197 results about "Channel reservation" patented technology

Backhaul traffic reliability is improved in unlicensed spectrum bands by using cross-protocol channel sensing and reservation. Physical carrier sensing may be employed to scan channel quality of a plurality of carriers of an unlicensed spectrum band and select a carrier for use in a wireless backhaul communications link between a first base station and a second base station based on the scanned channel quality. The described features may further include the first base station transmitting a self-addressed reservation frame on the selected first carrier prior to transmission of backhaul data from the first base station to the second base station over the first carrier.

In a relay scheme, a wireless source apparatus, a wireless destination apparatus and a wireless relay apparatus cooperate for handling transmission failures by space/time diverse channels. In the case of the successful direct transmission, reduced or no additional overhead for the relay selection is incurred. Thus, for a good SNR between source and destination, the inventive protocol has similar performance as a standard approach. In the case of a transmission failure e.g., due to small scale fading, a transmission via a different communication path implementing spatial diversity via a selected relay is supported. The device is to only activate the overhearing of signals in case of weak signal quality between sender and receiver. This selection of relay devices is done by demand only. A specific protocol for the reservation of the wireless medium for the entire cooperative communication has been specified.

An apparatus includes a first node configured to transmit both data frames and requests for channel reservations to a local contention neighborhood of a network. The first node is configured to compete with other nodes of the neighborhood for reservations to the channel. The first node is configured to dynamically update a stored value of an access priority for the first node and to transmit said requests with a rate that depends on the stored value.

Channel reservation systems and methods are disclosed herein, which schedule transmissions on a shared radio medium that is shared by a plurality of licensed network operators. In embodiments, priority access is pre-assigned to the network and the method determines whether to send a transmission based at least on the transmitter's priority class as compared to another transmitter's priority class and to which transmitter the time slot of a signal is dedicated. In embodiments, priority access may not be preassigned to the network and pre-grants may be used in conjunction with CR-Ts and CR-Rs to determine whether a transmitter transmits.

Systems and methods are disclosed for mitigating interference between Radio Access Technologies (RATs) sharing operating spectrum in an unlicensed band of radio frequencies. The mitigation may comprise, for example, identifying an upcoming signal transmission associated with a first RAT, with the signal transmission being scheduled for transmission on the shared operating spectrum during a transmission period. The signal transmission may be classified with respect to a protection status. Based on the protection status, a channel reservation message may be transmitted that is associated with a second RAT to reserve at least a portion of the shared operating spectrum for at least a portion of the transmission period.

Techniques for co-existence on a shared communication medium are disclosed. To foster co-existence, operation of a first Radio Access Technology (RAT) may be cycled between active periods and inactive periods of transmission, on a communication medium shared with a second RAT, in accordance with a Discontinuous Transmission (DTX) communication pattern. An identifier may be selected for association with the first RAT. A channel reservation message associated with the second RAT may then be transmitted, over the communication medium, to reserve the communication medium for one of the active periods, the channel reservation message including the identifier.

A setting unit sets a specified time serving as a clear-to-send time, during which a two-way frame transmission is possible between a local wireless base station and a wireless terminal station accommodated in the wireless base station, and as a wireless-channel reservation time used for a frame transmission between the wireless base station and the wireless terminal station, and wireless terminal station specifying information for specifying a wireless terminal station to which the specified time is applied, in a transmission control frame. A transmitting unit transmits the transmission control frame to the wireless terminal station.

Techniques for reservation coordination and related operations in shared spectrum are disclosed. Communication over a communication medium may be performed in accordance with a first Radio Access Technology (RAT) and in accordance with a communication pattern of active periods and inactive periods of communication. A channel reservation message may be transmitted in accordance with a second RAT to reserve the communication medium for one of the active periods. The channel reservation message may be transmitted randomly at a plurality of successive burst slots. In addition or as an alternative, one or more medium access parameters associated with the channel reservation message may be set to a value below a threshold associated with aggressive contention.

The invention provides a vehicle-mounted ad-hoc network asynchronous multichannel MAC access method based on time division multiplexing, and relates to a mobile communication system. According to the invention, a node which is not required to transmit and receive service information is used to continuously monitor a control channel in an audio way to obtain security information and channel synergic information. The access method comprises the following steps: when a node is to send service information, transmitting channel reserving information, after reserving the channel, immediately transferring to the corresponding service channel to transmit the service information, after transmitting the service information, immediately returning to the control channel to perform audio monitoring, and solving the problems of low channel utilization and the bottleneck of the control channel. Compared to the mechanism that according to the IEEE 1609.4 standard, the channels of all nodes are synchronously switched, the vehicle-mounted ad-hoc network asynchronous multichannel MAC access method can avoid idle channel; in addition, the time division multiplexing method can solve the bottleneck problem of the control channel and reduce conflict possibility of the control channel; the node synergic method is used to reduce the influence caused by data packet collision on the service channel.

Detection and reporting techniques for collisions between transmitters of two different radio access technologies (RATs) transmitting in a shared radio frequency spectrum band is described. The collision may occur following a listen-before-talk procedure but prior to transmission of data, and may not affect the reception of the transmitted data. Collisions may be detected using for example, energy sensing, preamble or ready-to-send (RTS) signal detection, or unsuccessful decoding of all or part of a channel reservation signal. A transmitting device may determine a collision has occurred by detecting an energy level during a preamble transmission is greater than a threshold level or by detecting that an energy level during a transmission gap of a time-domain energy pattern is above a threshold level. A receiving device, such as a user equipment (UE), that detects the collision may report the collision to the transmitter.

