Nec Usa, Inc.

Hai Xie

Dipankar Raychaudhuri

Ruixi Yuan

A data link control procedure for wireless ATM access channels based on a dynamic TDMA/TDD framework provides integrated ATM services including available bit-rate (ABR) data and constant/variable bit-rate (CBR/VBR) voice or video through the addition of wireless-specific medium access control and data link control protocol layers between the physical and ATM network layers. Generally, a data link control is used to insulate the ATM network layer from wireless channel impairments by selective retransmission of erroneous or lost cells before they are released to the ATM layer. The data link control methods disclosed use the on-demand ABR burst transmission capability of the dynamic TDMA channel to retransmit unacknowledged cells in available slots not allocated to service data. Specific error recovery procedures for both (asynchronous) ABR and (isochronous) CBR services are provided.

Data link control protocols for wireless ATM access channels

A medium access control (MAC) layer protocol is used in a wireless ATM system for integrated support of ATM services, including constant bit-rate (CBR), variable bit-rate (VBR) and available bit-rate (ABR) services. The MAC protocol supports both connectionless packet and connection-oriented virtual circuit modes, with appropriate service parameter and quality-of-services selection. A dynamic time division, multiple access/time division multiplex (TDMA/TDM) approach accommodates the service classes in an integrated manner. A supervisory MAC procedure integrates ATM ABR/VBR/CBR virtual circuits, providing burst-by-burst allocation of ABR cells and call-by-call allocation of VBR and CBR bandwidth parameters. A mechanism is provided for the dynamic allocation of subframe capacities, assignment of ABR slots based on desired queueing rules, assignment of VBR slots based on ATM traffic shaper parameters and assignment of CBR slots based on bandwidth requirements.

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Highland Park, NJ, United States of America

Hai Xie