Canon Kabushiki Kaisha

Masanori Nakahara

Kenichi Fujii

Mitsuhiro Watanabe

Hiroshi Mashimo

Kazutoshi Hara

Ken'ichi Fujii

Ken′ichi Fujii

Ken'ichi Fuji

This invention has as its object to set a one-to-one relationship upon establishing a wireless communication channel between a wireless communication device on the information transmitting side and a wireless communication device that receives and processes the information even in an environment including a plurality of wireless communication devices, and to assure simple user's operations at least until the communication channel is established. To this end, when the user inputs a wireless communication channel establishment instruction to both a digital camera and printer having wireless communication functions, these devices execute wireless communication establishment processes within an allowable time period which is specified by a time set in a timer and a retry count. When the devices can seize each other within that time period, the communication channel is established. After that, the digital camera sends a sensed image to the printer, which prints the sensed image.

Wireless communication system, device, and control method for searching multiple communication frequency channels and processing cryptographic communication in an infrastructure mode using a received communication parameter including information of an encrypted key

Wireless communication system, and wireless communication device and control method for establishing a connection with another wireless device before an elapsed time period without the intervention of a base station

Power saving cannot be implemented in the adhoc mode by only the IEEE 802.11 standard. This is because communication partners mutually utilize the power save mode in the adhoc mode, and their states must always be managed. In the adhoc mode, the number of communication partners is not always one, and all stations which join a network are candidates, increasing the load of implementation. To solve this problem, a communication apparatus notifies a change to power save mode by an ATIM packet, RTS packet, or null packet. When the ATIM packet or RTS packet is transmitted, the communication apparatus can notify the partner of a change in mode regardless of whether the partner is in the power save mode. When the null packet is transmitted, the communication apparatus can rapidly notify the partner without waiting for any beacon.

Communication apparatus and communication method

In the power save mode of an IEEE 802.11 adhoc network, a packet loss occurs unless the power save state of a receiving side is detected, failing in communication. However, there is no explicit notification on joining/leaving in/from a network, and it is difficult to detect and manage the state of a partner, including the detection timing. To solve this problem, a terminal always transmits an information notification packet (ATIM packet) in a time during which all terminals can receive it, prior to data transmission regardless of the power save state of a partner. With this mechanism, the terminal also explicitly notifies the partner of a change in the power save state of the terminal.

Method and apparatus for reducing the load of managing the power save state of a partner

Wireless communication system, and wireless communication device and control method for establishing a one-to-one relationship between wireless communication devices

This invention has as its object to establish a wireless communication between wireless communication devices and to provide a desired service without any troublesome setup operations. To this end, a digital camera and printer of this invention have wireless communication functions. When it is determined that a wireless communication instruction is issued by a console of the digital camera, a beacon from a network is detected. Upon detection of the beacon, search request information used to confirm the presence of a wireless communication processing device on a network identified by network identification information included in the beacon is transmitted in accordance with that network identification information. If response information to this transmitted request information is detected, identification information of a partner wireless communication device included in the response information is stored, and is displayed to allow the user to select a connection target device.

Wireless communication system, and wireless communication device and control method

A communication apparatus which starts communication using a power-saving function changes, with its communication counterpart, a key for a confidential mode and performs power-saving communication. When terminating the power-saving function, the communication apparatus returns, with its communication counterpart, the key for the confidential mode to the original one. Then, after returning the key for the confidential mode to the original one, the communication apparatus performs an IP address reassignment process.

Communication apparatus having power-saving communication function, and communication method

This invention enhances the security strength of wireless communications in the ad-hoc mode. To this end, it is checked if the communication apparatus and a terminal of a communication partner can concurrently use different encryption keys in correspondence with a plurality of communication destinations. When at least one of the communication apparatus and the terminal of the communication partner cannot concurrently use different encryption keys in correspondence with the plurality of communication destinations, an encryption key uniquely set in the wireless network is set as an encryption key for a communication with the terminal of the communication partner.

Communication apparatus and method thereof

This invention has as its object to set a one-to-one relationship upon establishing a wireless communication channel between a wireless communication device on the information transmitting side and a wireless communication device that receives and processes the information even in an environment including a plurality of wireless communication devices, and to assure simple user's operations at least until the communication channel is established. To this end, when the user inputs a wireless communication channel establishment instruction to both a digital camera and printer having wireless communication channel establishment instruction to both a digital camera and printer having wireless communication functions, these devices execute wireless communication establishment processes within an allowable time period which is specified by a time set in a timer and a retry count. When the devices can seize each other within that time period, the communication channel is established. After that, the digital camera sends a sensed image to the printer, which prints the sensed image.

Wireless communication system, wireless communication device, and control method for establishing a one-to-one relationship

Method for rapidly shifting a communication apparatus to a power save mode in an adhoc network

In a communication apparatus for wirelessly communicating directly with a communication apparatus that is participating in a network, a filter is set so as to receive only a signal from a communicating party before start of a power-saving control function at the time of standby, the set filter is removed after the power-saving control function for standby is terminated, and a logical address on the network is reset. As a result, when the power-saving control function is utilized, collision of physical addresses is prevented and it is possible to perform data communication without mismatch.

Communication apparatus and method with physical address filter for power-saving control state

In an image distribution system comprising a camera controllable by an external device, a camera server having a function of digitizing and transmitting an image signal acquired by the camera via a network and a function of issuing authorization to control the camera, a viewer which receives and displays the transmitted digitized image signal, further requests to control the camera, and a network connecting the camera server and the viewer, in a case where the camera server issues the authorization to control the camera to the viewer and communication between the viewer and the camera server is undesirably terminated while the viewer holds the authorization, when the viewer restores the communication within a predetermined period, it is allowed to continuously control the camera under the same conditions as at the time of the undesired termination.

Growing community of inventors

Chigasaki, Japan

Masanori Nakahara