The invention discloses a multi-channel multiple access method based on a channel reservation mechanism in a wireless ad-hoc network. The invention works in a fully distributed network without requiring synchronization of the entire network. In the network using this protocol, the nodes complete the exchange of handshake information on a common channel, and use the reservation mechanism to reserve the sending of a certain number of data packets at the same time as the handshake information is exchanged. The reservation mechanism enables multiple data packets to be sent with only one handshake information exchange, which reduces the load of the public channel and greatly improves the throughput of the network. At the same time, because the time of sending the reserved data packets can be determined, the protocol is particularly suitable for transmission Services that require very high real-time performance, such as video.

Techniques are described for wireless communication. A first method includes contending for access to a first channel of a radio frequency spectrum, and transmitting, upon winning contention for access to the first channel, a first channel reservation indication. The contending may be performed by a first node operating according to a first radio access technology. The first channel reservation indication may be understood by a second node operating according to a second radio access technology.

The invention discloses a multi-frame transmission method. The method comprises the following steps that: based on amount and/or length of data to be sent to the current receiving station in the current access queue, a sending station determines the time for occupying a channel to perform frame exchange with the current receiving station; the sending station generates channel reservation time information according to the determined time for occupying the channel to perform frame exchange with the current receiving station; and the sending base station performs frame exchange with the current receiving station according to the generated channel reservation time information. The invention further discloses a multi-frame transmission system. With the method and the system, the channel reservation time of the stations in an OBSS (Object Based Storage System) is reduced, thus, an auditing station can set shorter NAV (Network Allocation Vector) settings, the system throughput of the OBSS is improved, and the high efficiency of each station in the OBSS under the condition of large-bandwidth is ensured.

Wireless communications systems and methods related to solving deafness problems in directional clear channel assessment (CCA) procedures. A first wireless communication device transmits, to a second wireless communication device in a first beam direction, a first channel reservation for receiving a data burst. The first wireless communication device receives, from the second wireless communication device, a first portion of the data burst. The first wireless communication device transmits, in the first beam direction, a second channel reservation for receiving one or more remaining portions of the data burst. The first wireless communication device receives, from the second wireless communication device, a second portion of the data burst. Other aspects, embodiments, and features are also claimed and described.

There is provided a method for defining at least one channel reservation window the method comprising: setting length for each of the at least one channel reservation window such that each channel reservation window comprises a plurality of sub-frames; dividing the length of each channel reservation window into a transmission part and an idle part, wherein the idle part consists of one or more symbols in one sub-frame; maximizing, at a symbol level accuracy, the length of the transmission part such that a ratio between the length of the idle part and the length of the transmission part fulfils a predetermined criterion; and concatenating the transmission part and the idle part so as to form the channel reservation window.

The invention discloses a method and a device for message transmission. By employing channel occupying parameters and message retransmission parameters as adjustment references, message transmission treatment is conducted by dynamically enabling a channel reservation mechanism to work and stop working; accordingly, when in severe spatial environment and busy time, the channel reservation mechanism of an RTS/CTS mechanism or a CTS-To-Self mechanism is reasonably used to transmit messages; the method decreases use conflicts of system resources and improves WLAN network application quality.

Systems and methods for co-existence between wireless Radio Access Technologies (RATs) employing channel reservation on a shared communication medium are disclosed. One or more channel reservation messages defined for a first RAT may be received to reserve the communication medium for a reservation duration, with the communication medium comprising a plurality of component channels. A first component channel may be determined among the plurality of component channels to be protected for operation of a second RAT in accordance with the one or more channel reservation messages. Communication via the first RAT may nevertheless proceed on a second component channel among the plurality of component channels during the reservation duration.

Techniques for reservation coordination on a shared communication medium are disclosed. An access point, for example, may contend for access to a communication medium, and transmit a channel reservation message in accordance with a first Radio Access Technology (RAT) to reserve the communication medium for a transmission opportunity (TXOP) duration based on the contending. The access point may then transmit, during the reserved TXOP duration, a reservation coordination signal in accordance with a second RAT to convey reservation coordination information associated with the reserved TXOP duration.

The invention relates to a channel reservation switching control method based on service priority. The method comprises the following steps: a current cell acquires the position information of users regularly; when the users move to the border of the current cell, the current cell notifies a neighboring cell to be switched to; the neighboring cell sets different reserved channels for different users on the basis of service priority according to the occupation condition of channels of the neighboring cell; and when the reserved channels are not enough, urgent users occupy channels reserved for users with low priority in a complete occupation way, and the users with low priority enter a queuing line and wait for scheduling. By utilizing the method disclosed by the invention, the switching failure rate of the users can be reduced obviously, the switching performance of the urgent users can be guaranteed, and the requirements of urgent communication tasks can be met.

The invention relates to a channel allocation method for a low-orbit satellite communication system. By combining a self-adaptive channel reservation strategy with an enhanced queuing strategy, channel allocation schemes are dynamically adjusted according to different channel occupancy rates. The method comprises the following steps: carrying out pre-allocation to enable the number of fixed channels of satellite beam cells to be same, and dividing the channels in each satellite beam cell into common channels and preservation channels; sending a resource request to a satellite control center by virtue of a terminal; judging whether the common channels are idle by virtue of the low-orbit satellite communication system after resource request arrives; and if yes, determining different channel allocation schemes according to the occupancy rate of the common channels, and carrying out channel allocation. By combining the self-adaptive channel reservation strategy with the enhanced queuing strategy, the channel resources are adequately utilized, and requirements of different users are furthest met, so that the integral service quality of the system is in a relatively high level under the condition that a small part of low priority businesses are inevitably sacrificed.