Abstract: The present invention is configured such that, in a multicast service providing system in which multicast information distribution service is made from an information distributing apparatus to radio terminals present within a service area via a radio section, the radio terminal has service continuation request signal transmitting a service continuation request signal for requesting continuation of the multicast information distribution service to the information distributing apparatus, the information distributing apparatus has service continuation management means managing as to whether or not request for the service continuation has been made by the radio terminal for the multicast information distribution service, and the information distributing apparatus transmits information indicating as to whether or not continuation request has been made for the multicast information distribution service managed by the service continuation management means.

Abstract: In a wireless base station, when a newly provided control unit receives an IP packet from one mobile station (102), it refers to a destination address in control information added to the IP packet (104), and determines whether the IP packet is one to be broadcast or multicast (106). If the value of destination address is at a value indicative of broadcasting or the like defined by IP, the IP packet is copied according to the subnet, and is sent back to a wireless link layer processor with its contents intact (108). Further, the wireless link layer processor is commanded to broadcast the sent-back IP packet in a wireless area and so forth (110), whereby the IP packet can be broadcast into a cell and so forth.

Abstract: In a retransmission control method for a multicast information distribution service, when information which requires retransmission is generated, a wireless terminal transmits the retransmission request for the information to an information distribution apparatus when a timing determined for the wireless terminal is reached. The information distribution apparatus which receives the retransmission request transmits retransmission information which indicates the information requested by the retransmission request, with respect to each of the wireless terminals within the service area, and retransmits the information requested by the retransmission request at a predetermined timing.

Abstract: The present invention is configured such that, in a multicast service providing system in which multicast information distribution service is made from an information distributing apparatus to radio terminals present within a service area via a radio section, the radio terminal has service continuation request signal transmitting a service continuation request signal for requesting continuation of the multicast information distribution service to the information distributing apparatus, the information distributing apparatus has service continuation management means managing as to whether or not request for the service continuation has been made by the radio terminal for the multicast information distribution service, and the information distributing apparatus transmits information indicating as to whether or not continuation request has been made for the multicast information distribution service managed by the service continuation management means.

Abstract: One preferred embodiment of the invention provides a wireless base station which provides a multicasting service to simultaneously transmit identical data to a plurality of wireless terminals. A wireless base station is connected to a plurality of wireless terminals and provides a multicasting service for a plurality of wireless terminals. The wireless base station determines autonomously whether it provides the multicasting service for the plurality of wireless terminals. Another preferred embodiment of the invention provides a method of selecting a wireless base station for a wireless terminal, the wireless base station providing a multicasting service for the wireless terminal. When the wireless terminal can receive the same multicasting information from a plurality of wireless base stations, the wireless terminal selects one of the plurality of wireless base stations so as to make the number of the wireless base stations that send the same multicasting information as small as possible.

Abstract: One preferred embodiment of the invention provides a wireless base station which provides a multicasting service to simultaneously transmit identical data to a plurality of wireless terminals. A wireless base station is connected to a plurality of wireless terminals and provides a multicasting service for a plurality of wireless terminals. The wireless base station determines autonomously whether it provides the multicasting service for the plurality of wireless terminals. Another preferred embodiment of the invention provides a method of selecting a wireless base station for a wireless terminal, the wireless base station providing a multicasting service for the wireless terminal. When the wireless terminal can receive the same multicasting information from a plurality of wireless base stations, the wireless terminal selects one of the plurality of wireless base stations so as to make the number of the wireless base stations that send the same multicasting information as small as possible.

Abstract: One preferred embodiment of the invention provides a wireless base station which provides a multicasting service to simultaneously transmit identical data to a plurality of wireless terminals. A wireless base station is connected to a plurality of wireless terminals and provides a multicasting service for a plurality of wireless terminals. The wireless base station determines autonomously whether it provides the multicasting service for the plurality of wireless terminals. Another preferred embodiment of the invention provides a method of selecting a wireless base station for a wireless terminal, the wireless base station providing a multicasting service for the wireless terminal. When the wireless terminal can receive the same multicasting information from a plurality of wireless base stations, the wireless terminal selects one of the plurality of wireless base stations so as to make the number of the wireless base stations that send the same multicasting information as small as possible.

Abstract: In a wireless base station, when a newly provided control unit receives an IP packet from one mobile station (102), it refers to a destination address in control information added to the IP packet (104), and determines whether the IP packet is one to be broadcast or multicast (106). If the value of destination address is at a value indicative of broadcasting or the like defined by IP, the IP packet is copied according to the subnet, and is sent back to a wireless link layer processor with its contents intact (108). Further, the wireless link layer processor is commanded to broadcast the sent-back IP packet in a wireless area and so forth (110), whereby the IP packet can be broadcast into a cell and so forth.

Abstract: The present invention is configured such that, in a multicast service providing system in which multicast information distribution service is made from an information distributing apparatus to radio terminals present within a service area via a radio section, the radio terminal has service continuation request signal transmitting a service continuation request signal for requesting continuation of the multicast information distribution service to the information distributing apparatus, the information distributing apparatus has service continuation management means managing as to whether or not request for the service continuation has been made by the radio terminal for the multicast information distribution service, and the information distributing apparatus transmits information indicating as to whether or not continuation request has been made for the multicast information distribution service managed by the service continuation management means.

Abstract: In a retransmission control method for a multicast information distribution service, when information which requires retransmission is generated, a wireless terminal transmits the retransmission request for the information to an information distribution apparatus when a timing determined for the wireless terminal is reached. The information distribution apparatus which receives the retransmission request transmits retransmission information which indicates the information requested by the retransmission request, with respect to each of the wireless terminals within the service area, and retransmits the information requested by the retransmission request at a predetermined timing.

Abstract: A digital modulation and demodulation scheme for radio communications which is capable of reducing errors due to fading while maintaining the characteristic of the M-ary modulation and demodulation scheme that it is robust against interferences. At the transmitting side, transmission data are divided in advance into blocks of LN bits length each and each block is divided into N sets of L bits data sequences. Then, orthogonal codes of M bits length each corresponding to L bits codes given by the L bits data sequences are generated, and N sets of orthogonal codes for each block are multiplexed into a multiplexed signal, such that M bits constituting each orthogonal code are dispersed in time in the multiplexed signal. A digital modulation is then applied to a carrier using the multiplexed signal.

Abstract: A retransmission control method in a multicast service providing system in which an information delivery apparatus delivers multicast information to radio terminals within a service area of the information delivery apparatus, includes two steps. The first step determines at least one radio terminal permitted to be placed in retransmission control. The second step delivers, when a request for retransmission about the multicast information sent by the above-mentioned at least one radio terminal is received by the information delivery apparatus, the multicast information to the radio terminals within the service area.