Alaxala Networks Corporation

Hitachi, Ltd.

Hitachi Computer Engineering Co., Ltd.

Hitachi, Ltd. and Hitachi Microcomputer System Ltd.

Atsushi Anzai

Yoshihiko Sakata

Hideki Hinosugi

Takeshi Kumagai

Hidehiko Jusa

Shinsuke Nakashima

Takeshi Aimoto

Hiroki Yano

Kazunori Nakamura

Kenichiro Orita

Takaharu Aoyama

Kaoru Okano

A packet relay device comprises a distribution processing unit classifying traffics into groups and users based on header information of packets received; a calculation unit calculating available frame rate of each user from peak frame rate, minimum frame rate, and weight information set for each user; a scheduling control unit updating a transmission schedule point-in-time calculated based on the available frame rate of each user, and judging which packet should be transmitted in accordance with the transmission schedule point-in-time updated; and a shaping unit updating a transmission schedule point-in-time calculated based on the peak frame rate of each user, and performing a shaping of packets at the peak frame rate on each user basis in accordance with the transmission schedule point-in-time updated; and a priority-control processing unit performing a strict priority control over transmission of packets of each group in correspondence with degree of priority of each group.

Traffic shaping method and device

A bandwidth calculation section calculates a usable bandwidth from a communication amount of each user or a session connection time stored in a statistic management memory and minimum bandwidth information and maximum bandwidth information recorded in a bandwidth setting memory. The bandwidth calculation section allocates a large usable bandwidth to a user with a small communication amount or a short session connection time. A transmission control section performs transmission scheduling of packet information stored in a packet buffer based on a transmission scheduled time calculated from the usable bandwidth stored in a transmission scheduled time memory.

Bandwidth control apparatus

A traffic shaping apparatus calculates a minimum transmission interval, an allowed transmission frame rate of a user frame, and a reference transmission interval for each user according to a minimum transmission frame rate and a peak transmission frame rate specified for each user. The traffic shaping apparatus also calculates a first estimated transmission time according to the reference transmission interval, and a second estimated transmission time according to the minimum transmission interval for each user. The traffic shaping apparatus determines the user having the earliest first estimated transmission time, and determines according to the second estimated transmission time of the user whether a user frame is to be transmitted.

Traffic shaping apparatus and traffic shaping method

In a wireless LAN system, each wireless terminal device determines whether or not the wireless terminal device has entered into a wireless LAN domain established by a base station, and if it has entered, transmits an entry terminal identification information update control frame including identification information of its own device to the base station at a predetermined time interval. The base station receives the entry terminal identification information update control frame from the wireless terminal device, stores in a storage the identification information of the wireless terminal device entered into the wireless LAN domain established by its own base station, and when it receives an information frame from a wired transmission line connected to its own base station, relay-transmits only the information frame to the wireless terminal device having the identification information thereof stored in the storage by referring the information stored in the storage.

Wireless LAN system, base station device and wireless terminal device

A wireless LAN system which allows the transmission and reception of various data without lowering the transmission efficiency and the transmission quality even in an overlapping environment of areas of a plurality of wireless LANs and a base station apparatus therefor are provided. The wireless LAN system has a plurality of wireless LANs including base stations and wireless terminal devices, and the base stations and the wireless terminal devices in the wireless LANs communicate while sequentially hopping carrier frequencies to conduct the intercommunication between the base stations in the wireless LANs through inter-base station communication units. Each base station includes a unit for transmitting and receiving a specific frame to and from other base stations through the inter-base station communication unit to determine whether its own base station is a master base station or not and a unit for assigning different hopping start frequencies to its own base station and other base stations when its own base station is determined as the master base station.

Wireless LAN system and base station apparatus

Growing community of inventors

Ebina, Japan

Atsushi Anzai