Method for practicing carrier sense multiple access at the application layer

摘要

A system and method for controlling a radio transmitter from the application layer is presented. The method includes monitoring an uplink state of a shared channel at a cell manager and processing the uplink state, at least in part, in the application layer in the cell manager to produce processed uplink state. The processed uplink state is then broadcast in a control packet on a downlink of the shared channel to a subscriber manager. The processed uplink state is then further processed, at least in part, at the application layer in the subscriber manager to produce transmitter control data. The transmitter control data is then used control the radio transmitter.

主权项

1. A method of controlling a subscriber station (SS) radio at the application layer of an Open Systems Interconnection (OSI) 7-layer model of the International Organization for Standardization (IOS) comprising the steps of:
providing, to logic operating in the application layer, parameters associated with a shared channel to be shared with a other radios; and based, at least in part, on the application layer parameters, controlling from the application layer when the SS radio is to transmit on the shared channel; communicating the SS radio with a base station (BS) radio; implementing a virtual carrier sense multiple access (V-CSMA) protocol at least in part by: polling the BS radio with a cell manager to receive at least one of the group of: a receive signal strength indicator (RSSI) and a carrier lock indicator (CLI) from the SS radio; determining if the shared channel is available based, at least in part, on the RSSI and the CLI; and transmitting whether the shared channel is available on a downlink to the SS radio; wherein the step of implementing the V-CSMA protocol further includes the steps of: calculating at the cell manager at least partially in the application layer virtual-carrier sense (V_CS) parameters that include at least a current channel state indicator (CSSI) and a time till release (TTR) parameter, wherein the TTR parameter indicates how much longer the shared channel is expected to be occupied and if unoccupied then how long ago the shared channel was occupied; and providing the V_CS parameters to a subscriber manager that uses the V_CS parameters to determine when the SS radio can transmit; using at the subscriber manager at least partially in the application layer a most recently received set of V_CS parameters to content for channel access including: polling a queue for a queue status; when the queue is not empty, using the V_CS parameters to determine if the shared channel is occupied; when the shared channel is occupied, setting a contend (CNTND) flag to indicate that the subscriber manager is contending for the shared channel; and when the shared channel is occupied, determining how long ago a previous transmission was sent to determine if the SS radio can transmit; wherein the determining how long ago a previous transmission was sent further comprises: receiving at the subscriber manager a maximum access time (M_ACC_TM) from the cell manager that indicates the maximum access time that the shared channel can be used by the SS radio during one transmission; receiving at the subscriber manager a per user occupancy (PU_OCC) that determines how frequently the subscriber manager can contend for the shared channel; receiving at the subscriber manager a last transmission end time (LST_TX_END) and determining at the application layer if current time (CRNT_TM)>(M_ACC_TM/PU_OCC)+LST_TX_END; and if CRNT_TM>(M_ACC_TM/PU_OCC)+LST_TX_END then enable the SS radio to turn on its transmit and begin transmission otherwise set the CNTND flag.