Abstract: A method and system for conveying contextually relevant information to a wireless client are disclosed. More particularly, a transmitter transmits a diffuse infrared signal to a client having an IrDA compliant communication interface. The transmitter communicates with the client by making a link layer in the transmitter compliant with an IrDA link layer running on the client. To perform communication, data is received at the transmitter from a service provider. The data is formatted into an IrDA compliant diffuse infrared signal and transmitted to the client. The client receives the data and parses it to extract contextually relevant information contained therein. The client may reply to the transmitter if a user of the client is interested in a service offered by the service provider. If the service provider receives a reply from the client, the service is made available to client.

Abstract: An apparatus and method for conveying contextually relevant information to a wireless client (112) is disclosed. More particularly, an emitter (108) transmits a diffuse infrared signal to a client (112) having an IrDA infrared communication interface (130). Emitter (108) communicates with client (112) by making a link layer in emitter (108) compliant with an IrDA link layer running on client (112). To perform communication, data is received at emitter (108) from a service provider (102). The data is formatted into an IrDA compliant diffuse infrared signal and transmitted to client (112). Client (112) receives the data and parses it to extract contextually relevant information contained therein.

Abstract: A system and method for determining the context of a wireless device is disclosed. An emitter (108) transmits an infrared signal to a wireless client (112). Emitter (108) is placed at a known location and has a known coverage area associated therewith. The location and coverage area form a locational context for emitter (108) and a client (112) located within the coverage area. Emitter (108) receives data from a service provider (102). The received data is relevant to the locational context of emitter (108). Emitter (108) transmits the data to client (112) using a diffuse infrared signal (142). Client (112) receives the signal and processes it such that only information of interest to a user of client (112) is displayed.

Abstract: A system and method for distributing services to a handheld device in a constrained networking environment is disclosed. A service provider (102) creates an advertisement containing information about a service. The advertisement is sent to emitter (108). Emitter (108) transmits the advertisement to a wireless client (112) using a wireless optical signal (142). Client (112) receives optical signal (142) if it is located within a coverage area associated with emitter (108). The advertisement is displayed on client (112) if a user of client (112) has previously expressed an interest in the service.

Abstract: A system and method for performing reliable unidirectional communication in a data network is disclosed. Unidirectional data is sent from a transmitting device to a receiving device. Prior to transmission, the data is divided into a window (401a) comprised of data bytes. A checksum value (407) is computed across data bytes comprising window (401a). Checksum value (407) is placed into an XML integrity element (402) that encapsulates window (401a) in a manner allowing a receiving device to use the contents of integrity element (402) to validate the received window (401a). Checksum value (407) is compared to a second check sum value computed across window (401a) at the receiving device. If checksum value (407) matches the second checksum value, window (401a) is validated.

Abstract: In an optical switching network, a master optical space switch is interconnected with remote slave equipment for switching block-multiplexed messages among the remote equipment. The master optical space switch responds to a frequency reference clock and steps through a sequence of states, or configurations, for establishing various routes among the remote equipment for appropriately routing the messages to correct destinations. The frequency reference clock also is distributed to the remote equipment. During one of the states per frame, each remote slave equipment transmits a distinct signature signal. All of the slave equipments are connected through the master optical space switch to return to themselves their own signals transmitted during that time slot. Each remote slave equipment compares the returned signal with the originally transmitted signature signal to determine how much the round trip delay has varied from a nominal value.