Abstract: A paging communication system providing functions of two-way communication and control (supervisory) for one-way pager groups, comprises a monitoring server having functions of monitoring pager status/dispatch/response/tracking for control and two-way communication between a controller (managers)/commander of an emergency rescue group and pagers of all group members; the group of using pagers can access to the monitoring server for registration via Internet; after linking to the monitoring server, the controller of the pager group and all group members can transmit messages, such as dispatch messages and Ack messages, to the monitoring server in process of classification/statistics and storage in a database, and then the controller can access to the database via Internet to search and look at each message, and also each group member can retrieve the paging messages from the monitoring server via GSM/GPRS system; the group which has logged in the monitoring server has the ability of two-way communication.

Abstract: A structure of a keyboard is combinable with an electronic device, and includes a keyboard body and a frame. The frame is of a U-shape having two limbs that has end portions slidably fit in elongate slots defined in two side walls of the keyboard body to be movable along the slots and rotatable with respect thereto. When the keyboard body and the frame are assembled together, the keyboard structure defines in a top thereof a receptacle for receiving and retaining the electronic device. The keyboard body includes a signal output structure engageable with a signal transmission interface of the electronic device. When combined together for operation, the electronic device is movable with the frame to expose keys of the keyboard. The electronic device is detachable from the keyboard structure for independent operation thereby reducing the overall size for easy carrying.

Abstract: An emergency communication and dispatching system has an operating console and a plurality of 2-way radios. 2-way radios are carried separately by the staff on duty and communicated with the operating console or other staff. Of which, the operating console could receive the event information and pictures from the reporting source and transmit them to the 2-way radio of any staff, while a camera could be used by the staff to take the pictures at the scenes. The 2-way radio is used to transmit the pictures and position data to the operating console or the receiver of other staff, so as to improve the communication and execution efficiency of public security or military personnel.

Abstract: A communication system and method for dispatch service is suitable for RF communication system of a group, wherein the mobile device receives dispatch services of paging message on the first channel, then executes quick reply function via 2-Way Radio or GSM network, so as to transmit text or voice message to the dispatch center; the mobile device also comprises a channel scanning function and a double frequency scanning function, of which the channel scanning function is used to monitor and select a second channel and write into the device, and then the double frequency scanning function is executed to transmit message on the second channel

Abstract: A method of implementing push-to-talk (PTT) communication between network phone clients utilizing Session Initiation Protocol (SIP) Voice over Internet Protocol (VoIP) and multicast RTP, includes pushing a “Talk” button on a talking client to generate a PTT invitation message (via SIP INVITE or MESSAGE), transmitting the PTT invitation message from the talking client to a SIP server, transmitting the PTT invitation message from the SIP server to a PTT server, consulting a group list stored on the PTT server to identify a plurality of receiving clients associated with the talking client, sending the PTT invitation message from the PTT server to the plurality of receiving clients, the PTT server receiving acknowledgement of the PTT invitation message from the plurality of receiving clients. The PTT server arbitrates the token-requests of the clients, translates a unicast-to-multicast RTP of token-request and talk-burst packets, and then broadcasts to all clients.

Abstract: A personal digital assistant (PDA) with a foldable memory card adapter has a PDA and a memory card adapter. The PDA is formed with a connecting slot in one edge of the PDA. The memory card adapter is connected to the PDA by a slide connector on an end a signal bus made of flexible material. When the card adapter is attached to the PDA, the slide connector is linked to the connecting port, whereby the memory card adapter can be folded to overlap the rear of the PDA. Thus the entire size of the PDA device is reduced and convenient to carry.