will guarantee minimum service to ATs with poor channel conditions.

Slot assignment algorithm

When an application is activated, a mobile station 10 detects external devices 20, 30, 40 as candidates for a BLUETOOTH connection out of external devices existing in the surrounding area, and presents a list of the devices to a user. When the user selects from the list an external device 20 with which a connection is to be attempted to make, a link is established by a connection procedure according to a security level described in an ADF of the application. Namely, when “high” is described as the security level, an authentication process and an encryption process requiring input of a PIN are executed prior to the establishment of the link. On the other hand, when “low” is described as the security level, a link is established without executing these processes.

Mobile station and communication control method

The present invention provides a wireless communication system that comprises a plurality of communication networks operating with different communication parameters and protocols and at least one communication terminal having multiple communication modules each adapted to operate with specific communication parameters and protocol for access to at least one corresponding communication network operating with the same communication parameters and protocol. A module in the communication terminal is activated to prepare for communication with the corresponding network when it is expected likely that the communication terminal is heading to access the corresponding network. The activated module is deactivated when the same is expected unlikely. The communication terminal is usually battery-powered. Since modules are deactivated when not necessary, the battery life can be prolonged.

Wireless communication system

PROBLEM TO BE SOLVED: To provide a transmission control method for improving the throughput of data communication to an access terminal positioned in an area, where interference from an adjacent access point is strong, on a wireless digital communication network having a plurality of access points to respectively communicate with a plurality of access terminals SOLUTION: By using a parameter for providing high error durability between adjacent access points, each of access points is controlled so that communication can not be simultaneously performed The transmitting parameter is transmitting power, modulating system or encoding rate, for example The error durability is made different depending on the difference of transmitting power, and the size of a communication zone defined as an area, where communication can be performed at a certain error rate, is changed depending on the difference of the error durability The access point can change the transmitting parameter according to a predetermined schedule as well

Akira Shibutani

Papers

Transmission control scheme

Slot assignment algorithm

Mobile station and communication control method

Wireless communication system

Transmission control method