Systems and methods for orthogonal frequency division multiplexing are provided. In one embodiment, a multi-carrier modem comprises: a receiver configured to de-modulate symbols from at least one of a plurality of spectrally overlapping carrier signals to produce a receiver output; a transmitter configured to modulate symbols onto at least one of a plurality of the spectrally overlapping carrier signals; a processor coupled to the transmitter, wherein the processor outputs data for transmission by the transmitter, wherein the processor applies an inverse Fourier transform to the data transmitted by the transmitter; the processor coupled to the receiver, wherein the processor applies a Fourier transform to the receiver output; and a controller programmed to instruct the transmitter to transmit at least one symbol representing a request for bandwidth allocation on a first carrier; wherein the controller is further programmed to determine when a collision has occurred on the first carrier.

Systems and method for orthogonal frequency divisional multiplexing

The present invention relates to methods and apparatus providing for a switching hub in which an asynchronous transfer mode (ATM) switch is utilized as a backplane bus. Bus arbitration, i.e., allocation of bandwidth, on the bus for autonomous ATM and LAN switching modules coupled thereto is dynamically controlled according to the needs of the various modules. In particular, the present invention allows time division multiplexing of the bus under programmatic control such that each module, e.g., an Ethernet or Token Ring module, is allowed a desired number of cell slots on the bus during which to transfer data, which the module has translated into ATM cells, across the bus.

Method and apparatus for dynamically allocating bandwidth on a TDM bus

A congestion detection system and method for an advanced ATM network measures congestion in a number of dimensions. In one embodiment, cell traffic is measured on a per virtual channel basis, per service class queue basis and a per device basis within an input routing table, and additionally on a per virtual output and per service class basis within an output routing table. In a specific embodiment, upon each measurement, cell traffic is compared to thresholds corresponding to that measurement's congested and maximum limit and a congestion or maximum signal is sent if that threshold is exceeded.

Many dimensional congestion detection system and method

A facility is provided for operating an asynchronous packet transmit bus (140) such that isochronous information packets may be transmitted from a source to a destination with a fixed, constant delay. The fixed, constant delay is achieved by employing a bandwidth management bus (145) and assigning to port modules (110) which contend for access to the transmit bus respective levels of priority, in which the highest level of priority is associated with isochronous information and in which lower levels of priority are associated with other types of information, such as asynchronous information. In addition, each port module which transmits isochronous information is assigned at least one time slot of each frame of time slots. In this way, a port module that needs to transmit isochronous information is granted access to the transmit bus during its assigned time slot if the module asserts such highest level of priority in response to its address being transmitted over the bandwidth management bus. If the module fails to assert such priority, then the time slot is marked for open contention, thereby allowing the other port modules to contend for access to the transmit bus during that time slot.

Method for operating an asynchronous packet bus for transmission of asynchronous and isochronous information

A system and method for managing a communication link between a consumer electronic device adapted for two-way, wireless communications with at least one peripheral. The communication link is managed using a controller that is associated with the consumer electronic device that functions to assign communication slots to the peripheral to facilitate communications between the peripheral and the consumer electronic device.

System and method for managing communication links

A method and apparatus for providing communication among N modules connected to a common communication bus uses a bus structure with a reserve line for signaling the occurrence of a reservation time slot during which time each of the N modules which have information to transmit may reserve a time for transmission over the bus. A plurality of at least N data lines are used for transmission of data words over the bus. Each of the N modules are also assigned use of one of the plurality of data lines for signaling during the reservation time slot that the module has information to transmit over the bus. The reserve line is also used for signaling, that a word of data being transmitted over the plurality of data lines is a last word in a current transmission to be transmitted by the module currently transmitting.

David B. Fallin

Papers

High speed module interconnection bus