Method and protocol to support contention-free intervals and QoS in a CSMA network
First Claim
1. A method of operating in a CSMA network in which a plurality of peer devices communicate over a medium, comprising:
- having a first device, which can be any of the plurality of peer devices, transmit messages to at least a second device, which can be any other of the plurality of peer devices, over the medium using a CSMA contention-oriented service to establish a contention-free interval within the CSMA contention-oriented service for use by the first device for a contention-free transmission between the first device and at least the second device, and wherein at least some of the other peer devices are made aware of the contention-free interval and refrain from contending during the interval.
6 Assignments
0 Petitions
Accused Products
Abstract
A CSMA Media Access Control (MAC) scheme for supporting both centralized and distributed shared medium access control in a CSMA network. A master device exchanges connection control messages with a slave during using contention-oriented access to establish a connection and a session of periodic contention-free intervals. Once the session is established, the contention-free intervals alternate with contention-oriented intervals according to the timing parameters specified by the connection control messages. Each of the contention-free intervals is divided into slots, the master transmitting in a downstream frame and the slave device transmitting an upstream frame in a following slot if the downstream frame indicates a source address matching that of the master device, a contention-free access at a highest priority and a connection number corresponding to the connection established between the master device and the slave device, thus downstream frame thus serving to poll the slave device and trigger the slave device'"'"'s upstream frame. Master control is passed from one device to another device during the contention-free interval using additional control information, more specifically, a master flag for indicating which device has master control and a control flag for indicating the direction in which master control is being passed. Arrangements to change session parameters or change session control are made using connection control messages using contention-oriented access. Session control is passed from one device to another during a contention-free interval following the exchange of appropriate connection control messages between the devices.
269 Citations
48 Claims
-
1. A method of operating in a CSMA network in which a plurality of peer devices communicate over a medium, comprising:
-
having a first device, which can be any of the plurality of peer devices, transmit messages to at least a second device, which can be any other of the plurality of peer devices, over the medium using a CSMA contention-oriented service to establish a contention-free interval within the CSMA contention-oriented service for use by the first device for a contention-free transmission between the first device and at least the second device, and wherein at least some of the other peer devices are made aware of the contention-free interval and refrain from contending during the interval. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 46, 47)
-
-
25. A computer program residing on a computer-readable medium for operating in a CSMA network in which a plurality of peer devices communicate over a medium, the computer program comprising instructions for:
-
having a first device, which can be any of the plurality of peer devices, transmit messages to at least a second device, which can be any other of the plurality of peer devices, over the medium using a CSMA contention-oriented service to establish a contention-free interval within the CSMA contention-oriented service for use by the first device for a contention-free transmission between the first device and at least a second device, and wherein at least some of the other peer devices are made aware of the contention-free interval and refrain from contending during the interval. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 48)
-
Specification