Industrial Technology Research Institute

Yao-Tzung Wang

Tzung-Pao Lin

Ray-Guang Cheng

Nen-Fu Huang

Chung-Ju Chang

Huan-Pin Tseng

Paul Huang

Kuo-Yen Fan

Tai-Chung Chang

Hung-Ming Chi

Trung-Pao Lin

Ming-Chia Hsieh

A shared memory management mechanism and method for a high-speed network releases network packets efficiently and maintains the requirement of First In First Out. A series of linked lists including a linked list for each output queue and a linked list of used broadcast packets aids a buffer manager in efficiently managing the buffers in the shared memory. The linked lists include a special data format that encodes the broadcast status, links, and whether the next entry in the list is for unicast or broadcast frames. A scanning procedure scans the broadcast status to efficiently release the broadcast frame buffers. A dynamic scanning procedure consumes less bandwidth than the scanning procedure to efficiently release the broadcast frame buffers.

Shared buffer management mechanism and method using multiple linked lists in a high speed packet switching system

A scheme for arbitrating access to a data bus shared among a plurality of competing sources is provided. Each competing source is assigned an adjustable priority weighting value (PWV) which is initially set to an initial value based on the bandwidth requirements of the competing source. During arbitration, the PWVs of those competing sources requesting access to the bus are compared, and the competing source with the smallest PWV is granted access. The PWV of the competing source which was granted access to the bus is reset to its initial value and the PWV of each competing source which requested, but was denied, access is reduced by one for subsequent comparisons. The arbitration scheme of the present invention is further applied to two-level arbitration. Each competing source is classified into a competing source group, and the requests from the grouped competing sources are processed by first level arbitration. First level arbitration passes one competing source for each group to a second level arbiter. The second level arbiter compares the PWVs of the competing sources resulting from first level arbitration to determine the competing source with the smallest PWV, and adjusts the PWVs after access to the bus has been granted.

Fair data bus arbitration system which assigns adjustable priority

A method and system are disclosed for constructing a power spectrum based connection admission control table and using such a table in a communications network, such as an ATM network. Power spectrum parameters, such as the power spectrum DC component .gamma., half power bandwidth B.sub.w and average power .PSI..sub.w are transformed to .gamma., an equivalent half power bandwidth B.sub.e and an equivalent average power .PSI..sub.e, where B.sub.e is a predetermined constant. Since B.sub.e is constant, the transformation reduces the memory requirements for constructing a connection admission control table.

Power spectrum-based connection admission control for ATM networks

A method and system are provided for implementing virtual local area networks (VLANs) over ATM using LAN over ATM emulation technology. Server nodes which provide address registration/resolution and which enable multicast and broadcast routing on each VLAN are interconnected into multiple trees. The root server nodes of each tree are interconnected according to a hypercube topology. Data structures for maintaining the locations and routing information of mobile terminals is provided. Methods for constructing and updating the data structures when a mobile terminal moves from location to another also provided. Methods are also provided for routing packets using the data structures to and from mobile terminals.

Method for maintaining virtual local area networks with mobile terminals

An exclusive VCC is maintained between each two communicating work stations (MT pair). The handoff method differs if the MT moves to a coverage area having a base station connected to the same switch as the previous coverage area (intra-switch mobility) or to a coverage area having a base station connected to a different switch than the previous coverage area (inter-switch mobility). In intra-switch mobility, the switch changes the path directly to the new base station and eliminates the path through the original base station. In inter-switch mobility, the switch performs the path set-up. The path may be elongated from the switch connected to the original BS, to the new BS, rather than from the original BS to the new BS. This eliminates the path through the original base station. The exclusive VCC between the MT pair permits path elongation to be minimized.

Seamless handoff for a wireless lan/wired lan internetworking

A system and process are provided for controlling congestion at a node of an asynchronous transfer mode (ATM) communications network. The process and system utilize fuzzy logic in determining whether or not to 'admit,' i.e., allocate a virtual channel (VC) for, new communications (or calls) to the node. Fuzzy logic is also use to control the rate cells are transmitted to the node for communications already 'admitted,' i.e., for which a VC has already been allocated. The fuzzy logic rules for bandwidth estimation in admission control may be developed from an 'equivalent capacity' model. The fuzzy logic rules for adjusting cell transmission rates may be developed from a 'two-threshold' congestion control model.

Growing community of inventors

Hsinchu, Taiwan

Yao-Tzung Wang