Ntt Docomo, Inc.

Johnny M Matta

Atsushi Takeshita

Ravi Kumar Jain

Khosrow Lashkari

Christine Pepin

A method of estimating bandwidth capacity, available bandwidth and utilization along a path in an IP network is disclosed. ICMP time-stamp requests are sent from a source host on the edge or inside the network to all routers on the end-to-end path to a desired destination. Differences between time-stamp values are used as indicators of QoS service at each router. The collected measurements are then processed at the sending host to infer QoS parameters in terms of path capacity in bit/sec, available bandwidth in bits/sec, individual link utilization and congestion at each router. These parameters can be combined to infer the QoS service in terms of bandwidth on the end-to-end path.

Catprobe

A coding system and method for a terminal including a multi-rate codec is disclosed. The terminal includes a multi-rate adaptive coder that is capable of transmitting a continuous voice stream transmission at a source code bit rate and a channel code bit rate. A quality of service probing module probes an end-to-end network path of the continuous voice stream transmission to obtain at least one quality of service parameter. A quality of service management module determines at least one constraint associated with the continuous voice stream transmission. An adaptive bit rate algorithm module dynamically adjusts the source code bit rate and the channel code bit rate as a function of the quality of service parameter and the constraint to obtain a maximum value of perceived user performance during the continuous voice stream transmission.

Source and channel rate adaptation for VoIP

A method for providing a triggering mechanism in an all-IP wireless communication system. A plurality of communication paths are established between a mobile terminal and a correspondent node to obtain at least one QoS parameter associated with each communication path. Each communication path that provides a predetermined acceptable level of performance is then identified. A handoff trigger is then generated to the communication path that provides the highest level of performance to the mobile terminal.

Layer three quality of service aware trigger

A method of estimating QoS for making a handoff trigger decision for a remote terminal in a wireless IP network is disclosed. At least a first and second probing packet is generated with an access router from a plurality of access points. The first and second probing packets are then sent from the access routers over a fixed core network having a plurality of routers to a correspondent access router and then back to the access routers. At least one collector packet is also generated and sent to follow the first and second probing packets to gather at least one predetermined QoS parameter from the routers after the first and second probing packets have left the routers. The QoS parameters are then processed with the access routers to make the handoff trigger decision preferentially along with layer two QoS parameters of the wireless hop.

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San Jose, CA, United States of America

Johnny M Matta