Selection from plural run-length encoding methods to compress a data string

A run-length encoding method is selected (502) from a plurality of such methods based on content of a bit string (such as a traffic indication map TIM in Smart Meter networks). Encoding parameters (such as codeword length) are also selected (504) based on the content, and the bit string is encoded (506) according to the selected method and parameters. In various non-limiting examples: different run-length encoding methods arc selected (508) based on whether the bit string has sequences of consecutive same-value bits interspersed with isolated. opposite-value bits or interspersed with sequences of consecutive opposite-value bits; the codeword length parameter is selected (510) based on how many consecutive same-value bits arc in the bit string; and encoding entails disposing a marker between code words to indicate that the codeword continues.

Allocation

A method, apparatus and computer program facilitate the assignment of stations to slots of a restricted access window (RAW) to support communications between the stations and an access point. In a method for use in an access point, a broadcast message is caused to be provided to the station(s) 34. The broadcast message includes an indication of a type of stations to access the RAW and one or more of a duration of the slot(s) in the RAW allocated to a first type of station, a duration of the RAW allocated to the first type of station, a duration of the slot(s) in the RAW allocated to a second type of station or a duration of the RAW allocated to the second type of station. The method also provides for access 36 for one or more stations of the type that was indicated within the slots of the RAW.

Transmitting information concerning an operational parameter of a wireless device mode

A wireless device switching (or desiring to switch) from a first mode of operation to a second mode, e.g. power saving modes, transmits information relating to at least one operational parameter of the second mode, e.g. the battery level of the device. In one embodiment the device transmits the information as part of a message containing data if the device has data to send, otherwise a separate message is transmitted. In another embodiment, the information is transmitted in a header of a message containing data (figure 5), e.g. in a Frame Control field of the header, or as part of the data payload of a message. Other examples of the information include whether the device decodes a Traffic Indication Map (TIM), listen interval parameters and group information. The device may operate in accordance with the IEEE 802.11ah standard.

Optimising feedback in a multicast system

The invention concerns the multicasting of data between a source device and a plurality of destination devices. Destination devices receive data from the source device and also an indication of the maximum number of packets to be transmitted and determine the progress of data reception on the basis of the number of packets received or not received. The destination devices then determine whether or not to transmit a feedback of data reception to the source device on the basis of predetermined criteria. Where feedback is transmitted, it includes an indication of the determined progress. The feeback is used by the source device to determine whether to change its the transmission characteristics. The sending of feedback from the destination devices may be ordered according to the progress of each of the devices such that the device with the least progress sends feedback first. Any devices with progress the same as or better than the device with the least progress need not transmit feedback ...

Reserving shared medium resources in overlapping wireless networks

Embodiments of the present disclosure solve problems of throughput reduction due to collisions, busy medium, and deferred transmission due to overlapping wireless networks (e.g. IEEE 802.11 overlapping basic service sets, OBSS) by allowing devices suffering from overlapping interference to have sufficient chances to transmit and/or receive successfully. Embodiments include methods for a first device (e.g. 802.11 AP) to communicate data via a medium shared with other devices (e.g. 802.11 APs and/or STAs) located in an overlapping service area but not under common control with the first device. Embodiments also include methods for a first device (e.g. 802.11 AP) to negotiate reservation of a shared medium requested by a second device (e.g. 802.11 AP), the two devices being in overlapping service areas but not under common control. A station (STA) may monitor for the existence of an interference condition and may identify the interfering access points (APs) and stations in the shared medium ...

Scheduling transmission of sensor data

Scheduling wireless transmission of sensor data to minimise contention and also to reduce energy consumption, particularly for industrial, scientific and medical (ISM) applications where a large number of sensors may be taking measurements and forwarding data to a single access point (AP) on a regular basis. Each of N sensor stations takes measurements at set intervals (ti the traffic period for station i) and obtains a consistent amount of sensor data. Stations transmit their sensor data over time slots (of duration T); in a preferred embodiment this time slot is the same length for each station, but alternatively it could differ between stations. At the commencement of a first transmission round each station may have sensor data available for transmission, and each station may then transmit its data in consecutive time slots. For subsequent transmission rounds there will only be transmission from those stations having data available in their buffers for transmission. The length of the ...

A data request message sent from a wireless device to a second device comprises low-power timing information for the first device

A wireless communication device, such as an IEEE 802.11 station, receives an indication 615 that a second device, such as an IEEE 802.11 access point, has a data message intended for the first device 620. Low-power timing information is determined for the first device 630 and is included in a data request message sent to the second device 640. If a response to the data request message has been received 650, the wireless device enters a low-power state or mode corresponding to the low-power timing information 600. The low-power timing information may comprise discontinuous reception (DRX) pattern parameters indicating one or more durations that the wireless device will spend in a low-power state or mode and a non-low-power state or mode.

Assigning a station to a group associated with a sector based on location information and link sufficiency

A geographic region in which an access point (AP) lies is divided into sectors, each sector associated with a group. A station is assigned to a group based on location information of the station relative to the sectors. The station's location information is utilized to test whether a first link between the station and a first node of a first group is sufficient 202. If the test indicates that the first link is sufficient, the AP can assign the station to the first group, else it will utilize the location information to test whether a second link between the station and a second node of a second group is sufficient 204. The respective test may account for transmit power, path loss or transmission rate on the respective first and second link, or antenna gain at the station and/or the respective first and second node.

