Airvana Network Solutions, Inc.

Ascend Communications, Inc.

Airvana, Inc.

Ericsson Evdo Inc.

Sanjay Cherian

Arthur J Barabell

Vedat Eyuboglu

Woojune Kim

Andrew T Hebb

Dennis Ng

M Vedat Eyuboglu

Gopal Harikumar

Deepak Garg

Suresh Ramaswamy

In connection with a mobile wireless subnetwork having multiple radio network controllers and multiple radio nodes, a session established for an access terminal is associated with a serving radio network controller. The association is maintained as the access terminal moves from the coverage area of one radio node to the coverage area of another radio node within the same subnetwork. Access channel packets are routed from an access terminal having an existing session to the serving radio network controller by determining the IP address of the serving radio network controller using a session identifier.

Radio network control

In a radio access network, multiple radio network controllers are connected to several radio nodes using a network. The interconnected radio network controllers and radio nodes are addressable, and, therefore, each radio network controller can communicate directly with each radio node and visa versa. The radio access network can be configured to avoid active handoffs between radio network controllers by maintaining a traffic channel set up between an access terminal and a radio network controller even as the flow.

A radio network controller and methods for reestablishing sessions in a wireless network are described. At least a portion of session information associated with a first session is saved; and in response to detecting an unexpected degradation of the first session, reestablishment of the first session is triggered using the portion of the session information.

Preserving sessions in a wireless network

Techniques for network-initiated session recovery are described. A relationship is maintained between two identifiers both associated with a session between a first device and an access terminal in a wireless network. The first identifier is associated with the first device, and the second identifier is associated with a second device in communication with the first device. After a breach of the session, communications associated with the session are preserved based on the relationship between the first and second identifiers.

Network-initiated session recovery

A first session is established for a first mobile access terminal on a first radio network controller via a first radio node. A first traffic channel is established between the first mobile access terminal and the first radio network controller. A first plurality of packets are sent and received over the first traffic channel. The first plurality of packets travel between a first radio node and the first radio network controller without passing through a second radio network controller. The first traffic channel is maintained as the first access terminal moves from a coverage area of the first radio node to a coverage area of a second radio node. A second plurality of packets travel between the second radio node and the first radio network controller without passing through another radio network controller.

A Route Lookup Engine (RLE) for determining a next hop index is disclosed. The RLE receives a lookup key and performs a multi-bit trie search with prefix expansion and capture of a variable stride trie. The data that the RLE returns comprises the next hop information and status flags. The RLE uses a compact, field reusable data structure. The RLE performs both unicast and multicast IP address lookups on Virtual Private Networks. The RLE uses separate indexing and forwarding memories. The upper bound of the search time for the RLE is fixed regardless of the route table size.

Route lookup engine

Packet classification apparatus includes a rule memory and a criterion memory. One type of rule memory entry contains an operator and a pointer to a criterion memory entry. The operator defines a comparison operation to be performed, such as EQUAL (exact match) or LESS THAN. The criterion memory entry contains one or more values to be used as comparands on one side of the comparison, where corresponding values from a received packet appear on the other side of the comparison. Control logic responds to packet classification requests to retrieve a rule memory entry from the rule memory, retrieve the criterion memory entry identified by the criterion memory pointer in the rule memory entry, and perform the operation specified by the operator in the rule memory entry on the values in the criterion memory entry and corresponding values included in the classification request. This procedure is repeated for a sequence of rule memory entries until an ending condition is encountered, whereupon a packet classification result is generated reflecting the result of the classification operations. This result is provided to a packet processor to take the appropriate action based on the classification result.

Packet classification engine

Packet processing logic includes a request queue for receiving lookup requests from a packet processor, where each request includes information elements from a received packet and indicates that a route lookup and a packet classification are to be performed based on the information elements. Both a route lookup engine (RLE) and a packet classification engine (PCE) have respective inputs coupled to the request queue for receiving selected information elements from the requests. Based on the information elements in each request, the RLE searches for forwarding information indicating how the packet corresponding to the request should be forwarded, and the PCE performs a classification process and generates classification information about the packet corresponding to the request. For each request, the forwarding information from the RLE and the classification information from the PCE are combined into a single result stored in a result queue. Each result is provided to the packet processor in a single communication transaction therewith.

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Brookline, NH, United States of America

Sanjay Cherian