Method and Apparatus for Controlling Wireless Devices

A device in wireless communication with an access point is provided, by the access point, with a first group identifier indicative of the identity of a group of devices with which the device is associated. Control data is received from the access point wherein at least a part of the control data is associated with the first group identifier and is indicative of at least one operating condition with which devices provided with the first group identifier are configured to operate. The device is caused to determine that a change of group is desired based, at least in part, on the received control data. A request is sent to the access point for a change of group. A response is received from the access point indicating whether the request for a change of group has been allowed. The device changes to a group more suited to its requirements, for example a QoS or transmission rate or latency requirement.

Methods and apparatus for multicast transmission

Simultaneous transmission of uplink and downlink data in a wireless network

Systems and. techniques are disclosed for configuring wireless transmissions, in particular to achieve full-duplex wireless networking between a wireless network access point and a wireless network station. An access point configures a transmit opportunity (TXOP) 302 in a contention free period (CFP) 300 to provide for a full-duplex mode, including at least one uplink frame 304A for transmission by a station and. at least one downlink frame 306A for transmission by the access point. The uplink mode and the downlink mode provide for simultaneous transmission. The transmit opportunity 302 may be configured so that uplink frames 304A and their corresponding downlink frames 306A are of equal duration, either through configuring frames to be of equal duration, or by adjusting frame durations during transmission. May be used in a WLAN operating under the IEEE 802.11 standard.

Placing some of the circuitry for sending and receiving data, in a wireless device, in a low power state and buffering data for a time period

Apparatus, methods and computer program products are provided for use in controlling operation of a device that is in wireless communication with an access point and comprises a buffer in which data to be sent to the access point is stored. An exemplary embodiment comprises the steps of causing the device to operate in a first mode in which the device is capable of sending data to, and receiving data from, the access point; receiving control data from the access point, the control data comprising first data indicative of a time period, and second data indicative of a control parameter which comprises a contention value; causing the device to operate in a second mode for the time period specified by the first data and on the basis of the control parameter, in which, in the second mode, at least some circuitry of the device used for sending data, and at least some circuitry of the device used for receiving data, is placed in a low power state, and data to be sent to the access point is stored ...

Dynamic back-off period for accessing a transmission channel

A method for determining a dynamic back-off window value for accessing a transmission channel in a Carrier-Sense Multiple Access/Contention Access (CSMA/CA) arrangement. The method comprises receiving 100, at a first wireless node, a first set of time-varying parameters for at least one second wireless node; and using 102, by the first wireless node, the received first set of time-varying parameters at least partially and a second set of time-varying parameters of the first wireless node in determining a back-off window value for the first wireless node for accessing the transmission channel. The first set of time-varying parameters may comprise at least one of: number of packets in the second nodes buffer; average packet size of packets in the second nodes buffer; total buffer size of the second node; relative buffer size; quality of service requirements of the second nodes traffic; or weight associated with the second node. The second set of time-varying parameters may comprise at least ...

Scaling an idle period for maintaining an association between and access point and a station

An idle period may be defined in a tailored manner, such as on a per station or per class of stations basis, as opposed to on a per access point basis. An indication of an idle period is provided to a station and causes an association with the station to be maintained for a period of time that is at least partially defined by the idle period. The period of time for which an association is maintained with the station is different than a period of time for which an association is maintained with another station in an absence of communication with the station. An indication of a scaling of the idle period to be provided to the station may also be provided, wherein the association with the station is maintained for a period time that is defined by a combination of the scaling and the idle period. The indication of the scaling of the idle period may be broadcast for each of a plurality of different classes of stations. Sensors that are anticipated to only infrequently report to the access point ...

Method apparatus and computer program for encoding a bit string

Generating a control message frame to instruct the end of a contention-free period

A wireless network communication device comprises a host processor, a network interface coupled to the host processor and a transceiver operable to generate and transmit a control message frame. The control message frame includes: a short training field 72, a long training field 73, and a signal (SIG) field 74 including modulation and coding scheme subfield 76 to hold message type information, transmitter address information 77, receiver address information 78 and frame check sequence information 82. Enables instructions for ending a restricted access window (RAW) period to be implemented in a short message structure which excludes the MAC header normally present in IEEE 802.11 WLAN CF-End / CF-End + CF-Ack messages and instead includes selected information normally present in the MAC header in a specially modified SIG field of the PHY preamble, thereby facilitating more efficient reuse of surplus contention-free periods.

Methods and apparatus for managing acknowledgements

A method, apparatus and. computer program product arc provided. for designating an acknowledgment of data. A method and apparatus may designate a mode of operation, in a signal, for acknowledging receipt of data. The method and apparatus may assign an aggregation period, to the signal, 'including a time period in which one or more stations 10 are designated to communicate one or more items of data to an intermediate node 10. The method and apparatus may also transmit the signal to enable the stations to detect the designated mode of operation and the time period of the assigned aggregation period in which to communicate the items of data to the intermediate node.

Finding a transmission opportunity window in a wireless mesh network with fairness provision

A fairness metric is obtained (101) during a mesh profile negotiation performed in order for a wireless station to join a wireless mesh network. Predetermined mesh transmission parameters of the wireless station are sent (102) to previously joined wireless stations in a predetermined neighbourhood of the wireless station. Respective predetermined mesh transmission parameters are received from the previously joined wireless stations (102). In response to a first predetermined event, a transmission opportunity window is determined for the wireless station based on the obtained fairness metric, the predetermined mesh transmission parameters of the wireless station, and the predetermined mesh transmission parameters of the previously joined wireless stations (103).